With about half of our survey party having just spent a week out here, we returned to site in the wee hours of Wednesday morning with a good idea of what lay in wait for us- lots of sand! This has so far turned out to indeed be the case, though we have observed fine (i.e. muddy) and coarse (i.e. gravelly) sediments accompanying the sand in some of the samples and video tows collected. Fauna potentially seen so far include the bryozoan Flustra foliacea, the Dead Man's Fingers coral Alcyonium digitatum, assorted sponges, starfish, brittlestars, hermit and swimming crabs and some fish species, including dogfish, sandeels and plaice. I say potentially as the above species have been "identified" via a live feed from a camera positioned above the seabed to a moving vessel full of over excited scientists- the data will be fully analysed and species confirmed (where possible) back in the relative comfort of the lab.
|Alcyonium digitatum and anemone (JNCC/Cefas, 2013)|
|Sand eel, Ammodytes sp., in the 1mm sieve once the fine sediment had been sieved through (JNCC/Cefas, 2013)|
We have also seen Ross worm (Sabellaria spinolosa) tubes, which provide a surface for other species to attach and can increase species abundance in sandy sediments. Biogenic is defined as "produced by living organisms or biological processes"- in the case of the Ross worm, tubes of sand are formed which can clump together to form biogenic reefs which protrude from the seabed. These give a hard substrate with nooks and crannies for other animals to attach onto and live in, and as such function in a similar manner to coral reefs or a rocky seabed.
|Sabellaria spinulosa tubes with the starfish, Asterias rubens (JNCC/Cefas, 2013)|
Our objectives on this survey are twofold. Firstly, we are trying to find evidence of Ross worm reef in the site, as biogenic reef habitats (including those formed by the Ross worm) are listed as being of conservation importance by the EU Habitats Directive (http://jncc.defra.gov.uk/page-1445). Secondly, we hope to ascertain whether infauna communities found in different habitats within the site are statistically different from each other. To achieve this we are aiming to collect a sufficient amount of data from three different depth zones identified before the survey: sandbank troughs, flanks and crests. Answering these types of questions is paramount to understanding the relationships between biological communities and the environments that they inhabit.
To date we have been concentrating on the first objective, as well as enjoying some very nice sunrises.
|Sunrise (Joey O'Connor, 2013)|