Phantom fishing nets endangering marine turtles in northern Australia15/01/2013 22:23:33 Huge quantities of discarded fishing nets killing marine turtles
January 2013. Australia's national science agency, Commonwealth Scientific and Industrial Research Organisation (CSIRO) scientists working with GhostNets Australia and Indigenous rangers are identifying hotspots where lost fishing nets are threatening marine biodiversity.
640,000 tonnes of fishing nets discarded every year
Impacting marine turtles
"Using a model of ocean currents and data collected by Indigenous rangers on the number of ghostnets found during beach cleanups, we simulated the likely paths ghostnets take to get to their landing spots on beaches in the Gulf of Carpentaria," Dr Hardesty said."Combining this with information about the occurrence of turtles in the area, we found that entanglement risk for turtles is concentrated in an area along the eastern margin of the Gulf and in a wide section in the southwest extending up the west coast," she said.
"Most ghostnets enter the Gulf from the northwest and move clockwise along its shore. This means we can help protect biodiversity in the region by intercepting nets as they enter the Gulf, before they reach the high density turtle areas along south and east coastlines," she said.
Home to 6 species of marine turtle
"Our predictions of the distribution of turtles washing ashore entangled in ghostnets matched the actual frequencies of turtles found in ghostnets during beach surveys, suggesting our model is accurate," Dr Hardesty said.
Ghostnets are a global problem, capturing seabirds, marine mammals and sea turtles worldwide. Lost or abandoned fishing gear makes up only 20 per cent of marine debris but has a disproportionate effect because it is designed to capture wildlife.
This research used information on ocean currents generated by the BLUElink Ocean Data Assimilation System to simulate the paths of ghostnets.
Ghostnet impacts on globally threatened turtles, a spatial risk analysis for northern Australia' was published by CSIRO and GhostNets Australia in the January 2013 online early issue of Conservation Letters.