After being delayed for a month by Hurricane Sandy, we are back on Abaco with the hope of figuring out where the island’s bonefish go to spawn (We were able to tag more than 600 bonefish with external “dart” tags in the two days before Sandy hit – more on that in a future post). While The Marls on the west side of Abaco supports a world-class bonefish fishery, this vast maze of mangrove cays and shallow flats is miles away from the nearest deep water – deep water that bonefish use for spawning according to a study by scientists at Cape Eleuthera Institute. In Eleuthera, bonefish migrated from their usual shallow-water haunts to pre-spawn congregating areas immediately adjacent to deep ocean waters during fall and winter full and new moons. These huge schools then made quick offshore spawning runs under the cover of darkness. With the help of some high-tech acoustic tracking technology, we hoped to identify similar patterns in Abaco’s bonefish. Keep reading after the break.
Based on the results of our first Abaco bonefish study it looked like at least some fish from The Marls were making a 40+ mile run to theCrossHarbour area presumably to spawn. This year, we hoped to catch even more fish making this run to show that the health of The Marls’ fishery may be intrinsically linked to the health of theCrossHarbour area. To do this, we will surgically implant electronic acoustic tracking tags into the bellies of sexually mature migrating bonefish in The Marls, and then “listen” for these tagged bonefish with automated underwater receivers in and aroundCrossHarbour.
To get things started, we spent yesterday setting up an array of underwater acoustic receivers near the south end of Abaco, where pre-spawn schools of bonefish have been spotted in the past. Hopefully, the fish that we implant with acoustic tags in The Marls over the next few days will eventually be detected by these receivers.
Today brought less-than-ideal weather for catching bonefish to tag – 25 mph winds and rain showers. Thanks to the hard work and dedication of Buddy and Cindy Pinder, Justin Sands, and Paul Pinder of the Abaco Fly Fishing Guides Association, we were able to find large schools of bonefish on the move in The Marls. By the end of the day, we had surgically implanted tags into 12 bonefish (6 males and 6 females). All 12 fish were sexually mature and “running ripe” (eggs and sperm were fully developed, and spawning is likely to occur in 24-48 hours). One of our biggest surprises of the day was finding a sexually mature female bonefish that was only 15” long. This means that bonefish are spawning at much smaller sizes than we had previously thought. It also means that most bonefish caught by recreational anglers have probably already reached sexual maturity and are contributing offspring to the fishery.
We still have a few days of tagging left ahead of us, so stay tuned for more updates.