When I first visited Alphonse and St. Francois Atolls back in March 2018, I was awestruck by the pristine nature of the environment and truly amazing recreational fishery. What made the place extra special beyond just the diversity of species to be caught, their size and abundance, and the beauty of flats, reefs, and offshore waters, were the people and their drive to help keep the fishery and atolls this way. From the leadership and staff of Blue Safari and the Alphonse Fishing Company, to the Island Conservation Society and Seychelles Fishing Authority, there was such a sincere vibe related to using research to guide conservation efforts, including the conservation of species being targeted by the recreational anglers, such as giant trevally…GT… GEETs.
Shortly after returning home, and with that positive experience under my belt, it was time to pull together the resources needed to successfully launch a research project focused on how the movement patterns of GT’s change throughout the year, as well as how they respond to varying degrees of angling pressure. This type of project was going to involve acoustic telemetry – and in this case, surgically implanting transmitters in the GT’s, and then tracking their movements using a network of receivers moored in the lagoons, the passes, and on the oceanside of the atolls. Fortunately, I had a bunch of receivers in my lab at UMass that were from another project., however, given the size of the Alphonse group of atolls, we were going to need many more receivers to pull this off, not to mention funding for the transmitters, graduate student support, airfare, and everything else that goes into making research like this happen.
Whether with luck or with skill, in very little time, we were successful at obtaining a grant from SeyCCAT – the Seychelles’ Conservation and Climate Adaptation Trust – to help fuel the GT project. To add to this, we also obtained funding from Bonefish & Tarpon Trust to help support a Ph.D. student at UMass (Caitlin McGarigal), and were able to borrow additional acoustic receivers from the Seychelles Fishing Authority. Moreover, Blue Safari, Alphonse Fishing Company, and the Island Conservation Society were all committing invaluable logistical and in-kind support. I also brought in some additional scientific horsepower – my colleague and long-time friend, Dr. Steve Cooke, from Carleton University (Ottawa, Canada).
Altogether, we had the funding and team for the GT project, but now it was crunch time, especially if we wanted to start the research around the beginning of the fishing season on Alphonse. By mid-August the remainder of the receivers, as well as all the acoustic transmitters arrived at UMass – now it was time for them to be shipped to Alphonse, which was no small feat. By early September, we were also packing duffle bags full of other research equipment, including enough PIT tags and PIT tag readers for all of the guides on Alphonse. PIT tags are the same type of chip that a veterinarian would put it a cat or dog, and each GT being caught for our study was getting ‘chipped’ so that we could keep track of their capture history and a secondary way to track movements if they are recaptured. While all this was happening, the team on Alphonse was making the super burly concrete moorings needed to keep the receivers from getting moved around by strong currents, tides, and waves.
But by mid-October, we (Caitlin my Ph.D. student and I) arrived on Alphonse to officially launch the project. Given that I teach a large undergraduate course each fall, I could only spend a week on Alphonse, while Caitlin was staying for the entire season. With that, we needed to hit the jets and get the 71 receivers deployed as soon as possible, especially since there would be no use in tagging any GTs until the receivers were in the water ‘listening’. With each mooring weighing in at well over 100 pounds and having to strategically place them throughout Alphonse group of atolls, we definitely had some very long days! Before I departed, we also needed to put transmitters in some of the resident GTs in the Alphonse lagoon.
Now with almost five months behind us and with the amazing help from the Alphonse Fishing Company guides and many of their clients, we have over 45 GT’s double tagged with acoustic transmitters and PIT tags and an additional 90+ GT’s marked solely with PIT tags. We are currently in the midst of the first complete download of the receivers and are already noticing some very cool movement patterns of the GTs, including that some of the homebody residents of Alphonse definitely do roam. With 20+ more GT’s left to implant with acoustic transmitters, and other receiver downloads to happen this year and next, we are poised to learn a great amount about GT movement patterns. Starting the next fishing season, we will also be testing whether temporarily closing certain fishing beats will reduce angling pressure on GT’s, as made evident by changes in their movement patterns. Understanding how GT’s respond to angling pressure and even boat traffic will help shape the future of the recreational fishery on Alphonse, and potentially other atolls in the Seychelles.