Markets & Economic Development Community Leadership Downeast Groundfish Initiative Hatchery Outreach and Education

How the Hatchery Works

Currently the hatchery is the largest scale U.S. hatchery operation to date using current technology Designed by Dr. Brian Beal and Sam Chapman to achieve the highest observed survival rates (up to 60%) for rearing lobsters to stage IV, when they are no bigger than a penny but mature enough to settle on the ocean floor. This is twice the survival rate of traditional hatchery systems.

The hatchery operates seasonally, spring to fall, staffed by a manager, an assistant manager, a college intern and two locally hired technical assistant, under the supervision of hatchery director Ted Ames. In 2010 we suspended operations for the time being, having demonstrated that the hatchery can successfully produce an abundance of stage 1V juveniles. Between 2005 and 2009, the hatchery produced hundreds of thousands of stage IVs. Lobster stocks are currently very healthy and we have temporarily shifted our research to continued monitoring of the lobsters that have been hatchery reared and are already resettled. The Zone C Hatchery has been "mothballed" for eventual re-opening.

The Production Process

It takes about two weeks to rear a juvenile lobster to stage IV, an age when the lobsters are no bigger than a penny but mature enough to settle on the ocean floor. Larvae are obtained from the eggs of a wild female lobster brought in by specially-licensed fishermen. One female egger can produce 50,000 eggs. The hatchery is set up to grow algae (under sterile conditions) to feed to brine shrimp, which are then fed to larval lobsters. The lobsters are grown in 100-gallon conical tanks, which are constantly aerated – this keeps the lobsters from eating each other. When ready for release, the lobsters are transferred from the tanks into a cooler, where they sit in layers of wet paper towels. A lobster boat, usually run by a volunteer fisherman, takes the juveniles to carefully selected sites, where they are released directly onto the bottom through a 30-foot weighted hose. In four years, the hatchery has released close to 198,000 Stage IV and 17,000 Stage V lobsters grown especially for the dive monitoring research.

Production Details

 

Step 1: Two strains of algae (Chaetoceros calcitrans and Isochrysis galbana) that were originally isolated in the tropics are prepared and grown in a "clean room" of the hatchery. Once the algal cultures are mature (~6-10 days), they are transferred to the Algal Grow Out room where they are allowed to mature for an additional 6-10 days in 20-gallon cylindrical tubes filled with filtered water and nutrients. Once mature, they are fed to brine shrimp and lobster larvae.
Step 2: Brine Shrimp A common fish food, the brine shrimp (Artemia salina) are ordered from aquarium suppliers and arrive in the hatchery in cyst form. The brine shrimp cysts are first decapsulated and allowed to grow for up to seven days in 50-gallon tanks. Algal cultures are fed daily to the brine shrimp.
Step 3: Larval Lobsters Algal cultures and brine shrimp are then fed to larval lobsters, hatched from gravid female lobsters also called seeders, eggers, or berried. Gravid lobsters are brought in by Zone C fishermen who are listed on a special license given to Penobscot East by the Maine Department of Marine Resources. The license permits fishermen to bring in egg-bearing lobsters after notifying the Maine Marine Patrol. In the hatchery, the egged females are kept in individual tanks until they release their eggs. The larval lobsters are then removed and grown in 100-gallon conical tanks, which are vigorously aerated to reduce cannibalism. Lobsters are raised until they reach Stage IV, the age at which they begin to settle on the ocean floor. At this point, the lobsters are about 6/10 of an inch.

 

Resettling the Juvenile Lobsters

Hatchery staff meets with Zone C lobstermen to determine the areas where lobsters have recently become depleted, and the locations of nearby juvenile habitats. The results of these conversations create the underlying strategy for where to restock. The technique of combining hard science with fishermen’s knowledge is one that Ted Ames pioneered in earlier research into codfish stocks, for which he was recognized with the MacArthur Fellowship. This is a critical part of collaborative research, using fishermen’s knowledge and involving them in the process of science, all of which contributes to their expanded role as stewards of the marine environment and deepens their stake in the work of the Zone C Hatchery.

When ready for release, the lobsters are transferred from the tanks into a cooler, where they sit in layers of wet paper towels before being transported to sites selected by local fishermen. They are then released directly onto the sea bottom through a 30-foot weighted hose.

The hatchery has released over 198,000 stage IV and 17,000 stage V lobsters to more than 24 sites in the nine Zone C districts. Stage V juveniles are raised for research purposes in a collaborative effort with Dr. Rick Wahle who has conducted four consecutive years of releases and diver surveys. The introduction of a new, in-house culture technique for rearing lobster from Stage IV to Stage V – from free swimming to bottom-dwelling -- for the Maine Sea Grant-funded monitoring research conducted jointly with Bigelow Laboratory for Ocean Sciences, along with the construction of a "grow-out" room to accommodate the Stage V lobsters.