Sawfish – (probably) the most endangered fish on the planet
Conservation status and current distribution of the largetooth sawfish Pristis pristis in the Tropical Eastern Pacific
What is a sawfish? Sawfishes are shark-like rays, characterized by their large, toothed rostrum that can make up to 25% of their body length and is used in the detection and capture of their prey. They live in shallow coastal waters and can tolerate different gradients of salinity, being found from marine to freshwater ecosystems. In total there are five species of sawfishes around the world and all considered highly threatened with extinction.
Sawfish in the ETP? One species of sawfish can be found in the Tropical Eastern Pacific region (Ecuador, Colombia, Panama and Costa Rica), the largetooth sawfish (Pristis pristis), also estimated to be the most widely distributed species from the Pristidae family. The largetooth Sawfish is classified by the IUCN as Critically endangered and they are considered as the most threatened marine fishes worldwide. Their numbers have declined significantly around the world and they are currently extinct or rarely seen in many areas of their original distribution. It is estimated that in the Eastern Pacific area alone, populations have decreased by more than 80%, with extant populations limited to Colombia, Nicaragua and Panama, but their status still unclear in this region. For these reasons there is urgent need to assess and understand the current status of this species in some of the regions where they were previously very abundant.
Why are they threatened? Sawfish are demersal predators meaning that they live and forage over the sea bed. They are also an inshore species, distributed in shallow water, and even travel up rivers to reproduce. This means that they are extremely sensitive to habitat loss or development, such as dam construction. However, the most likely cause of their rapid demise has been the widespread expansion of the use of monofilament gill nets by inshore fishers. The tooth lined rostra of the sawfish become very easily entangled in these nets, and due to the potential danger posed to fishermen to extricate them, they are often killed and rarely released.
What are we doing? To evaluate the status of the Largetooth Sawfish on the Pacific coasts of Colombia, Panama and Costa Rica, surveys will be carried out with fishers in coastal villages to document their historical and traditional ecological knowledge of the sawfish, but also to identify and map areas that may prove to be the last remaining refuges of a species on the brink of extinction, based on fisheries records, anecdotal information and identification of sawfish rostra.