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A STUDY OF THE INTERTIDAL FAUNA OF BARNSTABLE HARBOR, MASSACHUSETTS 1
Author(s) -
Sanders H. L.,
Goudsmit E. M.,
Mills E. L.,
Hampson G. E.
Publication year - 1962
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1962.7.1.0063
Subject(s) - detritus , intertidal zone , omnivore , fauna , detritivore , sediment , ecology , biomass (ecology) , biology , crustacean , organic matter , bioturbation , invertebrate , predation , paleontology
An intensive investigation of 6 localities on the intertidal flats of Barnstable Harbor, Mass., was undertaken during the summer of 1959. The number of animals ranged 7,000– 355,000/m 2 . The total dry weight varied from 17.6–60.2 g/m 2 . A less detailed study was carried out on the same stations during the summer of 1960. A total of 82 species were collected during the 2‐year period. Stomach contents of 234 individuals representing 36 species showed that many of the forms considered to be carnivorous are, in reality, omnivores obtaining most of their food as deposit‐feeders. This explains why many of these species are present in such large numbers. With the exception of molluscs and crustaceans, the supposed carnivores, selective, and non‐selective deposit‐feeders can each be divided into three groups with respect to stomach contents: 1) Smaller species with only diatoms, detritus, and sand grains in the gut; 2) Intermediate‐sized species with these components plus fragments of macroalgae and occasional animal remains; 3) Larger species with conspicuous animal remains in the gut in addition to all the other components. Despite the fact that the sediment at 5 of the stations consisted almost entirely of fine sand with very little organic matter, most of the biomass (78%) was made up of animals that are primarily deposit‐feeders. The presence or absence of large populations of deposit‐feeders in sandy sediments was correlated with the stabiltiy of the sediment surface; in unstable sediments, as indicated by ripple marks, the standing crops were small; in stable sediments where the ripple marks were absent, dense concentrations of benthic diatoms and dinoflagellates were found which provide the major food source for the large biomass of deposit‐feeders. The chlorophyll readings obtained from the sediments were about intermediate between the highest values reported for sea water and a rich terrestrial environment. Observations were made on the natural history of the three dominant species: Gemma gemma, Glymenella torquata, and Glycera dibranchiata.