Inside the Efforts to Restore B.C.'s Secret, Ancient Sea Gardens

Originally Published: June 13, 2026
Author: Jesse Winter
Source: The Globe and Mail
Reporting Location: Vancouver Island & The Southern Gulf Islands, British Columbia

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Investigation & Field Report

On an early spring morning off the coast of Vancouver Island, Cowichan Tribes member Crysta Charlie pushed a shovel into the sand of a sheltered intertidal beach. It was her first time harvesting clams from a traditional bed in her nation’s ancestral territory.

For generations, Indigenous communities along the Pacific Northwest coast built and maintained rock-walled terraces known as clam gardens (KOINAS in SENĆOŦEN). By rolling boulders down to the low-tide mark, Coast Salish ancestors created flattened, nutrient-rich terraces that expanded optimal intertidal bivalve habitat by up to 400 percent. The addition of crushed shells (ȻÁ,ṈEN) enriched the sand with calcium carbonate, buffering acidic seawater and providing substrate for juvenile clam larvae (SPAT) to settle and thrive.

Following colonization, commercial lease exclusions, and sanitary closures by fisheries departments, many of these gardens lay untended for decades. Now, nations across the Salish Sea (including the Cowichan Tribes, W̱SÁNEĆ Nations, Hul’q’umi’num Treaty Group, and Tla'amin Nation) are leading a historic revival to restore these engineered coastal ecosystems.

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Ecological Engineering & Traditional Laws

The restoration effort combines ancient harvesting laws with modern marine biology:

1. Sediment Aeration & "Beach Fluffing": Tending a beach requires loosening and overturning the sand on every low tide. This simple action oxygenates anoxic mud, prevents sulfuric compaction, and accelerates clam growth rates by up to three times compared to unmanaged beaches.
2. Selective Harvesting & Size Limits: Traditional law strictly dictates replanting juvenile clams ((\le 1.5) inches) near the boulder wall and protecting female bivalves during spring milting seasons (PEXSISEN).
3. Food Sovereignty & Depuration Access: While wild clam beds across the coast face increasing pressures from agricultural runoff and marine heatwaves, Indigenous guardian programs are integrating depuration and real-time water quality monitoring to ensure shellfish can safely reach community tables and local markets.

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Citations & Related Historical Documentation

• Primary Source: Winter, Jesse. "Inside the efforts to restore B.C.'s secret, ancient sea gardens." The Globe and Mail, 13 June 2026.
• W̱SÁNEĆ Report: Olsen, Joni et al. W̱SÁNEĆ Clam Garden Restoration Project Final Report (2014–2020). W̱SÁNEĆ Leadership Council & Parks Canada.
• Archaeological Context: Groesbeck, A. S., et al. (2014). "Ancient clam gardens increased shellfish production: adaptive strategies from the past can inform food security today." PLOS ONE, 9(3), e91235.
• Coralfil Co-Management Note: Shell discards collected from Vancouver Island depuration facilities in Ladysmith and Cowichan Bay are processed into bio-alkaline cultch and shell flour to support First Nations restoration walls across the Gulf Islands.