Kia ora MARMAM, We are pleased to announce the recent publication of our article in PLoS ONE.
Tom Brough, William Rayment and Steve Dawson. 2019. Using a recreational grade echosounder to quantify the potential prey field of coastal predators. PLoS ONE 14(5): e0217013. Abstract Quantifying the distribution of prey greatly improves models of habitat use by marine predators and can assist in determining threats to both predators and prey. Small epipelagic fishes are important prey for many predators yet their distribution is difficult to quantify due to extreme patchiness. This study explores the use of recreational grade echosounders (RGE) to quantify school characteristics of epipelagic fish and link their distribution to that of their predators at Banks Peninsula, New Zealand. The hydro-acoustic system was groundtruthed with 259 schools of epipelagic fish. During 2015 and 2016, 136 hydro-acoustic surveys were conducted with concurrent observations of Hector’s dolphin (Cephalorhynchus hectori) and little penguins (Eudyptula minor). The relative abundance of the two predator species during surveys was modelled according to the relative abundance of potential prey using generalised additive mixed models. Schools of epipelagic fish were readily detected by the RGE system and were more abundant in summer compared to winter. The models performed well, explaining 43% and 37% of the deviance in relative abundances of dolphins and penguins respectively. This is the first study to link the distribution of Hector’s dolphin to that of their epipelagic prey and confirms the utility of RGE in studies of habitat use in marine predators. Limitations associated with a lack of formal acoustic calibration and data formatting can be overcome and would make RGE valuable, inexpensive tools for investigating variability in populations of small pelagic fishes. Full text pdf copies of the article are available at https://doi.org/10.1371/journal.pone.0217013 Alternatively, feel free to email me at tom.broug...@gmail.com for a copy, Many thanks, Tom Brough *Marine Mammal Research Group* *Department of Marine Science* *University of Otago, Dunedin* *Aotearoa/New Zealand* *http://whaledolphintrust.org.nz/ <http://whaledolphintrust.org.nz/>* *https://www.facebook.com/whaledolphintrust/ <https://www.facebook.com/whaledolphintrust/>*
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