Key Elements for Sustainable Harvesting of Wild Maine Seaweeds

Over the past four decades I have noticed about a dozen key components in assuring a sustainable harvest for certain species of sea vegetables growing in the Downeast coastal area: Saccharina latissima (sugar kelp), Laminaria digitata (digitata), Alaria esculenta (alaria), Palmaria palmate (dulse) and Porphyra umbilicalis (wild nori). I am defining sustainable as simply being able to return to the same bed, year after year and take approximately the same quantities. All species have different life cycles, growth rates and tolerances for stress, but here are some of the commonalities that will go a long way in keeping their populations healthy:

  1. Evaluate plants/beds/communities at the beginning and end of each harvest season. If possible do a biomass assessment before or after harvest, or both.
  2. Notice and document population changes and trends over time. The longer you stick with one area the better for tracking history.
  3. Choose the healthiest beds to harvest. Leave the sparse areas for another year. They should fill out.
  4. Selectively harvest, one piece/plant at a time. If it looks stressed leave it. Take time and only take what looks in its prime.
  5. Leave more than you want to, particularly with kelps (that need certain bed density for spores to settle well). See the MSC Harvesters Guide for suggested %’s. Make sure to leave all holdfasts. These are often the launch pads for the next generation, particularly with dulse, where the tiny female is still living and tiny shoots will mature.
  6. Think cultivation (plants) not capture (animals). Think thinning not clear cutting populations.
  7. Get well paid, or pay well if buying. Making a living wage means having enough to live well without depleting what provides your living.
  8. Zero waste. As a harvester, this means find buyers for first quality, seconds, and culls (if any). For a buyer this means find a market for all of the above or create value added products from different qualities, so you can buy and sell all that’s harvested.
  9. Diversify species. As a harvester look for other species in the area to supplement your main harvest. As a buyer develop markets for multiple species so shortages have less financial impact.
  10. Promote reasonable regulations with DMR. This means educating and working with regulators to fashion rules that protect the plants/ecosystem and allow for a modest/sustainable harvest.
  11. Start growing species to supplement a shortage of wild harvest. Seaweed aquaculture is a known technology here in Maine and can be complementary to shellfish and finfish operations.
  12. Be patient. Wait for the right season, tide, weather, plant maturity, bed density, etc. and be grateful for what you get. These plants are ancient, giving us oxygen/nutrients, absorbing our excess carbon/minerals. Be respectful.

– Shep Erhart is the president and co-founder of Maine Coast Sea Vegetables.