The only specialised marine publication in Oceania that focuses on the maritime industry, from super yachts to small craft to large commercial ships, including coastal shipping, tugs, tow boats, barges, ferries, tourist, sport-fishing craft
Issue link: https://viewer.e-digitaleditions.com/i/56633
NEWS CONTINUED FROM PAGE 5 impacts of the virus. "However, at this stage it is not anticipated that these initiatives will impact on the stock available for processing in future years." The Kaeo site will continue to be the base for Sanford's marine farming operations in Northland. OYSTER HERPES VIRUS HITS AUSTRALIA The presence of ostreid herpesvirus-1 µ variant (OsHV-1 µ var) was confi rmed on oyster leases in Woolooware Bay on Botany Bay on December 5. Unhealthy oysters were observed after a plume of discoloured water was seen in the area following rainfall. The Australian Animal Health Laboratory confi rmed tests by the New South Wales Department of Industry and Investment using conventional polymerase chain reaction or PCR. The die-off has also been observed in wild Pacifi c oysters in the nearby area. Mortalities have not been observed in other mollusc species, including adjacent Sydney rock oysters (Saccostrea glomerata). Oyster leases in other locations within Botany Bay have not been affected, and are under surveillance. Mortality in Pacifi c oysters has been 100 percent for spat (2.2mm) and 95 percent for market-sized stock. The New South Wales Food Authority advises there is no evidence to suggest any food safety issues with infected oysters. No Pacifi c oysters from the area are now available for market. Surveillance outside and within containment and/or buffer zone, including testing of source stock, is being planned. This virus has also spread throughout Europe to New Zealand. OCEAN TRAWL REVEALS MEGAVIRUS The largest virus yet discovered has been isolated from the ocean off the coast of Chile. The virus (Megavirus chilensis) is 10 to 20 times wider than the average virus. The particle measures about 0.7 micrometres (thousandths of a millimetre) in diameter, bigger than some bacteria. Scientists writing in the journal PNAS said megavirus probably infects amoeba, single-celled organisms that fl oat free in the sea. "You don't need an electron microscope to see it. You can see it with an ordinary light microscope," said Professor Jean-Michel Claverie, from Aix-Marseille University in Marseille, France. A study of the DNA shows it to has more than 1000 genes. Viruses cannot copy themselves but need to invade a host cell if they want to 14 ■ NZ AQUACULTURE ■ MARCH/APRIL 2012 Dr John Taylor (left) and MIT Director Paul Decker with a resident eel replicate. Megavirus has hair-like structures, or fi brils, on the exterior of its shell, or capsid, that probably attract unsuspecting amoeba looking to prey on bacteria displaying similar features. Professor Claverie said viruses had previously only been discovered because they caused disease in humans, or animals and plants. "But now we are initiating what might be called environmental virology and we are looking for viruses everywhere," he said. "You just go to lakes, seas and oceans and pick up the water, and then you fi lter it and try to rescue the virus by co-cultivating it with some potential host." More generally, there was interest in ocean viruses because they have a major infl uence on populations of plankton, the base of many marine food chains. When the viruses kill plankton they are also helping to regulate the planet's geochemical cycles, as the dead organisms sink into the deep, locking away their carbon for aeons. BBC News EEL RESEARCH EXCITES WELSH VISITOR A fi sh culture manager from Wales has enthusiastically endorsed the Mahurangi Technical Institute's research into eel farming. "The work at MTI has achieved international recognition," said Dr John Taylor. His visit was so he could see the MTI's research into developing methods to commercially farm shortfi n eels and its work with native freshwater fi sh for conservation and education. Dr Taylor manages the fi sh hatchery and farm at Brecon for the Environment Agency Wales, where threatened British native fi sh are produced for re-stocking projects across the United Kingdom. "Increasingly our focus is falling upon eels, given the perilous state of that species in Europe, where stocks have fallen 95 percent in the last 20 years," he said. New Zealand's three species were not in great shape but our wild stocks were still better than populations elsewhere. Our native longfi n eel is classifi ed as threatened and the shortfi n and Australian longfi n eels are only marginally better. Dr Taylor spent a day touring the MTI aquaculture research and educational facility in Woodcocks Rd and discussing methods of artifi cially maturing, spawning and rearing New Zealand shortfi n eels. Preparing hatchery-bred native fi sh for transition to the wild was also discussed, including training captive bred fi sh and others like koura (freshwater crayfi sh) to recognise predators in an effort to help improve their chances of survival when released. Dr Taylor's visit was supported by the Winston Churchill Memorial Trust. CHEF ENDORSES FARMED HAPUKU A video produced by NIWA showing chef Al Brown preparing hapuku reveals the potential of our fi nfi sh farming. Brown is one of a growing number of chefs in New Zealand and around the world who are endorsing the benefi ts of eating farmed fi sh. "It's about cooking fi sh and serving fi sh with a clear conscience," he says in the video. "It's all about transparency, sustainability [and] understanding the process of how fi sh are farmed, from water quality to feed to how they grow. I think this will be the best farmed fi nfi sh in the world." According to NIWA's website, since 2003, it has accumulated the world's largest broodstock resource for hapuku. Research staff have overcome several technical hurdles, including: • the system design for the successful incubation of egg and yolk-sac larvae • initiation of fi rst feeding, and • he transition from live to formulated feeds to produce weaned juveniles ready for on-growing and transfer to sea. The hapuku is reared from eggs into fi ngerlings in tanks, then transferred to cages at sea until it is big enough to be sold to restaurateurs around the globe.