The Guyana dolphin (Guiana sotalia) is one of the smaller species of dolphin and lives exclusively in South America along a narrow coastal strip from Honduras to Brazil. Due to its coastal distribution, this species is severely affected by human activities. In Venezuela, the main areas of distribution are the Orinoco River and Lake Maracaibo. The International Union for Conservation of Nature IUCN Red List classifies the Sotalia dolphin as near threatened (NT). At the regional level, however, the species is classified as endangered. Due to increased fishing activity throughout its range and habitat destruction, there is concern that local populations may be at risk of disappearing entirely in the future. Lack of monitoring and control has dramatically worsened the situation for these dolphin populations.
Several genetic and morphological studies suggest that the Guyana dolphin population from Lake Maracaibo must be considered a separate management unit due to its differences from the rest of the population. Lake Maracaibo has the highest bycatch rate for this species, with 180 individuals caught per year. It is the only region in Venezuela where a dolphin species is exploited for human consumption. In addition, there are regular problems with oil pipelines, with disastrous consequences for the environment. There are approximately 15 oil spills per year in Lake Maracaibo, which in turn leads to contamination with heavy metals and other toxins. Initial studies have already demonstrated negative effects on marine mammals.
Although studies on the population size, behavior, and biology of the Sotalia guyana dolphin are available on a global level, such findings are unknown for the population in Maracaibo. A monitoring program is important in order to better evaluate the extent of the bycatch problem.
Successes and progress to date
Thanks to PROYECTO SOTALIA and YAQU PACHA, various studies on the biology and endangerment of the Guiana dolphin have been conducted in Lake Maracaibo (13,000 km²) since 2016.
For example, since 2016, data on the number of animals killed by fishing has been systematically collected and consumption by the local population has also been documented. These figures can be used to better define the mortality rate. In addition, tissue samples from dead animals are examined to determine possible contamination with mercury and heavy metals. This data is relevant for assessing the health status of this dolphin population, but also for highlighting the danger to humans. Initial figures indicate that the levels of some harmful substances are particularly high, meaning that consumption of the meat by humans poses a health risk. In collaboration with other NGOs, a campaign has been launched to warn people against eating dolphin meat and thus protect Guyana's dolphins.
Equally important is the recovery of so-called ghost nets, which repeatedly cause animals to become entangled and subsequently die. This work is carried out in cooperation with various other NGOs, including the CIT Venezuela shark research center.
In the area of awareness and education, with the support of YAQU PACHA, a poster was designed about the impact of heavy metals on the ecosystem of Lake Maracaibo and distributed to fishermen and other people living there. Informative posters have also been produced and distributed in recent years. Visiting schools is another important part of environmental education work.
On International River Dolphin Day, our partners at Proyecto Sotalia held an information event in Venezuela.
Many interested people attended the event, and our biologist Yurasi Briceño reported on the work being done to protect dolphins and our activities in Venezuela.
Ethnobiology of the Guiana dolphin (Sotalia guianensis) and traditional knowledge of artisanal fishermen in the state of Espírito Santo, southeastern Brazil
The Guiana dolphin (Sotalia guianensis) is a dolphin species threatened by accidental capture in gillnets used in artisanal fisheries in the central coastal mesoregion of Espírito Santo (ES) in southeastern Brazil.
There is little information available to the Brazilian government about these dolphins. The Brazilian National Action Plan for the Protection of Endangered Whales and Dolphins (PAN dos Cetáceos Marinhos) emphasizes the urgent need to collect data on traditional knowledge for the Espírito Santo coast. The aim of this study is to use the knowledge of fishermen to determine the interactions between Sotalia dolphins and artisanal fisheries in the areas where they occur in the mesoregion of the central coast of Espírito Santo. In addition, environmental awareness activities will be carried out with children from public schools in fishing communities.
The results obtained will make it possible to understand the areas of use and human interactions with the species and to achieve the objectives of the PAN of Marine Cetaceans, the Decade of the Oceans, and Sustainable Development Goal No. 14 "Life Below Water" of the 2030 Agenda. This part of the Sotalia Dolphin project is being carried out in collaboration with our partners ECOLOGIA HUMANA DO OCEANO.
Latin America Team | Sea Otter Project | Chilean Dolphin Project | Chilean Dolphin | 30 Years of YAQU PACHA e.V. | Information about the Dolphin Species| Species Conservation | Manatee Project | Vaquita Project | Bottlenose Dolphin Project | La Plata Dolphin Project | Expedition to the Inias in the Rio Casiquiare