Green Sea Urchin Aquaculture
The green sea urchin (Strongylocentrotus droebachiensis) is highly prized for its roe, which can comprise 10 to 25% of the body weight. The major market for the product is Japan where it is known as "uni". During the mid 1990s, the New England fishery for this species was one of the most important sources of the product, and in 1993 39 million pounds were landed worth around $40 million (see Figure below). The industry became a significant employer and according to the Department of Marine Resources (DMR), the number of harvesters, from fishermen to buyers and processors numbered 1,840 in 1995. Signs of over-fishing prompted the DMR to implement measures in 1995 including limits on the number of licenses and the establishment of two zones. Fishing days were reduced from 94 days in each zone, to 10 days in Zone 1 and 45 days in Zone 2. Despite these measures, the fishery had reduced to 3.8 million lbs by 2006 (DMR 2006) and the number of people employed in the fishery was just over 500. Many academic and industry experts believe that aquaculture may play a valuable role in revitalizing this fishery. Hatchery and growout has been under development in Japan, Norway, France, and Ireland for many years. In these countries a variety of techniques are used including ranching and land based growout from egg to harvest. The CCAR is currently working with Friendship International and the Scott brothers (Brad and Adam) in Maine as well as Prof Larry Harris (UNH), Jay Gingrich and Chris Hill in New Hamsphire. Between us we have 2 state of the art hatcheries established with year round spawning ability and the capacity for large scale juvenile production. We have demonstrated cage based, pilot scale nursery growout, and have tested various short term planting out strategies. We have also carried out a number of feed trials. Now we are testing different methods for growout.
Green sea urchin landings (million lbs) in Maine 1987 to 2006 (Source: Maine DMR)