Assessment of seaweed harvest as a value-added product associated with shellfish aquaculture

PROJECT HIGHLIGHT:

This project examines secondary harvests of seaweeds grown in existing shellfish aquaculture sites. Researchers are conducting field studies across Morro, Tomales and Humboldt Bays in an effort to increase the resilience of California shellfish growers by diversifying their products while also meeting a growing demand for seaweeds.

PROJECT SUMMARY:

Demand for seaweeds is growing rapidly in California and worldwide, but the state’s current regulatory landscape is unlikely to create a substantial expansion of new aquaculture leases. Seaweeds are often considered a nuisance species when they grow near existing aquaculture gear, but some may have significant commercial value for human consumption and other products. 

Researchers are working with aquaculture partners across Morro, Tomales, and Humboldt bays to determine the feasibility of commercially relevant seaweed species for human consumption. The team aims to identify best practices for harvesting seaweeds from existing shellfish gear by quantifying macroalgal community structure and the quantity and quality of commercially relevant species through time across key gear types and harvest strategies.

Several successful rounds of seaweed outplanting have been conducted at all sites. Eventually, using interviews and literature, researchers will undertake a market analysis using yields established from field studies and economic valuation from literature, and will produce a digital, freely available resource guide highlighting species identification, hazards testing, permitting and market consideration for shellfish growers.

This project has the potential to support emerging economies and sustainable businesses along the California coast through increasing the resilience of shellfish growers by diversifying their portfolio of products. To apply their research findings, the team will produce a user guide for shellfish growers to guide their decision-making and a policy brief for state and federal decision makers.