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Are voluntary vessel speed reduction initiatives protecting whales?

Imagine this – you’re an 85 foot blue whale feeding at the surface of the water off of Santa Cruz and Santa Rosa Islands in the Santa Barbara Channel. You’ve traveled far to find this meal – roughly 3,000 miles from mating and calving grounds off of Central America – and this area is packed right now with your favorite food, a small invertebrate known as krill.

A blue whale spouts at the surface of the ocean in the Santa Barbara Channel
A blue whale in the Santa Barbara Channel

Krill enlarged under a microscope
Blue whales feed on krill, a small invertebrate.

But you’re not the only giant traversing this area today. A 1,300 foot container vessel – a ship longer than the empire state building is tall – is headed due southeast at 18 knots to the port complex of Los Angeles and Long Beach to deliver and offload toys, electronics, furniture, clothing, and everything else American consumers are ordering online or expecting to find on their market shelves.

As a whale - even as the largest known species on earth - the bad news is that crossing paths with these ships can be deadly for you, since collisions are regularly documented on the California coast and around the world. And eye-opening research from 2017 from Point Blue Conservation Science has suggested that these collisions - referred to as ship strikes - aren’t rare occurrences, with an average of 80 endangered whales estimated to be killed this way each year off of the U.S. west coast.

The good news is that humanity is beginning to more widely acknowledge and raise the alarms on this issue, and there are measures available and already in place that can greatly reduce the risk and likelihood that these fatal collisions occur.

On both the east and west coasts of the United States, NOAA and the U.S. Coast Guard have worked together with other federal agencies and the International Maritime Organization to reconfigure the locations of the shipping lanes - the equivalent of ocean highways - in the ocean to reduce the overlap of whales and ships as much as possible. For the last decade, NOAA and USCG have also worked together to request that large vessels slow to 10 knots or less in whale-rich areas off of southern CA and San Francisco, since past research has shown that slowing down large vessels to those speeds reduces the likelihood and lethality of a fatal collision occurring by 50%.

But, like with all policies, these slow speed requests can only be effective if they’re adhered to. With that in mind, alongside colleagues from NOAA’s Channel Islands National Marine Sanctuary and NOAA’s National Marine Fisheries Service and with partners from The Nature Conservancy and Greater Farallones Association, we co-authored an original research article in Frontiers in Marine Science that examined ship speed data and evaluated cooperation levels with voluntary slow speed requests in southern California from 2010-2019.

The study shows that, despite a recorded increase in cooperation with the voluntary slow speed requests in later years of the study timeframe (from 12% in 2010 to 46% in 2019), cooperation by large vessels with the voluntary requests is lower than research partners estimate is needed to reduce whale mortality to levels that do not inhibit reaching and maintaining optimal sustainable populations.

The article also shows that the complementary, incentive-based Protecting Blue Whales and Blue Skies Program - which California Marine Sanctuary Foundation administers alongside great partners like NOAA sanctuaries and California air district agencies - contributed to the recorded increase in cooperation across the large vessel community, along with contributing to estimated air emission reduction (over 700 tons of NOx) and measured underwater noise (decrease of 4dB per transit) benefits. However, given the uncertainty of continuing to fund and sustain the grant-funded incentive-based program into the future, cooperation levels recorded over the 10-year study timeframe suggest that mandatory speed regulations - like what is currently implemented along the east coast to protect North Atlantic right whales - warrant consideration in California.

You can access the publication here. The article is titled, “Evaluating Adherence With Voluntary Slow Speed Initiatives to Protect Endangered Whales.”

The Protecting Blue Whales and Blue Skies Program is a collaborative effort by the California Marine Sanctuary Foundation; Santa Barbara County Air Pollution Control District; Ventura County Air Pollution Control District; Bay Area Air Quality Management District; Channel Islands, Cordell Bank, and Greater Farallones national marine sanctuaries; The Volgenau Foundation; National Marine Sanctuary Foundation; Greater Farallones Association; Environmental Defense Center; Point Blue Conservation Science; Starcrest Consulting; and Scripps Institution of Oceanography. The 2022 program season runs May 1 through December 15, 2022.

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