An endangered dolphin species face being wiped out by the combined threat of fishing along with the building of several dams, warns new research.
Scientists used satellite tags to track eight Amazon River dolphins to find out where they went in relation to fishing areas and the proposed dams and dredging sites.
On average, 89 percent of the dolphins’ home “range” – the area they live in the Peruvian Amazon – was used for fishing.
The dolphins were found to be an average of 157 miles (252 kilometers) from the nearest proposed dam and 78 miles (125 kilometers) from the nearest proposed dredging site.
“While they are significant distances, the dolphins’ ranges spanned over 30 miles (50 kilometers) on average, and dams and dredging can affect large stretches of river habitats,” said the researchers.
Many of them also live closer to the proposed sites than the seven males and one female tagged in the study, published in the journal Oryx.
The research was conducted by the University of Exeter scientists along with and Peruvian conservation group Pro Delphinus.
“It’s clear that the Amazon River dolphin is facing increasing threats from humans,” said Dr. Elizabeth Campbell, of the University’s Centre for Ecology and Conservation.
“Fishing can deplete populations of the dolphins’ prey, and dolphins are also at risk from intentional killing and accidental catching, known as bycatch.
“Bycatch has been known to be a threat to these dolphins for the last 30 years, but there’s no real data on how many dolphins are caught per year.”
“The construction of dams, mainly in Brazil, is an “expanding” threat, with 175 dams operating or under construction in the Amazon basin, and at least 428 more planned over the next 30 years,” said Dr. Campbell.
The Amazon Waterway has also been approved and is under contract for construction. It will involve dredging sites across four main rivers of the Amazon basin, and the expansion of ports to enable ship navigation across the Amazon, Ucayali and Marañón rivers.
But the researchers say the Peruvian government has a chance to protect biodiversity.
“Peru has a chance to preserve its free-flowing rivers, keeping them a safe and healthy habitat for river dolphins and many other species,” said Dr. Campbell.
“Given that many of these dams and dredging projects are still in the planning stage, we advise the government to consider the negative effects these activities have already had on river species elsewhere.”
She added: “River dolphin tracking programs should now be expanded to span multiple seasons, to track more females at our study sites, and to increase the numbers tracked in other areas to improve our knowledge of the movement patterns of this species.”
Produced in association with SWNS Talker
Edited by Judy J. Rotich and Newsdesk Manager
