the photographic expedition
A new approach to fish biodiversity surveys
Traditionally scientists have inventoried fishes on islands by assembling a boat-load of fish biologists and collecting intensively, usually by nets and localized poison stations, placing all of the capture in preservative and later trying to work it all out in a museum, sometimes decades later, and after the fish have lost their colors. These collections often missed small, rare, cryptic (well hidden or buried), deeper, and highly mobile or elusive species.
How we do it
Last year, we pioneered something new, a coordinated expedition bringing together fish biologists and a cadre of superb underwater photographers to comprehensively document all the fishes present on an island, and to target tiny, rare, inconspicuous, and elusive species that are often overlooked. We hand-collected specimens of these fishes for DNA-sequencing to assemble a DNA "barcode" database. This novel approach, where high quality, in-situ, diagnostic photographs of living fishes are followed by targeted collection for an in-depth analysis and DNA sequencing, can resolve the status of many fish species that fall in the "grey area"- those that are undiscovered or uncollected, one-of-a-kind or uncertain records, or poorly known, rare, or deep taxa.
it works!
We tried this new type of expedition in 2022 at the remote Revillagigedo islands, 250 miles south of the tip of Baja California. The archipelago is rarely visited and needed a comprehensive survey of fish species. In our two weeks in the islands, we created an image library of more than 5,500 photos, photographed more than 152 fish species, extended the range of more than 100 species within the archipelago, DNA-sequenced dozens of species which had never been DNA barcoded before, and added 7 species previously unknown in the islands, 3 of which are new undescribed species, including a beautiful new wrasse, so rare and elusive it had never been collected and had been photographed only once many years before. The wrasse is described in a paper presently in press.
Check out the YouTube video about the Revillagigedos Expedition by Allison & Carlos Estape
We anticipate a similar result in Galápagos, where no expedition has so intensively photographed and surveyed the fish fauna.
A new species. Halichoeres sanchezi
Our first publication from the expedition was describing the rare wrasse we had discovered and collected for the first time. It was named for Dr. Carlos Sanchez, who arranged the expedition and, fortuitously, he was the one who found and collected the first specimen on the very last day of the expedition. The description is published in the journal PeerJ and can be found on their site. To download a smaller size pdf, it is available here. An article presenting the full results of the survey is in preparation and two more new species discovered on the archipelago will be described in forthcoming months.