Allonby Bay MCZ: a ‘slimy dangerous place?’

2011_09_01 074 Allonby criffel sab

Low tide at Dubmill, looking across to Criffel (Thanks to Alan Sawyer for this photo)

Allonby Bay, on Cumbria’s Solway coast, recently became a Marine Conservation Zone; there are now 50 MCZs in English and ‘non-devolved’ waters and proposals for more are under consideration.

Most people, probably, neither know nor would they care.

Here are some figures, taken from a 2008 survey carried out for Natural England (1):

  •  99% of the 4000 people surveyed couldn’t name a feature or creature associated with the (general) undersea landscape;
  •  44% thought it was ‘barren’.
  •  For 60% of the sample the instinctive response to the undersea landscape “is characterised by a mixture of fear, disgust and shame: fear because it is a dangerous place, disgust because it is thought to be cold, dark and slimy … and shame because it is thought to have been allowed to get into this state …”

There’s also a North-South divide: “Northerners describe ‘their’ sea as dirtier and colder than the rest of the country and cite industrial pollution as a big factor in this.”

Sir Martin Holdgate, Trustee for Cumbria Wildlife Trust, noted at the North-West Wildlife Trusts’ Irish Sea conference a couple of years ago that “it is difficult for us as land-mammals to understand what is going on in the oceans.”

A sea of acronyms

Another part of the problem is the complicated sets of acronyms and conservation designations, and legislative bodies (if any) who over see them. The Allonby Bay Marine Conservation Zone (MCZ) is a type of Marine Protected Area (MPA); much of the Firth is also a European Marine Site, which encompasses various other types of designation (SAC, SPA etc).

It is a relief to know that so much of the Firth’s special habitats and wildlife is under statutary protection (although unfortunately this doesn’t necessarily mean active protection and management), but most people – understandably – are unaware of, or don’t understand the meaning of, the acronym-ed areas. Conservationists banging on about, well, conservation, yet again. Hard to get excited …

To help with that, I strongly recommend the Solway Firth Partnership’s very readable, clear and informative explanation of the Solway’s various protected areas and their designations.

And the Joint Nature Conservation Council (JNCC) has a helpful interactive map of the UK’s MPAs – home in on the Solway, increase the magnification, and click on the areas outlined in colour to see what type of MPA they are and what are the features responsible for that listing.

Of course, more interest might be stirred if some major threat to the sea or shore is observed or proposed: dumping of rubbish on a large scale, say, or huge jetties for a quarry, or large spills of oil or toxic chemicals. Even then, the emphasis might initially reference the economic and health consequences for the local human population.

This sounds like a harsh judgement, but realistically, how many people really care about fish? ‘Iconic’ species like whales and basking sharks (we don’t have any polar bears in the Firth) are always news-worthy, but who bothers about honeycomb worm reefs, starfish, soft corals, sea-slugs and the planktonic larvae of barnacles? Or the different colours and species of algae?

These organisms might sound trivial (invertebrates, weeds!) yet they are a vital part of the great web of interactions that populates our seas.

Belts and corridors

DEFRA, in their email announcing the new tranche of MCZs, explained how the MCZs ‘will extend the country’s ‘Blue Belt’ to cover over 20% of English waters providing vital protection for the diverse array of wildlife in our seas.’

The language helps. ‘Blue Belt’ has a good visual image.

‘Wildlife Corridor’ (which would be one important result of the Blue Belt) also gives us an image with which we are already familiar (animals scurrying through interlinking hedgerows, and along tree-clad motorway and railway embankments).

So, to imagine corridors in the sea, we need to populate those corridors with marine animals and plants.

To do that, we have to ‘see’ the features, and the creatures that move or are fixed in place, the prey and the predators, the larvae and other offspring – in what is essentially their own ‘urban’ environment: creatures living in a place that is not barren or slimy or disgusting (because if it is any of those things, we have made it so).

What is Allonby Bay MCZ?

Allonby Bay MCZ is an inshore site stretching approximately 9km along the coast from Dubmill Point to just north of Maryport, and about 4km out into the Firth; this map, taken from the designation document, shows the position and the co-ordinates.

mcz boundaries

It has an area of 39km – that’s an area approximately 1/540th the size of Wales, or equivalent to about 7000 football pitches (but volume, in terms of Olympic swimming-pools, varies according to the tide).

It was “recommended as an MCZ because of the diverse range of marine habitats and species it supports. In particular, this includes large areas of nationally important living reefs, formed by the honeycomb worm (Sabellaria alveolata) and blue mussel (Mytilus edulis) beds…. [which] can extend for tens of metres across and up to a metre tall. In an otherwise ever-changing environment, these reefs are able to support a wide range of other shore dwelling species including anemones, snails, shore crabs and seaweeds. … Allonby Bay supports some of the best examples of these reefs in the UK. The peat exposures provide a habitat which piddocks, a type of burrowing clam, and other species can tunnel into.” (Natural England document, p50

The whereabouts of the special features that make Allonby Bay an MCZ – including the mussel beds, honeycomb worm reefs and peat exposures (part of the submerged forest) – are shown in these maps.

And you can read much more about them in separate, illustrated articles, on Solway Shore Stories.

What can you do, and not do, in Allonby Bay MCZ?

You can still enjoy swimming, recreational sea-angling, sailing and wind-surfing, kayaking, walking the dog and eating ice-creams – there will be no change.

As for commercial fisheries, the fishing industry and the North-West Inshore Fisheries Conservation Authority (NW IFCA) were amongst those involved in the initial discussions. Dredging and trawling within the MCZ would clearly damage the sea-bed but, as Dr Emily Baxter, Marine Conservation Officer for the North-West Wildlife Trusts, told me, “They are not automatically prohibited”; however neither trawlers nor the shrimp-boats from Silloth work in this area. As David Dobson, formerly of NWIFCA, said, “The ground’s too rough – the shrimp-boats avoid it like the plague, it does too much damage to their nets.” Again, no change.

Who will oversee the protection?

There are various organisations responsible for overseeing the MCZ status, listed on the government fact-sheet about MCZs in general (an extract is shown here). mcz regulators

The Marine Management Organisation (MMO), based at Whitehaven, oversees fishing within the 6-12 nautical mile zone – but their management won’t be necessary since that’s outwith the Allonby Bay MCZ’s limits.

NW IFCA will oversee the shell-fisheries: the cockle- and mussel-fisheries, neither of which have actually operated for several years, are protected by Bye-Laws and have in any case always required licences and oversight from NWIFCA.

Some – although not all – of the intertidal honeycomb worm reefs, too, are already protected from bottom-towed fishing gear by NWIFCA’s Byelaw 6.

In reply to my question about management, Mandy Knott, Senior Scientist at NWIFCA, told me: “You are right in that we do not anticipate at this stage that there will be any additional management required for the Allonby Bay MCZ as far as fisheries are concerned. … The Conservation Objective [CO] for the site is ‘maintain’ and there are therefore no immediate causes for concern as long as activity within the site remains constant or decreases. The NWIFCA monitors all fishing activity in its District, both commercial and recreational, and should levels increase then a relevant assessment of risk and impact on features will be carried out, in consultation with Natural England. Should evidence show that management is required then the NWIFCA will act accordingly.”

However, Dr Emily Baxter of the NW Wildlife Trusts thinks it might well be necessary to keep an eye on the fisheries: “Even though the CO is ‘maintain’, this does not mean do nothing, and active management may be required to manage existing activity and future-proof the area from potential damage.”

This at least gives hope that the MCZ will not merely be a ‘paper park’, as Professor Callum Roberts maintains for MCZs in general; you can read his Guardian article here, or watch him talking to Tom Heap on BBC’s Countryfile (at about 8 minutes in)

As for harbours and ports, the Port of Silloth is outwith the MCZ, although the Solway Buoy is stationed just within the area.

But one important aspect of management is down to DECC – and that concerns coal and oil extraction. We shouldn’t forget that Cluff Resources are maintaining their Solway licences for underground coal gasification in the Allonby Bay area; at the moment all is quiet on that front, but …

Basically, then, it’s all rather unexciting,  and we can probably all carry on much as before, in Allonby Bay. Or can we?

The ‘barren’ undersea?

When I’ve taken people down the beach on good low tides, we reach the first signs of the honeycomb worm (Sabellaria) reef and I often ask if anyone notices something different about the rocks. Some do, but at first many don’t, notice that the ‘rocks’ are actually intricate masses of sandy-tubes built by the Sabellaria. And so often, someone then remarks, “I just thought they were rocks!”

And within the next hour or so, we watch crawling, grazing winkles; find dog-whelks preying on barnacles; ‘baked bean’ tunicates and different types of sponges living amongst the reefs; dahlia and beadlet anemones, feeding tentacles extended or tucked inside their stomachs; eggs of dog-whelks and ragworms; the shelly tubes of mason-worms; the coils and holes of lugworms; gammarid shrimps, small fish, brittle stars …  Many of the sessile animals are quiescent, just waiting for the tide to come in. Many of the predatory animals – ragworms, crabs – have hidden, leaving behind only their footprints. We see how every hard surface in the intertidal area is coated with animals and algae.

All this, so many species, so much busy-ness, even when the tide is out! (Enjoy these photos of organisms in the new MCZs on the Guardian website.) At low tide we get a snapshot of the Allonby Bay Marine Conservation Zone.

But now imagine it when the tide comes in, bringing food, planktonic larvae, predatory fish. Colourful algae, flattened on the rocks when the tide is out, are buoyed up and swaying in the current; tube-worms and anemones and barnacles extend their arms and legs, mussels filter the water to catch their food, ragworms and crabs hunt for live prey, limpets and chitons crawl, grazing. Fish browse, chase, mate.

All these organisms interacting in different and subtle ways, a complex meshwork – a ‘Living Sea’.

Let’s celebrate!

That’s what our MCZ is about. We need to shout it out, celebrate how lucky we are to have something special and precious here on our Solway shore. And spread the news that it’s part of something special and precious about our seas – and the health and beauty of the world’s seas.

Allonby Bay is not just about ice-creams and acronyms.

 ***

Join me on a low-tide shorewalk to discover more about Allonby Bay. Full details are on the Solway Shore Stories website.

Visit the excellent Lake District Coast aquarium at Maryport to see local marine species.

Find out more about the WildlifeTrust’s Living Seas Project, and how you can be involved, on their website , and specifically on Cumbria Wildlife Trust’s website. You can also find Living Seas North West on Facebook,Twitter @LivingSeasNW or www.irishsea.org

(1) ROSE, C., DADE, P. & SCOTT, J. 2008. Qualitative and Quantitative Research into Public Engagement with the Undersea Landscape in England. Natural England Research Reports, NERR019.

 

Posted in Allonby, Marine Conservation Zone, sea-bed & undersea | Tagged , , , ,

Peat-coring on Kirkconnell Flow

Kirkconnell Flow, South of Dumfries and West of the River Nith, is one of those valuable and unusual peat-bogs known as raised mires or, more poetically, Mosses. There are several around the edges of the Solway Firth, all protected in various ways and by various organisations.

Kirkconnell Flow is a Scottish National Nature Reserve (NNR), a UK Site of Special Scientific Interest (SSSI) and an EU Special Area of Conservation (SAC) – but don’t be put off by all the conservation acronyms. It’s a special place, with a complicated history and, as is already apparent, a place with optimism, and insights, about the future.

IMG_4046

Dr Lauren Parry and some of the Borderlands#2 group

 

At the end of April this year a group of artists, poets and fiction-writers, scientists of various sorts, sound-artists and composers wandered out onto the Flow as part of the Borderlands#2 gathering – not only to experience what being on a Moss or Flow or Mire might mean, but for a more practical purpose, too: to get our hands dirty – to go peat-coring.

 

Like all the other raised mires around the Upper Solway, Kirkconnell Flow is a dome of peat. I’ve borrowed Scottish Natural Heritage’s beautifully visual description of its origin: “When the glaciers retreated from Scotland 10,000 years ago, the landscape was littered with many pits, often within a layer of watertight glacial debris or till. These basins formed lochs and were colonised by a fringe of fen plants, which slowly spread across the lochs until no open water was left. A combination of loch sediment and plant material eventually led to many lochs completely infilling. As the loch basin filled with fen peats and sediments, the plants could no longer root in the mineral soils below.

Plants in the outer fringes of the swamp soaked up all of the nutrients flowing in from the surrounding ground, leaving the centre of the swamp waterlogged and nutrient-poor – just the right conditions to encourage a bog to form. Sphagnum bog mosses thrive in these conditions and started to dominate the vegetation. The steady upward growth of the living Sphagnum layer and the slow accumulation of the dead vegetation below combined to produce peat.

As peat accumulated, it began to rise above the level of the former loch surface. Once a layer half a metre or more in thickness had formed above the old surface, the peat became isolated from groundwater. The bog therefore became dependent on rainwater alone, deriving all its nourishment from the atmosphere, and as a result is poor in nutrients [my italics].

In other words, it’s ‘ombrotrophic’: a new word, one of many that I learnt that afternoon from Dr Lauren Parry, of Glasgow University, who had come to lead us through the heather to the central dome. An ombrotrophic , literally ‘cloud-fed’, bog is one that is wetted only by rain, not by springs or burns, and is isolated from the surrounding landscape. Rain is poor in nutrients, so only those plants that tolerate acid, low-nutrient conditions live there: the richly-coloured Sphagnum mosses; the berry-bearing plants such as blaeberry and crowberry; bog-myrtle and bog rosemary with their crushed-leaf scents; pale ‘reindeer moss’ lichen; and the white fluffy flags of the bog-cottons. It was early in the year when we visited, but the hints of past and future were there – even wizened last-season crowberries amongst the cotton-buds.

To reach the dome of peat we had walked a woodland path ringing with the descending chromatic scales of competing willow-warblers, and waded through knee-deep tangles of heather. The Flow had for decades been gnawed and battered by humans: first by peat-cuttings, then by heather-burning for grouse-moors. Birch carr and pine forest encroached as the water-table dropped and the peat dried out; the trees themselves transpired water and hastened the drying and destabilisation of the mire.

The SNH document describes well the history of the Flow and the damage inflicted upon it. But in 1998 they purchased the Reserve and – as is the case with conservers of the Solway’s other Mosses – are attempting to restore the raised bog’s hydrology. One of the first, and major, tasks, has been to cut down and remove the trees from the central area of the Flow

As Lauren Parry said, “Removing the trees has been an ‘encroachment issue’ which is different from a ‘plantation issue’” (which would have involved probably lengthy discussions about ownership of the plantation, and compensation).

Lauren’s PhD research related to the composition of peat; since then she has concentrated on carbon sequestration – the ways in which peatlands store carbon and how the carbon levels relate to changes in the climate.While very well-practised in the technique of peat-coring, she’s now also exploring less ‘dirty’ techniques such as ground-penetrating radar to get information about the ‘bulk density’, the relative amount of solid, organic material within the peat. I hadn’t realised that a peat-bed may be riddled with ‘pipes’ and cavities and cracks.

And now, out on the Flow proper, there are more words, too; hard-edged words and musical words with a cadence: acrotelm and catotelm, the lagg fen and the haplotelm; the ‘Russian’ corer, proxies, testate amoebae.

“We really love taking cores and looking at them under a microscope,” Lauren says. “The peat’s a wonderful archive.”

Why “an archive”?  Vegetation growing on the thin ‘living’ top layer of the bog (the acrotelm) responds in different ways to the environmental conditions – the amount of rain, warmth, nutrients, pollution. Different species – of plants and of microscopic animals – grow more slowly or out-compete others depending on their favourite conditions. Pollen, even radioactive particles (remember Chernobyl)  blown in from surrounding areas is deposited or incorporated amongst the stems.

acrotelm diag rspb doc

The acrotelm and catotelm: diagram from Richard Lindsay’s document for the RSPB (see below for link)

And as plants die and are replaced, they are grown over by new individuals. The combination of new plant growth and water-logging means that oxygen diffuses into the lower layers so slowly that the decomposition of dead plants uses it faster than it can be supplied, and so the lower layers (the catotelm) are anaerobic. Layers of only partly-decomposed plant matter build up in an ‘active mire’.

Dr Richard Lindsay, of the Sustainable Research Unit, University of East London, has written a long, but delightfully easy-to-read and very informative discussion document for the Scottish RSPB on Peat bogs and Carbon, a critical synthesis (2010) – what he calls his ‘Big Bogs Report’ (unfortunately it’s only available online).

‘Peatbogs are responsive systems with homoeostatic mechanisms that are not far removed from those found in living organisms … features having many similarities to tree-rings can be found in the equally-thin layers of peat which are successively deposited in a bog over millenia. These narrow bands of peat tell the same tale as tree-rings but over a much longer time-scale.’

And the peat (or ‘turf’ as it’s called in Ireland – but then, in County Mayo they call herons, ‘storks’) is ‘a direct product of the vegetation which created it. Consequently the characteristics of this peat soil reflect the nature of the vegetation which created it, while the vegetation itself reflects the prevailing hydrological and nutrient conditions.’

So, an archive: which can be examined by drilling down and taking a core, slices of which can undergo a battery of chemical, spectroscopic, radiological and microscopical examination in the lab for the range of minerals and isotopes, for types of pollen, for the hard cases of the unicellular testate amoebae, and more. Amoebae, pollen – these are ‘proxies’, different species flourishing or dying out according to prevailing conditions and therefore acting as indicators. All these measurements provide clues as to what climatic conditions prevailed at the time that ‘peat-ring’ was laid down.

Taking a core doesn’t need a drilling-rig, just patience, organisation, and some brute manual force. It required the help of ‘the Russian’ – ‘who’ turned out to be type of metal corer, a side-filling sampler with a sharpened edge; when rotated clockwise the blade cuts a core which is then held in the chamber by a plate. Back on the surface, the corer is rotated in the opposite direction and the undisturbed sample is slid out into a plastic ‘gutter’ which is marked with felt pen for ‘top’ and depth, and the whole is then wrapped in cling film and kept horizontal.

The first core, from the acrotelm, was fibrous with roots and decaying grass and other plants. Fifty-centimetre lengths were gradually added as the Russian penetrated deeper; each time it was then pulled back to disgorge its sample.

The core from 150-200 cms represented life about 2000 years ago.

Gloop-gloop. The corer made wet, sucking sounds as it was pulled free. Deeper cores became smoother and sloppier.

More rods were added: taller, able-bodied men were co-opted to help lift the rod vertically into place. An artist was taking photos of cranberries; someone was watching skylarks through his binoculars; others were sitting on the ground chatting; someone was making notes in a tiny ring-bound book; three of us bounced on the mire’s surface several metres away from the group, and startled faces turned towards us as the quake spread out in waves.

IMG_4063

The final, clay, core – from 6.5metres

And then, at 6.5 metres’ depth, the bottom of Kirkconnell Flow was reached! The sample chamber of the corer revealed a glossy grey cylinder of clay, formed by the friction of glaciers against rocks, and deposited around 9000 years ago.

At that time, there would have been forest growing each side of the Firth, birch, hazel, oak and pine. But as the climate became wetter and freshwater drained down towards the Firth, sphagnum mosses formed blanket-bogs in these low-lying areas, the tree-roots became waterlogged, trees died; the remains of this mighty ‘submerged forest’ were preserved in the peat-beds that are occasionally revealed on the Cumbrian shore. Further inland, though, the peat domes of Kirkconnell, Drumburgh, Wedholme and the other raised mires grew and developed, becoming isolated ecosystems with their own special character.

As for ‘our’ peat core, the sections have been frozen and await investigation by Lauren Parry with the help of the creative practitioners of Borderlands#2

***

  1. There is a very good and useful BBC video of Natural England’s Alasdair Brock explaining about peat-coring and the restoration of Wedholme Flow, in the South Solway Mosses.

2. Since I wrote this blog-post, Kate Foster – artist, writer and organiser of the Borderlines#2 event – has written a lovely piece about how peat, and what it contains, including the proxies of testate amoebae, are inspiring her art.

Posted in bogs and moors | Tagged , , , ,

Snippets 9: ‘Seeing’ the Solway’s bottom

chart with buoys outlined

“Between Solway Buoy and Corner Buoy, it’s a critical region, the region that gives us the most trouble. At Corner Buoy there’s a narrow corridor – that channel is our window [to Silloth], to the East of it are big boulders, to the West are shifting sands.’ Captain Ed Deeley, harbourmaster at the Port of Silloth, and a ship’s pilot, explains one of the major problems of navigating the Solway Firth – the sea constantly re-sculpts the sea-bed.

The Admiralty charts for the Firth show areas of sandbanks and ‘changeable depths’. Sediment is constantly on the move, being lifted and deposited, eroded and accreted. This affects fishermen – trawlers, scallop-boats and shrimp-boats, lobster-pot men and haaf-netters – and vessels that service the windfarm, as well as the larger ships that transport goods around the coasts. Ports and harbour entrances need to be dredged, the depths of channels charted and surveyed.

In recent years, the route up to Silloth has been periodically surveyed by the Association of British Ports (ABP), who own the ports of Silloth and Barrow on the Cumbrian coast. Ed Deeley had previously shown me some of ABP’s bathymetric charts for the ‘critical region’ and we were both intrigued by a flat-bottomed, apparently unchanging area South of Corner Buoy. Could it be a layer of peat or boulder clay such as occasionally gets exposed on the shore?

 

Chris Heppenstall, ABP’s Hydrographic Surveyor, was very willing to show me the data and talk about the surveying, so I went down to Barrow to meet him. Chris grew up in nearby Ulverston; he told me that he originally trained as a land surveyor, studying at Newcastle University. ‘Then I read that offshore survey companies were recruiting and I thought “that sounds quite interesting”.’ He took a job surveying for an offshore construction company, but then in 2011 saw that ABP in Barrow were advertising for hydrographical surveyors, so he applied and was accepted.

The Port Office is a red sandstone Victorian building, now almost hidden from its raison d’etre by a large office block built on an area where once there would have been warehouses and cranes. Barrow is still a large and important port and home to a ship- and submarine-building industry and Chris explained that the deep, straight channel from the docks, out past Walney Island, needs surveying ‘every few months, and dredging once a year, sometimes more’.

But as well as surveying the approaches to his home port, Chris goes up the Solway to Silloth. His first survey, using a multi-beam echo-sounder, was in early 2013. ‘We were using the [ABP’s] harbour tug, it’s 20 metres long with a 2.5 metre draught but we found it was affected by the strong currents and progress was very slow. Also we always work from Whitehaven, it’s just not viable to work from Silloth due to the limited access. We sometimes finish off on the last day in Silloth to survey the dock, but most of the work is done from Whitehaven, then the incoming tide pushes us towards the survey site, and the falling tide helps us on the way back.’

Despite the difficulties, they had good weather, and a good Spring tide; on that first survey, Chris said, they looked at a wider area than the pilotage channel to get a general idea about the surrounding sea-bottom.

A multibeam scanner sends out a broad fan-shaped pulse of sound, which bounces back, the length of the time delay creating a ‘picture’ of the topography of the sea-bed. Accurate postitioning of the device is necessary (eg by GPS), and the received signals have to be corrected for factors such as wave height, and pitch and yaw of the boat.

‘There are swathes of coverage, we try to overlap the corridors. The width of the beam is about four times the water depth – so the area scanned depends on water depth, it’s greater when there’s more water. Obviously, if you’re vertically above a spot, the beam has a smaller footprint, so you get greater detail. At Barrow, we do overlapping scans, so each bit gets done twice and this gives much greater resolution. But at Silloth this is too difficult, because of the currents and the limited access.’

The ways in which the scanner results can be displayed is impressive. I had already seen the large print-outs of the charts showing each recorded depth point. The chart below shows the position of the survey relative to the three buoys; the paler the colour, the deeper the water. For obvious reasons, the depth in metres is corrected to the depth of the Sill at the entrance to Silloth port.

sept15

September 2015 survey, with position of the 3 buoys marked

In Chris’s office we were able to look at multi-coloured 3D images on the computer, the colours relating to the measured depth. Images from different surveys could be stacked and tilted, to show changes in height of the seabed.

On these images, the colour range from red through yellow through green to blue indicates increasing depth.

2-18 jan14

January 2014 survey: rocky scaurs and sandwaves

Though not at the greatest possible resolution, the detail is excellent, showing the large regular sandwaves in the NW corner of the survey (for much more about sandwaves and sand-ripples see elsewhere on this blog). Parallel bands of unchanging material trending NE-SW near the southern-most part of the survey are probably part of the same rocky bands that form Dubmill and nearby scaurs; later surveys show them dotted with a scattering of boulders.

And of course, what was of greatest interest was to compare the position of the sandwaves and sandbanks relative to the pilotage channel throughout the three years of periodic surveys. Looking at the shifts in position of the red-orange (shallow, ie sandbanks) and blue-green (deeper) colours between January and September 2014, it’s easy to see how the sandbanks have been moved towards the East, filling in the channel.

panorama 3 surveys

from left to right: January 2014; September 2014; September 2015 (thanks to Chris Heppenstall and ABP)

Between September 2014 and September 2015, however, the sandbanks in the NE have been moved in a westerly direction again and the (green) channel is more extensive. In September 2015, there are obvious boulders (seen more clearly in the previous image) scattered over the surface of the rocky scars towards the South – probably revealed as sand has been swept away.

sept14-15

However, there doesn’t seem to be much evidence for the flat-bottomed channel which Ed had mentioned, and which I had surmised (and hoped) might be peat or clay. On reflection, peat would have been unlikely anyway, as the peat ‘horizon’ on the shore is much higher; but glacially-derived clay remains a possibility. The only relatively unchanging smooth area is to the very South of the surveys, seen in January and September 2014. Now what we need is a diver!

 

My grateful thanks to Chris Heppenstall of ABP for so generously sharing these data and images.

Posted in ports, sea-bed & undersea, Snippets | Tagged , , ,

Snippets 8: A non-conformist on the shore

‘Brockram’ and ‘breccia’: the first word suggests something that is solid and long-lasting, the other has a hint of transience, of frippery. But Brockram is a form of breccia; it looks like a congealed and lumpy mess of porridge that has been spilled onto the shore.

It’s a non-conformity, it’s pretending to be older than it is.

We had slithered down a slope of muddy red sandstone, with the ‘protection’ of a knotted rope fixed to an insubstantial metal stake, and had reached the shore of Barrowmouth Bay, a little to the North of St Bees’. Over the centuries, great boulders of the red St Bees’ sandstone have eroded from the high cliffs along this part of the coast, and have tumbled onto the shore. Large and slippery, often coated with green algae, they make progress along the shore difficult but always interesting, because one is forced to stop and look and feel and question the shapes and colours.

Some boulders have drifts of mica embedded in them, hinting that the delicate flakes were swirled by a river’s current into a small depression. Others have marks of ripples, that were formed on the bed of the river delta when the sandy sediments were deposited; still others have swellings or circular indentations, where stones or mud were pressed against the sediments as they were compressed and lithified, and turned to stone. (There is much more about Barrowmouth and St Bees’ sandstone on Solway Shore Stories.)

an anchor

An anchor-stone?

 

I find a bright red stone that is perforated by a hole, the edges of which are scored with grooves. Are they marks worn by ropes, was it perhaps used as an anchor?

 

Most of the boulders are the New Red sandstone but they are tumbled upon rock from a much older age, a sandstone that is darker, purplish, in colour; there are patches too of a paler yellow-green variant. This is Carboniferous, ‘Coal-Measures’, sandstone within which the West Cumbrian coal-fields are embedded.

Finally we reach the rock that is an intruder. Even though the Brockram looks artificial and unattractive, out of place both aesthetically and geologically, it’s a special thing to see. It caps wave-washed boulders; it has spilled into crevices, and forms a smooth-topped platform over the sandstone; it is lumpy with gravel and pebbles.

This ‘non-conformity’ and the way it arose is extraordinary. The surface of the Coal Measures sandstone had been smoothed and hollowed, slowly eroded as it was exposed and oxidised in the desert air – and then suddenly, into every dip and joint had poured this mess of Brockram, forming a dramatic contrast of colour and texture. In the Permo-Trias a river torrent had flashed out onto the sandstone, its powerful currents carrying a mixture of volcanic material, limestones, sandstone and even Ennerdale granite from the ‘Lake District’ region (which was then at about the latitude of the current Sahara desert), and had deposited this breccia in a fan.

It does not ‘conform’ because there is a gap in the geological record between the old sandstone and the younger breccia – the rock from the top of the Coal Measure sandstone had been eroded and removed.

We sit on the rocks and drink coffee, watching the sea, hearing the regular thump-thump-thump of an engine, a trawler unseen in the fog, heading West to the Irish Sea. Two oyster-catchers fly low over the water’s quiet surface, their wing-tips almost touching their mirrored reflections. A seal watches us and, unimpressed, sinks down into the water and disappears.

The tide is coming in and eventually, we leave this out-of-the-way and unusual place, to scramble back along the shore, haul ourselves up the rope, and climb the long steep path to the top of the cliff.

Posted in quarries, sandstone, Snippets | Tagged , , , , , ,

Piloting a ship up the Firth to Silloth

view from the office

View from the Harbour Office window: Marshall Dock at low tide

You have probably never thought what  it would be like to pilot a ship: to be in charge of, say, a cargo vessel with a hold-full of sticky molasses, that is about to enter the narrow dock gates of a port. But imagine yourself as the pilot: you have boarded the ship as it approaches its destination in order to explain to the captain how to manoeuvre his ship at this, the end, of his current voyage. You are responsible for the safety of a very large and expensive piece of kit which doesn’t belong to you. And if you’re piloting the vessel to the Port of Silloth, you also have a trip of about 90 minutes ahead of you before you reach the port near the inner end of the Solway Firth.

“Only the Victorians could have thought this was a good place to put a port,” Ed Deeley says of Silloth. “To put the entrance at 90 degrees to the main flow!”

Ed took on the job of Harbour Master in 2011, though he tells me that piloting ships has always been what he most enjoys; when we meet he has just returned from a piloting job at Ayr. Unlike Ayr, Silloth can only be reached via some of the most changeable channels and, on occasion, the largest Spring tides around the British coast. Any ship longer than 50 metres is required by law to wait off the Port of Workington to take on a pilot before it can head to Silloth. Timing is crucial because the port at Silloth is tidal – the  depth of the water within the inner dock is maintained by lock gates – so the ship must arrive there just before high tide when the gates are open.

 

Despite the multiple layers of difficulty – the weather, the sea-state, the shifting channels, the time constraints, the angle of entry – Ed Deeley enjoys the challenge: “All these different factors – you’re trying to juggle them all!” Chris Puxley, the former Harbour Master and also a pilot, once told me that negotiating the entrance to Marshall Dock always provided “a gentle adrenalin rush”.

But the first job of a pilot is to board, and learn about, the ship. The pilot boat Derwent takes him out from Workington to the waiting ship, where he goes straight up to the bridge to meet the Master. Both Chris Puxley and former pilot Bill Amyes have previously told me stories about their experiences in The ship’s pilot’s story , but I was keen to meet Ed and get an update on piloting and the port itself.

Unlike many Harbour Masters, Ed dresses informally, no blazer or peaked cap, and he doesn’t like to be referred to as ‘Captain Deeley’; he smilingly hints that some of the Masters might find this a little unusual. Despite this, he needs to find out about the ship (“The captain knows his ship, we don’t”), and there’s an important check list to complete: the stability of the ship, the types of equipment, whether the anchors are free (“sometimes they’re cemented in place and you don’t want to be hammering at them to get them free if you really need them”). And there is the Passage Plan: the pilot discusses the course with the captain, and explains, with the use of diagrams, what will happen when they reach Silloth.

 

Then, they are ready for the journey up the Firth, keeping to the ‘English Channel’ amongst the sandbanks and the ‘Changeable Depths’. From an aerial point of view of the Firth during the low water of a ‘big’ Spring tide, it’s obvious why a pilot is necessary – and why frequent bathymetric surveys need to be carried out on the channel: rocky scaurs project out into the Firth, and the whale-backs of sandbanks are pale against the glistening sea.

chart with buoys outlined

Detail of  Admiralty Chart to show the three buoys that mark the channel (note ‘Changeable Depths’). Photo: Ann Lingard

 

At the North end of Allonby Bay the course is marked by buoys. “Between Solway Buoy [off Dubmill Point] and Corner Buoy, it’s a critical region, the region that gives us the most trouble,” Ed tells me. “At Corner Buoy there’s a narrow corridor, that channel is our window – to the East of it are big boulders, the shrimp fishermen won’t go there, to the West are shifting sands. So we have to head North to North-West between the two sandbanks, then North-East towards the Beckfoot buoy.”

The ‘trouble’ is due to the shifting sands. “After the winter storms of 2014/15 we had it surveyed, and a lot of sand had moved around. The channel by Corner Buoy had been 3.8 metres deep and it had gone to just 1.3 metres deep. The sandbanks had spilled over. We need at least 1.3 metres by the Solway Buoy because there are boulders and rocks, so it was an awful situation.”

But interestingly, the survey, using multibeam sonar which is accurate enough to pick up details of sand-ripples, showed that for two or three cables (1) the bottom of the corridor – although less than half-a-kilometre wide – had remained unchanged.

“To the West were sharp sand-waves six to seven metres high, with channels or trenches between them,” Ed says, “but the bottom of the corridor looks smooth, it’s quite linear. They reckon the sand can’t take a hold.”

This is fascinating. We discuss whether this could be a peat-bank, like those sometimes exposed beneath the sand and shingle on the shore. Or a thick layer of boulder-clay or glacial till? Both those substrata are smooth and fairly stable. (For more recent information on the bathymetry and bottom of the channel, see ‘Seeing the Solway’s bottom’.)

(Photos of the tug Furness with thanks to John Forrester; there are many more relevant and interesting photos of Solway shipping on his website)

Every major storm sequence causes changes, and not only to the sea-bed and shore. In the  winter of 2015/16, Beckfoot Buoy was swept away: in March 2016 three new buoys were lined up against a harbour wall, awaiting a tug from Barrow to tow them and their anchors, the IBCs (2) filled with concrete, out to their new positions.In September, the tug Furness did just that.

Not just the sea, but the rivers too

While attention is naturally concentrated on the effect of the storms on land, few people think of the effects on our ports and rivers – and the consequent enormous costs to the port authorities of the clean-up. The storms’ aftermath has seen enormous quantities of silt and débris such as tree-trunks brought down by the rivers, as well as dramatic changes to the profiles of the shores. At Silloth, sediment that builds up in the outer Dock, can be flushed out at low tide by opening sluices in the New Dock gates.

At Maryport, a specialist dredger, the BORR,  was working throughout March, blasting the mudbanks with high-pressure water-jets, so that the stirred-up sediment was carried out with the tide. At Workington, two different types of dredger have worked at the mouth of the River Derwent and in the port’s turning basin for almost two months, scooping or sucking up the sediment and carrying it out to sea. Their  activities have been followed by Danny Ferris and John Forrester, whose websites Solway Shipping and Cumbria Ship Photos,  respectively, provide valuable insights into the workings of the West Cumbrian ports.

Entering Silloth docks

The entrance to Marshall Dock is at right-angles to the tidal flow: difficult at any tide but especially so when the biggest Spring tides – potentially 9-10 metres at high water – are running. Entry must be at high water when the tidal flow is at its minimum, but “there’s no slack water at Silloth”, Ed says. “There’s a counter-current, especially on the big tides, just off the port entrance – it rips in the opposite direction. And there’s a ‘top run’ where it ebbs earlier at the entrance.” Pencilled diagrams on Ed’s Passage Plans give graphic explanations of the ship’s potential movements.

(The Baltic Sailor, piloted by John Munro, on a blustery day in August 2016)

‘We stop the ship three cables off the entrance and wait for the tide to drop off, then I’m aiming at West Beach, crabbing in – the counter-current off the entrance is pushing the stern in the opposite direction even as the bow is inside the dock.”

Entering the dock presents different problems, too. “When you enter  a narrow channel, there’s a hydraulic effect, the water speeds up under the ship. It’s asymmetrical and unbalances the ship. Then you enter New Dock, which is the shallowest point and the hydraulic effect increases. The flow underneath causes the ship to ‘squat’ – it sits lower in the water, it becomes deeper.”

New Dock isn’t huge, and there may be other vessels there already, ranging from scallop-boats and trawlers to cargo vessels, taking up space along the quays.

 

“We get into the dock and then we have to turn the ship. The captain needs to tell us how the ship behaves when going astern – it’s an effect of the propellors – whether the ship tends to swing port or starboard.” Tricky enough on a calm day, but even harder when there’s a strong wind and the space is limited. Tricky at night, when the two onshore leading lights must be lined up for the correct angle to approach the gates (see Master’s Passage Plan diagram above). And even trickier when the vessel being piloted is the Zapadnyy.

If you are now realising a little of what piloting a ship entails, enjoy considering the Zapadnyy. This cargo vessel carries molasses, for use in animal feed; molasses presents a special problem because it must not be allowed to get too cold or too warm. I first heard about her in connection with some emergency welding that had to be carried out on the dock, and all the pilots have stories to tell about her.  “She’s unmanoeuvrable!” (Bill Amyes); “It’s anybody’s guess which way she’s going to go” (Ed Deeley); “She’s got such a broad beam. It’s like trying to steer a coracle” (Chris Puxley).

zapadnyy-dannys-pic-sept16

The day the Zapadnyy got it wrong. September 13th 2016. Photo thanks to Danny Ferris

(See more of Danny Ferris’s striking photos on his Solway Shipping website)

But Ed also adds, “She’s a Bulgarian bunker barge. She’s got a very competent bridge team as well as a very good echo-sounder! And she’s the only vessel that manages to keep molasses in a good state.”

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The Zapadnyy, unloading warm molasses through a pipe (photo: Ann Lingard)

 

(1) A cable length is 180m

(2) IBS: Intermediate Bulk Container

There are more stories about the Port of Silloth and Ships’ Pilots on Solway Shore Stories.

Posted in ports, sea-bed & undersea, ships | Tagged , , , , ,

The Walls of Parton

staircase rsz

On top of the wall

‘Are you looking for the old port?’

The man seemed to have appeared from nowhere, yet he was tall and strongly built, white hair sticking up straight, not easy to overlook.

‘Port?’ I was bemused – I’d been poking at pink Corallina fringing a pool.

A wet black labrador jumped up at me, whining, tail thrashing, a long stick protruding each side of his mouth. I took the stick and threw it, my hand slipping on the glutinous slobber.

‘There was a port here in the 1700s, it was built to take the coal from Parton to Dublin. If you go down there across the rocks—‘he pointed to where a flat tongue of sandstone jutted into the sea, ‘you’ll just be able to see some remains of the walls. And there’s a few dressed blocks of stone lying round down there, too.’

Until then, I had had no idea that Parton had been a port. The man then told me about fossil plants in the mudstone, and how he and his daughter had picked up about 20 specimens in half-an-hour. My husband joined us and told the man about a large ‘trace fossil’ – feeding marks possibly made by a sedentary worm – that we had just found in a boulder by the car-park. I had been collecting sea-weed, and the man told me about the channel wrack on the rocks nearby. He was a retired zoologist; we chatted some more, shook hands and said ‘Well met’, and the man and his dog strolled away across the shore.

Parton is just to the North of Whitehaven, where coal has been mined for at least three centuries. In the late 17th century and early 18th century Parton was apparently a busy and thriving town. There were two tanneries, a glassworks, a saltpan, and also considerable business associated with coal. All this I discovered later when we left the shore for the Wagon Way, where there is an information board and an audio system that will not be silenced after you have pressed the button; its calm, reasonable voice continues to echo from the cliff even after you’ve bidden it goodbye.

The rocky shore that edges the village is a mixture of the geological and industrial past so common on this stretch of coast, where coal-mining and steel-making once guided the economy and peoples’ lives. In places the sand and shingle have been washed away to expose hard banks of ash and embedded coloured, gaseous pebbles, the slag from the Bessemer converters which was poured onto the shore. Piles of limestone boulders, brought from inland quarries, have been mounded at the shore’s upper margin to protect the land from the sea’s battering; the curved fossil shells within them – bivalves, brachiopods – show the marine origin of the rock.

And the ‘country rock’ of the shore is old, Carboniferous sandstone, both purple and creamy-yellow, in flat plates and ridges, bored into by the waves to form deep alga-fringed pools. Surfaces and crevices are coated with barnacles, mussels, gaggles of Littorina, and the tall-shelled limpets indicative of an exposed, wave-pounded shore.

This rocky shore-scape is so different from the sandy expanses further up the Cumbrian coast. Here at Parton are algae of all colours coating the rocks and pools, providing a richness of habitats for intertidal animals. There are encrusting patches of tubes of the honeycomb worm, Sabellaria. Foot-marks and ‘teeth’-marks on the smooth rock betray the wandering, feeding activity of winkles and limpets when the tide comes in: incipient ‘trace-fossils’.

There are other rocks, too, sea-smoothed pebbles and boulders: different-coloured sandstones, Carboniferous and New Red, coal, and slate. There are more clues about former lives and endeavours: the sea sorts them into bands along the shore – fragments of decorated china and lumps of thick green glass scoured by the sand, the base of a bottle with ‘WHITEH’ in raised glassy letters, cloudy green marbles from bottle-stoppers.

parton glass & china

Clues to former lives

As so often, a chance encounter – this time with one man and his wet dog – brings questions, this time about the vanished port. The main players were Lamplugh, Fletcher, and Lowther, then as now a major land-owner: Lowther already had a suitable port and quay at Whitehaven, but feared the competition from Lamplugh’s proposed quay at Parton.

What a long psychological and verbal battle was stirred up between them by the necessity to export coal – coal from coastal pits like Lowca and Moresby and Saltom – easily and cheaply by sea. There had previously been a small harbour at Parton which was damaged by storms and barely usable. Lamplugh arranged for the pier to be ‘re-built’ between 1695-8, and – of course – the re-built pier was considerably bigger than before, and a certain amount of dredging and re-arranging of the outlet of a beck was required to improve the harbour. In 1705, the First Parton Harbour Act was passed in Lamplugh’s favour; followed by Acts 2 and 3 in 1724 and 1732, all of which permitted the raising of funds for the continuance and upkeep of the harbour by the levy of dues on ships. The twists and turns, the Acts and weasel-words, are recounted in delightful detail by David Bradbury in the online background material for his book, Parton Part One.

But in the end, it was the Solway’s wild waves that eventually finished off the harbour and the export business. In February 1796 a tremendous storm thrashed the West coast of Britain, and Parton’s port was totally destroyed, its sandstone quay swept away, the bay’s sandbanks and shingle shifted and redistributed. Where there is now a piece of flat ground and the War Memorial, on the village side of the railway, there was once a harbour.

After the man and his dog had left, I looked for remnants of the harbour wall, but the sea had already covered them for there was nothing to be seen beneath the silty incoming tide.

wall & tunnel rsz

A tunnel to the shore

With the loss of the port as its hub, it seems that Parton went into a decline. The village, hidden at the base of the great red cliffs, is unseen from the main coastal road, and the shore is hidden from the village behind a high red wall that is punctuated by a few low tunnels through which a car, or horse and wagon, might drive, carefully, to the shoreward side. The clues to the reason for this wall are high above, spiky silhouettes of gantries with signals, and warning signs: the embankment carries the coastal railway on which Parton is a request stop.

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A Sunday train heads South

It’s Sunday and several men in high-vis jackets are chatting, and clattering with metal tools, on the line. Later, we watch the two-coach train creeping round the foot of the distant headland and then, unrequested, passing through the station, continuing quietly to Whitehaven.

We pass through another tunnel under the railway, back into the village. There are more high sandstone walls, some of the stones show cross-stratification, the lines of intersecting underwater sandbanks; square holes are inhabited by jackdaws who turn their heads to peer down at us; two rusty hinge-supports give away the presence of a bricked-up door, behind which there is the sound of rushing water. These stone walls are the artificial face of the cliff, built to restrain the soil and shale from slipping down onto the street.

From a higher vantage point we look down onto the roofs of houses and into their backyards, a view that takes in the railway, the bay, and distant Moresby church and Hall, and that is still – with notable absences – recognisable from Percy Kelly’s paintings and drawings. Author Chris Wadsworth records that in an interview in 1964 Kelly ‘said there was an urgency in drawing and painting [Parton] because it was disappearing as he worked. In fact the council were demolishing a lot of the old houses which were unfit for habitation and relocating people to the new housing estate on top of the hill.’

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The cover of Chris Wadsworth’s guide: Parton seen from the South

Kelly was born further up the coast at Workington in 1918, and  his extraordinary story has been told by Chris Wadsworth, who as a former gallery owner in Cockermouth has done more than anyone to bring Kelly’s works and life to our notice. He was a difficult man – paranoid, narcissistic, hypochondriac, arrogant, twice married, befriended by the rich and famous, cross-dresser (long before Grayson Perry, and while living in a rural area in less-tolerant times) … He was a man who inspired many unflattering epithets, but whose works, including his now-famous illustrated letters, have become highly sought-after and enormously admired.

Kelly was also, for a while, a friend of Millom poet Norman Nicholson; the dwellings, works and harbours of the industrial coast of Cumbria inspired them both. His drawings and paintings of this area are visual echoes of Nicholson’s 1943 poem Whitehaven :

‘… suburbs like a waking beast

Hoist their backbones to the east,

And pitheaps at the seaward gate

Build barricades against the light.

Deep as trenches streets are dug

beneath entanglements of fog …’

Parton isn’t on a ‘tourist route’. While we are there, the shore is busy only with locals walking their dogs; a lone fisherman waits for sea-bass.

fisherman rsz

Waiting for sea-bass as the tide comes in

But a new guide to Parton, one of several ‘Percy Kelly Trails researched and designed by Chris Wadsworth, might persuade enthusiasts for the artist’s works and life to visit the village and search for the buildings and views which inspired him.

Our intention – the reason we have come to Parton – is to search for those plant fossils that the man had mentioned. We head South towards Whitehaven along the Wagon Way, a smooth track once used by horses hauling coal and now ideal for cyclists, walkers, buggy-pushers.

We are distracted by more red walls: low walls against the cliff’s base, and a waist-high wall above the railway embankment, curving around the headland in the distance.

lines of walls rsz

Walls: Wagon Way and railway lead where the horizon fades into the sky

 

The walls demand our time, our attention; they are so perfectly constructed of blocks, some as much as a metre long and 300cm high. Red sandstone, St Bees’ stone, probably quarried from the cliff between Parton and Whitehaven, then transported to where it was needed; the block faces cut and dressed and worked to almost perfect squares and rectangles.

 

Mica flakes glitter, green algae smear the surface; here and there the exposed surface has been deeply eroded. Imagine the difficult and unsafe work that went into the quarrying and transporting of the stone; the cutting, the dressing, the lifting and placing of all those stones. There are holes in the blocks that would have been used for swinging them into place. How many men, how long, did it take for the walls of Parton to be built?

Guttural quacking draws attention to pairs of fulmars, raising their necks in bonding display, high above on rocky ledges. The site we are looking for is part-way up their cliff, a dark patch of shale-y mudstone, formed millions of years ago when a stream in spate burst its banks and deposited metres of fine mud onto surrounding vegetation. To get to it we must climb over a wall and fight along an indistinct muddy track, up through brambles and briars and last year’s pale nettle stalks. But we are Prepared: we have secateurs and an old piton-hammer that has found new use as a geological hammer. And then, several metres below our objective there is a landslip, a talus slope of mudstone flakes, within some of which are embedded smooth dark shapes – single perfectly-preserved leaves, stems fringed with leaves, straight ridged stalks.

Each tiny plant is as delicate as gold-leaf that has been stroked onto a substrate with a paint-brush.

parton plant fossils1

Plant fossils pressed within the layers

Later, as we walk back along the Wagon Way, the narrowing strip of shore below is empty of people, but as we turn the corner onto Main Street a wolfhound as tall as a miniature horse ambles towards us. He is neither wet nor carrying a stick. His owner tells us, ‘He’s lazy, he’d rather lie on the sofa all day.’

Posted in coal, coastal heritage, fossils, industrial heritage, ports, sandstone, slag-banks, stones | Tagged , , , ,

Freshwater mussels in the West Cumbrian coalfield

saltom winding-house

The coalfield beneath the sea: view SW from above the Saltom winding-house

The late Norman Hammond once told me that he used to go out in his boat to count the basking sharks when they came into the Solway. One time, he was motoring off Fleswick Bay near Whitehaven during a coal-miners’ holiday; the men had been spending the day with their families on the beach, and one shouted across to him across the water.“I was asked if I could take them out to have a closer look, which I was glad to do,” Norman told me. “One man said he’d love to swim with them and I told him to slip over the side – off came his clothes and in the nude he swam with the sharks from Fleswick to St Bees’ Bay.”

Norman, who died in 2005, was the founder of Solway Shark Watch and he and his wife Florence were founder members of Cumbria Wildlife Trust. He was one of those rare people, so knowledgeable and enthusiastic about the natural history of the Solway that he wanted to share his knowledge with everyone. He was a story-teller – if you asked a simple question he would reply with such a wealth of information and anecdote that you became caught up in the tale. When he told me that one of the miners had given him a ‘freshwater mussel that he’d found in the mine’, that was a piece of information to remember and treasure.

So I immediately thought of Norman when geologist Eric Gozlan mentioned ‘musselbeds’ during his talk to the Cumberland Geological Society about West Cumbria Mining’s plans.
West Cumbria Mining (WCM) are exploring the West Cumbrian coalfields beneath the Solway Firth to the South-West of Whitehaven, with the view to extracting coking-coal (there’s a fuller discussion of the background, drilling and future plans elsewhere in this blog). An enormous amount of relevant geological data already exists but, as Eric pointed out, there is a considerable amount of faulting in the coal-field – in other words, there have been upheavals and slippage so that a band of coal and the rocks that sandwich it might have dropped several metres relative to their main position. Understanding the depth and extent of any fault is obviously important – there’s no point trying to carry on mining a band of coal if it has been pushed aside by a fault.

coal-seam-sequence-1-wcm-website

Stratigraphy diagram from WCM’s website

 

So, to map the coal-bands in three dimensions, it is necessary to drill bore-holes at different locations and extract cores. By knowing the depth of each rock-type on the core, it’s then possible to fit this information to the corresponding data from other cores and plot the extent and depth of the coal seam.

 

As Eric said during his talk, “The exploration geologist is always trying to find out where he is.”

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Eric Gozlan in WCM’s wooden office inside the warehouse

And one way he (or she) can navigate down through the rocks is by looking for specific markers of geological time. That’s where the fossil musselbeds become so important.
Knowing of my interest in the mussels from the mines, Eric had generously suggested that I come and visit the office to look at the cores. I met him and his colleague Steve Craig in mid-February at WCM’s office and ‘core store’ in Whitehaven. Their office is located within an airy warehouse adjoining a garage on an industrial estate – it was cold both outside and inside, and the heating was turned up high.

Eric has been leading WCM’s exploration project since September 2014; he has a Master’s Degree in Geophysics and Geology from Monash University, Melbourne and before joining the WCM team already had 10 years’ experience working in the mining industry. Stephen, who has a Master’s in Geochemistry from Leeds and is WCM’s site geologist, formerly worked in the goldfields of Western Australia. Within minutes of my arrival, they were both scurrying round, looking for technical papers for me and photocopying charts.

coal strat bgs

Taken from the BGS Memoir for the west Cumbria district (page 60)

The most useful chart is from the British Geological Society’s Memoir for West Cumbria [1], which shows the two main musselbands, one marine, one freshwater. Eric told me that the Vanderbeckei band – its local name is the Solway Band – ‘extends from Moscow to America’ and it is the ‘target boundary’ between the Middle and Lower Coal Measures that they look for in the core, identifiable by its fossil marine fauna such as the brachiopod Lingula.Then they search for other recognisable features.

‘We crack open the cores and look for freshwater mussels. Within the next ten to fifteen metres we should then typically find Yard Band, which is a good unfaulted band. Though it can be less than five metres depending on the [nearby] faulting,’ Eric said. Above the freshwater mussel band are Main Band and Bannock Band, both coal seams that are of interest to WCM.

Steve explained that there are as many as 20 different species of freshwater mussel fossils that are diagnostic of the depth of strata and the proximity of coalbands; or, as the BGS Memoir puts it, rather more euphoniously, ‘Palaeontological study of marine and nonmarine fossils has provided a chronostratigraphical framework for the coalfield.’

Eric and I go out into the core-store where metal shelves are stacked high with plastic core trays; black or mottled or wrapped in paper, the cylindrical cores are labelled with letters and numbers to identify their place and depth of origin.

The next batch of offshore drilling will start again in spring/summer 2016. ‘We will get tighter information on the kind of coalfield we’re going to intersect,’ Eric said, ‘– for example for the Sixquarter. We’re drilling to identify specific targets.’ Two drilling rigs will be running for up to six months – with two more geologists joining the current team of four.

He gives me a section of a core that has been varnished to show the freshwater fossils more clearly: there are two very obvious bivalve shells embedded in the rock – Steve says they are probably the mussel Anthracomya. Carbonicola (the only species whose name I knew) is older, found lower down. Two other sections of core show fragments of marine fossils, of the brachiopod Lingula and a couple of graptolites.

Seeing those fossils – marine fossils, freshwater fossils – in situ in rock that has been brought up from 400-500 metres below the seabed of the Solway, is extraordinary. It’s too easy to become blasé about fossils, there are boxes of them in museums and private collections. But these Anthracomya, whose fossil shells I could stroke with my finger,  were living, growing and filter-feeding on the bed of a river perhaps 300 million years ago.

That river ran across land that had previously, on occasions separated by tens of thousands, even millions of years, been submerged beneath the sea. The river delta had itself been inundated by the sea much later, on widely-separated occasions. That competition between sea and land had been carried out over millions of years; the climate had swung between tropical and temperate and glacial; the place those swamps and sediments and rocks occupied on the surface of our planet had drifted and been pushed through different latitudes and longitudes across the planet.

Norman Hammond would surely have had a good story to tell about that.

 

[1] British Geological Survey: Geology of the west Cumbria district, Sheet Memoir 28, 37& 47. NERC 1997

Posted in coal, fossils, industrial heritage, sea-bed & undersea, shells | Tagged , , ,

What’s been happening at Robin Rigg? An update

robin rigg

The distant wind-turbines of Robin Rigg, seen from the Allonby shore

Live shipping maps – watching vessels move around the seaways in real-time – can become addictive. I can easily be distracted by Danny Ferris’s Solway Shipping website with its live coverage, photos and notices of the ships that are due into the ports of Workington and Silloth.
During the past months there have been plenty of opportunities to be distracted, with considerable activity around E.ON’s Robin Rigg Wind Farm in the Solway, including much coming and going of E.ON’s own boats, Solway Spirit and Solway Challenger, and several other twin-hulled boats belonging to Turbine Transfers. There was also the unmissable presence of the massive jack-up barge MPI Adventure.

I first wrote about Robin Rigg in 2011, a year after it came into full operation, and I also spent several very amusing hours with the crews of the two service boats, Solway Spirit and Windcat 3.

Since then, there have been several changes. Tim Morgan became Plant Manager for Robin Rigg in 2013; a former materials engineer, he tells me he has ‘been in wind’ since 2004, both onshore and offshore. He kindly agreed to give me an update on Robin Rigg – especially since I assured him that I think the offshore windfarm is (unlike the piecemeal onshore scatterings of turbines) a handsome and efficient addition to the Firth. There are several important changes he’d like to tell me about, and I have several questions to ask. Our conversation at E.ON’s building at the Port of Workington is relaxed and informative – within the bounds of what he is permitted to discuss (as with my previous articles about Robin Rigg, I knew boundaries would exist and respect them.)

Offshore Maintenance teams
The Danish firm Vestas built and supplied the turbines, but Tim tells me that when their five-year maintenance contract came to an end in December 2014, E.ON decided to bring the whole offshore maintenance team in-house from January 2015, creating 12 permanent jobs for local people. ‘The in-house approach is working really well,’ he said, ‘and we’re becoming a close-knit team.’

Specialist teams have also had to be hired in the short term to do a ‘health check’ on the turbine blades, and subsequently some repainting and minor repairs; the work involved a special expertise, abseiling and rope-work high above the sea.

(Photos with permission from Alpha Offshore)

 

The service vessels have also been busy, due to around 40 maintenance staff working over the last 18 months, on an industry-wide issue with grouting inside the foundations.

So, what is grouting?

The structure and construction of an offshore turbine is described in more detail on Solway Shore Stories, but basically the monopile base is hammered into the sea-bed; then a cylindrical Transition Piece (TP) is lowered onto the monopile and levelled. The 80-metre tower is bolted to the TP, and eventually the nacelle, blades, generators and so on, are installed at the top of the tower.
The TP is like a collar over the top of the monopile, and it is fixed in place by a special sort of cement-like substance, the grout; the grout is thus essentially a loaded component, carrying the weight of the turbine.

It became apparent at several wind farms that there were weaknesses in the grouted connection, and checks on the turbines at Robin Rigg showed up weaknesses in the design.

Court-Rules-Against-MT-Højgaard-for-Robin-Rigg-Work

The tower sits on the (yellow) TP – and the turbines offer a perch for increasing numbers of cormorants (photo with thanks to E.ON)

Tim explains that the ‘remediation work’ to safeguard the site against any longer term problems was estimated to take around two years’ work; it is well under way and can be carried out inside each turbine foundation (a surprisingly large space, 4.5 metres in diameter).

A decision to find where the responsibility for the incorrect ‘design code’ lies is ongoing. In April 2014, MT Hojgaard (MTH), the company responsible for undertaking the grouting work, was taken to the High Court by E.ON and found liable for damages.
MTH appealed the decision at the Court of Appeal in April 2015, arguing that it had ‘observed the applicable international standard as required by the client’ – and won: it was ruled to be not liable for the remediation costs.
In November 2015 E.ON took the case to the highest legal authority, the UK Supreme Court – and has recently been granted the right to appeal.

Meanwhile, remediation continues inside Robin Rigg’s foundations.

Service vessels: operations, maintenance, and decommissioning

The maintenance technicians, rope-access teams and others are ferried between the wind farm and the Port of Workington by the service boats. E.ON commissioned their second vessel in October 2013; one of the pupils at Northside Primary School in Workington won a competition to choose the name, the Solway Challenger, and the vessel was blessed and named at a special ceremony at the Port. Solway Challenger is a twin-hulled, 19-metre vessel, and with her twin-deck wheelhouse is “very comfortable and spacious”, Tim assures me.

eon boats2

Twin-hulled Turbine Transfers’ O&M vessels at the Port of Workington

Windcat3 is no longer on site, but other Operations and Maintenance (O&M) vessels are contracted to E.ON on a varying time-scale. Turbine Transfers has had several vessels working in the area, such as Port Wen, Rhoscolyn Head, Porth Diana, Aberdaron and Lynas Point (you might have guessed that it’s a company based in Wales). The grey twin-hulls are especially designed to enable them (like Windcat before them) to nose up to a turbine and allow people and kit to be transferred despite the swell. O&M is keeping crews and vessels busy.

The jack-up vessel, MPI Adventure (a newer design than MPI Resolution which put the monopiles in place) steamed onto the scene on October 2nd 2015. She is contracted to E.ON, and Tim says she arrived following work on a project in the German North Sea. The Solway’s weather was very changeable and often wild during the autumn and “although Adventure’s stable when the legs are down, you can’t be using cranes and so on in high winds”– so whenever the wind got up, Adventure paused or headed back to Belfast until the working window of the next Neap tide.

I watched from the Senhouse Roman Museum at Maryport in November on one occasion when she returned, and she was an imposing sight, travelling fast for such a giant.

mpi adventure from eddie s

MPI Adventure at Robin Rigg (partly removed turbine to the left). My thanks to Eddie Studholme for this fine photo.

Why was she at Robin Rigg? To decommission  two of the turbines, A1 and B1: in other words, to take them down. Tim explained, “After the storms of winter 2013/14 there was an effect on the channel causing it to move. We made a proactive decision to take out the two turbines after monitoring the movement of the sandbank and loss of seabed.”

Generation by these two turbines was halted back in April 2015; they were dismantled in October. There is no impact on the remaining turbines at the wind farm.

Artificial reefs

I’ve written elsewhere about Natural Power’s drop-down video survey of the monopiles, and the clusters of mussels, brittlestars, sea-anemones that have found a foothold on their surfaces, on some of the few places in the Firth where there is a firm substratum.

Offshore wind farms provide discrete artificial reefs, a specialist niche which might also be supposed to provide food and shelter for some species of fish.

It was interesting, therefore, to hear that one of the monopiles removed by MPI Adventure was encrusted with organisms; the photo shows what an astonishing biomass of marine organisms have attached and grown on the base of the turbine, forming a dense and interconnected ecosystem.

 

encrusted base from Tim M rsz wmk

A turbine base removed from the sea, densely encrusted with marine organisms (I’m grateful to E.ON for this photo)

The Solway’s shifting sands

The Solway Firth is “raw and beautiful” according to Tim Morgan; he also called it “chaotic and unpredictable.” Colin Sharpe, Development Manager at the Port of Workington calls it “one of the most aggressive estuaries in the UK.” Marine biologists at Natural Power refer to the Solway as a ‘highly dynamic estuarine environment.’

It is infamous for its shifting sands and channels, its changing bathymetry and sedimentation. In the region of the wind farm, the seabed is in fact a series of banks (Dumroof Bank, Robin Rigg, Two Feet Bank and Three Fathoms Bank) orientated in a northeast – southwest direction. Here, according to a bathymetric survey (see section 5.2 for Robin Rigg) there are ‘finer grained granular sediments … ranging from laminated sands, silts and clays to organic silts and clays.’ Across the whole of the turbine array area sediments ‘generally comprise mobile, shelly fine to medium grained sands’.

When Natural Power ecologists Jane Lancaster and Fraser Malcolm carried out surveys of fish and benthic invertebrate fauna during the pre-construction, construction and operational periods, their ‘baseline survey sampling locations were selected, through consultation with local fishermen, to maximise catch by following the channels adjacent to the sand banks within the study area. Subsequent surveys during the Construction and Operational periods were conducted at the same survey locations in accordance with the MEMP [Marine Environmental Monitoring Programme]. However, as the Solway Firth is a mobile sand bank system influenced by tidal currents, the original sandbanks surveyed in 2001 had shifted by the commencement of the construction period surveys.[1]

I see the offshore wind farm as a compact and coherent way to harness the wind’s power, one of the forms of ‘renewables’ that we must have in the UK’s portfolio. That 60 wind-turbines and two transformer stations could be built in the adverse conditions that are so much a part of the Solway’s ‘character’ is a major triumph of engineering and persistence. And while many people might enjoy the schadenfreude of perceived difficulties with the windfarm, that ‘I told you so’ moment, there are good things to report. Last year, according to their newsletter Round Robin, ‘Turbine availability reached over 97% during this time, which is an industry leading performance level’

***

However, with regard to the difficult environment that the Firth presents, the proposers and architects of other forms of renewable energy related to the Firth should pause in their rush to create over-large schemes, and consider very carefully what the Solway can throw at them: and then design accordingly.


Note: I met with Tim Morgan in November 2015, and he submitted my draft blog-post to E.ON’s communications and legal teams in early December 2015 for consultation and approval. I received this, their edited (and sixth) version, on February 19th 2016 – hence the delay in its publication.

 

[1] p49, Chapter 2, Migratory Fish, in Analysis of the Marine Ecological Monitoring Programme Data for the Robin Rigg Offshore Windfarm, Scotland (Operational Year 3), EOn Climate & Renewables; http://www.gov.scot/Resource/0046/00463655.pdf )

Posted in renewable energy, tide & wind, ships | Tagged , ,

From ‘killing field’ to wetland and woods: Watchtree Nature Reserve, Cumbria

From the hill at Watchtree Nature Reserve you can look across to the upper reaches of the Solway Firth, the Borders and, to the East, the Northern Fells. It’s early February and the snow-coated top of Skiddaw is glistening  in the sun; a skylark is singing, and the clutter of tree-sparrows squabbling in a hedge are momentarily silenced as a sparrowhawk sweeps through.

Frank Mawby, a Director of the Reserve’s Trust (and former Reserves Manager for Natural England in this area) drives along the runway to meet me; he has been organising the volunteer work-party. He tells me he’d like to get some funding to build a tree-top hide ‘so that people can see where we are in relation to the Firth.’

Ideas and plans and optimism about the future – these have always characterised the development of Watchtree, right from its inception. I came here in 2011, on the tenth anniversary of the Foot-and-Mouth (FMD) epidemic that swept through Cumbria and now, on the fifteenth anniversary, I have come back again to see how the Nature Reserve has progressed since then.

Watchtree is on the site of one of the Solway’s several wartime airfields, Great Orton, which, abandoned after the War, became an unofficial ‘community resource’ used by microlite flyers, clay-pigeon shooters and youngsters learning to drive.
But then, in February 2001, it was commandeered as a mass grave, an enormous engineering and logistical feat that saw 26 burial ‘cells’ dug – and filled. The name, Great Orton, became synonymous with ‘the killing field’, the great trauma of the county, which many find hard to talk about even today.
There is a plaque at the gate, mounted on a piece of Criffel granite, a glacial erratic that was dug up nearby:

“A Symbol. To the birth of Watchtree Nature Reserve, dedicated this day the 7th May 2003, the second anniversary of the final burial.
A Memorial. To 448,508 sheep, 12,085 cattle, 5,719 pigs buried here during the Foot and Mouth outbreak of 2001″

memorial stone2 rsz

Half-a-million animals; so few infected. This is not the time or place to dwell on the impact of the disease, but you can read a fictional account (based on fact) of what happened to Madeleine, a Herdwick sheep-farmer, in this extract (page 20, Firecrane) from my novel, The Embalmer’s Book of Recipes.

But now, one can almost forget what lies beneath the wildflower meadows, the woods and the lagoons.

Next to a hide overlooking a pond, Frank opens a wooden door in a fence (this requires some spectacular contortions as the clasp is on the far side) and takes me into a grassy, scrubby, wetland area by the four lagoons. These lagoons are ‘operational’ and not open to the public; the richness of the surroundings is breath-taking even at this wintry time of year – the common reed Phragmites and bulrushes Typha latifolia fringe the water; the leaves of yellow flag and golden-cup are starting to show at the edges. A teal takes off, and then three snipe, zig-zagging with flickering wing-beats. Willow and birch are growing along the sloping banks, and Frank shows me how they are coppiced on different sides each year. There is gorse, too – as always, some of it in flower (‘When the gorse is not in flower, then kissing’s not in season‘).

The still water reflects the blue sky and slowly-moving clouds. ‘It’s very clean water, and biologically it’s got an awful lot growing in it,’ Frank tells me. ‘We get Great Crested Newts, tadpoles, dragonfly and damselfly nymphs. And Great Diving Beetles – though they’re mainly in the main lake. They’re voracious predators, they’ll even clean out the tadpoles.’
As for the birds that have been seen around the lagoons, ‘We’ve had sedge- and reed-warblers – they were a surprise. Six or eight pairs of linnets, goldfinches, willow warblers – and the usual dunnock, wren, robin. Coot, moorhen, Little Grebe. Reed bunting. White-throat. And swallows love it here, feeding over the surface.’

To understand why there are wetlands and lagoons here, on a former airfield, you have to understand what happened during 2001. If you stand by the gate and look along the western runway it’s impossible to ignore what lies underground. There are regularly-spaced green metal boxes and metal cowls and the ends of pipes. Part-hidden in the wood at the northern end are the buildings, with humming machinery and computerised read-outs from the biodigester plant where the contaminated liquid from the burial cells is processed. ‘Leachate’ became part of our common vocabulary for several years after FMD; one estimate is that it could take 40-60 years to disappear.

‘The whole site is very complicated,’ Frank had explained to me in 2011. ‘We have to consult Interserve [the company contracted to oversee the drainage] and look at all the plans, especially when we’re digging ponds. There’s masses of electrical wiring as well as the drainage schemes.’ The whole burial area is lined by a wall of bentonite, a mix of clay and slurry that is 12 metres deep and pressure-driven into the bed-rock. There is a ring-drain within each cell, and leachate is pumped out of the cells to the biodigester where bacteria break it down. Drainage of the whole site is indeed complicated, in that surface water (from rain) is collected into ditches, where it joins with the deep ground-water and treated effluent, and is sent to the lagoons and reed-beds for the sediment to settle and excess nitrogen to be taken up and removed. ‘We’re at the top of a hill, so any water coming off must be absolutely pure – it’s tested at all stages, for ammonia, solids and pH.’

And also back in 2011, Frank had told me, ‘Although the waterbodies were created by us, everything in them is developing naturally, reeds are coming in and we should soon get reed-buntings. The Great-crested Newts wouldn’t be here if it wasn’t for us. And they’re going further afield, spreading and spreading every year.”

Now, five years on, the reed-beds are flourishing, and he can reel off the number of bird species and say, ‘It’s an amazing bird list!’

Nest-boxes, and bird-feeders with seeds and nuts, hang from some of the trees: ‘The tree-sparrows are doing well. They’ll clear out one of those feeders in a day. Visitors get a lot of pleasure seeing the birds’. We see a yellowhammer on a bird-feeder, and I remember that there had been hopes that they would breed on the Reserve. ‘They’re not yet breeding here – but the hedgerows are about right for them now, so hopefully we’ll see some nesting this year.’ And although the sandmartins are still resisting the invitation to nest in the artificial bank that was built for them, oyster-catchers nested on top of the bank instead.

What is Frank most pleased about? ‘Ah,’ he pauses and considers. ‘All things are doing reasonably well – the grasslands are difficult, but the wetlands have come on nicely, there are abundant birds on them. The lake attracts a lot of birdlife in winter too.’

lake3 feb16 rsz

The lake, seen from the hide

We climb the wooden steps to the hide overlooking the lake, and open the long windows to view the birds; the water is blue and scarcely ruffled by the biting wind; the reeds are pale and rustling. There are tufted duck and gadwall on the lake, a coot and a Little Grebe, and Frank is surprised to see that there are now four swans, one of them high up on the bank. ‘We had a big starling roost here a year ago.’ How many birds? ‘About 20, 000 – a good murmuration. But one night the lake froze and they went away the next day – perhaps they know that predators can get at them more easily when it’s frozen. But they’ll probably come back.’

From the hide I also see two humans, cycling along a tarmac-ed strip of runway towards the woodland. The ‘Watchtree Wheelers’, overseen by Ryan Dobson, were set up with £25,000 in Lottery Funding to provide a range of bicycles, tricycles and motorised wheelchair carriers, as well as a hard track around the Reserve,

watchtree bikes2 rsz

The Watchtree Wheelers

so that disadvantaged and disabled people might enjoy some ‘quiet recreation’ around the wood; this was the brain-child of another of the Trust’s Directors, Bill Knowles.

The soil
As on my previous visit, the quality of the soil is a topic of conversation. The soil has had a history of disturbance by men with diggers: during the War when the runways were built and in 2001 when the burial chambers were dug.
The clue that it varies from place to place is provided by the vegetation.
We walk down the edge of one of the old runways. The wind-turbines scythe rhythmically overhead. Overburden from the excavation of the burial chambers was laid along the runway and a ‘commercial mix’ of grass was seeded and grew well; but it out-competed the herbs, so Frank brought in haybales from a wildflower meadow and much of the seed they contained ‘took’. ‘It’s now one of our best wildflower meadows,’ he says, and brown hares are frequently seen there. The meadows are grazed in the autumn to stop the build-up of rank grasses – three local farmers bring in cattle and sheep to graze the different areas.
There’s another, newer, wildflower meadow beneath the fourth turbine, sheltered by a hawthorn hedge. ‘It takes time,’ Frank says. ‘It might take 50-60 years for it come right. But I’ve always said we should go for meadows rather than just plant more trees – planting more trees seems to be everyone’s answer these days! Wildflower meadows have been our biggest loss [in the countryside], so if we can make it work, in time it will be really valuable’.

Into the woods
We walk along along another runway, the date ‘28/4/42’ scratched in the cracked concrete, towards the woodlands: two patches of woodland had existed previously, and more than 80,000 trees have been planted to link them, a mixture of Scots pine to encourage the red squirrels, and broad-leaved trees like rowan, hazel, willow and grey poplar. There is a plantation of self-seeded alder, and as we walk along the trail the sunlight picks out the trunks of the birches where brush and saplings have been cut back to create a ‘woodland glade’ effect to encourage butterflies.Great Tits and Coal-tits flitter and chatter amongst the trees.
In one place the Scots pine and other saplings have not grown well: the soil is poor and compacted.

stunted growth feb16 rsz

‘The trees will quickly tell you if they don’t like the soil’

‘The killing-sheds were here,’ Frank tells me. ‘The trees will quickly tell you if they don’t like the soil.’

But some of the volunteers have dug holes in the hard pan, and these have filled with water – ‘transitional pools’, Frank calls them, where there are now three species of newt. ‘These areas of different soil, they’re creating structural diversity. We’ve got a range of habitats.’

This is what draws me to Watchtree, not only its size and its range – the mix of woodland, wetland and open water, scrub, wildflower meadow and rubbly, well-drained ground – but the unbounded optimism of Frank and everyone else I meet who is involved with the Reserve. The approach to this site has been empirical, experimental, and – as with all good science – there is a pragmatism and a willingness to understand what is going on, and to either build on the results or take a new approach.

We go through a gate into Pow Wood, where a student is standing by a camera on a tripod, waiting to capture an image of woodland birds. There are huge tree-stumps, draped with sumptuously mossy growth; there are lichens and fungi; a mix of birch and alder and willow, with a little rowan and oak. ‘The trees were cut down by the Ministry [of Defence] during the war when this was an airfield. All this has regrown naturally.’ Brambles and saplings fill in gaps between the more established trees. ‘The woodlands have got to the stage they need thinning. That’s part of the Management Plan we’ve put forward – the volunteers can do some, but beyond a certain size we need contractors. We’re going to do some training in charcoal burning  with the thinner stuff – we’re thinking we could sell the charcoal to our visitors.’

The burial plots
The underground cells are lined up beneath the edges of another runway; although they are covered with vegetation the regularity of their outlines, and the green metal boxes and spinning, shimmering ventilation cowls mark their presence. Ten of the plots have been used over the past 10 years to trial various seed mixes. ‘It’s quite a challenge,’ Frank tells me – just as he told me five years ago. ‘It’s old glacial mineral soil, quite alkaline, pH 7.3. If you try to plough it, you’re turning up rocks and stones. It’s a wet heavy clay mix, and we’re having a problem with rushes starting to take over. About the only thing that will kill them is glyphosate and you have to apply that with dabbers. But we’ve sown a seed mix on them and we get self-heal, knapweed, a variety of grasses.’
Of the hand-planted Devil’s Bit Scabious – several thousand when I was last here – ‘hardly any have survived’, though some have self-seeded and are growing on the stony margins of the runway.

watchtree trial plot scabious2 rsz 2011

Wildflower plot with scabious, above a burial cell, 2011

Scabious are the food-plant of caterpillars of the Marsh Fritillary butterflies and, although no butterflies have yet established here, Watchtree’s annual Captive Breeding Programme is still ongoing, rearing the caterpillars in cages. The butterflies are then sent out to various donor sites – to Ennerdale as before, where ‘they’re doing well’, and more recently, to nearby Finlandrigg wood.

Where does the funding come from?
Last time I visited, DEFRA’s ten-year funding package was half-way through; it has now ended. This has meant a re-organisation of staffing – former Warden Tim Lawrence has left, leaving one full-time staff member and, for the present, two students working part-time in education and conservation. The Trust’s Directors have been very pro-active in seeking extra funding over the years and currently have a couple of projects proposals under review – a proposal to Cumbria Waste Management and the Community Fund for a compostable toilet at the far end of the reserve, and a large Woodland Management Plan proposal to the Forestry Commission.
At present, the Reserve’s income comes from several sources including the very popular Watchtree Wheelers, membership fees, donations, and the Café. By using volunteers in so much of the conservation work, it has been possible to put some money aside. The day of my visit, a Wednesday, there are two groups of volunteer helpers, with loppers and saws, cutting and laying hawthorn hedges. ‘We still have financial reserves,’ Frank says. ‘We’ve got three or four years to make up the difference between what we spend and what we need to keep going.’ As for the volunteers, ‘They get through an awful lot of work. We’ve got a nice little group at the moment. Mostly retired folk, but we get three or four years’ work out of them!’

As we walk back along the runway towards the smart visitor centre and Café an old tractor approaches and the driver, William Little, stops to chat to Frank. William is a retired local farmer who, as Chairman of Great Orton Parish Council during the Foot-and-Mouth crisis became involved with Watchtree Nature Reserve through the local liaison committee. He, like Frank and some of the other Trustees, has been working for the Reserve since its beginning.

Watchtree Farm, Great Orton airfield, Great Orton burial ground, Watchtree Nature Reserve: it’s a place of such mixed histories. Yet, as on my first visit, I am impressed at the spirit of optimism, of looking to the future, that continues to drive the Nature Reserve forward. It feels a happy place.
Last year it had 16,000 visitors: people coming to enjoy the views, the birds, the flowers, the varied scenery; people coming to use the Wheelers’ facility, to visit the Café, to volunteer; school-parties coming to dip ponds and learn about the countryside that they live in; and on the final Sunday of each month, an increasing number of runners coming to take part in the 5K run.Watchtree has become a symbol of diversification and biodiversity.

As William Little said in a television interview, ‘[The reserve] has turned what could have been a disaster for the local community into an asset’.

 

Useful information:
The Reserve’s  website has lots of information about events, volunteering, Watchtree Wheelers, contact details, map, and more.

A 2001 report on ‘The killing field of Cumbria’ and links to daily reports on the FMD epidemic of 2001

Posted in conservation, Foot-and-Mouth epidemic, wetlands | Tagged , ,

Some things I didn’t know about sand-ripples and the sea

‘ ... the tide holds back from the flat wet sands / That darken from tawny to brown, where little pools / Are stranded like starfish in the rippling ribs’.  Norman Nicholson, The Bow in the Cloud

(I am grateful to Joe Dias for allowing me to use these images of his paintings)

There is a very low Spring tide and we’re setting off down the shore, a group of people, all ages. We cross a bank of shingle, chatting, asking those questions that are a preliminary to spending time with each other for a couple of hours: ‘Where do you live?’, ‘Do you know so-and-so?,’ ‘What’s your dog’s name?’ Then we go down onto the sand, an apparently featureless expanse that stretches down to the distant rocky scaurs. ‘It looks pretty flat and boring, doesn’t it?’ I say.

OLYMPUS DIGITAL CAMERA

Water-sculpted ‘waves’ of sand, and wind-sculpted dunes (photo: Ann Lingard)

But as we walk, we find domes and repeating ‘waves’; there are hollows and inexplicable smooth-walled channels. In places the domes are smooth, elsewhere the sand’s surface is patterned with ripples, patterns that can differ from metre to metre. Some of the hollows between the crests have accumulated finely contrast-y grains of coal. Photographers get busy.

 

Do the ripple-patterns form when the tide comes in or when it goes out? Do they form and reform all the time they are submerged, according to the ebb and flow of the water?

The shore is a good place for stimulating simple questions. But, as we might expect, the answers aren’t always simple.

Dunes and jumping sand-grains

There has always been research into wind-blown, ‘aeolian,’ ripples and dunes, and geologist Michael Welland and physicist Philip Ball, both of whom have written about sand and patterns and are excellent science communicators, refer to early work by Bagnold.

Bagnold, incidentally, is currently being celebrated – on Mars. This NASA image  nasa image(NASA/JPL-Caltech/MSSS) shows the rippled surface of ‘High Dune’, the first Martian sand dune ever studied up close, and part of the ‘Bagnold Dunes’ field. Amazingly, the dunes are actively migrating, at up to about one metre per year.

 

Ralph Alger Bagnold joined the Royal Engineers in 1915 and was posted to Egypt, where he fell in love with deserts, and subsequently spent his leave-time exploring these ‘seas of sand’ in Egypt, Libya and Sudan, where “Instead of finding chaos and disorder, the observer never fails to be amazed at the simplicity of form, an exactitude of repetition and a geometric order …”.

Back in England, although he considered himself an amateur scientist, he built his own wind-tunnel with some help from the hydraulic lab at Imperial College and carried out research on the physics of sand movement and the evolution and migration of sand-dunes.

ripples on the move

Rippled migrating dune (Photo: Ann Lingard)

His 1941 book, The physics of blown sand and desert dunes, is a classic.

 

On a windy day in the Moroccan Sahara desert, experiencing the saltation of sandgrains for myself and seeing evidence of dunes’ migration across the bed of a long-gone river, I did indeed think of Bagnold.

 

 

 

 Water-formed ripples

Many of the ripple patterns I saw in the arid Sahara were the same as those we walk over on the Solway shore at low tide, so I was delighted to find that Bagnold – now interested in the effect of waves on the sea-bed as a marine engineering problem – had moved on in 1946 to look at the effect of water in forming sand-ripples and vortices.

bagnold fig8 brick

Bagnold’s ‘brick pattern’

He used a tank of still water in which he oscillated a flat bed of sand, so his results don’t answer my simple questions, but a couple of his photos, including the ‘brick pattern’, nevertheless show patterns similar to those that we can find on the shore.

There has of course been more recent research into the effects of waves on the formation of ripples in both deep and shallow water. This hasn’t been merely from an aesthetic point of view. Instead engineers have been interested in the effect of the shape and migration of ripples on sediment transport on or off a shore, and geologists and geophysicists want to know how the orientation of present-day ripple-patterns in sedimentary rock, such as sandstone, relates to the shape of ancient shores. (There are some excellent diagrams, photos and videos about the origin of ripples, from a geological point of view, on this US Geological Survey website.)

Moreover the migration or collapse of undersea sand-waves interests hydrographers – and is especially relevant to ships’ pilots here on the Solway Firth.

Much of the research has been done in labs under controlled conditions with single variables (here’s a useful film of sand in a flume-tank, showing development and migration of ripples, formation of vortices and scour-pits).

Research which has been done ‘in the field’ has used acoustic methods such as sonar to measure height, time-lapse photography to measure changes in shape, still photos to examine types, and other types of measurements to determine grain size, friction and angle. Many of the interpretations rely on equations for flow and drag and friction – and field studies are complicated by the everchanging conditions of wind and sea.

So what answers have I learnt to those ‘things I didn’t understand’ about ripples?

Some are self-evident, others too complicated for this blog-post (or me). But good words = new concepts, in relation to the shore: bedform, vortex, orbital movements, equilibrium, boundary layer.

 

1. Ripples come in different shapes. Straight ripples are two-dimensional, 2D; those that bifurcate – branch – are 3D. The pattern depends on the direction and velocity of the waves.ripple patterns boyd et al 1988

Boyd and colleagues’ time-lapse photos taken on a beach show 6 types (shown diagrammatically above) : Straight-crested 1 and 5 were in ‘equilibrium’ with local dynamic conditions (the angle of the waves’ approach, and the nature of the flow over the surface) – when the bedform is fully adjusted to local conditions, then you see these simple geometric patterns. The other types show disequilibrium in both shape and orientation, in other words they’re shape-changing and readjusting to local conditions.  Type 3 is a decay form of type 1 as a storm wanes. Type 6 shows reorganisation during a complete change in wave conditions such as the onset of a storm.

Several of these types can be created in a flat bed of sand in a flume tank; their shape-changing is mesmerising.

2. Ripples grow in size as the tide comes in. As measured on a tidal beach in France, Austin and colleagues found (2007) that both the height and length of ripples increased during the rising tide – and remained constant during the ebb. (In contrast, Dingler’s team (1984) found that the spacing of ‘high-tide’ ripples changed dramatically as the tide ebbed; but there was no change in the pattern of ripples nearer the bottom of the shore.) And a stormy ebb tide may delete or smooth out the ripples formed during the flood.

3.The orientation of ripples changes. Ripples respond quickly to changes in wave direction. Boyd and colleagues found that the ripple-pattern on their beach shifted through 15 degrees during a 4-hr period, then back through 38 degrees during the next 36hrs. Moreover – probably a disappointment to geophysicist detectives – ripple orientation was not related to orientation of the adjacent shoreline.

4. Ripples migrate. Each wave sets up an orbital flow of water that moves sandgrains. Ripples build up asymetrically, with a steeper offshore side. Since the onshore velocity of water is higher than the offshore, sand is carried up the offshore side of the ripple and over its crest. Some of this sand is caught in the developing lee vortex, which also captures sand from the onshore flank.
As wave-flow slows, the vortex increases and captures more sand – this is ejected into the main flow above the ripple at about the same time as the wave’s flow reverses. Nevertheless, most of the sand that has been carried over the crest during onshore flow instead slumps down the onshore side – and because of this, the ripple effectively migrates onshore.  Well, mostly: Doucette (who must have had such a tough project, based on an Australian beach) found that large 2D ripples migrated onshore during a ‘narrow-banded swell period’, but when a sea-breeze was present too, the ripples migrated offshore.

5. Sediment migrates. Some of the sediment that is carried over the ripple’s ridge is stirred up and ejected from the trough during the suck and flow; when the flow is strong, this sediment may be carried offshore again – so although ripples migrate onshore, the net sediment transport might be offshore.
But it depends on the size of grains. Medium-sized grains tend to behave differently, and net transport is onshore. Sand at Sennen Cove (Cornwall, Masselink’s work) behaves differently from sand at Allonby Bay (Solway).

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Coarser particles – coal – on the onshore side of ripples

6. Sediment ‘sorts’. Sediment sorting means coarser sand moves onshore with ripple migration (the ‘Brazil nut effect), and there is net offshore transport of finer sediment in suspension. Coarser particles – including coal fragments – are found on the onshore side of ripples.

7. Mega-ripples and sand-waves. The former develop at higher current speeds than ‘ordinary’ ripples, and may be up to 1 metre high with wave-lengths of several metres. Sand-waves are even larger – longer and higher, with a longer wave-length and are formed on the sea-bed at current speeds. Which type forms depends on the bedform and the current speed – sand-waves can break down into mega-ripples at slower current-speeds. Mega-ripples can have smaller ripples on their backs (‘Big fleas have little fleas upon their backs…’).
Seen from the vantage-point of a gyroplane flight during a very low tide over the Inner Solway, the patterns of the  mega-ripples and sand-waves, in shallow water or exposed, are striking.

Other answers and ‘known unknowns’

The shore is not a lab: you can’t control the variables.

I have learnt (from reading) that on the shore, even if measurements are made at the same place under similar conditions of wind and tide, no two results will be the same.

I’ve learnt that such is the diversity of response of the Solway’s sediment and sand to the sea, that it must surely provide one of the most challenging and potentially fruitful places for further research on ripples.

And I have learnt (from experience) that the patterns of ripples on the Solway shore are beautiful, and tantalising, and tell stories of the dance between the sea, the estuary, and the sediments, on calm days and on windy days.

 

***

(There’s a good BBC video of [aeolian] barchan dunes on YouTube, showing saltating sandgrains, vortices, migrating dunes and more).
Ball, Philip (2009) Flow. Part 2 of a Trilogy, Nature’s Patterns. OUP (website)
Welland, Michael (2009) Sand, a journey through the imagination. OUP
Welland, M. (2015) Desert: The land of lost borders. Reaktion Books
Welland, M. Through The Sandglass blog

Some research papers:
Austin, MJ., G Masselink, TJ O’Hare & PE Russell (2007) Relaxation time effects of wave ripples on beaches. Geophys Res Letters 34, L16606
Bagnold, RA. (1948) Motion of waves in shallow water: interactions between waves and sand bottoms. Proc Roy Soc Lond, Series A., 187, 1-18
Boyd, R., DL Forbes, & DE Heffler (1988) Time-sequence observations on wave-formed sand ripples on an ocean shoreface. Sedimentology 35, 449-64
Dingler JR & HE Clifton 1984. Tidal cycle changes in oscillation ripples on the inner part of an estuarine sand-flat. Marine Geology 60, 219-33
Doucette, JS (2002) quoted in JS Doucette & T O’Donoghue, Sand ripples in irregular and changing wave conditions: a review of laboratory and field studies (2002) Sandpit, University of Aberdeen Dept of Engineering.
Masselink,G., MJ Austin, TJ O’Hare, & PE Russell (2007) Geometry and dynamics of wave-ripples in the nearshore zone of a coarse sandy beach. J Geophys Res 112, C10022

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