Recruitment of Juvenile Fishes to Different Artificial Substrates in the Northwestern Gulf of Mexico

The Gulf of Mexico (GOM), alike other aquatic environments, faces various detrimental impacts caused by overfishing, trawl net fishing, and other harmful fishing practices. As a result, a wide range of artificial reefs (ARs), have been implemented in the GOM, and while these have shown recruitment of diverse assemblages of reef-associated species, most have recruited large predatory species indicating lack of juvenile habitat required by some of these reef species. The objective of this study was to deploy small, inexpensive ARs, standard monitoring units for the recruitment of reef fish (SMURFs), as habitat for juvenile fishes in the northwestern GOM around the perimeter of South Padre Island-1047 Reef (26°31'32.10" N and 97°9'12.91" W) to understand and determine the effects of substrate type on juvenile fishes recruitment. In total 32 SMURFs were deployed at eight different sites at -20m. Each site contained four SMURFs with two non-overlapping categories of rubble diameter (~10 and ~20 cm), oyster shells, and a bare substrate treatment at 10 m spacing. Visual and video surveys conducted on SCUBA, revealed recruitment of 39 juvenile reef species including one of the most economically important species, Lutjanus campechanus, which was present across all replicates, and Haemulon aurolineatum, Pareques umbrosus, and Balistes capriscus. Highest abundance and richness across all sites occur in the SMURFs containing small or large rubble while the control SMURFs have the lowest; suggesting that deployment of low-relief structures with different substrate materials might affect recruitment of certain species and could therefore be an effective tool to increase juvenile recruitment of economically targeted species. Moreover, this might help estimate an optimal low-relief artificial reef substrate for the recruitment and survival of targeted species and provide further information useful to individuals designing current and future AR projects aiding fisheries production.