- In late March and early April of this yr, a crew of researchers and native fishers caught, sampled and launched greater than 50 sharks and rays within the Bijagós Archipelago of Guinea-Bissau, together with a number of threatened species.
- A primary for conservation, researchers tagged members of a critically endangered ray species, the blackchin guitarfish (Glaucostegus cemiculus), with satellite tv for pc transmitters.
- Group chief Guido Leurs says the analysis will present essential data for policymakers to raised shield sharks and rays in Guinea-Bissau.
- Fisheries administration inside the archipelago, which spans 12,950 sq. kilometers (5,000 sq. miles) and 88 islands, is a problem for the West African nation.
In late March and early April this yr, researchers from the College of Groningen within the Netherlands teamed up with fishers, conservationists and scientists in Guinea-Bissau to catch, research, pattern and launch greater than 50 sharks and rays off the coast of the West African nation.
The crew, which included specialists from the Guinea-Bissau-based Institute of Biodiversity and Protected Areas (IBAP), took blood and different tissue samples from the animals for DNA analyses, decided their intercourse and maturity, and regarded for indicators they just lately gave beginning. In all, the animals belonged to 10 completely different species, together with the smalltooth stingray (Dasyatis rudis), scalloped hammerhead shark (Sphyrna lewini), tiger shark (Galeocerdo cuvier) and bull shark (Carcharhinus leucas).
The crew performed the analysis within the Bijagós Archipelago, a UNESCO Biosphere Reserve that covers 88 islands unfold throughout 12,950 sq. kilometers (5,000 sq. miles). The area has struggled with fisheries administration for many years: unlawful fishing is pervasive amongst foreign-owned industrial vessels, in accordance with a 2018 paper, and small-scale fishing continues to function inside marine protected areas.
“As taking the animal from the water is anxious, we wish to take the time as fast as attainable, however on the similar time be sure that we are able to be taught as a lot from the animal as attainable,” crew chief Guido Leurs, from the College of Groningen, mentioned in an electronic mail.
One species acquired particular therapy: the critically endangered blackchin guitarfish (Glaucostegus cemiculus), probably the most threatened ray species in West Africa. The crew connected satellite tv for pc transmitters to 2 blackchin guitarfish to trace their actions, marking the primary time this species has been tracked with this technique.
At the moment, nobody is aware of the place native blackchin guitarfish migrate to exterior the archipelago, leaving questions on what could possibly be impacting their survival unanswered. Leurs mentioned he hopes this analysis will present solutions, giving Guinea-Bissauan policymakers extra data to guard the species.
“In 9 months from deployment (275 days to be actual) we’ll hopefully discover out the place these animals have been!” Leurs added.
The crew is saving one satellite tv for pc tracker to put on a scalloped hammerhead throughout their subsequent expedition.
Practically one-third (32.6%) of shark and ray species are threatened with extinction because of overfishing, in accordance with a research revealed within the journal Present Biology late final yr. This is a rise from the primary international evaluation of chondrichthyes (sharks, rays and chimeras) performed in 2014, which discovered roughly 1 / 4 (24%) of species had been threatened. Within the tropics, the menace is disproportionately excessive.
Sharks and rays play an essential cultural and religious function for the folks of the Bijagós, inspiring dances, costumes and even buildings. Whereas industrial and artisanal coastal fisheries goal them inside and out of doors the marine protected areas of the archipelago, Leurs mentioned that due to their cultural significance, Bijagós fishers typically don’t, nor do they wish to catch them by chance as bycatch. Leurs mentioned the fishers on his crew hope the analysis outcomes will assist them learn to scale back charges of bycatch.
Igualdino Titi, a fisherman who has labored with Leurs’s crew for 4 years, helped catch the 2 guitarfish. In his honor, they named one of many fish “Titi,” after his household title.
“I can nonetheless see his face after we informed him,” Leurs mentioned. “It was simply such a second of satisfaction for him.”
Banner picture: The primary critically endangered blackchin guitarfish being launched with a satellite tv for pc transmitter. This grownup feminine is called Aissa after IBAP conservationist Aissa Regalla, who works for improved safety of pure areas in Guinea-Bissau. Researchers can now comply with this guitarfish and one other of its type to be taught in regards to the migration of the little-studied species inside the area, with a watch to raised defending it. Picture by Maarten Zwarts/College of Groningen.
Mike DiGirolamo is Mongabay’s viewers engagement affiliate. Discover him on Twitter @MikeDiGirolamo, Instagram, or TikTok by way of @midigirolamo.
Intchama, J. F., Belhabib, D., & Tomás Jumpe, R. J. (2018). Assessing Guinea Bissau’s authorized and unlawful unreported and unregulated fisheries and the surveillance efforts to sort out them. Frontiers in Marine Science, 5. doi:10.3389/fmars.2018.00079
Dulvy, N. Okay., Fowler, S. L., Musick, J. A., Cavanagh, R. D., Kyne, P. M., Harrison, L. R., … White, W. T. (2014). Extinction threat and conservation of the world’s sharks and rays. eLife, 3. doi:10.7554/elife.00590
Dulvy, N. Okay., Pacoureau, N., Rigby, C. L., Pollom, R. A., Jabado, R. W., Ebert, D. A., … Simpfendorfer, C. A. (2021). Overfishing drives over one-third of all sharks and rays towards a worldwide extinction disaster. Present Biology, 31(22), 5118-5119. doi:10.1016/j.cub.2021.11.008
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