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In order to create an in-situ sample of the benthic macro-organisms, an underwater camera was deployed at set locations and a video was recorded for approximately ten minutes. Following this, the species of both macro-fauna and macro-flora were identified down to genus level along with their abundances and distributions, in an attempt to quantify the majority of the benthic epifauna.

In addition, in order to create a qualitative sample of the benthic macro-organisms, specifically the infauna, a Van Veen grab was deployed at a set location. This Van Veen grab was made at the coordinates: E181917.3 N31510.9.  

Photographs were taken of the samples and the ecological processes taking place were also examined, such as evidence of durophagy in the shells of bivalves presumably by predatory dog whelks.

Asterias rubens – Common starfish

The common starfish is found on mussel and oyster beds across most of the British and Irish coasts. This starfish usually grows to an approximate size of 25-30cm in diameter and has five broad tapering arms, a small central disc and distinctive upward curling of its arm tips. It is typically orange-yellow in colouration and if this starfish is found at greater depths, its colouration shifts to become paler. A. rubens diet consists of smaller molluscs and can frequently be seen with a bulbous central disc, indicating recent feeding activity.

Marthasterias glacialis – Spiny starfish

The spiny starfish typically inhabits hard substrata as well as occasional muds across all British coasts except the east coast of England and the eastern half of the Channel. This starfish can grow to an approximate size of 80cm in diameter and has five tapering arms, a very small central disc and distinctive rows of heavy spines along its arms. It has a brown-yellow base colouring with grey-green markings on its dorsal surface. M. glacialis diet consists of fishes, crustaceans, echinoderms (specifically A. rubens) and molluscs as its ecological niche defines it as both a voracious predator and a scavenger.

Chorda filum – Dead man’s rope

The dead man’s rope is a species of brown macro-algae that inhabits loose substrata such as gravel and pebbles and can even live on other macro-algae; it is found across all British and Irish coasts but is less frequent in south east England. This macro-algae can grow to an approximate length of 8m, with an average growth of up to 17cm per month. It has distinct long, unbranched, hollow, rope like fronds with a disc shaped holdfast and a slippery coating.

Ensis siliqua - Razor Shell

The Razor Shell is a burrowing bivalve mollusc found across all British coasts in soft sediments and sands. E. siliqua has straight, elongated dorsal and ventral margins which are parallel. It lives its life with most of its body buried; feeding and breathing through a siphon. Once E. siliqua have burrowed, all that is visible is this opening which is referred to as the keyhole. They grow up to 200mm long and are white or cream, with pale purple, pink, or reddish stripes. When we observed them they were only found on the finer sea floor sediments, which is an attribute of being a burrowing organism.

Laminaria digitata - Oarweed

Oarweed a brown macro algae which grows up to 2m in length, with a claw-like holdfast. It is very common in the lower intertidal and shallow subtidal growing on rocks and other hard substrate. It can be found all around the British Isles, but more sparsely on the east coast of England, and can form extensive meadows at low water and the correct conditions. When we found this species, the fronds were covered in a species of hydrozoan that were using the L. digitata as a host.

Species Identified

Introduction