Global search for vanishing ocean giants

“Sawfish are close relatives of sharks that have a long, toothed rostrum that means they look like a cross between a shark and a hedge trimmer that can grow to over 6 metres long,” said Project Coordinator, Professor Colin Simpfendorfer from James Cook University.

There are five species of sawfish that live in tropical and subtropical coastal waters, estuaries and rivers. However, accidental capture in fisheries and loss of coastal habitats has seen them disappearing from many areas where they were once common.

“Historically they occurred in the waters of 90 countries, but are now believed to be extinct in 20 countries, and 43 countries have lost at least one species. In countries where they remain, populations have declined dramatically and many are nearing extinction,” said Professor Simpfendorfer.

He said that without significant conservation efforts these species are unlikely to recover and continue to decline until they are globally extinct.

The situation for sawfish is so dire that they now have their own day – International Sawfish Day – which is today, October 17^th, to increase the recognition of the need to save the animal.

To help boost sawfish conservation efforts, James Cook University, working with partners around the world, and with funding from the Save Our Seas Foundation, is launching the Global Sawfish Search project that will use a new approach to seek out the remaining populations of sawfish.

The project will use Environmental DNA, or eDNA, that tests water for fragments of sawfish DNA to work out where they still occur.

“The rarity of sawfishes makes traditional fishing surveys largely ineffective, unreliable and cost-prohibitive at the scales needed to locate now scarce sawfish,” said Professor Dean Jerry, one of the project leaders.

“That means Environmental DNA, which we have recently shown to be effective for sawfish, is a great alternative because it can be deployed rapidly and at lower cost than fishing surveys,” he said.

"We're thrilled to support innovative researchers like JCU's Colin Simpfendorfer," said Michael Scholl, Chief Executive Officer of Save Our Seas Foundation. "To make a lasting impact on the health of sawfish populations, our organisation is currently investing in 11 research and conservation projects globally to gather data and educate the world about this critically endangered family of fish."

The project will work with partner organisations around the world to collect eDNA samples. Partners will use their local knowledge of sawfish, and eDNA kits provided by the project, to sample water bodies where sawfish are thought to occur.

A small number of partners working on known sawfish populations will also test the technique to ensure its accuracy. These partners include Dr David Morgan from Murdoch University, Dr Peter Kyne from Charles Darwin University and Dr John Carlson from the US National Marine Fisheries Service.

The results from the project will be used to build a clear picture of the current distribution of sawfish and help direct conservation efforts into the future.

Images here.

Link to more information the SOSF Project: here.