Technology Transfer: Growing Mussels on Submerged Longlines in an Open Ocean

Environment

Rollie BarnabyExtension Educator, Sea Grant & Marine Resources

UNH Cooperative Extension/Sea Grant

Submerged Longline Culture of Blue Mussels (Mytilis edulis) in Exposed Oceanic Environments:

Design, Operation and Production Strategies

Longline Schematic

160 m

18 m

120 m

22 m

12 m

Mussel socks Pearl nets

Submersible floats

UNH Open Ocean Aquaculture Demonstration Project

A Component of the NOAA/UNH Cooperative Institute for New England mariculture and Fisheries (CINEMAR)

Rollie Barnaby

Funding Provided by NOAA Sea Grant and OAR

Aquaculture in Unprotected Oceanic Environments

Advantages• Excellent Water Quality

• Lots of Real Estate

• Minimal User Conflict

Challenges• Systems Engineering

• Biological Limitations

• Most waters unclassified

• Increased risk of biotoxins (PSP)

• Permitting Uncertainties

• Multiple Use Conflicts with navigation and fishing

• Environmental Issues (marine mammals)

Goal: To stimulate the commercial development of open ocean aquaculture of bivalve molluscs

Objectives: To demonstrate the engineering, biological and economic feasibility of open ocean culture

To design technology and operations for compatibility with existing capture fisheries

Approach:Adapt existing technologies and methods to open ocean environments

Develop new technologies and methods as needed

Develop production strategies

Develop business plans for several different operational models

Transfer Technology

Troubleshoot and solve industry problems

5 miles from shore

180 ft deep

Current velocities .3-2 kts

Significant wave heights > 25”

• Seed Collection

Wild caught seed; issues are timing, location, materials and fouling

• Nursery Culture

On seed lines; 4-6 months

• Growout

Suspension from submerged longline

Discrete lengths of mesh socking

Continuous with mesh socking

Continuous with rope core and biodegradable cotton sleeve

MUSSEL CULTURE

Submerged Longlines

Longline Site Layout

Fishing boat… to mussel boat

Inshore Seed Collection Raft

Seed Collection

Mussel seed ready for socking

Preparing Seed for Growout

Offshore Operations

•Attaching socks and growout ropes

•Adjusting buoyancy as weight increases

•Monitoring growth and meat yield

•Harvesting

•Longline maintenance

•Water column monitoring

Tubular Mesh Socking

Mussel SummaryGrowth

• Approximately 4 mm (0.2 inches)/month

• Average Growout from spat set 14 months

4-6 months on seed collectors (nursery)

8-9 months on longlines (growout)

Production

• Seed line to growout line ratio 1 ft: 3ft

• Two production cycles per year

• Optimal seed density on growout ropes: 200-225 seed/ft

• 2,000 ft* of growout rope per longline; max of 3,000 ft**

• 12,000 -18,000 lbs per longline

Technology Transfer Process

• Objectives:

• To demonstrate the engineering, biological and economic feasibility of open ocean culture

• To design technology and operations for compatibility with existing capture fisheries

Commercial Fishermen Partners from the Beginning of the Project

• There were a lot of informal discussions with fishermen before there was a proposal

• Fishermen were an important part of a meeting with University administration and Senator Gregg

• They gave input on the original proposal• A local fisherman serves on the project

Advisory Committee• The local fishermen’s cooperative was listed on

the aquaculture permit

Fishermen were hired to work on the project

• A fisherman helped design and built the mussel mooring system

• Fishermen were hired to move fish, equipment, and people to and from the project site

• The finfish part of the project hired fishermen to feed the fish

• The project paid the fishermen’s cooperative for the use of their docks, winches, forklifts, and storage space

Fishermen were very important in identifying the project site

• Lobster, gillnet, dragger, and recreational fishermen actively fish the area where the project is located

• Meetings were held with each group to identify the best site

• Not one person spoke against the project at the public hearing for the aquaculture permit

Extension Activities

• Contacted fishermen that participated in all aspects of the project

• Met with the two fishermen’s cooperatives board of directors periodically to update them on the project

• Organized mussel aquaculture workshops each year for the past four years

• Produced video and fact sheet on growing mussels on a submerged longline system

• Met with New Hampshire Fish and Game the agency responsible for aquaculture permitting

• Organized stakeholder meetings to identify sites for mussel farms

• Have identified areas in state waters that seem to be acceptable to all users

• Now working one-on-one with fishermen helping them through the permitting process

Thank You!

Any Questions?