DEVELOPMENT OF SEA URCHIN AQUACULTURE IN MAINE

PRINCIPALS INVESTIGATORS
Jim WadsworthM (Friendship International)
Nick Brown (Uaine Center for Cooperative Aquaculture Research)
Larry Harris (University of New Hampshire)

FUNDING
MTI: $10,000
Matching Funds: Friendship International, UMaine, UNH: $13,025

PROJECT SUMMARY DESCRIPTION

SCOPE OF WORK AND APPROACH
Commercial harvesting of sea urchins has become a major world wide industry. Interest in sea urchin fisheries in the Gulf of Maine followed population explosions of Strongylocentrotus droebachiensis in the Canadian Maritime Provinces and the Gulf of Maine in the 1970’s. Large scale harvesting of urchins in Maine and New Hampshire began in 1987 and expanded rapidly to become the second largest wild fishery behind lobsters. The harvest of urchins peaked in 1993 at an estimated 20,000 metric tons (MT) and has declined each year since.

The 2002-2003 yield was about 3,600 MT and fishery regulations will aim to reduce the harvest to approximately 2,300 MT as a result of an annual stock assessment funded by the Maine Sea Urchin Zone Council and a fisheries model by Dr. Yong Chen of the University of Maine in Orono.

The sharp decline in wild stocks of sea urchins throughout the Gulf of Maine has stimulated a great deal of discussion about various forms of stock enhancement and aquaculture of urchins. It has become clear that there will be no sustained fishery of urchins in the northeastern portion of the Gulf of Maine without a hatchery system, due to consistent minimal recruitment of urchins in this region.

Friendship International is a business that has been shipping live sea urchins to Japan for 15 years. The Maine sea urchin is highly regarded in Japan and the company has gained a reputation for supplying quality product. The company is able to offer good prices for urchins and this has meant that we have strong collaborative links with many of the best divers involved in the fishery. As a key player in the supply chain for the Maine sea urchin, the company has a strong interest in ensuring the sustainability of the urchin fishery. Friendship is proposing to establish a hatchery to supply seed urchins and a network of urchin aquaculture sites in cooperation with the divers that have traditionally supplied them.

The spawning and cultivation of larval sea urchins entails a well-documented set of procedures. The newly reared urchins however are not suitable for planting out due to susceptibility to predation and difficulties in settling. Studies have shown that success of planting out is greatly enhanced if the juveniles are grown out to a size of 10 to 20mm. To grow urchins to this size, they need to be held in nursery systems, either on land or in suspended structures in the sea. The latter is likely to be more cost effective but effective holding systems and methods need to be developed that are economical. The proposed project will address this part of the cycle by testing specially designed envelopes with substrates suitable for young urchins, held in a test tank. The aim will be to devise a system that reduces the cost of maintenance and promotes more uniform growth rates among first year urchins. Water currents have been shown to enhance growth and survival and so these will be induced in the holding tank.

Bags will be fabricated from Vexar plastic mesh folded over like an envelope with a trough of heavy plastic coated wire as both a spreader and to support about 100 large mussel shells. About 500 juvenile urchins (0.5 to 1.0 mm) purchased from a hatchery in Portsmouth would be stocked into each bag. One hundred such bags will be suspended in a tank 65ft diameter, 13 ft deep, with circulating seawater from April to November. During this time it is expected that the urchins will grow to around 10 mm in size, ready for planting out no earlier than December. Planting out prior to this time is likely to fail due to crab predation.

The urchins, once ready for planting out would be sold to fishermen who own lease sites in the Gulf of Maine. One such fisherman is Mr. Chris Hill, who has a sea urchin aquaculture lease site in Kittery, Maine. There is also one site in New Hampshire, the lease for which is held by Mr. Jay Gingrich, who is also collaborating in the hatchery effort in Portsmouth with our main consultant on this project, Dr Larry Harris.

RELEVANCE TO BUSINESS STRATEGY.
It is important that an economical method for growing juvenile sea urchins is developed in Maine. Once this is achieved, Friendship International will establish a hatchery presence in the Downeast/ Midcoast Maine area in order to supply the seed urchins to the waiting fishermen. The other parts of the process are more or less in place; there are a group of divers ready to apply for aquaculture lease sites (see attached letter) and supply the final product and the market for urchins is well established. As previously mentioned, there are already pilot scale urchin hatcheries in operation in New England and some of the operators will collaborate on this project. The group expects that the future urchin aquaculture industry will involve a few hatcheries up the coast and several urchin lease sites for nursery and ongrowing.

CONTACT INFO:
Nick Brown
CCAR,
33 Salmon Farm Rd,
Franklin,
ME 04634
USA
npbrown@maine.edu