There is no simple answer to the question “how much ghost gear is in the ocean?”. In the 1970s it was estimated that 640,000 tonnes of ghost gear was produced each year, accounting for around 10% of ocean plastics. However, since ghost gear survey effort is often poor or sporadic, this is likely a gross under representation of the true amount of ghost gear in the ocean today. In Northern Australia alone, up to 3 tonnes of derelict nets have been reported per kilometre of coastline in a given year.
More research is needed to determine the current amount of ghost gear in our oceans today and to understand the effects that this is currently having on marine species at a population level. However, ghost gear is known to be cryptic and transboundary in nature. As a result, it can be extremely difficult to study.
References
- Gunn, R., Hardesty, B.D. and Butler, J., 2010. Tackling ‘ghost nets’: local solutions to a global issue in northern Australia. Ecological Management & Restoration, 11(2), pp.88-98.
- Macfadyen, G., Huntington, T. and Cappell, R., 2009. Abandoned, lost or otherwise discarded fishing gear.
- Wilcox, C., Hardesty, B.D., Sharples, R., Griffin, D.A., Lawson, T.J. and Gunn, R., 2013. Ghostnet impacts on globally threatened turtles, a spatial risk analysis for northern Australia. Conservation Letters, 6(4), pp.247-254.
