[12 July/Stuff]

An expedition on board the Amaltal Explorer to survey the orange roughy population off New Zealand waters has helped collect data on two of New Zealand’s key orange roughy fisheries. The vessel spent ten days around the closed Cook Canyon (7B) fishery on the South Island’s West Coast. Talley’s supplied the Explorer vessel for both surveys, and Sealord provided its multi-frequency Acoustic Optical System (AOS) developed by Australian CSIRO scientists and the NZ seafood industry. The AOS collected underwater acoustic and video data from depths of 1000 metres and allowed video to be viewed on the vessel in real-time. Footage of the fish was reconciled with acoustic marks to estimate the fish numbers and species present. Using the technology and biology of different fish species, scientists were able to use the frequencies to sort through the biomass clusters. The broadband resolution of the technology also enabled scientists to better measure the size of the fish.