Sunday, 31 March 2013

Stuck in the Middle

Hello from Bassurelle Sandbank Site of Community Importance (SCI), on this our penultimate day on survey! Bassurelle Sandbank SCI encompasses a sandbank in the Dover Strait which straddles the boundary between UK and French waters, and is formed by tidal currents. The part of the sandbank that extends into French waters is also a Habitats Directive site, and is managed by the French government. Back on the UK side, the site has a surface area of 67km2, so 20 Bassurelles could fit inside the Wight-Barfleur site that we've just come from. Bassurelle is also in the middle of the Dover Strait Traffic Separation Area. This means that we are surrounded by two of the busiest shipping lanes in the world, which is a bit like being on a lawnmower in the central reservation of a motorway with lots of trucks (in this case oil tankers and container ships) zipping past at high speeds!

A large ship (Photo Neil Golding, JNCC)

The Bassurelle Triangle!

As well as being smaller than Wight-Barfleur Reef, Bassurelle Sandbank is also much shallower- so much so that there is an area in the centre of the site that we've dubbed the "Bassurelle Triangle", as if we stray in there without a good tide underneath us we may have to get out and push!

Another thing that has changed is our sampling strategy. A sandy seabed means that we can use the camera sled instead of the drop camera- this runs along the surface of the seabed as opposed to being suspended above it. Using this on rock is not advised! So far we've seen sandeels, gobies, weaver fish, dabs, red gurnards, lemon sole, hermit crabs, masked crabs and razor shells.
Camera Sled (Photo Joey O'Connor, JNCC)

We've also taken a lot of sediment samples with the Hamon grab (the day shift completed 3 fully processed samples in three locations during one particularily productive 30 minute spell yesterday afternoon). Samples have contained mainly fine sand with shells, but there have been some fish (sandeels and a weaver fish), small crabs, razor shells, sea urchins, a variety of worms and a boring bivalve (the name is because they bore into soft rock).
Boring Bivalve, possibly from Pholadidae family) (Photo Neil Golding, JNCC)

Above the water, we have been joined by a large flock of seabirds. These tenacious birds have followed us day and night since we arrived here a few days ago. Though it is nice to believe that the seabirds are with us because we're good company, a cynic might argue that our ships' size, slow speed and habit of deploying and hauling in gear have resulted in the birds mistaking us for a trawler, and that they're hoping for a free dinner!  We have yet to ascertain whether the birds are English or French....  

Tenacious seabirds of ambiguous origin (Photo Neil Golding, JNCC)