July 01, 2010
Tagging studies aim to let anglers have their fish and eat them, too.
Originally published in July 2010 print edition
The crew of Terry Winn's T's Me watches as Tamithia Winn brings in the dolphin to be tagged with a satellite tag.
The best hunters know their quarry intimately. Every move, every pathway, every escape. When their quarry surprises them, that's luck—either good, or bad. Truth is, dolphin surprise most of us hunting them far too often.
That may be changing. Lately Don Hammond and his Dolphinfish Research Program have been notching breakthrough insights on the species' habits and migrations, which helps those of us in the know in our hunts and—Hammond and others hope—will also help to protect what is likely the most-targeted species offshore when the day comes to implement new regulatory measures in the fishery.
The breakthrough insights from his streamer and satellite tagging programs are profound—that dolphin feed at night, that they dive to depths of 400 feet, that they cross the Atlantic, that two supposedly distinct dolphin populations which intermingle come into Florida waters, and much more. Recently, a more distinct picture of the western Atlantic's dolphin migration has emerged from Hammond's work at the same time that he has broadened the scope of his work to include international waters. For example, a dolphin tagged in June 2009 off Marathon was recaptured on April 24, 2010 off Clarence Town, Long Island, The Bahamas. What route did it take to get there? The record of its recapture adds crucial missing information to a big, developing migration picture.
It's Hammond's conviction that all Atlantic and Gulf dolphin intermix, and that they're not separate breeding stocks with distinct migratory routes. And interestingly, he believes that South Florida fishing pressure on fish coming up from the Keys drives the fish over to the eastern side of the Gulf Stream. They may grow fast and fight hard, but maybe they learn fast too. Hammond also has evidence that many more dolphin than previously thought survive to make another pass by Florida.
“When you hear of greater or lesser dolphin activity on one side of the Gulf Stream,” Hammond says, “I think that you're actually looking at the phenomena of the Gulf Stream's position and its upwellings concentrating bait and bringing in fish, because we have fish that have crossed the Atlantic after being tagged, others that have gone all through the Caribbean, including south to Venezuela, and others gone north on the Gulf Stream. To me, that shows one population.”
Recently I joined Hammond, from South Carolina and a marlin tournament angler in his youth, Terry Winn of the Central Florida Offshore Anglers (CFOA), his wife Tamithia and club friend John Barber aboard Winn's 33 Contender T's Me!, running twin 350 Yamahas, on an extraordinary dolphin tagging trip out of Fort Pierce's Dockside Marina—a trip all rigged up by members of three Florida fishing clubs. Also fishing that day were seven other crews from the Sebastian Inlet Sportfishing Association (SISA) and the Florida Sportfishing Association (FSFA). Their charge: to place two satellite pop-up tags in dolphin big enough—greater than 20 pounds—to carry them on to the information motherlode. With everyone in radio contact, if a crew had a big fish on, Winn would race us there as Hammond prepared the tag, which is basically a mini-computer which records temperature, light intensity and water pressure every 15 minutes for 180 days.
Not only was the teamwork on the water coordinated, but so were the fundraising efforts. The three fishing clubs combined to provide approximately $5000 in total contributions to Hammond's program in 2009 to buy the tags.
Winn, currently president of the CFOA, has fished extensively throughout Florida for nearly four decades and has long been committed to the dolphin tagging program. He and Barber and others in his club are well-informed and active in fishery management issues, and they do not want to see dolphin fish poorly managed, or its populations damaged.
“Dolphin is everybody's gamefish, accessible and enjoyable to catch, but it doesn't get the attention and research that the high-dollar billfish do,” Winn said. “Don Hammond is an advocate of the fish and we trust how he gathers, uses and interprets the data. The federal managers don't really have any other data available to them. So if we don't help with his effort, what's going to happen when the managers decide to make changes to the fishery? If we keep dolphin stocks healthy, we can have an incredible fishery into the future.”
With tournament-like pressure to get good fish, conditions looked good: east-southeast winds under 15 knots, clear skies. Mitch Roffer of Roffer's Ocean Fishing Forecasting Service contributed a sea surface temperature chart for the day's fishing that identified three likely productive fishing locations, which gave us a good lead. I was ready to be witness to a fishing first in my life: the successful release of a healthy 20-pound dolphin, for a very good cause.
“If you look at how much money this offshore fishing costs per boat, and how many boats are out here for us today,” Hammond said, “there is no way that you could get enough federal money to do this level of research. My tagging is scattered up and down the Eastern seaboard, in the Caribbean, and now even in the Mediterranean. It's an international effort, which it needs to be, because this fish moves in international waters, but the costs, much less the cooperation, among governments is an insurmountable hurdle.”
Due east of Fort Pierce, right on the line indicated by the Roffer's report, we hooked up to our first dolphin, and Tamithia Winn took the rod. Steadily she brought it near, and the team took their positions: Winn at the wheel, Barber at the leader, and Hammond with the tag. The teamwork of tagging is a whole lot more challenging than gaffing and boxing. The focus is on having a healthy fish, and it's not always easy to accomplish.
Winn brought the fish boatside and Barber laid it up and Hammond sent the tag home with one good shot. Hammond unhooked it and with a kick it dove down, into the unknown—for now. Check back in about nine months.
Anyone who recovers and turns in a satellite tag gets a $500 reward from Hammond's project. But the bulk of Hammond's data comes from anglers placing, and just as critically, recovering and reporting streamer (also known as spaghetti) tags into young dolphin. The spaghetti tag carries a unique serial number and also has the mailing address where anglers who recover them can mail the information—and that's a crucial way that everyone, even if they don't tag, can play a vital role in this study: Just return the tag with good info on the capture. Hammond requests that precise GPS location, date and verbal description of where you caught it, and length of fish be included. “The length really gives us a better age-class identification for that fish, than the weight,” he says.
“And I really like it when people take pictures of their fish, too.”
Tag in place, dolphin gets a chance to rest before release. Dark streak is bruise-like damage in skin from placement of the tag. This fish kicked hard and dove away fast immediately after being freed.
In the nine years of his current program, Hammond has had 11,000 fish tagged with streamers, and so far, 9 tagged with pop-up satellite tags in 4 years. Seven of 9 provided useful information, and 2 tags failed to contact a satellite, unfortunately. In 2008, the CFOA club also placed two sat tags in big dolphin, but both fish were eaten that same day, one by a swordfish and one by a pelagic shark. How does Hammond know that? The tags kept on recording data from within the swordfish and shark and tracked their characteristic movements until they expelled them (by disengorging their stomachs or passing the indigestible tags). The tags then surfaced and transmitted their collected data.
Terry Winn takes one for the box. Not all fish need be released on a tagging trip. With stocks in good shape, these anglers want to ensure a future fishery.
Our next dolphin was too small for the tag, but not for the box. Winn took it. We caught a few more school fish and put streamer tags in them as the hours rolled on. Then, later in the day, we had a call from another crew, who had on a candidate. Winn took his location as we brought in our lines and we raced six miles there. We found them, tossed them our line and they clipped it to the angler's, and we brought the fish over. This fish, borderline big enough for the sat tag, wouldn't lie down and came unglued before Hammond could tag it. Placement of the tag—in the thick “shoulder” of the fish—above the spine, is crucial.
“Still, that was a really cool thing to see,” I heard the angler say.
Winn later reported to me that they were able to place the second archival tag, which Hammond left in his care. That tag, a 30-day archival, was placed on an approximate 26- to 27-pound bull dolphin on Friday, May 7th on a lure/ballyhoo combination. This fish was tagged approximately 85 miles east of Port Canaveral on the “otherside” of the Gulf Stream in approximately 2,700 feet of water. “Since this area is outside the normal realm of the recreational dolphin fisherman,” Winn reported, “it is hoped that the fish will give us data on another of the travel pathways that the dolphin fish utilize.”
With the Pros, Sending out a Message in a Mahi
Captain Jimbo Thomas and his crew on the Thomas Flyer in Miami got involved in Hammond's tagging program 6 years ago when they caught a tagged dolphin and reported it.
“These days tagging is part of dolphin fishing for us. We'll get the smaller fish tagged, and also, if we have enough in the box, we'll start tagging and releasing. More than once in the last four years we were the top tagging boat on the Atlantic East Coast in the charter boat division.
“Last year we had a terrible dolphin season, but to the north, in North Carolina, they had a spectacular season. Why would that be?” Thomas asked. “These are the kinds of quandaries that the tagging program will resolve.”
Captains Rob and Melissa Harris of Got TA Go Charters and owners of Conchy Joe's Marine and Tackle in Key West have been tagging dolphin for Don Hammond since the Dolphin Research Program started in 2002. Harris is also a member of the South Atlantic Council's Snapper-Grouper Advisory Committee.
“I contacted Don while he was still working for the South Carolina Department of Natural Resources,” Harris said. “Since I'm a lifelong fan of dolphin, and have fished for them in every ocean, tagging them for research is just a natural fit for me. Thankfully, as the South Carolina state project was winding down, Don started his own research company to keep the research moving forward.”
Harris and his wife have tagged more than 200 dolphin with external streamer tags for the project over the years and they have a high recovery rate for re-captured fish.
“We take great care in the treatment of fish that are going to be tagged to ensure survivability of the fish once placed back in the water and we have even re-captured our own fish while working a school. Nets, wet towels, light wire circle hooks and plenty of water on the deck and surfaces of the boat that may come into contact with the fish are the norm.
“Any fish that isn't hooked in the shallow area of the mouth or that gets banged around in the boat isn't considered by me to be a good candidate for tagging and will either be released without a tag or retained aboard. We use 50-pound leaders to lift the fish into the waiting towel being held by the ‘assistant' for better control once aboard. A strategically placed ruler gets us a quick measurement (fork length) before tag placement in the shoulder of the fish.”
At times, Harris has sensed that their work tagging dolphin has created more questions than answers when it comes to migration patterns.
“Being in Key West, we typically are the indicator area for what the seasonal dolphin run will look like. Oddly enough, during the spring run of dolphin, I will encounter small groups of larger dolphin that are moving to the west when I locate them in close to the reef edge. Of these tagged dolphin, none have ever been recovered. However, smaller dolphin I've tagged in the same time frame in waters far offshore have been re-captured.”
Recently, the Dolphin Research Program added another piece to the puzzle along those lines. In February of 2010, a dolphin that was tagged off Miami was recovered off Key West showing the first indication of a southerly migration of the species. Only time and more tagged dolphin will tell if this is a true pattern or an anomaly, says Harris.
If you are interested in learning more about the project or how to becoming a “tag team member,” contact Don Hammond of the Cooperative Science Services, in Charleston, South Carolina, via their web site at: http://dolphintagging.com or call (843) 795-7524.