MONTEVIDEO – Low temperatures in the waters of Uruguay’s rivers over the last two months caused the death of thousands of fish, according to a report released Friday by the country’s Livestock, Agriculture and Fishing Ministry.
After receiving several reports on episodes of fish mortality in several rivers, the ministry sent specimens of those species and of the waters to Uruguay’s Fishing Research Institute and to the Residual Pesticide Laboratory.
One of the waterways affected is the Uruguay River, which, according to some environmentalists in neighboring Argentina, is being polluted by the installation of a pulp mill on the Uruguayan side.
Analyses of the samples show that the fish’s deaths were “related to the low water temperatures at the time,” the ministry communique said.
According to temperature records registered by sensors of the Uruguay River Administrative Commission, during the present Southern Hemisphere winter temperatures have plunged as low as 5 C (41 F), the report said.
Water temperature directly influences multiple metabolic processes in fish, the study said, adding that in general the immune systems of species present in Uruguayan rivers require a temperature of between 15-20 C (59-68 F). EFE