A new potential equipment option for Great Bay oyster farmers

A team of three Australians representing the company SEAPA visited the Judd Gregg Marine Research Complex last Friday as part of their efforts to expand sales and offer expertise to existing users of their equipment. The team - Garry Thompson, Leon Stott and his wife Chris - talked with local oyster farmers about high quality basket developed by SEAPA to improve oyster quality and decrease labor costs for farms in Australia, France, Prince Edward Island and Cape Cod. N.H. Sea Grant marine aquaculture specialist Michael Chambers arranged for the presentation to provide new equipment options that might help oyster farmers improve their operations. 

There are currently seven individuals and partners that have permits for oyster farms in Great Bay, although some are in the early stages of setup. Those that have been established for a few years typically use “oyster condos” to grow the shellfish, made out of heavyweight mesh bags that slide horizontally into a PVC tower that remains underwater. However, a lot of biofouling — a term used to describe a build-up of barnacles, algae and other aquatic organisms on hard structures under the water — grows on the equipment, requiring the oyster farmers to power spray the equipment regularly. In addition to the increased labor costs, it can be a physically demanding part of the job because the biofouling adds a lot of weight to the equipment. 

Above: Ray Grizzle, professor of zoology at UNH, scrubs a bag full of young oysters with a sturdy brush to remove biofouling. These bags are part of the oyster condo setup typically used in Great Bay oyster farms. 

The SEAPA company, based out of Adelaide in South Australia, partnered with Garon Plastic to design oyster baskets made of sturdy injection molded plastic mesh. The baskets have clips that allow them to hang from line anchored to wooden posts in the intertidal zone of a bay. The lines can be pulled up and attached at various heights on the posts, allowing the oysters to be out of the water for part of the day. This reduces biofouling, slows down the oyster shell growth and enables the oyster meat to grow bigger. 

In many areas of the world, including Prince Edward Island, these lines and posts do not interfere with most people’s ability to enjoy the beauty of the water. But in Great Bay, oyster farmers face the challenge of balancing the need to farm effectively with the desire of the waterfront homeowners to have an unobstructed view of the water. 

Unlike New England, the areas outside of the metropolitan regions of South Australia are sparsely populated. The residents accept views of the oyster farms as a reminder that there are jobs available that help grow clean, healthy oysters to supply market demand, the team explained. That said, the SEAPA containers are versatile and could be stacked in a similar manner as the current oyster condos used in Great Bay or set up in a different manner altogether to meet everyone’s needs. 

Above: Great Bay oyster farmers Chris Phillips, Jon Bunker and Jess Cranney took a closer look at the SEAPA baskets to determine if that gear might work for their operations. 

Below: Garry Thompson demonstrates how the liner sock goes into the baskets to keep the tiny oysters from escaping. 

For more information on SEAPA, please visit www.seapa.com.au.