David Porter discusses kelp farming vs. harvesting of wild rockweed, and why it is important to protect rockweed from over-harvesting.
Dear Editor:
I was pleased to see promotion of seaweed aquaculture in the article “In the weeds” [Ellsworth American, 02/22/24, 2024 Overview insert]. Aquaculture of kelp, which grows from sporelings to 6 feet harvestable size in only six months is sustainable, profitable and environmentally sound. Kelp aquaculture is rightly being promoted as a winter season alternative commercial harvest with an ever-growing market value.
However, I was concerned that the article lumped wild rockweed harvesting into the same category as kelp aquaculture. Rockweed is not kelp, and readers need to understand the differences.
Intertidal rockweed along our coastline is a very slow-growing seaweed. So slow-growing that it cannot be profitably farmed by aquaculture.
In its natural state, rockweed forms a forest at high tide with upright branches and a canopy of fronds that is home to a multitude of organisms, especially commercially important fish and shellfish species. Its three-dimensional forest habitat is disrupted, and its habitat value ultimately destroyed when repeatedly cut down for fertilizer. Much of our Maine rockweed is shipped to fertilizer factories in Canada. You will often see rockweed as an ingredient in garden products but incorrectly labeled as “kelp.”
The commercial market for farmed seaweeds is worthy of promotion, but we risk losing our highly valuable commercial fisheries by removal of the wild rockweed forest that supports so much of our coastal economy by serving as a nursery habitat for those fisheries.
David Porter
Brooklin