Observations on the fish fauna associated with offshore platforms in the northeastern gulf of mexico florida usa
Hastings, R.W.; Ogren, L.H.; Mabry, M.T.
Fishery Bulletin (Washington D C) 74(2): 387-402
ISSN/ISBN: 0090-0656 Accession: 006013565
The fish fauna associated with 2 United States Navy reseach platforms, Stage I and Stage II, in the NE Gulf of Mexico off Panama City, Florida [USA] was studied at irregular intervals from 1970-1974. Such platforms function as artificial reef habitats and support diverse and abundant fish populations not normally characteristic of the open sandy bottoms in the area. A total of 101 taxa (identified to family or species) was recorded at the 2 platforms; 61 spp. were observed at Stage I in water 32 m deep and 86 taxa at Stage II in water 18 m deep. The greater number of species recorded at the shallower location may be more a result of the greater number of observations made there than of differences in the 2 habitats. The number of species present at the platforms varies considerably at different times of the day and year. Species numbers are greatest during the summer and fall, but many species begin to move offshore or southward as the water temperature drops, and only about 50-60% of those recorded at the platform remain in Dec. The number of species diminishes to about 16% in Feb. at Stage II, then increases gradually with the rising water temperature in the spring. Major species occupying the platform habitats include fishes usually characteristic of pelagic, inshore (coastal or estuarine) and rocky reef environments. At the platforms, the pelagic species and most of the larger predators occupy various levels of the water column, either directly below or surrounding the structure, while most of the other species are associated either with the pilings and cross-members of the platform or with the bottom. For some of the species, the platform provides food and shelter, while for others, it offers only shelter. Some species may be present only to feed on the numerous fishes and other organisms concentrated there. Diel rhythms of activity are obvious for many of the fishes, with some species active only during the day, and others only at night.