XXII.—Studies on the Scottish Marine Fauna. Additional Observations on the Fauna of the Sandy and Muddy Areas of the Tidal Zone

Abstract

In a previous paper (4) the quantitative distribution of the molluscs and polychætes in certain intertidal muds and sands on the Scottish Coast was discussed, but there still remained several other types of shore such as (a) a river mud-flat, (b) grounds at the heads of sea lochs on the West Coast, and (c) the more exposed shores of the Western Islands, where conditions might possibly differ greatly from those already considered, with corresponding changes in the fauna. Since the publication of the first paper quantitative samples have been collected in each of these areas. Taking the survey as a whole, collections have now been made on such widely different parts of the coast that the peculiarities of the distribution of the above two groups can be stated with a fair degree of accuracy. The present paper is divided into two sections, the first dealing with the additional observations, the second with the survey as a whole.

Seasonal and annual variations in abundance and species composition of fish and macrocrustracean communities on a Scottish sandy beach

“…Bivalve molluscs were more abundant subtidally and contributed significantly to both total numbers and biomass. Unusually, the most abundant bivalve was Cochlodesma praetenu, replacing Fabulina fabula which is the dominant subtidal mollusc on most Scottish beaches (Stephen 1929, 1930, Clarke & Milne 1955, McIntyre & Eleftheriou 1968, Ansell & Gibson 1990). …”

The sublittoral fauna of two sandy bays on the Isle of Cumbrae, Firth of Clyde

“…The volume of debris collected by the trawl at high tide when most of the movable debris is above station I and in the intertidal zone is given below. Elmhirst (1931), Stephen (1928Stephen ( , 1929Stephen ( , 1930 and Watkin (1942), who, between them, have described in considerable detail the zonation of animals in the intertidal part of the bay. The lowest station of Stephen (1928) corresponds approximately with the highest station in the present survey.…”

“…Nephthys hombergii is numerous sublittorally and indeed is' common in muddy deposits at all but the greatest depths throughout the Firth of Clyde. Yet although it appears in moderate numbers in the intertidal zone of other parts of the Clyde (Stephen, 1928), it does not do so in Kames Bay (Stephen, 1930;Watkin, 1942). According to these authors, Nephthys caeca is common in Kames Bay down to low tide level but it has not been recorded at all from the sublittoral of this bay.…”

The ecology of the Tamar Estuary VI. An account of the macrofauna of the intertidal muds

“…Nicol's figures are the only ones available for salting pools; but the concentrations which have been observed in favourable pools suggest that counts would have compared closely with those from optimum zones on intertidal muds. Author Thamdrup; " " " " " " Stephen, 1930 " Nicol, 1935 …”

“…In none of the stations worked on various types of ground in different localities on the Scottish coast by Stephen (1929Stephen ( , 193°, 1932 was a density found which, making full allowance for his use of a 2 rom. sieve, exceeds the higher values for St John's Lake.…”