STUDIES IN MARINE ECOLOGY: I. THE DISTRIBUTION OF COMMON LITTORAL INVERTEBRATES OF THE WOODS HOLE REGION

¹ MARINE BIOLOGICAL LABORATORY AND THE UNIVERSITY OF CHICAGO

1. Analysis of distribution records in the four major types of habitats of the Woods Hole littoral, viz., wharf pilings, rocks and rockweeds, flats, and the sea bottom in deeper water show that mere records of species present in the different habitats fail to indicate any relationship between the different types of associations.

2. By eliminating species known to be approximately equally distributed throughout and records for one year, only, and classifying the remaining species in terms of places where they are most abundant and next most abundant one finds:

(a) The association of the wharf pilings is closely related to that of the rocks.

(b) Species taken in dredging on clean hard bottom are found in next abundance on the rocks.

(c) The associations of the flats are highly independent of the others in the region but continue in the mud and sand under and around rocks.

(d) That some degree of quantitative work is necessary in order to determine the relationships of animal associations.

3. Preliminary collecting in a region tends to give the obvious forms and gives similar results in analysis to the type of quasiqualitative work described in this report.

4. The number of animals present in the Woods Hole region has not been noticeably affected by the intensive collecting carried on there during the nine years covered by these studies.