Rare dolphin species threatened by big fishnets
BRAZIL: The long-beaked La Plata River dolphin, a small
species living in in South America's Atlantic coastal waters, is
increasingly threatened with extinction from big-net fishing, Brazilian
researchers warn. At last 1,000 of these dolphins die every year near
the coast of (Brazil's) Rio Grande do Sul,” scientist Emanuel Carvalho
Ferreira told AFP Friday.
Ferreira led a study funded by cosmetic giant Boticario's Foundation
for Nature Protection on the mortality of these marine mammals which
“showed that fishnets have become increasingly bigger over the past few
years and now can be 30 kilometers (19 miles) long.” “This is a
virtually insurmountable barrier for these small dolphins,” said
Ferreira, who works with Rio Grande do Sul's marine mammals laboratory
and with the KAOSA non-governmental organization campaigning for the
protection of the La Plata River dolphin.
There are currently an estimated 40,000 to 50,000 of these river
dolphins, which grow to be between four and six feet long (1.20 to 1.80
meter) and weigh up to 50 kilograms (110 pounds).
It is the only species of river dolphins that can be found in salt
water.
Although their sightings are scarce, they can be found in Brazil's
Doce River, the Valdes Peninsula in Argentina and in the coastal waters
of Uruguay.
But they are most threatened in Brazilian waters because fishing in
Uruguay and Argentina is conducted in a less intensive manner.
“In Brazil, the boats are bigger with 20 fishermen (against four or
five in Uruguay and Argentina) who stay at sea for up to 20 days, which
leads to the accidental capture of many cetaceans,” said Ferreira.
To remedy the situation, he said his team recommends reducing the
size of fishnets and banning fishing up to a depth of 20 meters (66
feet).
“We did a simulation by excluding fishing up to a depth of 20 meters
and the accidental capture and dolphin mortality rates fell by 72
percent,” he added.
AFP |