Cooperative Science Services LLC, Dolphinfish Research Program of Charleston, South Carolina has announced the first results of this year’s dolphin tag recoveries.
Although the number of fish tagged in the 2011 winter/spring effort is among the lowest ever, number of tags recovered is unusually high at 19 tag recoveries.
The 2011 reported tag recovery rate of 4.17 percent is surpassed only by the 2009 recovery rate of 5.15 percent. The average recovery rate is between 2.5 and 2.7 percent .
Three of the tag recoveries this season offered little useful information. One was a tag picked up on the beach at Jupiter Inlet, Florida. Two other recoveries were mixed up with other data cards or were never reported.
Four tag recoveries were received for fish that had been at liberty from 2 to 15 days. Of particular interest are the days at large versus the tag recovery location, which yields a travel speed for particular fish. Of four tag recoveries, one of these fish showed a travel speed that averaged 37.7 miles per day; another 10.9 miles per day; a third , 9.8 miles per day; the fourth, a real thoroughbred, registered 44 miles per day.
Another recovery of particular interest is a fish that made a lap of the South Atlantic starting on September 5, 2010, off Deerfield Beach, Florida when it was estimated at 20 inches. Recaptured 265 days later, the fish appeared to have traveled north at least to Cape Hatteras, North Carolina, before it turned east into the Atlantic Ocean, then caught a southerly current for a ride toward the Caribbean Sea. If it traveled to Puerto
Rico and turned west along the island’s north shore to follow the deep trench between the Caribbean Island and the Great Bahamas Bank, and re-entered the Straits of Florida at Cay Sal Bank, before heading north to be recaptured just 71 miles north of its original tagging location. at recapture it was estimated to be 36 inches in length. Since both beginning and ending lengths were guesses, the only thing to be said for this fish is that it left the East Coast as a small schoolie and returned as a nice gaffer, says Don Hammond, CSS director. The trip of 3,200 miles would have required the fish travel 12.1 miles per day, or average just .5 mph to complete the trip.
The south Florida recaptures clearly demonstrated how much variation exists in the speed at which dolphin travel northward within a region. The fish that returned for a second pass along the U.S. East Coast reaffirms the benefit of U.S. anglers’ releasing small dolphin. The fish tagged off South Carolina showed how they continue to remain on the western side of the Gulf Stream as they travel north. Their greatly reduced rates of travel, compared to Florida fish, indicate the continued influence of the semi-permanent gyres off the Carolina coast, slowing their northward travel.
For more information, or to volunteer to help out in the dolphin tagging effort go to www.dolphintagging.com