When Manuel Lopes-Lima got down to survey aquatic biodiversity at the Corubal River in 2022, he’d set his expectancies very low. The river that straddles the West African countries of Guinea and Guinea-Bissau used to be, in any case, very faraway and grossly understudied.
Two expeditions later, the tale has became on its heels.
With the assistance of environmental DNA sampling and research, Lopes-Lima and his crew known 125 species of aquatic and terrestrial vertebrates within the Corubal. This contains severely endangered western chimpanzees (Pan troglodytes verus) and freshwater mussels (Pleiodon ovatus) in addition to 21 different species, most commonly fish, that weren’t identified to exist in Guinea-Bissau.
“We weren’t anticipating the massive variety that we discovered,” Manuel Lopes-Lima, staff lead on the Analysis Centre in Biodiversity and Genetic Sources on the College of Porto in Portugal, advised Mongabay in a video interview. “We have been anticipating so much much less.”
In a learn about= printed within the magazine Bioscience, the crew laid out the method they used to filter out DNA from water samples gathered from the Corubal. Consistent with the learn about, the findings emphasize the “conservation significance of the Corubal, supply a baseline for long term tracking, and spotlight the demanding situations and alternatives of eDNA surveys in faraway tropical rivers.”
“Corubal is likely one of the ultimate loose rivers in Africa,” Lopes-Lima stated. “There’s no primary large town alongside the river and no dams, and that makes this river in particular fascinating in the case of conservation wishes.”
Flowing just about 560 kilometers (350 miles), the Corubal rises from the highlands of Guinea, bureaucracy a bit of the border with Guinea-Bissau, then meanders throughout the latter nation prior to emptying out into the Atlantic Ocean. Alongside the way in which, it serves as a supply of freshwater for animals residing within the river basin. Massive-scale research to observe biodiversity within the river haven’t been undertaken in recent times. Then again, smaller expeditions up to now have discovered the river and its basin to be house to a large gamut of species, together with Senegal flapshell turtles (Cyclanorbis senegalensis), African manatees (Trichechus senegalensis), Nile crocodiles (Crocodylus niloticus) and hippos (Hippopotamus amphibius).
When Lopes-Lima and his crew determined to review the Corubal River, environmental DNA research appeared like one of the best ways to know the biodiversity that lives there. Prior to now, Lopes-Lima used to dive or cross snorkeling to review and observe aquatic species. However this got here with demanding situations. “Particularly operating in tropical rivers in faraway spaces, it’s on occasion bad,” he stated. “There’s a large number of parasites which could be vectors of illnesses, and likewise bad animals like crocodiles and hippos.”
Environmental DNA (eDNA) has discovered expanding recognition as a noninvasive way of accomplishing biodiversity surveys over huge spaces. It calls for gathering and detecting DNA left in the back of by way of animals in water, air and soil by the use of their hair, fur and saliva, amongst different issues. Contemporary research have additionally explored swabbing leaves in forests to assemble DNA samples of terrestrial animals.
Lopes-Lima and his crew undertook two expeditions, one in 2022 and one in 2023, to gather samples from the a part of the river that flows thru Guinea-Bissau. Touring in slender canoes, the crew gathered water samples from 25 issues alongside the river. From those, they extracted DNA to spot the species related to them.
The just lately printed learn about covers best the findings from the expedition in 2022. This contains species that had prior to now now not been recorded within the nation, such because the Egyptian fruit bat (Rousettus aegyptiacus) and the gray-throated rail (Canirallus oculeus). “It used to be fascinating to peer that lets perceive the biodiversity of the river itself, but additionally the animals that use the river to drink water or as a safe haven within the dry season,” Lopes-Lima stated.
The crew additionally concurrently labored on construction a reference database for species within the area. For this goal, they have been accompanied by way of a crew of scientists who gathered specimens and tissues from animals in an effort to construct a database, particularly for bugs, mollusks and smaller mammals that haven’t been well-represented in DNA reference databases. “The issue is that lots of the species in Guinea-Bissau have been by no means sequenced,” Lopes-Lima stated. “As a result of they’re so faraway and hard to review, we didn’t have references for lots of of them.”
Whilst the crew analyzes the samples from the 2023 expedition, it’s additionally making plans a 3rd travel that might probably duvet the upstream a part of the river that lies in Guinea. The power to assemble and procedure such a lot biodiversity information from a faraway tropical river has additionally inspired the researchers to solid a much broader web around the continent. Lopes-Lima stated he’s additionally recently operating to coach scientists, increase eDNA protocol, and construct capability to behavior fast biodiversity evaluate surveys in rivers in Namibia and different portions of Southern Africa.
“We’re seeking to standardize and optimize those tips on how to maximize the biodiversity you get whilst minimizing the price,” he stated. “Now not best to peer the biodiversity developments, however to make use of it for tracking and notice if conservation movements are serving to or now not.”
Quotation:
Lopes-Lima, M., Prié, V., Camará, M., Ceríaco, L. M., Fernandes, V., Ferreira, S., … Beja, P. (2024). Speedy eDNA survey unearths a singular biodiversity hotspot: The Corubal River, West Africa. BioScience, 74(6), 405-412. doi:10.1093/biosci/biae036
This article by way of Abhishyant Kidangoor used to be first printed by way of Mongabay.com on 6 September 2024. Lead Symbol: Probably the most species that had prior to now now not been recorded within the nation is the Egyptian fruit bat (Rousettus aegyptiacus). Symbol by way of Simon Willison by the use of Flickr (CC BY-NC 2.0).
What you’ll be able to do
Lend a hand to save lots of natural world by way of donating as low as $1 – It best takes a minute.
