The engineer and the Harrod's toilet brush

Newcastle upon Tyne, where we are based, has proud tradition of engineering. There is a lingering scatter of ship yards along the Tyne now used to pamper North sea oil and gas rigs and, over in the west end of the city, a massive workshop constructing armoured vehicles where once lord Armstrong's yards supplied battleships to the world. The heyday of engineering has largely gone nowadays, leaving a strange flotsam in the Discovery Museum which has galleries of shining engines, pistons, motors, winders, winches and mills. In the days of digital the knack of manufacture still has its place and research often brings out the best. We have been struggling with how to take a core of sediment from the ponds. We need to be able to drive down into the thickest mud, sometimes through mats of roots, pull out the whole core and not lose the gloop at the top. Dave has lovingly designed our very own corer, all the state of the art standard ones having proved a failure. Hand welded is resembles a hydrid between a bazooka and broadsword. We tried it out in the sudden sunshine up at Blakemoor farm on Thursday. The substantial metal pushes into the mud with satisfying substance, unlike some of the flexing and buckled plastic tubes we have tried. Dave laments the absence of foot braces to help push down but I’m sure they can be added. The metal tube has a cunning, calibrated plunger to push out the core. The only thing we need is something to clean out the inside of the tube between cores. Dave has the answer: a toilet brush from Harrods. This is the charm of research. Here we are struggling to pull out plugs of mud, accurately and precisely to measure weights and volumes and this has required a craftsman’s eye for design and an inexplicable bit of top quality bathroom shopping.

The ponds' Antiques Road Show

The month of March may have been cold but there has also been little rain. No wonder many of the shallow field flashes have dried out since November. The ponds of south east Northumberland have changed over the decades too. Here are some simple data from a talk I gave last week to the north-east branch of the Institute of Ecology and Environmental Management. Always glad to have people turn up; I still fret that ponds don't quite have the allure of the Large Hadron Collider even though ponds are especially rich in wildlife compared to the large lakes and rivers that dominate the imaginations of policy makers. The data are for the south east corner of Northumberland, in a triangle roughly from Amble, at the north end of Druridge Bay, south to Newcastle inland and Tynenouth, the latter at the coast. I counted all the ponds (...and moats, troughs, tanks and the like) I could find on 1:10,00 Ordnance Survey maps across all the historic editions. "Survey" in the table above shows the survey edition dates when maps were revised. Okay, it is not a complete pond census, only an audit of ponds that appear on maps but those Victorians in the Nineteenth Century were very detailed map-makers, capturing features down to 4 metre diameter. The overall number of ponds has not changed much, but the turnover of individuals ponds has been considerable, with an conspicuous late surge led by golf courses. The general increase in recent years matches data from the UK countryside Survey and recent audits by Pond Conservation. Which should be good news, unless all those old ponds were superb wildlife hotspots compared to these new sites.

"....til the wild geese have flown"

Shakespeare’s King Lear reckoned winter lasted until at least their departure. The cold has kept us indoors but Druridge Bay is exquisite in winter. Thursday morning I was up at Blakemoor and Ellington, the pastures still empty of ewes and lambs, the arable fields with bedraggled winter wheat rotting away. The North Sea has been churned all weak into a deep iron blue. Theatrical sheets of snow whipped in, the sort of snow dry as polystyrene bobbles, bouncing off jackets and hats. The easterly blast blew in some surpirses; a taxidermist asking me if i'd seen his friend who he'd lost searching for the wreck of puffins that has been washing up all week. The final snow wall was trailed by a barn owl, drifting in on the eddies behind the snow front. I was out doing the first complete census check of ponds. As usual there were surprises, many of the shallower sites dried out but many of the tiny pools and ruts in gateways more conspicuous. the number and extent of ponds chnages significantly with season and year, which begs some tricky questions for surveys which rely on just one snap-shot visit in one year. A few dollops of frog spawn wallowed unconvincingly. We are keen to get out and collect a full range of sediment cores from across the range of pond types, but have been waiting for some new corers after our experiments with open sided screw-cores out of which the runnier top sediments dribbled (see 1st March blog). This has left Scott and Pete largely stuck in front of computer screens. However Dave Cooke has been welding and forging a new design. If the wild geese ever leave we will soon be back out.

Wrong place, wrong time

The deluge and floods of 2012 have barely receeded, both from memory or the landscape and winter has lingered on into early March. Here is a stiking recollection from last summer; the scatter of silver shards are a shoal of sticklebacks marooned and doomed on the path to the hides at Druridge Pools. The water had overwhelmed drains and ditches, creating a single washland from the Pools across to the dune tracks. These sticklebacks had ventured out beyond their orginal home, as all species have to, at least some individuals (see blog 19th November for flying molluscs, 12th Jan for airborne pondweed) . This swarm's bad luck left them in trackway puddles as the high water receeded. Reminds me of those fossil fish beds in museums, which conjure up a picture of ancient pools and their floundering inhabitants. I quite often splash through scattering shoals on other paths and tracks around the Bay; adventurous sticklebacks seem ubiquitous. Others will have made it to new pools, their good fortune a curse for many of the invertebrates which are vulnerable to these voracious mini-hunters.

Pete explores pond types

Up at Druridge Bay the seasons are teetering. Winter’s sodden fields are still gluey wet, swathes of wheat shoots bedraggled or long dead. The calls of geese and the widgeons’ whistles carry in on the wind, but the robins are singing for spring and busy swarms of goldfinches decorate the headlines. There is a growing busyness. January and February have been relatively dry so we have started a central aim of our research: characterising how different pond types vary in their carbon capture. “Pond types” sounds like another quagmire as bad as lakes vs ponds in the last blog. How to describe ponds depends on what you want to know: could be done for their conservation value using scores for lists of invertebrates or plants, or by the nutrient levels or pond histories. We are starting with four broad types: (1) ponds in arable fields, which are usually temporary and support few plants, (2) ponds in pasture, often covered with fodder grasses but some amphibious species too, (3) the dune slacks and flashes overlying sand soil, vulnerable to occasional brackish overflows and (4) the permanent, plant rich wetlands. The photos show Pete coring a grass ley and amongst dune slacks at Blakemoor. Sounds easy but we have hit a snag immediately. The corer works well, screwing down into the mud but when we gently teased it out the top layers of mud dribble out. These upper layers are especially dark and rich in organic debris, we must capture their presence in the samples. Research is like that. Sounds easy, go out, drill in a core, take out the sediment, go back to the lab..... I like the practical struggle, working out how to engineer the equipment, which is often more a visit to B&Q DIY than Large Hadron Collider.

The recce proved useful though, revealing dark, perhaps anoxic mud under the apparently normal sediment surface of the grassy ponds and the distinctly sandy soils underlying the dune slacks. The photo above shows the grainy sand to the right in a core from the dune slacks under about 10cm of gooier mud.

"it's a lake"....

Pete is looking out over Druridge Pools, a glittering wash land of late winter submerging the verdant meadow. The Pools lie about half way along the Bay, on the north side of the site a deep lake that was once opencast, to the south the old mine infilled and landscaped and now a mirror to the sky. There are supposed to be five distinct ponds here, often hard to pick out low amongst the burst of rushes and wetland grasses. There are also lost ditches and sudden soak-aways: I know from gingerly feeling my way across the field a couple of years back, recording the plants whilst swallows scalpled the air, winnowing the mass of midges, and damselflies flickered around my feet. I tried to keep count but I was more concerned to keep balanced. Dave Cherry, a final year undergrad at Northumbria, has taken some sediment cores across the ponds in the summer of 2012. As with the other permanent, vegetated sites the organic carbon levels in the upper sediments proved markedly higher than in the soil adjacent to the ponds. Pete and I were checking the site to include in our first season of major sampling effort, but as Pete says “it’s a lake”. Which begs the questions when is a lake a pond? One of those questions I always get asked whenever I do a talk. I suspect everyone knows ponds when they see them, which can be confusing when they look like a lake

Back to square one

January ice and flood has kept us away from the experimental ponds at Hauxley Nature Reserve, but Scott, Pete and Dave were out at the end of January to begin regular recording of water chemistry, comparing three of the original ponds which were dug out in 1994 to their newly excavated neighbours. The new ponds are clouded with muddy water, the clay seeming to be whipped up by storm and wind. This is how the ponds first looked eighteen years ago too, but soon settled down, the water clearing to leave a faint blur of green algae. Pete is using a portable probe to measure the conductivity and pH, and waters samples will be taken back to the lab to determine nutrient levels, particular phosphate and nitrates. These can be surprisingly variable but that has more to do with the herons who loaf and preen and poo amongst the ponds. The new ponds also beg an ecological question: will their wildlife develop along the same broad pathways as their original inhabitants did eighteen years past? The first two or three years after 1994 were dominated by species thriving on the bare mud, amongst the strands of algae or a twine of Stoneworts. However the ponds are now surrounded by a changed landscape, with a rich cast of wildlife in the adjacent ponds. Perhaps a new sequence of species will colonise, or the old familiar species but faster. I am curious to find out, having recorded the animal life in the ponds ever January and early summer for ten years. It is partly a test of serendipity and history. Will the animals and plants reflect the stark clay walls and bed of the new ponds or will the wildlife be more the result of the variety of species around about, their availability overcoming the limitations of the raw habitat?