Essential Fish Habitat (EFH) Information for Commercially Important Offshore Species Generated Cooperatively by the South Carolina Department of Natural Resources, NOAA/Biogeographic Characterization Branch, and the South Atlantic Fishery Management Council (SAFMC).

Plots of the spatial distribution of offshore species were generated from the Marine Resources Monitoring, Assessment, and Prediction Program (MARMAP) data . The MARMAP Program at South Carolina Department of Natural Resources (SCDNR) is under contract with the National Marine Fisheries Service (NMFS) to monitor relative abundance of reef fishes, conduct life history studies on species of commercial importance, analyze and interpret long-term reef fish data, map habitats important to reef fisheries, tag species of commercial and recreational importance, and define offshore fish communities from North Carolina to Florida at depths ranging from 16 to 256 m. This fishery-independent survey program has been collecting data in the South Atlantic Bight region since 1973. A number of gear types are employed including trawls, traps, hook and line, longline, CTD, underwater television, ROV, and sidescan sonar. The program began 25 years ago as an ichthyoplankton and groundfish survey of shelf and upper slope waters from Cape Fear to Cape Canaveral, however, since 1978, efforts of the South Carolina MARMAP program have concentrated on fishery-independent assessments of reef fish abundance and life history.

The spatial distribution of sampling effort has varied considerably by gear type. Traps, which have constituted the bulk of the sampling effort (n=7458), were deployed randomly on confirmed hard bottom habitat during 1979-1997. Longline sampling (n=445) has usually been restricted to the deepest regions in the sampling area. Sampling strategy for trawls (n=2249) varied during 1973-1987. From 1973-winter 1977, a stratified random sampling strategy was employed. During summer 1977 to 1980, trawling was conducted over sand bottom habitat along offshore transects. From 1978 to 1987, a trawl survey targetted only live bottom areas at known hard bottom locations. MARMAP also conducted a trawl survey in 1982 to 1983 and 1985-1987 at depths < 18 m. Sampling effort with the different gear types varied seasonally, increasing during spring Months (n=205) to a peak in June (n=2301) and then declining by October (n=454) through the winter months. Maps portraying the distribution of offshore species were created with this temporal and spatial variability in fishing effort in mind.

The marine species EFH products requested by the SAFMC were catch-density plots. No attempt was made to interpret seasonal or habitat-specific catch distributions for individual species due to the low number of observations for many species and the sampling bias towards summer months and hard bottom habitat. Therefore, catch data for each species were pooled across all years, months, and gear types for each species and then plotted against regional bathymetry.

Catch distributions for each species are a function of spatio-temporal distribution of sampling effort for each gear and susceptibility of individual species to each gear. Therefore, each plot should NOT be interpreted as a comprehensive portrayal of an individual species' distribution. Certainly, many of the species presented here exhibit seasonal trends in abundance while others are more residential (Grimes et al. 1982; Chester et al., 1984; Sedberry and Van Dolah, 1984; Wenner and Sedberry, 1989). Instead, plots should be considered as point confirmation of the presence of each species within the scope of the sampling program. As importantly, the plots confirm the occurrence of the Snapper-Grouper Complex over hard bottom habitats.

For further information about the MARMAP program please contact Jack McGovern (mcgovernj@mrd.dnr.state.sc.us) or George Sedberry (sedberryg@mrd.dnr.state.sc.us) at the South Carolina Department of Natural Resources. For more information regarding the creation of the density plots contact Matt Kendall (matt.kendall@noaa.gov) or Mark Monaco (mark.monaco@noaa.gov).