Diversifying the New England Sea Vegetable Aquaculture Industry – Phase II: Line Seeding Technology and Grow-out Trials for Longline Nori Production

Seaweed aquaculture has exploded in the Gulf of Maine in the last ten years, with more than 140 kelp farms operating along the coast of Maine and New Hampshire. However, most of these farms depend on a single species – sugar kelp. Chris Neefus of the Department of Biological Sciences at UNH is developing the next sea vegetable for the Gulf of Maine – Wildemania amplissima, a local species of nori – the seaweed used in sushi and produced in a multibillion-dollar industry in Asia. This species grows to a similar size and in similar conditions to sugar kelp, but in spring and early summer instead of sugar kelp’s winter season, diversifying farms’ business without requiring big changes in practices or gear. Neefus will determine how best to seed and grow nori. The project will share its results with Gulf of Maine aquaculture operations in partnership with New Hampshire and Maine Sea Grant extension and outreach teams to help a growing industry become more resilient and profitable.

Principle Investigator

A headshot of Chris Neefus

Chris Neefus, Ph.D.

Professor, Biological Sciences, University of New Hampshire

Contact Dr. Neefus

Project Funding Cycle
2022-2023 NH Sea Grant Biennial Research Funding


Michael Chambers, PH.D.

Aquaculture Extension Specialist, NH Sea Grant and School of Marine Science, University of New Hampshire

Contact Dr. Chambers

Jaclyn Robidoux

Marine Extension Specialist, Maine Sea Grant, University of Maine

Contact Jaclyn Robidoux

Project Abstract

The aim of the project to help diversify the burgeoning New England seaweed aquaculture industry. The industry is presently base solely on longline kelp farming. Annual NH/Maine production exceeds a half million pounds and adds more than $13 million to the local economy. The proposed project would develop nursery methodology and carry out field trial for longline production of the red seaweed Wildemania amplissima, a local species of nori. For edible seaweed production on a global scale, nori is second only to kelp. Marketing potential of a range of food products using a local variety is substantial.

The proposed project builds on the accomplishments of our previous NH Sea Grant supported work where we developed innovative methods for establishing and maintaining laboratory cultures from wild collected Wildemania amplissima blades. We optimized the conditions needed for maintaining and expanding cultures and determined the sequence of conditions required to induce the release of ìconchosporesî. We currently maintain 24 Wildemania amplissima cultures from a dozen sites along the coasts of NH and ME. One goal of the proposed project is to develop methods for seeding conchospores onto spools of seed string. Through laboratory experiments, we will determine optimal conditions for nursery growth of bladelets on the seeded spools. In the second year of the project, we will work with kelp producers in New Hampshire and Maine to conduct field grow-out trials. One of the producers maintains a kelp nursery and is anxious to take over nori seed spool production.


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