The longest running coastal shark research survey along the East Coast has completed its 2015 field work, capturing and tagging more than 2,800 sharks, the most in the survey’s 29-year history. The results are very good news for shark populations.
The last survey was in 2012, during which 1,831 sharks were captured and tagged, compared with 2,835 in 2015. In all, 13 shark species were among the 16 species of fish caught.
The survey began in 1986 and 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.
“Sharks are very vulnerable. Even though they are at the top of the oceanic food chain and can live for decades, they are fragile in the sense that compared to other fish they grow very slowly, reproduce late in life and have only a few offspring,” said Karyl Brewster-Geisz, who works in the NMFS office of highly migratory species. “An increase in the numbers caught and tagged during each survey indicates a slow climb back. It is very good news for shark populations and for the ecosystem.”
This year, the survey was conducted aboard the 100-foot charter fishing vessel Eagle Eye II from Port Royal, South Carolina, from April 4 to May 22, and from just south of Ft. Pierce, Florida to North Carolina. As in 2012, poor weather and time prevented sampling further north.
“The number of fish this year was amazing. We captured and tagged more fish than ever before, but once again weather was a factor. It started off nice, but conditions worsened as we headed north,” said Natanson.
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 record the length, sex, and location of each animal caught. Environmental information, such as water temperature and ocean chemistry, was also obtained at each station.