Captura y Esfuerzo
In order to begin to quantify the impact of FADs on fisheries in Puerto Rico, 20 boat captains agreed to collaborate and provide high resolution catch and GPS data. The GPS data provide time and location, which along with catch allow us to calculate fishing effort as, catch per unit effort on a spatial scale relative to FAD locations. To date, we have collected two years of catch and effort data from participating captains for nearly every outing they embarked upon. The captains represent major charter, recreational, and commercial anglers from around the island. The first captain that agreed to participate was Captain Luis Lagrandier of Puerto Rico Sportfishing Charters, who routinely takes local and international clients fishing aboard his boat Makaira. When we started tracking Makaira’s catch and effort on October 25, 2016, all of the FADs were in place (See Fig 3A upper panel). Preliminary analysis of Makaira’s activity, show that while there was roughly equal catches at the FAD versus away, there was actually more time spent away from the FAD to get that catch, indicating that catch per unit effort is actually higher at the FAD. As the season progressed, FAD E was lost on November 28, 2016, and FAD F was lost on January 17, 2017, and this influenced Makaira to shift fishing effort toward FAD G, the next closest FAD to its home port, Dorado (See Fig 3A lower panel). With FAD E and F not in place, Makaira altered its fishing pattern, increasing both its average time and distance covered per trip. In addition, Makaira’s fishing grounds increased by approximately 106 square kilometers, which meant the vessel trolled a greater area in search of fish. Makaira’s shift toward FAD G, however, did seem to pay off, having caught 4 times more dorado at FAD G than caught elsewhere. Interestingly, Makaira’s catch away from the FAD included a more diverse array of pelagic species, which may be related to the propensity for some species (e.g., dorado) to show high fidelity with the FADs while others do not. Makaira’s case study is one of several compiled by our team and highlights the value of collaborative research to describe FAD-vessel dynamics. Collectively, data indicate that FAD presence can influence catch, effort, and fishing costs.
One of the key management decisions to install FADs in Puerto Rico was to increase sport fishing opportunities and to shift recreational fishing activity from stressed coastal habitats offshore. In order to investigate whether this goal was being met, in January 2017, we began monitoring the catch and effort of vessels that predominantly fish nearshore. Captain Luis Burgos of the Caribbean Fishing Academy (CFA), a predominantly light-tackle nearshore fishing charter that operates in San Juan Bay is the example described here (Fig. 3B). CFA embarked upon 88 trips, with the majority of the outings taking place throughout coastal habitats in and around San Juan Bay. Proximal to the mouth of San Juan bay are FAD C and D, 5.44 and 4.95 miles offshore, respectively. After analysis of 88 trips, 19 of those (or 21.5%) were taken offshore to fish the. While Offshore, CFA caught dorado, billfish, and tuna; while inshore, CFA caught 17 different species but predominantly tarpon, crevalle jack, snook, and guavancha. Because we do not have CFA’s catch and effort before the FADs were installed, we cannot determine if the FADs influenced CFA to move offshore or whether those trips were more successful. Nonetheless, the data and preliminary analysis do show that offshore catch and effort was highest immediately adjacent to FADs, which suggests they provided Captain Burgos with more fishing options and a more diverse array of sport fishing opportunities to his clients.