Excerpt from Carr et al. “Illegal Shark Fishing in the Galapagos Marine Reserve.” (2013)
On July 19, 2011 the Galapagos National Park, along with the Ecuadorian Navy, seized the Fer Mary I (a long line fishing vessel from Manta, Ecuador) and crew of 30 on the southeast side of Genovesa. The boat was equipped with 1 long line fishing set with 369 hooks, and 6 ‘‘lanchas’’, or 8 m outboard powered fiber-glass boats, for patrolling long lines. 379 shark carcasses were onboard the boat. The Fer Mary I was boarded on July 23rd, and each shark was identified to species, the condition of each body was determined, and body size and sex were recorded for each of the sharks prior to the mandatory disposal of the bodies, as required by Ecuadorian law (to ensure that no profit is earned whatsoever from illegally fished animals).
More on the composition of shark species within this catch: waters around the GMR. The shark species composition found on the Fer Mary I is consistent with both recent landings data from mainland Ecuador and other recent seizures of illegal shark fishing vessels. For example, blue sharks and thresher spp. currently comprise 90% of all shark landings in Manta, Ecuador [11]. On the Fer Mary I, big-eye threshers and blue sharks were the first and third most abundant shark species and together comprised 87% of the total number of individuals caught. Further, the shark species found among other unpublished seizures within the GMR from 2001–2004 were similar to those Table 1 Illegal shark fishing seizures in the Galapagos Marine Reserve from 2001 to 2004.
These results underscore the regional pressure concentrated on these species. It should also be noted that morphologically specialized species (i.e., species with disproportionately large fins) were abundant in this study, however whether these species were specifically targeted for increased economic profit is unknown. The ecological role of pelagic sharks (Galapagos sharks, smooth hammerheads, silky sharks, big-eye threshers) inhabiting Ecuadorian waters, including within the Galapagos archipelago, has never been explicitly studied. Trophodynamic models developed to describe the ecological role of pelagic sharks in different regions suggest they are weak interactors in pelagic food webs. Results demonstrated that either other predators will fill the ecological gap left by pelagic sharks (i.e., billfishes and tuna) [20], or that pelagic sharks only have transient effects on prey species [7]. However, empirical studies and mass-balance models demonstrate that at least some of the shark species (tiger, Galapagos, hammerhead) caught onboard the Fer Mary I can influence community dynamics via both indirect and direct interactions [21,22]. Therefore, to better understand the ecological consequences of pelagic shark fishing in sensitive areas like the Galapagos Islands and other remote island atolls, more site-specific models and studies are desperately needed.
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