VIDEO: Surveying the fishery

19 March / NIWA

The science of providing the information that helps manage the Bluff oyster fishery has been part of NIWA’s research work since 2000. This research programme is funded by the Ministry for Primary Industries, the Bluff Oyster Management Company and Seafood Innovations LTD. The research is undertaken collaboratively and includes wide ranging programmes such as improving fishing technology and methods, understanding the oyster fishery, the ecosystem from which it is fished and the key drivers of oyster production. Crucial to the research is keeping tabs on the health of the fishery through a survey carried out before each season. The survey estimates the size of the oyster population and levels of bonamia – a disease that kills oysters, though it’s harmless to humans.

These surveys are undertaken in February and, together with a spat monitoring programme,provide up-to-date information on the status of the fishery and its likely future status to inform harvest limits for the coming season. These limits are reviewed in-season based on the oyster skippers’ information from the first few weeks of fishing and the final results of the pre-season survey.

NIWA coastal fisheries scientist Keith Michael leads research on the fishery and says bonamia has devastated wild fisheries all over the world. It’s important work that affects not only the price and availability of Bluff oysters, but the livelihood of the fishing families and the businesses that support the industry.

Keith says the annual survey provides vital information for management. “Although little can be done to change the outcomes for the fishery, our science provides a ‘weather forecast’ that allows the oyster industry to prepare for a good or not-so-good seasons, and the ability to explain changes in the fishery with evidence from this research, he says.

Research is undertaken as part of a strategic research plan developed with the Bluff Oyster Management Company, the Ministry for Primary Industries, customary and recreational fishers to provide the key information required to better manage the fishery and fishing.

Keith says that the oyster population size has declined from 2014, mainly as a result of disease. “Bonamia killed 200 million legal-sized oysters in early 2014 while the oyster fishery harvested 13 million oysters,” he says. “Early indications for the 2015 season suggest fisher catch rates will be similar to the 2014 season.”

Graeme Wright, a spokesman for the Bluff Oyster Management Company, says: “Based on the science information we have from NIWA, the 2015 oyster season will start with a more conservative catch limit than 2014 and we will review the catch limit in-season.”

The Bluff Oyster Management Company represents all the fishery stakeholders, and Graeme Wright says the cooperative nature of the industry is its strong point.

“There has been a real emphasis in the past 20 years to involve the fishermen who work these beds plus everybody involved – customary and recreational groups, commercial fishermen and scientific researchers – and I think it’s at a stage where
everybody believes we’re managing the fishery, in the interests of everybody, for the future,” Graeme says.

“The key to the future of the fishery is information and the quality of information that NIWA gives us offers the fishery some certainty and security going into the future.”

• VIDEO: NIWA’s research work helps survey the size of the oyster population and levels of bonamia