The fauna associated with drift algae captured with a plankton‐mesh purse seine net1

Abstract

A plankton‐mesh purse seine used to encircle drift algae in open coastal waters was compared with seines in open water and conventional ichthyoplankton hauls. Densities of small fish and invertebrates were higher in association with drift algae than in open water. Most fish that occurred with drift algae were well pigmented. The fauna of drift algae differed from that of attached algae. Large numbers of epiphytic animals vacated attached algae which were experimentally detached from the substratum. The fauna on drift algae, therefore, is largely the result of colonization from open water. Fish and invertebrates were quickly attracted to clumps of experimental algae that were left to drift. This suggested that drifting algae may quickly influence the distribution of animals in open water. Appreciable quantities of drift algae may influence the survivorship and recruitment processes of species which associate with algae during the planktonic phase of their life cycles.