With the model, they tested how habitat, fishing pressure and socio-economy affect populations, and classified countries according to the risk of extinction of sawfish. According to the study, the availability of mangrove habitat was combined with less pressure due to fishing.
Colin Simpfendorfer, a sawmill expert at James Cook University in Australia, praised the study and said: “It’s not just an analysis of where, but also what needs to be done.”
Yan’s international research was complemented by the American team that led Graham. The study, published in January in Endangered Species Research, showed that the location of the small toothed fish in the United States is still confined primarily to Florida, but that it may begin to expand. By locating the fish with passive acoustic labels and a variety of receivers, her team recently tracked them as far north as Brunswick, Ga.
Although international trade in sawfish and their parts is prohibited under the Convention on International Trade in Endangered Flora and Fauna species, intentional killing and by-catches still occur. And countries have an incomplete record of enforcing the ban on trade in fish’s fins and teeth, which are still considered trophies and used in some cultural environments.
When caught unintentionally – shrimp toilets are a major threat, with mitigation efforts being studied – sawfish often die unnecessarily because they are so difficult to untangle or release, says John Carlson, a sawfish researcher at the National Fishers and Oceanic and Atmospheric Administration Fisheries. Their teeth rostrum “get caught up in everything. This is their Achilles heel, ”he says.
And with mangroves being the most important sites to help with conservation, Dr. Carlson’s sawfish research understands why some mangrove patches, although superficially identical, are preferred over others.
After two decades of increasing attention and targeted work by scientists and conservationists, “people’s appreciation for sawfish is really higher,” said Sonja Fordham, a co-author of Ms. Yan’s research and president of Shark Advocates International, said. But she warns that “we still have a long way to go and it really is a race against time.”