What is the Deadliest Net?

Turtle bones in a gill net, one of the deadliest nets found on Australian shores. Photo by Jane Dermer.

Which is the Deadliest Net to Turtles?

The partnership between GNA and CSIRO continues to be a rewarding one with positive outcomes. A new publication was recently released which highlighted the critical work carried out by rangers in the top end – and the importance of taking those net measurements!

In analysing measurements taken from the nets collected from 2005 - 2012, we found that nets with larger mesh and smaller twine size are more likely to entangle marine turtles. Larger ghostnets also seem to attract turtles, which increases their chances of catching turtles (and other marine wildlife). The results point to issues with trawl and drift-net fisheries in particular. From data in the Gulf of Carpentaria, we estimated that the total number of turtles caught by the nearly 9,000 nets samples analysed was between 5,000 and 15,000 turtles, assuming nets drift for one year. Given that more than 13,000 nets have been removed since 2005, the actual number of turtles killed may be even higher than our estimate.

Importantly, we suggest interception of the nets near Weipa, as this would potentially greatly reduce the impact of ghostnets on turtles and other marine species in the GoC. This work was highlighted at the recent International Whaling Commission meeting, showing not only how Australia is leading the way, but demonstrating the importance of the work rangers have been carrying out these last several years. The paper can be found here: http://onlinelibrary.wiley.com/doi/10.1111/cobi.12355/abstract or contact Riki for a PDF copy of the paper.

Thanks for all your hard work!

Denise Hardesty and Chris Wilcox, CSIRO