“Hold it, hold it….steady…OK… GO! GO! GO NOW!” Captain Anthony Mendillo gave us our marching orders and we dropped into the big blue swells of the western Caribbean swimming hard and looking up at the surface to check my position occasionally with the signature flock of frigate birds overhead. There they were….flashes of silver against the blue, large silhouettes moving rapidly, changing direction and in the middle of all these bodies, a large glinting shadow. Bait fish on the move. Sailfish and sardines…the ultimate open ocean diving experience and I was right in the middle of them shooting the amazing interaction of predator and prey.
The bait school was quickly consumed and the sailfish all went into cruise mode, dorsal fins tucked down, pastel colors and they looked like javelins, propelled by their large forked tails and headed off into the blue toward the main bait school invisible to me, but they knew where to go.
Back on the boat for a much needed rest and change of air tanks we, were elated and discussed the feeding behavior, the coloration changes of the sailfish and effectiveness of the feeding method by the group of sailfish. We rejoined the group of fifty or so sailfish and bait for more footage before going into catching mode.
The main goal of the expedition was to catch and tag twelve healthy sailfish and deploy Pop-up Archival Tags on these fish so researchers could get some information about where the sailfish go after leaving this area of the Yucatan. The Guy Harvey Research Institute was working with Dr. Molly Lutcavage of the Large Pelagics Research Centre http://tunalab.org/(University of Massachusetts Amherst). The GHRI purchased twelve mini-PATs for the study. Molly is best known for her research work on bluefin tuna in the northeast USA and Canada. The mission statement of the LPRC is to “work closely with fishermen using state of the art technology in conducting biological and ecological research on pelagic species including tunas, billfish sharks and sea turtles. LPRC endeavors to develop scientific understanding that supports effective ecosystem-based management strategies for these highly migratory Atlantic marine species.” Our ride for the expedition was the beautiful 48 foot Cabo “Chachalaca” owned by Lawrence Berry of Texas, and run by well-known local Captain Anthony Mendillo, who were very kind in supporting the GHRI/LPRC research efforts.
Isla Mujeres is a famous location for large numbers of sailfish attracting anglers from around the world from January to May each year. This is a catch and release fishery, circle hooks and dead bait are mandatory and anglers can expect 30 to 50 bites per day with many multiple hook ups. However no-one knows where the sailfish spend their time for the rest of the year. The attraction to the area is clearly the abundance of bait. The dominant species is the common sardine sardinella aurita, a round bodied fish attaining ten inches. Typically, these fish school near the bottom in 80 – 100 feet of water on the continental shelf. Just to the east of the shelf is the deep water and the strong north flowing current of the Gulf Stream
For Mexico, the sailfish is a sustainable source of income for local business as anglers travel great distances, stay in hotels, eat in local restaurants, use taxis, shop and generally spend money. The socio-economic value of the living sailfish is very high throughout its range in the western north Atlantic. Current Mexican laws allow for one sailfish to be taken per day, but catch and release is the main appeal. Local fishermen target food species such as tuna, bonitos, mackerel and bottom fish rather than sailfish.
Over the years a great many conventional spaghetti tags have been placed in sailfish caught here by recreational anglers. The system depends on the tag card being returned to the tagging agency (here it is The Billfish Foundation, TBF) but it depends on the sailfish being recaptured and the tag cut out and sent back to TBF. The result is a straight line displacement that shows where it was tagged, where it was recaptured but cannot provide information about where the fish spent that time or how it used the habitat.
Using 20 pound test, trolled dead ballyhoo bait rigged with a 7/0 circle hook and chin weight, Anthony pulled two dredges (imitation bait schools as teasers) and we fished an area 6 to 12 miles north of the island looking for telltale vortices of frigate birds to show us where the concentrations of sailfish were located. When the sailfish were hooked, fought and brought to the boat, our mate Ruben Garrido grabbed the bill of the sailfish and flipped it into the boat onto a plastic covered foam mat. The fish eyes were covered with a wet cloth and the deck hose placed in its mouth. The sailfish was measured by Molly and assistant Eric Jacquard, the mini-PAT was placed carefully in the right shoulder and the fish was jetted back into the water in less than 50 seconds. We have much more control over the tag placement when the sailfish is in the boat as opposed to trying to tag the fish in the water. They move around a lot, are hard to control on a light leader, so correct placement of these expensive tags was a priority.
Now we wait for 6 months to hear from these tags. Each one costs about $4,000 so we are taking a gamble as anything can happen between release and the tag detaching from the sailfish and floating to the surface. No news is good news, as to hear from a tag early would mean the fish did not survive or was eaten by a predator. Large mako sharks frequent the area as well and have the gear and speed to take on a sailfish.