The franciscana
Despite its appearance, the franciscana (Pontoporia blainvillei) cannot claim to be a true river dolphin. It typically inhabits shallow salt water areas and is distributed from the coastal waters of south-east Brazil, down to the central Argentinean region. Their long, slender beaks (at a whopping 15% of their body length, it is proportionally the longest of all cetaceans), broad flippers and rounded foreheads suggest a close relationship to all other river dolphins found in South America. However, they are classified as an entirely different family, the Pontoporiidae. One of the smaller species of cetaceans, they are characteristically inconspicuous and hard to spot in the wild due to their avoidance of boats and un-acrobatic tendencies. It is not often that cetaceans are referred to as prey species, but the franciscana has been known to be on the menu for orcas and a variety of shark species.
In keeping in common with the true river dolphins covered in this series of blogs, the future of the franciscana is under threat. Classified as ‘Vulnerable’ on the IUCN Red List, the overall population is decreasing rapidly, due mainly to by-catch in fishing gear. Franciscana populations are suffering additional pressure from reduced fish stocks as fishing fleets target many of the species they rely on for food. Further impacts on population size come also from ingesting foreign objects (predominantly from fishing gear), and chemical pollution. Some population estimates have been made and can appear relatively high. However, it is predicted that there has been at least a 30% reduction in population size over the past 3 generations (36 years) in a decline that has not slowed. The sheer scale of accidental by-catch is so high in most areas, that it is un-sustainable on its own merit. When combined with the other threats facing the franciscana, it is not hard to see the reasons for such a decline.
In response to this decline, a variety of organisations (both governmental and non-governmental) have compiled an action plan for the fraciscana dolphins residing in Brazilian waters. The Chico Mendes Institute for Biological Conservation drew up the final plans to halt the fall in population numbers over a 5 year period, finishing in 2015. The plan approaches the conservation of the franciscana on all fronts. Measures will be introduced to minimise the impacts of fishing and other practices on the dolphins and a large scale effort to understand the population structure will be implemented. Alongside this, the identity of the dolphins will be promoted throughout the regions of Brazil in which they occur and communication of their conservation will be improved. The hope is that political and international co-operation towards conserving the franciscana will significantly improve over the 5 years.
WDCS on Twitter
WDCS on Facebook
WDCS on YouTube
But kudos to the people who did their best to save him.