Cultivation of winged kelp (Alaria marginata) in Humboldt Bay

Author

Evan C. Simpson, Humboldt State UniversityFollow

Graduation Date

Fall 2025

Document Type

Thesis

Program

Master of Science degree with a major in Natural Resources, option Fisheries

Committee Chair Name

Dr. Rafael Cuevas Uribe

Committee Chair Affiliation

Cal Poly Humboldt Faculty or Staff

Second Committee Member Name

Dr. Rachael Wade

Second Committee Member Affiliation

Cal Poly Humboldt Faculty or Staff

Third Committee Member Name

Dr. Jose Marin Jarrin

Third Committee Member Affiliation

Cal Poly Humboldt Faculty or Staff

Keywords

Humboldt Bay, Winged kelp, Kelp aquaculture, Kelp, Seaweed, Alaria marginata

Subject Categories

Fisheries

Abstract

The cultivation potential of the winged kelp (Alaria marginata) was evaluated in Humboldt Bay, California, to further develop sustainable aquaculture in the region. Seasonality, depth, and system design were evaluated in regard to harvest biomass and quality. Results suggested that single-longline configurations at shallow depths (< 2 m) produced greater total biomass than a multi-longline system, suggesting enhanced water flow and reduced self-shading improved growth. Kelp grew best with a winter outplanting period (December-April), most likely due to environmental conditions (e.g., temperature, nutrients, and salinity) being within the kelp’s tolerable range, with as much as 2.24 kg/meter of kelp being harvested. These findings demonstrate that while the estuarine system has more variable conditions than predicted, A. marginata can be successfully cultivated in Humboldt Bay and highlight its potential as a viable crop for northern California’s emerging seaweed industry. Future work targeting the optimization of single-longline design and deployment timing may further improve yield and support regional goals for sustainable aquaculture and food security.

Citation Style

APA

Recommended Citation

Simpson, Evan C., "Cultivation of winged kelp (Alaria marginata) in Humboldt Bay" (2025). Cal Poly Humboldt theses and projects. 2530.
https://digitalcommons.humboldt.edu/etd/2530