This article has been peer reviewed and accepted for publication. It is in production and has not been edited, so may differ from the final published form.
Influence of Environmental Conditions on Cetacean Entanglements – A case study from the Gold Coast, Australia
Entanglements of marine mammals in fishing gear is recognised worldwide and is a continuous management concern. Gill net entanglement data from the Queensland Shark Control Program (QSCP) on the Gold Coast, Australia was analysed in this study. Environmental drivers that may influence entanglements of Humpback whales (Megaptera novaeangliae) and Common dolphins (Delphinus delphis) were selected. M. novaeangliae entanglements coincided with their annual migration with the greatest occurrences in the month of September. D. delphis were mostly entangled from March to November with the greatest occurrences in June. For both species, entanglements mainly occurred when the wave height was between 0.5 to 1.25 m, the wave power was between 0 to 5 kW/m and the wind speed was between 12 to 19 km/hr. M. novaeangliae entanglements were significantly more likely to occur in low rainfall (under 6mm/hr), and D. delphis entanglements to occur during spring tides. There was a correlation with the position of the East Australian Current’s (EAC), maximum velocity with 73% of M. novaeangliae entanglements and 79% of D. delphis entanglements occurring when the EAC was west (shoreward) of its average position at 154°E. This study provides a first set of possible management intervention targets associated with environmental conditions.
MF16302 Accepted 08 March 2017
© CSIRO 2017