The attraction of age-0 red snapper, Lutjanus campechanus, to artificially placed shell plots around gas platforms, a possible solution to bycatch mortality

Abstract

In 1998 and 1999, we built 30 4m{+2} reefs of shell and 30 4m{+2} reefs of shell/concrete blocks
at depths of 17 to 21 m, in the Gulf of Mexico, 14 to 25 km south of Dauphin Island, Alabama. Each
year there were 3 sites, 20 reefs each, placed at 20 m intervals. Sites 1 and 2 were centered around
gas platforms. Total mean counts for all red snapper, Lutjanus campechanus, were significantly
different between reef types and years: 14 fish/block, 19 fish/shell in 1998; 20 fish/block, 22
fish/shell in 1999 (P < 0.05). Separated into age-0 and age-1 year classes, few age-0 red snapper
were observed in July, while age-1 were common. In August 1998, age-0 red snapper reached counts
up to 113 fish/reef and 216 fish/reef in August 1999. In 1998, age-0 fish were significantly more
abundant on shell reefs, but in 1999 age-0 fish showed no significant differences between reef types.
In 1998 and 1999, age-1 fish were significantly more abundant on block reefs. In 1998, fish were
significantly more abundant at Site 1, but in 1999 fish were significantly more abundant at Site 2.
These results suggest that artificial shell reefs may attract young red snapper away from areas of
intensive trawl fishing, e.g., gas platforms, thus enhancing survival.