Working Waterfront

Seaweed as a Sustainable Resource for Maine’s Communities and Working Waterfronts

Although the output of Maine’s seaweed production is only ~1.5% (Kennedy, 2014) of the value of commercial fishing and seafood processing totals, it’s one of the few marine harvested products that show steady growth in landings. According to Maine’s Department of Marine Resources (MDMR), dockside landings of marine plants have increased 2.5 fold in less than seven years (MDMR, 2013 landings report) while in the same period the landings of lobsters, clams, groundfish and shrimp have declined (albeit recently for lobsters), some drastically.

Noting the importance of proper regulation of seaweed harvesting to protect the resource, a Fisheries Management Plan for Rockweed was written in early 2014 with the input of the industry, academia, and the environmental community. It’s Maine’s first commercial marine species to have such a plan. Under the regulations imposed by the plan, harvests will remain sustainable because stipulated cutting practices and zone limits will allow rotational recovery of harvestable areas in 2-5 years (Maine Sea Grant, 2013). While more than 17 million pounds of rockweed were harvested statewide in 2013 (MDMR, 2013 landings) reportedly creating a total economic impact of over $10 million (Kennedy, 2014), that’s a small percentage of the standing crop which for just one bay (Cobscook) is at least 111 million pounds (Maine Sea Grant, 2013). There’s good potential for responsible expansion of natural harvests within regulatory safeguards.

Sustainable growth of seaweed harvest is also enhanced with aquaculture techniques. About 4% of total harvests are non-rockweed species of sea vegetables (MDMR, FMP for Rockweed, 2014). More and more of the landings are sourced from aquaculture leases. While there are seven Maine companies that land and process sea vegetables from Portland to Steuben, three now actively farm kelps, dulce, and nori for edible products. Over the next few years that figure will double and then double again. Farming practices enhance productivity and quality because:

  • Farmers can harvest at the times of highest nutritional content and optimal sizes, while avoiding seasonal settlement of unwanted organisms on the fronds.
  • If quickly processed after harvest, the nutritional quality of the plants persists for many months and allows for prolonged storage and timely distribution to markets.
  • Crops can be seeded and harvested within a seven month season.
  • The crop cycle occurs during the colder months from November to May avoiding conflicts with many recreational boating and commercial fishing activities.
  • Having a complementary seasonal cycle, farming sea vegetables presents an opportunity for fishermen to augment their fishing income.

The 2014 harvests of wild and farmed seaweeds landed in 53 of Maine’s commercial ports (MDMR, landings data for 2014) and accrued economic value to over 50% on Maine’s coastal towns, using small boats and local workers. The landings rely upon the working waterfront infrastructure of those towns, and contribute to the town economies by direct and indirect spending. Over 200 seasonal and full-time workers benefit from this spending (Kennedy, 2014 and Maine Sea Grant, 2013), a number that will expand quickly considering the increasing demand for wild and farmed seaweeds for a host of processed products including:

  • Whole plants in bulk,
  • Chopped plants in energy bars,
  • Sliced and frozen plants in pasta and wraps,
  • Flakes for seasonings,
  • Powders for supplements.

The value of these products varies from about $15/pound (bulk) to $50 per pound (supplements). Even higher prices can be expected as new uses and preparations are identified.

Seaweeds use photosynthesis to grow and thus help mitigate excessive nutrient loading of seawater (nitrogen and phosphorus) while absorbing carbon dioxide and releasing oxygen. They cleanse seawater while producing highly nutritious foods and supplements, using minimal inputs and interventions. Their growth does not depend upon feeds, fertilizers, or pharmaceuticals, only sunlight. Sustainable seaweed harvests whether natural or farmed are a renewable resource benefitting Maine’s communities and working waterfronts without harm to the environment.

-Dick Clime is a Project Developer for the Working Waterfront at Coastal Enterprises, Inc. S

Works Cited

Kennedy, Brian, Bates College student thesis, 2014.

Maine Sea Grant publication, “Rockweed: Ecology, Industry and Management”, updated January 2013.

Maine Department of Marine Resources, “Fishery Management Plan for Rockweed (Ascophyllum nodosum)”, 2014.

Maine Department of Marine Resources, Landings Data for 2014, as reported by Robert Watts, MDMR staffer.