SOME QUANTITATIVE COMPARISONS OF OFFSHORE MEIOBENTHOS AND MACROBENTHOS SOUTH OF MARTHA'S VINEYARD

Quantitative samples were taken from the offshore area south of Martha’s Vineyard, Massachusetts, in June 1962, to compare the macrobenthos with the meiobenthos. Macrobenthos infauna ranged from 700 to 5,500 individuals per m2 and (excluding individuals larger than 5 g) from 21 to 82 g/m2. The principal taxonomic groups were Crustacca, Mollusca, echinodermata, and polychaeta. meiobenthos ranged from 117,000 to 988,000/m3 in number of individuals and from 0.6 to 4.6 g/m2 in weight. Major taxonomic groups were Nematoda, by far the most numerous component, Polychaeta, kinorhyncha, and foraminifera. Meiobenthos populations in offshore areas are shown to be at least as rich as those previously known from shallow coastal waters. Numbers and weight of both macrobenthos and meiobenthos were lowest in deep water and highest at shallow or mid‐depths. Meiobenthos was most plentiful on sandy sediments, and, although this applied to numbers of macrobenthos, the weight of the latter was generally highest on fine or moderately fine sediments. The ratio of macro‐ to meiobenthos over all samples was numerically 1 : 70 and by weight 24 : 1. These ratios were remarkably consistent from station to station in spite of variations in faunal components and the environment.