Molluscan Shellfish Culture in the US: Innovation, Economy, and Environment
Feeding the Nation: the Aquaculture Alternative- CHOW 05
Richard Langan, Ph.D. University of New Hampshire
Presentation Outline
• What is shellfish aquaculture?
• Where is it taking place?
• Shellfish culture and the environment
• U.S. Industry Characteristics
• Species and methods
• Economic Impact and trends
• Factors limiting industry growth
• Prospects for the future
Shellfish Culture……
• Controlled production of bivalve molluscs
Clams, oysters, mussels, scallops
Wide variety of species and culture methods
• Filter feeders… feed on naturally occurring microscopic plant cells
• Production requires no fertilizers, feeds, drugs, chemicals or antibiotics
• More than 100 years of history in the U.S.
• Land based hatchery and nursery
• Growout in estuarine and protected and exposed* marine environments
• Applied science and innovation
Production takes place in all coastal states
Shellfish Culture and the Environment
Documented Environmental Benefits
No external Feed Source
Improves Water Clarity
Provides Valuable Habitat
Removes Nitrogen
Improves Oxygen Conditions
Ecosystem Management Tool
Improves restoration success
Mitigate the Impacts of
eutrophication
Pollution credit trading
Integrated Aquaculture
Finfish + Bivalves = Integrated Aquaculture
Uneaten food
3-10%
Fish feces
10-25%
Feed Addition
Dissolved Nitrogen (NH4)
Metabolism
65-87%
Decomposition and Remineralization
Increased Primary Production
Bivalve Culture and Removal via Harvest
Denitrification
U.S. Industry Characteristics
• Highly Diverse
• Individuals to larger companies
• Several acres to hundreds of acres
• Discrete Sector to Vertically Integrated
• Low Tech to High Tech
• Niche products to commodity
• Innovation in production methods
• Alternative for commercial fishermen
• Applied science in action
Shellfish Species and Culture Methods
• Oysters
Eastern, Olympia, Belon, Pacific, Kumomoto, Asian
• Clams
Quahog, Manilla,
Goeduck, Softshell
• Mussels
Blue and Mediterranean
• Scallops
Bay, pink and sea
Culture Stages
• Larval stage production
Natural production
Hatchery maintained broodstock
• Nursery culture
Land based, in-water, upwellers
• Seed production
Natural settlement, hatchery production, remote setting
• Growout
Extensive, intensive
Oyster Culture- East, West and Gulf Coasts
• Larval Supply
Natural- NJ, CT, LA
Hatchery- E &W coasts
• Seed Production
Natural Settlement
Hatchery Production
Single seed, clusters
Oyster Culture (cont’d)
• Nursery
Upwellers, Bagged shell with attached seed
•Growout
On Bottom
Containment and suspension
Clam Culture-East and West Coasts
• Hatchery production of larvae and seed
• Upwellers for nursery culture
• Growout on bottom with predator netting
Mussel Culture - Northeast and Northwest
• Larval and Seed Supply
West- Hatchery
East- natural production
• Growout
Bottom culture
Ropes or sleves suspended from rafts,
surface longlines, and submerged longlines
Submerged Longlines - open ocean opportunities
http:// ooa.unh.edu
Scallop Culture
Larval and seed production
Hatchery techniques well developed for bay scallop
Growout- Experimental
Containment in cages and nets
Bottom Culture
Restoration and enhancement (bay scallops)
Sea scallop culture relies on wild caught seed
Economic Impacts and Trends
Farm Gate Value (2003) Trend Imports
All species $160 M $130 M
Oysters $100 M $14 M
Clams $ 56 M $38 M
Mussels $ 4 M $45 M
Scallops $ N/A $33 M*
Employment > 10,000
Limiting Factors to Industry Growth
• Coastal Pollution
• Competing Uses (incl. viewscapes)
• Disease
• Harmful Algal Blooms
• Biofouling (incl invasives)
• Predation
Prospects for the Future
• OpportunityDemand is high and continues to rise
Inshore and offshore site availability
Component of Integrated Coastal Management• Motivation
EconomyEnvironmentFood security
• NeedsSocial AcceptanceInvestment $$Gov’t supported R&D
Thank You!