Aquatic mammals in South America: their problems and a prospective view for their conservation within an economical and political background.

CRESPO, E.A

Malta

Congreso; 37nd ANNUAL SYMPOSIUM OF THE EUROPEAN ASSOCIATION OF AQUATIC MAMMALS.; 2009

The problems faced by aquatic mammals in South America are much like those they face in other parts of the world. They include incidental catch in fisheries, direct exploitation, competition for fishing resources and habitat loss and degradation.  Most of the species are insufficiently known. With few exceptions for most of them there is no information about abundance and population trends.  Incidental catches are reported in coastal and offshore waters affecting several species. Direct takes mostly for food, oil or bait also include the use of genital organs for aboriginal beliefs in the case of small cetaceans. Economic reasons were involved in turning an incidental into a direct catch in Perú during the 1980´s. These conditions can be amplified with poverty and hyperinflation. Regarding competition for fishing resources,  there is a general perception by fishermen that pinnipeds are currently depleting the target species of fisheries. Loss of habitat is the most important problem that face the fresh-water and coastal species. Indiscriminate clearing of rainforest for the use of land in agriculture and cattle growing is currently going on, and many species are declining sharply. Dams and other barriers in large rivers have been or are being planned for hydroelectric power, irrigation or flood control. These projects have important impact on regional development but have negative consequences in the river ecosystem for river dolphins,  manatees and  river otters,  leading to isolation of aquatic mammals and their prey, unnatural water flows and interruption of migratory paths. Other threats include pollution, mining, the use of dynamite for fishing and incidental and direct catches in fisheries.  In coastal areas the most important problems include intensive fishing and the pollution by hydrocarbons, agrochemical and heavy metal products and intensive boat traffic. The importance of each of these varies with the area considered. Most of South American aquatic mammals have a wide distribution and occur or breed passing through political boundaries. Legal protection or status is not the same in each country and sometimes even there is little or no enforcement. Even that most countries posses laws or decrees for conservation aquatic mammals, incidental mortality or by-catch is not considered a variable in fishery management models and decision making. At the international level,  agreements should be promoted between the countries of the region in order to give general or particular status of protection for a given species. S.A. has been characterised of political instability during the 70´s, return to “light” democracies during the 80´s and privatisation of public companies and offices, the increase of unemployment and decrease of educational levels in the population during the 90´s. These changes leaded to less control by the states on private developments and investments with higher environmental costs and loss of habitat. Some countries are also reluctant to sign international agreements in order to manage and conserve species and habitats. Conservation strategies should include highly trained human resources, cooperation between research and conservation groups within a particular region, within country agreements between national or lower level authorities, NGO´s and the private sector, international agreements for shared species or habitats and a balance between international / regional policies.