Monday 25 November 2013

The End is Nigh

Hello again from the Cefas Endeavour, where we are currently making good our getaway from North Norfolk Sandbanks and Saturn Reef SCI. Our time at this site complete, we are now steaming south towards the Thames Estuary to another site, from where we will be working for the final few days of this research cruise.

So what have we learnt from our time at North Norfolk Sandbanks and Saturn Reef SCI? Last week I described our two objectives for this survey- to try to find evidence of Ross worm (Sabellaria spinulosa) reef in the site and to see whether biological communities found in different seabed habitats within the site are statistically different from each other. While a lot of work remains to be done back in the lab to process and interpret the data we've collected, we have been encouraged by the amount of potential Sabellaria spinulosa formed reef observed on this survey, both in the sidescan sonar data and the grabs and camera tows collected, as well as some of the other critters we've come across.

Up close and personal with a potential biogenic reef formed by Ross worm (Sabellaria spinulosa) tubes (JNCC/Cefas, 2013) 
Dahlia anemone Urticina felina nestled in sand with hydroid species and Sabellaria spinulosa formed tubes (JNCC/Cefas, 2013) 
We have also collected grab samples from the troughs, flanks and crests of many of the sandbanks. Sample locations, or "stations", were chosen to include landward and seaward facing sides of the sandbank, as well as inshore and offshore locations. The samples collected will enable us to make comparisons between the communities living in and on the seabed at these sites. Some of the animals that form these communities can be seen below.

(Top) Sieve containing seabed sediment and associated fauna, including the Serpent brittlestar Ophiura ophiura, (Bottom) Masked crab Corystes cassivelaunus (JNCC/Cefas, 2013)  
Completing this work has very much been assisted by an improvement in our weather over the last few days (see below picture, and feel free to compare with the previous post's view from Beccy's cabin window!). And, of course, the work would have been quite difficult without the hard work and expert knowledge of our Cefas partners (not to mention their ship, our survey platform and home for most of this month!).

Leaving site (Joey O'Connor, 2013)