How would the proposed Humboldt offshore wind project affect the bottom of the ocean??

Humboldt Wind Energy Area ​Bathymetry Map Source: Sylvia van Royen, Humboldt Water Keeper (4)

The benthic zone is the bottom or lowest ecological zone (1) in the ocean. Benthic habitats are complex, consisting of a combination of physical, chemical, and biological conditions that are home to a variety of invertebrates and make up the largest single ecosystem on earth. Furthermore, many species of fish rely on the benthic for their food sources. 

Unlike offshore wind turbines on the East Coast and in Europe that sit directly on the ocean floor, projects off the coast of Humboldt would float far above the benthic zone. However, the anchors and chains necessary to keep the floating wind turbines in place would contact the ocean floor and could affect benthic communities. Similar to the scouring caused by oceangoing vessels’ anchors, the deployment of anchors and cables for floating offshore wind could also impact benthic communities. Different kinds of floating platforms and anchoring systems would have different magnitudes of effect with more taut mooring systems having less impact than more slack systems as the slack systems would be contact the ocean floor more and be more likely to drag across it. The proposed offshore wind farm in Humboldt raises concerns on how the projects development will affect local benthic zones. Examples of other offshore wind farms have disturbed these zones mainly during the construction phase through foundations, anchors, and cables. The pacific coast avoids many of the same disruptions from the turbine flotation technology being utilized which results in much of the typical construction phase being skipped. A main concern avoided is the pile driving (2) process, in which a heavy weight is lifted and dropped consecutively to drive foundations into substrate. This causes vibrations tinterfere with crucial organism behaviors.

Humboldt renewable energy company, RNE, plans to utilize an autonomous underwater vehicle (AUV) to survey the ocean floor (3). It will take high resolution images to create a detailed map of benthic habitats, allowing for better knowledge for how to mitigate impacts to those ecosystems. 

References

1. ​The importance of understanding benthic ecosystem functioning. Frontiers Research Topic. (2023, January 30). https://www.frontiersin.org/research-topics/52540/the-importance-of-understanding-benthic-ecosystem-functioning/magazine

2. Pile driving. Discovery of Sound in the Sea. (2024, May 20). https://dosits.org/galleries/audio-gallery/anthropogenic-sounds/pile-driving/

3. Simmons, M. (2024, May 29). Offshore wind company RWE plans to start site surveys this summer. EPIC Website. https://www.wildcalifornia.org/post/offshore-wind-company-rwe-plans-to-start-site-surveys-this-summer

4. Humboldt Wind Energy Area. Bureau of Ocean Energy Management. (2025b, May 9). https://www.boem.gov/renewable-energy/state-activities/humboldt-wind-energy-area