Friday, September 11, 2015

Atlantic Coast Shark Populations Survey

Scientists captured and tagged more than 2,800 sharks along the East Coast during the 2015 Coastal Shark Survey.

In all, 13 shark species were among the 16 species of fish caught. The three non-shark species were remora, cobia and gold spot eel. The largest shark captured on the 2015 survey was a tiger shark, 12.5 feet in fork length, off North Carolina.

The survey, which began in 1986, is conducted every two to three years.  It covers coastal waters from Florida, where coastal shark species concentrate during the winter and spring, north to Delaware, where many shark species migrate during spring and summer as more northerly waters warm. Following this migratory route, at this time of year, makes it easier to survey the whole population.

This year, the survey area ranged from just south of Ft. Pierce, Florida to North Carolina. As in 2012, poor weather and time prevented sampling further north. 

The surveys are conducted in the 5-40 fathom (30 to 240 feet) depth zone with most sampling between 11-20 fathoms (66 to 120 feet deep) and use commercial Florida-style bottom longline fishing methods to standardize survey results. This method uses a long, or main, line with baited shark hooks spaced at regular intervals along the line.

Most (2,179, or 77 percent) of the sharks captured were tagged and released, 434 (15.3 percent) were brought aboard, and 222 (7.8 percent) were released untagged or lost.

Researchers participating in the 2015 survey included members from the NEFSC's Narragansett and Woods Hole Laboratories, the Southeast Fisheries Science Center, Florida Atlantic University, and the University of New Haven.

source: NOAA Fisheries

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