NRAC Publication No. 103-2008 University of Maryland, 2113 Animal Science Building College Park, Maryland 20742-2317 Telephone: 301-405-6085, FAX: 301-314-9412 E-mail: [email protected] Web: http://www.nrac.umd.edu Marine Aquaculture Species for the Northeast Joe Buttner, Salem State College Gef Flimlin, Rutgers Cooperative Extension Don Webster, Maryland Cooperative Extension Introduction Current Commercial Production Many aquatic animals and plants are cultured commer- 1. Hard clam or cially in the northeastern United States, while others have Northern qua- been grown for restoration or for use in research. Finfish, hog (Mercenar- shellfish, aquatic plants, and other organisms are cultured ia mercenaria) commercially and recreationally for food, bait, stocking, — The hard research, bioassay tests, ornamental markets, and instruc- clam is one of tional aids. Table 1 lists 33 species or varieties of marine the most widely animals and plants cultured in the region. No one species successful mol- dominates production: an animal or plant cultured suc- luscs cultivated cessfully in one system or location may prove impractical in and outside Hard clams, from left: little neck, top neck, or unprofitable in another. the region, from cherry, and chowder (Photograph by Dale This fact sheet describes major species currently in Massachusetts to Leavitt, Roger Williams University) commercial production, those that have shown potential, Florida. Estab- and others now under experimental investigation. The lished markets exist and the product is recognized as a descriptions summarize culture methods and regulatory moderate to high price item in the restaurant trade, where considerations. Applicable regulations for proposed oper- the smallest, legally marketable clams bring the highest ations, particularly those that would employ non-native prices. Though hardy, they have been vulnerable to QPX, species or culture in public waters, can be obtained from a major disease that has diminished their prevalence. extension agents and specialists in your state. For a list of Adult clams are spawned under controlled condi- aquaculture extension contacts by state and current State tions. Larvae are maintained in a hatchery, fed specially Situation and Outlook Reports consult the NRAC website prepared algal diets, and raised in land-based upwellers, (http://nrac.umd.edu). tanks, or raceways. The nursery phase occurs on land or in the water. Spat or seed are stocked on the bottom in and either replanted on the bottom at much lower densi- coastal waters and grown to market size. Time to market ties than found in natural beds, or placed in long mesh size is site specific and varies widely: typically it takes sleeves suspended in the water column. Suspended culture two to five years to attain market-size, but improved of mussels using long-lines is increasingly popular and strains, good site selection, and proper management can yields a superior product. reduce culture time significantly. 4. Softshell clam or 2. Eastern oyster steamer (Mya are- (Crassostrea vir- naria) — These ginica) — Culture clams can be pro- techniques for oys- duced in large num- ters are well docu- bers using standard mented. Oysters hatchery techniques. have been farmed The market is strong in the Northeast for for steamed or fried over 100 years and product. Prices for Softshell clams (Mya arenaria) are grown com- steamers have risen: (Photograph by Joe Buttner) mercially through- coupled with the out the eastern Eastern oysters (Crassostrea virginica) absence of MSX and Dermo diseases that plague Eastern United States and (Photograph by Sandy Rodgers, Mary- oysters and QPX disease that has attacked hard clams, land Sea Grant) the Gulf Coast. there is renewed interest and expanded production of soft Recent advances in clams from Maine to Massachusetts. genetics have led to the production of selected lines and A modest but growing industry exists in New Eng- triploids that survive better in areas where diseases have land where softshell clam spat or seed are stocked on depleted natural populations and have led to shorter pro- raked substrates and covered with predator exclusion net- duction cycles. ting. It takes approximately two years from stocking to Oyster seed or eyed larvae may be purchased and harvest. “set” on appropriate substrates by the process known as “remote setting.” “Set” oysters may be cultured directly 5. Atlantic salmon (Salmo salar) — Cultured commer- on the bottom or off bottom in racks. Essential manage- cially for nearly three decades, this species now consti- ment efforts include controlling predators, grading by tutes the majority of all salmon consumed globally. While size, periodic cleaning, and ensuring good water quality most coastal waters in the Northeast are too warm to sup- and flow. The greatest impediments to oyster culture are port net pen culture of salmon, a major salmon industry disease, restrictive laws, and regulations (i.e., Federal, exists in northern New England. Many coastal communi- state, local), and theft. Prospective culturists should thor- ties in Maine have benefited greatly from net pen culture oughly research potential sites. of salmon. Typically, adult salmon are spawned, eggs incubated, 3. Blue mussel and resultant immature fish raised in land-based, freshwa- (Mytilus edulis) — ter systems. When salmon fingerlings smolt and transform Through aggressive from a freshwater to marine fish, they are transferred to marketing, the demand and retail price for mussels has improved steadily. Most mussels are cultured in Maine, with offshore demon- stration projects on- going in New Hampshire and Massa- Blue mussels (Mytilus edulis) (Photograph by Joe Buttner) chusetts. Atlantic salmon (Salmo salar) (Photograph by Chris Bartlett, There is no hatchery phase for commercial cultiva- Maine Sea Grant College Program/University of Maine tion. Recently “set” wild spat are collected from nature Cooperative Extension) 2 net pens in coastal waters and grown to market-size. The ing of blue crabs in a industry is heavily regulated and considerable capital is hatchery and rearing them needed to setup and operate a commercial scale farm. to juvenile stages. The resulting production has 6. Macroalgae, been used for restocking most notably nori and population studies. seaweed (Porphyra Profitable commercial pro- sp.) — Cultured in duction of hard crabs has Blue crabs (Callinectes sapidus) (Photograph from www.ag. Maine, microalgae not been demonstrated, auburn.edu/fish) are under study for largely due to the cannibal- use as a finishing istic nature of the animal. A high-value market does exist biofilter around for “soft shell” crabs — the soft shell stage occurs imme- net pens and as a diately after molting. Crabs with body signs indicating an lipid substitute in impending molt (peeler crabs) are collected from the wild fish feeds. While and held in shallow tanks until they emerge from their the potential of Nori seaweed (Porphyra sp.) shell — the shedding systems are fairly simple and the macroalgae in inte- (Photograph by Joe Buttner) potential for commercial success is good, provided an grated aquaculture is strong, commercial viability for pro- adequate supply of high quality and reasonably priced duction of algae as a single crop throughout the Northeast peeler crabs is readily available. remains to be demonstrated. 3. European oys- Potential Commercial Species ter (Ostrea edulis) — Cultured in the 1. Bay scallop Northeast, this (Argopecten ir- species is tricky to radians) — produce in the These scallops hatchery and vul- can be cultured nerable to Bon- in the hatchery amia disease in the or obtained from field. No commer- the wild. Rela- cial production tively little atten- occurs at this time. tion has been Investigations to directed to their define and refine culture. Over- hatchery, nursery, European oysters (Ostrea edulis) (Photograph by Joe Buttner) winter survival Bay scallops (Argopecten irradians) (Photo- and growout tech- can be problem- graph by Rick Karney, Martha’s Vineyard niques are ongoing. atic in the North- Shellfish Group) east; in addition, 4. Marine fishes and invertebrates for the pet industry scallops can move, so containing them is a challenge. — As with freshwater ornamental fish, much production Lantern nets have been used to culture scallops in Asia, is diffuse and occurs in basements and garages. Commer- though similar efforts in the United States have proven too labor intensive for commercial success. Some production in lantern nets and bags occurs in Massachusetts and New York for enhancing wild populations. Subtidal culture in racks and use of a predator fence to restrict dispersal are being investigated. Prospective culturists should carefully assess the management and economics of scallop culture before proceeding. 2. Blue crab (Callinectes sapidus) — Long popular in the Clownfish (Premnas sp.) (Photograph by Bud Borque, Roger marketplace, recent research has led to successful spawn- Williams University) 3 cial operations exist in Maine and Maryland. Consider- been defined. At this time, it is unclear how or whether able potential exists for expanded production of these and culture techniques can be pursued commercially. other marine organisms for aquarium hobbyists, particu- larly in modest-size recirculating systems. However, 2. American lob- because culture procedures are established for only a few ster (Homarus species, culture of ornamentals must be viewed as americanus) — experimental. This species is regarded