Effect of environmental conditions on cetacean entanglements: a case study from the Gold Coast, Australia

• Published in: Marine and Freshwater Research
• Main Authors: Volep, E, Carroll, AR, Strauss, D, Meynecke, J-O, Kobashi, D
• Format: Article in Journal/Newspaper
• Language: English
• Published: CSIRO Publishing 2017
• Subjects: Environmental management not elsewhere classified; Environmental engineering not elsewhere classified; Megaptera novaeangliae
• Online Access: http://hdl.handle.net/10072/356061; https://doi.org/10.1071/MF16302

Entanglement 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, from 1990 to 2012 were analysed in the present study. Environmental drivers that may affect 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 September. D. delphis were mostly entangled from March to November, with the greatest occurrences in June. For both species, entanglements primarily occurred when the wave height was between 0.5 and 1.25 m, the wave power was between 0 and 5 kW m–1 and the wind speed was between 12 and 19 km h–1. M. novaeangliae entanglements were significantly more likely to occur in low rainfall (<6 mm h–1), and D. delphis entanglements were more likely to occur during spring tides. There was a correlation between entanglements and 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’s maximum velocity was west (shoreward) of its average position at 154°E. The present study provides the first set of possible management intervention targets associated with environmental conditions. Griffith Sciences, Griffith Centre for Coastal Management No Full Text