The across-shelf larval, postlarval, and juvenile fish assemblages collected at offshore oil and gas platforms west of the Mississippi River Delta

Abstract

A cross-shelf transect of three oil and gas platforms in the north-central Gulf was sampled to examine the role that platforms (hard substrate habitat) may play in the early life history stages of reef-dependent and reef-associated fishes. The ichthyoplankton and juvenile fish assemblages were sampled at Green Canyon, Grand Isle, and South Timbalier with passive plankton nets and light traps. At all sites, clupeiforms were the dominant taxa collected, comprising 59–97% of the total catch. Reef-dependent fishes were relatively rare at all platforms, while reef-associated taxa were generally more common. High numbers of piscivorous juveniles were collected, indicating that predation during early life history stages may be important in determining local reef assemblages. Similarity indices indicated that the larval and juvenile fish assemblages collected at the platforms differed across the shelf… With the limited amount of hard-substrate habitat available in the northern Gulf, the addition of artificial habitats (platforms) may increase the chances of adult fishes finding suitable spawning habitat, as well as increase the number of settlement sites for juvenile fishes.