Seaweed and Shellfish Farm Coming to Washington State
Shellfish Farm

What a seaweed and shellfish farm looks like under the surface of the water. Graphic by GreenWave

by Jenna Dennison

Mike Spranger is currently in the permitting process to operate a 10-acre seaweed and shellfish farm in Colvos Passage, on Vashon Island in Washington State.

Mr. Spranger became inspired to launch his own seaweed and shellfish farm after listening to the podcast “Freakonomics” on the topic and was “intrigued by the notion of seaweed being a sustainable, regenerative crop.” Having spent the last 30 years working for a logistics company in Seattle, he was looking for a career change as well.

He plans to grow sugar kelp as the primary crop on his farm, with a small number of oysters, clams and mussels being produced as well. This type of aquaculture differs from fish farming, as it uses no nets. Growing a seaweed and shellfish farm provides many different benefits, he says, including the production of food sources, giving back to the wider ecosystem, and being an example of regenerative farming.

“Seaweed, in particular, sequesters carbon, and carbon is one of the things that’s leading to ocean acidification,” said Mr. Spranger. “It also takes in nitrogen and phosphorus…from all of the agricultural and pollutants that go into the water.”

He describes the shellfish on the farm as “incredible water filters,” as the shellfish filter the water and help to clean it. “Together, the whole farm creates a really rich, biodiverse marine environment that’ll benefit other species like herring, which supports salmon, which supports seals, and otters and ultimately orca,” he says.

While Mr. Spranger’s enterprise will only be the second seaweed and shellfish farm in Washington (Blue Dot Sea Farms was the first in the state, and is located off Hood Head, Washington), seaweed farming includes supporters such as the Puget Sound Restoration Group, the Nature Conservancy and the National Oceanic and Atmospheric Administration (NOAA) due to its environmental benefits.

Though Mr. Spranger is still obtaining permits from various agencies, so far he has received the necessary approvals from the Puyallup Tribe, Washington Department of Fish and Wildlife, and the Washington State Department of Ecology. Ultimately, he plans to lease waters from the Washington State Department of Natural Resources and hopes to have all permits in by this summer and establish the farm in the fall. By November, he plans to plant seaweed, as the crop grows when the water is colder.

Mr. Spranger selected the 10-acre section of Colvos Passage because strong currents in that stretch of water will provide rich nutrients to the seaweed and shellfish. The section also has easy boat access and little proximity to residences.

With the opening of his new farm, Mr. Spranger hopes to expand the market for seaweed-based products on grocery store shelves, especially in North America.

“Instead of always having to go to the Asian food store or the specialty aisle, we’re going to try and change the snack aisle so that it includes more seaweed-based products or more seaweed-flavored products,” he said.

The North American market for seaweed-based products is starting to grow, said Mr. Spranger, with items like seaweed flavored popcorn, seaweed salsa and seaweed hot sauce showing up on shelves. “One of the fastest growing consumer items is going to be snacks.”

Source: Vashon-Maury Island Beachcomber

All rights reserved. Permission required to reprint articles in their entirety. Must include copyright statement and live hyperlinks. Contact Algae Planet accepts unsolicited manuscripts for consideration, and takes no responsibility for the validity of claims made in submitted editorial.

seagricultureusa 2023 Portland ME



  • March 28, 2023: South Korean biotechnology startup Seawith recently signed a new partnership to assess and explore Seawith’s proprietary, cutting-edge microalgae technologies in commercially cultivated meat projects. Read More…
  • March 23, 2023: Provectus Algae has announced that Steven F. Schnittger has joined the company as a cosmetics industry advisor. Mr. Schnittger is the former Vice-President of Global Fermentation and Microbiology R&D at The Estée Lauder Companies Inc. and served over 37 years there. Read More…
  • March 21, 2023: Testa Omega-3 has launched its Vrill Omega™ supplement, an innovative plant-based and vegan alternative to krill oil. It represents a new class of highly bioavailable omega-3 supplements offering both essential polyunsaturated fatty acids (DHA and EPA), as well as the potent antioxidant astaxanthin, in a formulation that is rich in easily-absorbed polar lipids – phospholipids and glycolipids — derived from microalgae and plants. Read More…
Seaweed Industry Job Board

A Beginner’s Guide