Hooked on science: Billfishing Series is a treasure trove for fisheries biologists

Wallace Jenkins of the S.C. Department of Natural Resources measures a dolphin during the Bohicket Marina Invitational Billfish Tournament this month.

Photo courtesy S.C. Department of Natural Resources

A blue marlin caught by Chip Dukes aboard Syked Out, owned by David Sykes of Isle of Palms, had a satellite tag that remained with the fish for 280 days before releasing and uploading information about where the fish had traveled and the depths it followed.

The South Carolina Governor's Cup Billfishing Series is about a lot of things -- competitive fishing, camaraderie and, believe it or not, science.

State fisheries biologists say the information derived from the annual series helps them provide valuable insight into the fishery. State wildlife biologists work the docks to mine data about blue marlin, white marlin and sailfish, the primary targets of the anglers, but they also get information about wahoo, dolphin and tuna, also part of the series.

The Governor's Cup was formed in 1989, with the support of then-Gov. Carroll Campbell, an avid offshore fisherman. Conservation was at the heart of the series and it helped change a mind-set.

In the early days of billfishing off the South Carolina coast, virtually every fish, no matter the size, was brought to the dock for display.

Conservation is a now theme of the tournament, held this year over May and June.

Over the past 10 years, only 17 blue marlin have been brought in during Governor's Cup events (including the state record 881.8-pound catch in 2005).

Governor's Cup participants have released 330 blue marlin during that period, along with 149 white marlin and 931 sailfish. Released blue marlin are worth 600 points in the series scoring system. Billfish that are brought to the dock and weighed are scored at one point per pound. The few blue marlin that are brought in are usually caught by boats that are in contention for optional competitions which can offer payouts reaching six figures. All white marlin and sailfish must be released.

Though the emphasis is on releasing billfish, biologists Wallace Jenkins and Amy Dukes of the S.C. Department of Natural Resources welcome the occasional blue marlin that is brought to the dock.

"When a billfish comes to the dock, people just flock around it," Jenkins said.

The biologists measure the fish and take samples from the reproductive organs, stomach and tissues. Later, there usually is someone willing to fillet the large fish for eating.

"It's definitely a nice treat for me as a scientist and biologist," added Dukes. "When the one blue marlin (515 pounds) was brought to the dock last year at Bohicket, kids were excited to be able to see her, to touch the eyeball, to see how sharp her bill was, to look inside her mouth. When we dissected her, I was actually educating as we went along."

When boats return after each day of fishing, captains or boat owners are interviewed by Dukes, Jenkins or Jesse Alderson, another biologist who works Governor's Cup events.

Dukes said fishermen generally are helpful and understanding about the interview process that takes place when boats return to the dock.

"We know exactly how much effort is being made at these individual tournaments by all the boats," Dukes said. "We ask the number of crew members on board, when lines went in and out of the water, the number of lines they fished. The newest thing we are asking is about the federal law that went into place in 2009 requiring the use of circle hooks when deploying natural or combination of natural and artificial baits."

Dukes said they also measure all the fish and ask about other species, such as barracudas or sharks and what they did with those fish.

"It all gets entered into a massive database," she said. "Our data actually goes back to 1977. We send this information to the National Marine Fisheries Service as well as to the individual tournament."

Jenkins has been assisting a University of North Carolina graduate student by taking liver, tissue and stomach samples from tuna, dolphin and wahoo. The UNC student, in turn, shares samples of billfish caught in North Carolina.

Jenkins said tissue samples can reveal pesticide burden, which in turn will tell if animals are feeding in the eastern Atlantic, where certain pesticides that have been banned in the U.S. might be found.

"Fishery management can work. Unfortunately it takes time," Jenkins said. "We think, for the moment, that all of these billfish populations are stable but still overfished.

"Most of these fish are managed on an international level. South Carolina is just a small cog in the wheel. But the data we generate is important to the overall management."

WHAT: Five satellite tags will be implanted in blue marlin during the 2011 S.C. Governor’s Cup Billfishing Series.

COST: New satellite tags cost $4,000 each, but the tags being deployed during the Governor’s Cup were left over from a previous research project and have been refurbished (a new battery installed) at a cost of $800 each.

HOW THEY WORK: The tags, which somewhat resemble a hand-held microphone, are designed to release from the fish at a predetermined time, as little as 30 days or as long as a year. When they release from the fish, they float to the surface and then upload the recorded data in quick bursts to a passing satellite over several days to make sure all the data is received. The Governor’s Cup pays a certain fee, depending upon how much data is uploaded.

TALE OF THE TAGS: Satellite tags provide the latitude and longitude the fish travels on a daily basis, the depth of the water in which the fish are swimming both day and night, the temperature ranges they prefer and how quickly they move up and down the water column. Wallace Jenkins of the S.C. Department of Natural Resources said satellite tags show that blue marlin go down “as far as 1,100 feet, that they stayed in a range of 59 degrees to 86 degrees (water temperature) and that they are at the surface at night more than in the daytime. It’s invaluable information, especially the migration pattern they follow.”

Tommy Braswell

Billfish caught in the S.C. Governor's Cup:

Year BM WM SF BML

2001 37 (BM) 7 (WM) 29 (SF) 0 (BML)

2002 25 (BM) 11 (WM) 54 (SF) 1 (BML)

2003 18 (BM) 5 (WM) 41 (SF) 4 (BML)

2004 18 (BM) 13 (WM) 26 (SF) 3 (BML)

2005 26 (BM) 18 (WM) 77 (SF) 6 (BML)

2006 86 (BM) 54 (WM) 81(SF) 1 (BML)

2007 32 (BM) 7 (WM) 140 (SF) 1 (BML)

2008 31 (BM) 8 (WM) 185 (SF) 0 (BML)

2009 28 (BM) 17 (WM) 142 (SF) 0 (BML)

2010 29 (BM) 9 (WM) 156 (SF) 1 (BML)

Total 330 (BM) 149 (WM) 931 (SF) 17 (BML)

BM-blue marlin; WM-white marlin; SF-sailfish; BML-blue marlin landed (brought to the dock)