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How would the proposed Humboldt offshore wind project affect whales and other marine mammals?

Despite potential impacts, whale scientists are cautiously optimistic (1) about offshore wind turbines as an effective form of renewable energy, as they see climate change as one of the greatest threats to whales. To take just one example, scientists believe that warming ocean temperatures could significantly reduce the amount of breeding habitat (26) available to humpback whales. In addition, many of the potential threats to whales associated with offshore wind turbines already exist to some degree due to current ocean uses; therefore, solutions ought to be implemented for all industries, and not just offshore wind. Click here to learn more about whales and offshore wind (2) from the New York State Environmental Technical Working Group.

Humpback whale (Megaptera novaeangliae) tail flip.

Humpback whale (Megaptera novaeangliae) tail flip.

Source: Jim Harper via Wikipedia (CC BY-SA 1.0) (3)

Potential vessel strikes (4) associated with turbine construction and maintenance are the largest threat to whales from Humboldt’s proposed offshore wind project. Anytime vessels are moving through the ocean, there is a risk of potential collisions with marine mammals. To mitigate these risks, the California Coastal Commission has set a 10-knot speed limit (5) for all ships associated with offshore wind, and is requiring all vessels to have trained “protected species observers” to monitor for whales and other at-risk species. These precautions are more stringent than those placed on fishing and shipping vessels.

 

Although there is currently a lot of misinformation (6) circulating about the impacts of offshore wind to marine mammals, as of March 15, 2024, there has yet to be a documented case (7) of a marine mammal being harmed by activities associated with an offshore wind project. Early reports of potential fatalities from fixed-bottom offshore wind turbines on the East Coast were later determined to be primarily caused by ship strikes (8) associated with other ocean industries, and not caused by the wind industry (9). 


Another risk to marine mammals is entanglement (10), which occurs when a marine mammal gets wrapped up and trapped in some kind of humanmade object, and consequently gets injured or cannot swim safely. This happens depressingly often (11) with crab and fishing gear, as well as trash, and is one of the leading causes of whale deaths off the coast of California. Researchers have found little risk (12) of direct entanglement in offshore wind transmission cables because, at approximately 8 to 11 inches in diameter (13) (or about the size of a dinner plate), the cables are large and obvious enough for whales and other marine mammals to easily avoid. The cables will also be kept taut in order to keep the floating wind turbines from moving around too much, which further reduces the risk of direct entanglement.

A humpback whale entangled in fishing gear.

A humpback whale entangled in fishing gear.

Source: E. Lyman / HWS and NOAA (14)

However, there is a risk of secondary entanglement, in which whales and other marine mammals could become entangled in loose, discarded fishing gear or trash that gets caught on offshore wind cables. Solutions to this problem include fishers using alternative gear (15) that is safer for marine mammals, and offshore wind operators monitoring for litter and refuse near their wind turbines and cables. 

 

Another potential impact to marine mammals could come from electromagnetic fields (EMFs) associated with offshore wind cables. Every type of cable that conducts electricity inherently emits EMFs, and offshore wind cables are no different—but the EMFs are minimal. Common household appliances, including TVs, hair dryers and electric drills, can emit EMFs similar to or higher in intensity (16) than those emitted by offshore wind cables, and most offshore wind-related transmission cables are buried under the seafloor, further reducing EMFs. Research is ongoing into the effects of EMFs on marine mammals and other wildlife, but early indications (17) are that the effects are negligible.

 

Another potential risk to marine mammals is from sound. Ironically, the survey equipment used to locate marine mammals and other sensitive animals and objects during site assessment could inadvertently harm the marine mammals (18). Fortunately, the federal government has developed strict rules (19) surrounding surveying techniques in order to protect marine mammals. The first seafloor surveys are scheduled to begin this summer, and are using very low intensity survey equipment — well below what the federal government allows. RWE (20) announced the start (21) of its site investigation on June 12, 2024.


Offshore wind energy has suffered from repeated attacks by the fossil fuel industry (22), resulting in exaggerated and distorted beliefs about the environmental impacts from this form of renewable energy development that are contrary to what science tells us. Listen to this informative report on the “Complicated Truths About Offshore Wind and Right Whales” (23) by the Science Friday team.

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Click here to read more about potential impacts to whales and other marine mammals due to floating offshore wind in California (27) from the California Ocean Science Trust in July 2024.

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Watch this California Coastal Commission presentation discussing potential impacts from floating offshore wind infrastructure to marine mammals and sea turtles (24).

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Watch this video from the U.S. Bureau of Ocean Energy Management (BOEM) regarding the interactions between floating offshore wind turbines and California’s humpback whales (25):

References

  1. Zuckoff, E. (2024, March 29). The Complicated Truths About Offshore Wind And Right Whales. Science Friday. www.sciencefriday.com/segments/offshore-wind-misinformation-right-whale-deaths/ 

  2. New York State Environmental Technical Working Group. (n.d.). Wildlife and Offshore Wind Resources. www.nyetwg.com/wildlife-and-offshore-wind-info

  3. Harper, J. (2005, April 20). Whale tail flip [Image]. Wikimedia Commons. https://chr.m.wikipedia.org/wiki/File:Whale_tail_flip.jpg

  4. NOAA Fisheries. (n.d.). Understanding Vessel Strikes. www.fisheries.noaa.gov/insight/understanding-vessel-strikes 

  5. Kalt, J. (2022, May 31). Coastal Commission Approves Offshore Wind Exploration Plan—with Conditions. Humboldt Waterkeeper. https://humboldtwaterkeeper.org/offshore-wind-energy/1572-coastal-commission-approves-offshore-wind-exploration-plan-with-conditions 

  6. Marvell, P. (2023, September 19). Wind opponents spread myth about dead whales. Yale Climate Connections. https://yaleclimateconnections.org/2023/09/wind-opponents-spread-myth-about-dead-whales/ 

  7. Larson, C., McDermott, J., Whittle, P., Perry, W. (2023, December 23). Contrary to politicians’ claims, offshore wind farms don’t kill whales. Here’s what to know. AP News. https://apnews.com/article/offshore-wind-whales-deaths-trump-5158af7f5bf0f5ef9e1530564ff791a9

  8. Lewis, A.S. (2023, March 8). The East Coast Whale Die-Offs: Unraveling the Causes. Yale Environment 360. https://e360.yale.edu/features/humpback-whale-strandings-u.s.-east-coast 

  9. Axelrod, J. (2024, June 26). The Science is Clear: Offshore Wind Isn't What's Killing Whales. Scientific American. https://www.scientificamerican.com/article/whales-are-dying-but-not-from-offshore-wind/

  10. National Oceanic & Atmospheric Administration Fisheries. (n.d.). Entanglement of Marine Life: Risks and Response. www.fisheries.noaa.gov/insight/entanglement-marine-life-risks-and-response 

  11. NOAA Fisheries. (2024, January 22). NOAA Announces Confirmed Large Whale Entanglement Numbers in 2022. www.fisheries.noaa.gov/feature-story/noaa-announces-confirmed-large-whale-entanglement-numbers-2022 

  12. Jaramillo, C. (2023, March 31). No Evidence Offshore Wind Development Killing Whales. FactCheck.org. www.factcheck.org/2023/03/no-evidence-offshore-wind-development-killing-whales/ 

  13. Offshore Wind Scotland. (n.d.). Fact Sheet 4: Cables & Accessories. www.offshorewindscotland.org.uk/media/g3mbquou/04-cables-accessories.pdf 

  14. National Marine Sanctuaries. (n.d.). Whale Disentanglement. NOAA Fisheries. https://sanctuaries.noaa.gov/news/nov15/whale-disentanglement.html 

  15. Sommer, L. (2023, June 25). This fishing gear can help save whales. What will it take for fishermen to use it? National Public Radio. www.npr.org/2023/06/25/1183727733/this-fishing-gear-can-help-save-whales-what-will-it-take-for-fishermen-to-use-it 

  16. U.S. Bureau of Ocean Energy Management. (2023, December). Electromagnetic Fields (EMFs) from Offshore Wind Facilities. www.boem.gov/sites/default/files/documents/renewable-energy/state-activities/BOEM-Electromagnetic-Fields-Offshore-Wind-Facilities_1.pdf

  17. Tethys Engineering. (2022). Electromagnetic Field Effects on Marine Life. U.S. Offshore Wind Synthesis of Environmental Effects Research. https://tethys.pnnl.gov/sites/default/files/summaries/SEER-Educational-Research-Brief-Electromagnetic-Field-Effects-on-Marine-Life.pdf

  18. Shuman, M. (2024, March 16). Morro Bay group says offshore wind development surveys kill marine life. Is that true? San Luis Obispo Tribune. https://www.sanluisobispo.com/news/local/environment/article285819371.html 

  19. U.S. Bureau of Ocean Energy Management. (2023, November). Offshore Wind Activities and Marine Mammal Protection. www.boem.gov/sites/default/files/documents/renewable-energy/state-activities/Offshore%20Wind%20Activities%20and%20Marine%20Mammal%20Protection_2.pdf 

  20. RWE. (2024). https://americas.rwe.com/our-energy/offshore-wind/ 

  21. RWE. (2024, June 12). RWE Announces Start of Site Investigation Campaign for its Canopy Offshore Wind Project off the Coast of Northern California. Canopy Offshore Wind. https://canopyoffshorewind.com/-/media/Project/Team/Canopy/press-and-news/2024-06-12-rwe-announces-start-of-site-investigation-campaign-for-its-canopy-offshore-wind-project/2024-06-12-rwe-announces-start-of-site-investigation-campaign-for-its-canopy-offshore-wind-project.pdf 

  22. Lutz, M. and Rowland-Shea, J. (2023, December 11). The Oil and Gas Industry Is Behind Offshore Wind Misinformation. Center for American Progress. www.americanprogress.org/article/the-oil-and-gas-industry-is-behind-offshore-wind-misinformation/ 

  23. Science Friday. (2024, March 29). The Complicated Truths About Offshore Wind And Right Whales. www.sciencefriday.com/segments/offshore-wind-misinformation-right-whale-deaths/ 

  24. California Coastal Commission (2023, May 11). Informational Briefing on Offshore Wind [Video]. https://drive.google.com/file/d/18DmNJakFcDvb5CuVjGZdFF1y7f3lTg1d/view 

  25. U.S. Bureau of Ocean Energy Management (2020, December 29). Humpback Whales and Floating Offshore Wind Farms [Video]. YouTube. https://www.youtube.com/watch?v=G8bKpuSNUZ0&t

  26. Kieran Mulvaney. (June 8, 2022). National Geographic. Humpback whales face a major setback from climate change. https://www.nationalgeographic.com/environment/article/humpback-whales-face-a-major-setback-from-climate-change

  27. California Ocean Science Trust. (2024, July). Impacts to Whales and Other Marine Mammals. www.oceansciencetrust.org/wp-content/uploads/2024/07/OST-Science-Factsheet-4-Whales-Final.pdf

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