Professional Skipper - Free Sample issue (July/Aug 2011)

RESEARCH PAYS OFF FOR BLUFF OYSTERS THE NEWS APPEARS to be all good for a successful oyster season up until it finishes at the end of August. "The bonamia parasite, which has greatly reduced catches in the Bluff oyster fishery over the last 25 years, was at a relatively low level last summer. At this low level of mortality, the oyster fishery is continuing to rebuild," says NIWA scientist Keith Michael. There was a real sense of celebration at the Bluff Oyster and Food Festival, held on May 21, not only because the fishery is doing well, but also because closer collaboration between those in the oyster industry and researchers provided a better understanding of the fishery, Michael said. Recreational and customary fishers, the Ministry of Fisheries, oyster boat skippers and industry representatives all meet regularly to assess how the fishery is doing and to exchange information. The five-year Foveaux Strait Oyster Fisheries Plan, begun in 2009, gave top research priority to gaining a better understanding of the relationship between bonamia and oysters. "We don't just focus on what are safe harvest levels, we work across a broad range of key research projects to better understand the fishery as part of a larger ecological system," Michael said. The plan also includes research into improving fishing equipment and fishing methods, and understanding the interaction between oysters, disease and fishing in different parts of the oyster fishery. Because of the information available, researchers can now reliably predict trends in the fishery for three years ahead. This provided confidence that the harvest levels have no affect on its ability to rebuild, and that mortality from bonamia ultimately determines its fate. Bonamia has infected Bluff oysters since 1963 and maybe much earlier. It is unlikely to disappear and is expected to be a recurring problem. If the research can help predict where and when the deaths will occur, vulnerable areas can be fished, rather than areas with low infection, allowing these areas to rebuild further before the oysters are harvested. NIWA also works closely with a group of 11 oyster skippers, who own the information and the process by which it was derived. "The skippers get together and discuss the state of the fishery and harvest levels and areas … and we can communicate information to all participants in the fishery," says Michael. The Bluff Oyster Management Company invests heavily in research every year. Funding is also provided by the Ministry of Fisheries and the Foundation for Research Science and technology through Seafood Innovations Ltd. Seismic tests pulp squid and octopus LOW-FREQUENCY SOUND from seismic testing destroys the organs of squid, octopus and shuttlefish, says the Environment and Conservation Organisations of New Zealand. The research by scientists in Spain and France showed the animals were damaged after just two hours exposure to low- frequency noise from 50Hz to 400Hz, the "acoustic smog" typical of oil and gas exploration and shipping. The scientists found the organ that allows squid, octopus and cuttlefish to regulate their positions, balance and direct how and where they swim was damaged, leaving them unable to move or feed, and vulnerable to predators. "This research is further reason to be very concerned about seismic surveys in the sea, including those of Petrobras off East Cape," said Barry Weeber of ECO. The news was bad for everyone, including the fishing industry, he said. "It adds to the already known damage to whales and dolphins from seismic noise." The government needed to rethink its approach to deep-sea oil exploration and development, Weeber said. July/August 2011 Professional Skipper r 43 VIP.S78

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