SEAMAP Reef Fish Survey
Breadth of Reef Fish Survey
The objective of the annual Southeast Area Monitoring and Assessment Program (SEAMAP) offshore reef fish survey is to provide an index of the relative abundances of fish species associated with topographic features (banks, ledges) located on the continental shelf of the Gulf of Mexico (Gulf) in the area from Brownsville, TX to the Dry Tortugas, FL. The total reef area surveyed is approximately 1771 km²; 1244 km² in the eastern and 527 km² in the western Gulf.
A two-stage procedure is used to select sample sites. Sample blocks are first selected using stratified random sampling, with strata defined by region of the Gulf of Mexico and size. Reef sites within each block are then selected randomly from previously collected bathymetric data. Each reef site selected is sampled with a four stereo camera array and a Seabird 911 CTD which measures temperature, salinity, dissolved oxygen, fluorescence and turbidity profiles of the water column. Additionally, one or two sites from a days work are randomly chosen to be sampled with the chevron fish trap after being sampled with the four stereo camera array. Video gear used to assess relative abundance and length frequencies consists of four black-and-white Videre stereo cameras along with a color mpeg camera housed in specially manufactured underwater housings. Each housing is mounted orthogonally in a custom aluminum array at a height of 30 cm above the bottom. The chevron fish trap measures 1.83 x 1.83 x 0.75 meters with 3.81-cm mesh, and is employed to capture fish for aging and other life history studies. The camera array is allowed to soak on the bottom for 45 minutes, and the fish trap soaks for 60 minutes.
The indices of abundance of snappers and groupers obtained from this survey have been used for stock assessments.
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URL: http://www.moc.noaa.gov/ot/fish.htm
Updated: August 26, 2008