...more mosquitoes

Mosquito larvae are not straight forwardly lovely to look at. They are adorned with whiskers, sprout combs of spines and tufts of bristles.  Fan-like mouth parts strain algae form the water or hoover fine grains of detritus. They have the steam-punk feel of being slightly over-engineered, with a snorkel  tail and directional antennae.  Culiseta morsitans is the most widespread along the Bay and common in the UK too, although the map (from the National Biodiversity network, http://www.nbn.org.uk/ ) tells us more about how few people record mosquitoes than it does about the overall spread of the species. For example there are no red squares, which represent a record, plotted on a 10x10 km scale in national data bases, shown along the Bay (the arrow).  Culiseta morsitans is catholic in its needs for breeding; slacks, pools, ditches, freshwater or brackish. The females attack birds for a blood meal more than they do mammals, although humans are targeted. The fields and slack inland of the dunes have been submerged in the latest storm, but the new puddles and pools make a home for the mosquitoes as water levels rise and eggs are prompted to hatch. It is an ill wind.....

Sun, sea and sequestration......

.... says Scott. The late November storm blew through over night. Today the sun, low in the southern sky, was picking out the Blakemoor windfarm blades as they appeared to thresh the winter rooks out of the trees around Queen Elizabeth park. At Hauxley the oblique rays picked out every shade of gold at the experimental ponds. Dave and Scott have excavated the pond from which we sliced out the sections of sediment earlier in November. The slabs of clay topped with a thick crust of organic debris and black mud, which they removed, are now being ground down in the lab to measure the trapped carbon. Scott will be monitoring the newly cleared pond to record the productivity and accumulating detritus from the very beginning of the pond’s new life. We ended up as an incarnation of some medieval farming scene, puddling the clay on the base of the pond flat in a squidgy tap dance,  to create as neat and precise a volume as we can. The next storm is on the horizon, the pond is likely to fill up in any downpour. In the first spring after the ponds were  dug in Autumn 1994 they choked with snaggled clumps of Stoneworts (Chara), often called 'Quarry Weed' because it appears quickly in new, bare wetlands. I am keen to see if ecology repeats itself or the newly cleared pond develops along a novel path.

Pools, snooker and pea mussels

Once or twice a year nervous secretaries gingerly hand me an unexpected envelope, the contents often swathed in bubble wrap or, occasionally and rather beautifully, squashed flat with by a Post Office franking machine with a precision that the most perfectionist Victorian naturalist would admire. I look forward to these letters asking for an identification of the creature enclosed. My favourite was the Great Diving Beetle letter. The beetle, a species of Dytiscus, 3cm of clockwork black and yellow mechanical precision, had crash landed on a snooker table in garage, mid game. The sender was worried that this intimidating creature was woodworm; we were able to provide re-assurance.  Great Diving beetles can fly well and, like many pond creatures, their mobility is a way of finding new homes and surviving tough times. Other pond life cannot fly but can cadge a lift. The illustration above comes from Kew's 1893 book The Dispersal of Shells. Clamped around the hand front leg of the Diving Beetle is a pea mussel, a small clam, the two valves of its shell holding firm, possibly enough to be taken on a flight by the beetle. Beetles, bugs and birds make good vectors for moving smaller wildlife from pond to pond. Charles Darwin famously wrote of his experiment dunking the feet of a stuffed duck into an aquarium to see what little creatures might attach to this potential lift. Tricky to do with birds in the wild but next time you are checking the ducks, geese and herons pottering in the shallows you are watching an arrivals and departures terminal to rival any airport.

The mosquito coast

There is a furtive quality to adult mosquitoes, unlovely and fidgety.  They do not inspire affection, instead a sense of nuisance and recoil, as if they set out wantonly to persecute us, worse still to spread disease. Autumn is a time they seem more obvious, conjured out of the gloom which their colours and manner match. They are, at least, an insect we pay attention to. The Health Protection Agency has revamped a Mosquito Recording Scheme, partly out of concern at the surprisingly little we know about the distribution of species in the UK but also the possible arrival of new species, part of a wave of continental insects whose very delicate fragility is no hindrance to being wafted across the North Sea. The wetlands and pools along Druridge Bay and along the whole Northumberland coast offer attractive habitats to the discerning mosquito, and they do discern. The females of some species in search of somewhere to lay eggs are able to sense the presence of predators or competitors and so move on in search of more promising sites. Along the Bay Anopheles claviger and Culiseta morsitans are common but I have not searched in any systematic way letalone some of the more brackish sites. Further north at Low Newton I’ve found larvae that appear to be Anopheles algeriensis , Aedes cantans and Culiseta litorea, the latter much further north than other UK records. The squirming shoals of mosquito larvae in the Druridge Dune slacks,  and further north along our coast, hint at a new invasion shoreline and would be well worth an expedition to record our mosquito infested swamps. Here is the HPA mosquito Recording Scheme website. (http://www.hpa.org.uk/Topics/InfectiousDiseases/InfectionsAZ/Mosquitoes/MosquitoRecordingScheme/)

The power of ponds

There are moments, rare and sometimes only dawning slowly, when science tears itself away from the trench warfare of lab processing and statistical output, to become an object of compelling fascination. I dare say the slab of drooling clay shown above is not, at first sight, a object of great beauty but the picture speaks of the power of ponds and how the underwater world holds important secrets. The wall of mud and clay is the bed of a little pond that we have cut into from the side, a slice through the sediment. You can see the edge of the original pond at the left and right sides of the image, with a meter rule lying on what was the bottom of the pond before we drained the water. We have stitched together photos from across the width of the cut (hence the floating green box in the sky.... it appears in several of the photos). The slice shows a dark layer, run through with roots and plant debris overlying the paler clay which was the original bed of the pond when it was dug in November 1994 at Hauxley. That black top layer is what we are interested in; the colour suggests a rich seam of orgnaic matter has built up, trapping carbon, a lack of oxygen slowing down decay. We will measure the carbon content precisely, produce tables of data and graphs of trends and gradients, but for now that image has us in its thrall. Pete Gilbert and Scott Taylor thought that slicing through a pond would be a good idea. I thought it would be a muddy mess. Shows how much I know....

A question of extremes

Watching Storm Sandy bring New York to a halt carried echoes of Thunder Thursday in Newcastle: the irresistible raw power, tower blocks left as blacked out stumps, cars wedged into flooded underpass caverns as if by a child wrecking their toys. An extreme event, even by the USA’s practised hyperbole. Trouble is trying to define what an extreme event is. Not a priority in the desperate hours of the storm or the drawn out agony of the clear up but important eventually because climate predictions suggest more extremes and we need to know how to recognise shifting patterns in the weather that may result. The British Ecological Society, the UK’s learned body for ecologists, has set out to crystallise what we know about extreme events and their impact on freshwater habitats. Lakes, rivers and ponds all depend on water, how much of it and the quality, but these vary naturally. All these habitats develop as an interplay of landscape with climate, the changing seasons and occasional unusually high rainfall or prolonged dry spell. These ups and downs are important, creating new habitat and rejuvenating the old. Humans are very good at taming natural changes, for the understandable reason that we do not want to be flooded or have our crops fail for want of water. We are good at engineering out the everyday rhythms  of nature. A genuine extreme is much harder to define: something that is both remarkable in amount or duration or timing but also that has a demonstrable effect, resetting the ecological stage. Storm Sandy certainly fits the first criteria and for many people in Newcastle, Morpeth and any of the other flood-struck neighbourhoods I suspect the storms have altered their world irrevocably. The stickies above capture part of the British Ecological Society’s concern, especially at “double whammies” as multiple problems pile up: droughts and floods, habitats fragmenting and climate shifting. Working on a large enough scale across whole landscapes is one approach to resist extremes. We cannot put a giant dome over the whole of the Bay to protect it. Instead give nature room for manoeuvre, refuges to hunker down and space to change.