Secondary productivity within biotic fouling community elements on two artificial reef structures in the northwestern Gulf of Mexico

Abstract

Secondary productivity of two platform artificial reefs was examined seasonally. The study examined seasonal differences and annual secondary productivity of epifaunal elements associated with the fouling community, known to be specific to the diets of selected reef fishes. Examination of the fouling community using cohort-size analysis revealed the annual amphipod production of 3-4 cohorts per species/yr-1. Seasonal variations in amphipod density were striking, ranging from 600 to nearly 12,680 individuals/m2. Densities were correlated with water temperature and depth. Mean standing stock in mgDW/m2 was used as a measure of productivity and also varied significantly depending on season and species. Mean standing stock ranged from 16.33 to 1024.6 mgDW/m². Annual production ranged between 64 and 4100 mgDWm^-2 yr^-1.

This study has implications for the placement of platform structures for the purpose of productivity enhancement. It is clear that secondary productivity from the platform structures is significant and does supplement the diets of reef dependent finfish.