[Truncated] Pelagic fish are ecologically important to marine ecosystems and are a highly valuable resource, yet little is known about the population status and ecology of many species. Research on the biology and ecology of pelagic fish largely relies on fishery-dependent data from commercial and recreational fisheries. However, the use of fishery-dependent data alone can lead to sampling biases due to gear selectivity and heterogeneous fishing effort. Alternatively, fishery-independent surveys can adopt more robust sampling designs, but often employ the same fishing gear and as such, catchability and size-selectivity biases remain. Emerging technologies like remote sensing, acoustic cameras and video-techniques are providing new nondestructive options for cost-effective ecological sampling in vast and remote environments such as the open ocean.
Baited Remote Underwater Video systems (BRUVs) have proven to be a robust fishery-independent method to obtain estimates of biodiversity, relative abundance, behaviour and, when stereo-cameras are used, size and biomass of a range of marine species. Stereo-BRUVs had not been tested in the pelagic environment, but evidence suggested that they could overcome some of the difficulties of sampling in the water column. In this thesis, I develop and validate the use of pelagic stereo-BRUVs as a non-destructive fishery-independent technique to study highly mobile species in the pelagic environment, and I examine the strengths and limitations of this method in order to optimise their implementation in future studies.
|Qualification||Doctor of Philosophy|
|Publication status||Unpublished - 2015|