Aquaculture news

A scientist monitors mussel crop
26 June 2014

Future proofing New Zealand's shellfish aquaculture

Ocean acidification is the name given to the on-going decrease in the pH of the earth's oceans, driven by increasing levels of carbon dioxide (CO2) in the atmosphere.

This increasing acidity could have negative consequences for marine-based calcifying organisms (those that create shells or hard outer skeletons) across the food chain, from the microscopic foraminifera through to corals, crustaceans and molluscs.

It also has implications for industries that farm or harvest these species, such as the aquaculture sector, as increased acidity can affect shell formation, energy usage and ultimately growth and survival of stock, in particular the young shellfish.

In December 2013 the workshop, 'Future proofing New Zealand's shellfish aquaculture: monitoring and adaptation to ocean acidification', was held in Nelson to help marine farmers, industry groups and government agencies understand and plan for potential effects of ocean acidification on commercial shellfish operations.

The two-day workshop was organised by the Ministry for Primary Industries, NIWA, Cawthron Institute, Sustainable Fisheries Partnership, and the US State Department, among others.

This video was produced as a direct result of the workshop:

At the workshop, United States' marine farmers and researchers shared their experiences after CO2 -rich upwelling off the Pacific northwest coast initially caused an 80 percent decline in production of Pacific oyster larvae.

"There are key lessons to be learned from our colleagues in the United States that will assist us in focussing research, planning and management practices to enable the industry to grow despite pH decline," Cawthron shellfish physiologist Dr Norman Ragg says.

Read about the workshop on the Ministry for Primary Industries' website.