By DAVID RAINER, 黑料天堂
The return of the shark category to the 89th annual 黑料天堂 Deep Sea Fishing Rodeo (ADSFR) was a rousing success with 15 sharks weighed in during the three-day event, with one riding the ferry from Fort Morgan in the back of a pickup to get to the rodeo site on Dauphin Island.
Tiger sharks pretty much reigned taking the top nine places on the leaderboard. James Mullek-Russell weighed in a 674.2-pound tiger to win the category, followed by Ethan Miller鈥檚 658.4-pounder and Brett Rutledge鈥檚 630.8-pounder. The top bull shark of the rodeo was a 434.2-pounder weighed in by Eric Vandrlessche.
As excited spectators and anglers waited for the sharks come to the weigh station, a bevy of marine scientists and students waited to advance the science on these predatory species.
Assistant rodeo judge Dr. Marcus Drymon of Mississippi State University and Mississippi-黑料天堂 Sea Grant Consortium is renowned for his knowledge of the shark species in the northern Gulf of Mexico. He said sharks weighed in at the rodeo certainly provided a unique opportunity to gather a variety of samples from each species.
鈥淚鈥檝e been researching sharks in the north-central area of the Gulf along with Dr. (Sean) Powers for almost 20 years,鈥 Drymon said. 鈥淎 lot of the research we do is tracking their trends, their relative abundance and distribution as well as doing studies on their age and growth, reproduction, movements and migrations, post-release mortality and things of that sort.
鈥淗ere at the 黑料天堂 Deep Sea Fishing Rodeo, we鈥檙e taking the opportunity to take vertebrae from these very large individuals.鈥
Sharks don鈥檛 have bones; their skeletons are completely made up of cartilage. However, Drymon said scientists have a way of aging these fish other than counting the growth rings on the otoliths (ear bones) that are present in most fish species.
鈥淭heir vertebrae are calcified but not completely ossified,鈥 he said. 鈥淚t鈥檚 kind of a fine line, but technically speaking, sharks have no bones. The cartilage in their backbones and the cartilage in their jaws are the closest they have to true bones. Sharks don鈥檛 have otoliths like a bony fish. That鈥檚 how you determine the age of, say, a red snapper. Since we don鈥檛 have those, we use the next best things, which are the vertebrae. We section those and count the concentric band pairs to age those fish.鈥
Drymon said the scientists were able to gather samples from the reproductive organs, fins, livers and muscle tissue. Samples of bile, gall bladders and kidneys also were taken to assess overall health.
鈥淲e look at their stomachs, but they are usually empty,鈥 he said. 鈥淭hey鈥檝e evacuated their stomachs during the process of being captured.鈥
Most of the sharks weighed at the ADSFR were males, which are usually similar in length to but weigh less than the females, Drymon said. The rodeo placed stringent length requirements on the shark category with an 80-inch minimum for tiger, bull and hammerhead sharks and a 60-inch minimum on blacktips.
鈥淭hese sharks are great samples, especially because they are the larger individuals of those species, so they鈥檙e a little more rare in the population,鈥 he said. 鈥淪o, for example, having the vertebrae from those individuals is very valuable in trying to determine the maximum age of that species.鈥
Drymon said the impact of the rodeo harvest will have a minimal effect on the shark populations.
鈥淔or the species being caught, their populations in the north-central Gulf of Mexico are in good shape,鈥 he said. 鈥淲e know this because we鈥檝e seen their population trajectories slowly increase after decades of overharvesting. Due to strong management measures from NOAA Fisheries and the State of 黑料天堂, we see these shark populations are starting to recover and can stand a limited, sustainable harvest.鈥
Of course, sharks weren鈥檛 the only species being studied. Marine scientists gathered samples from a variety of fish during the rodeo, which experienced near-perfect fishing conditions with calm seas and diminishing squalls.