{"id":42247,"date":"2026-04-13T07:15:00","date_gmt":"2026-04-13T14:15:00","guid":{"rendered":"https:\/\/www.lifeandnews.com\/articles\/?p=42247"},"modified":"2026-04-13T09:36:30","modified_gmt":"2026-04-13T16:36:30","slug":"gray-whales-are-dying-in-san-francisco-bay-at-an-alarming-rate-this-isnt-normal","status":"publish","type":"post","link":"https:\/\/www.lifeandnews.com\/articles\/gray-whales-are-dying-in-san-francisco-bay-at-an-alarming-rate-this-isnt-normal\/","title":{"rendered":"Gray whales are dying in San Francisco Bay at an alarming rate \u2013 this isn\u2019t normal"},"content":{"rendered":"\n

Josie Slaathaug<\/a>, Sonoma State University<\/a><\/em> and Daniel Crocker<\/a>, Sonoma State University<\/a><\/em><\/p>\n\n\n\n

At least six gray whales have died<\/a> in San Francisco Bay from mid-March to early April 2026. These deaths follow a pattern over the past few years, and they are raising concerns among marine biologists like us<\/a> that 2026 is becoming another dangerous year for a struggling population<\/a>.<\/p>\n\n\n\n

The majority of eastern North Pacific gray whales<\/a> migrate closely along the California coastline from their winter breeding grounds in Baja California, Mexico, to their summer foraging grounds in the Arctic.<\/p>\n\n\n\n

These whales, which can grow to 90,000 pounds<\/a> and over 40 feet in length, haven\u2019t stopped over in San Francisco Bay consistently throughout history. When they have, it has coincided with years when their food supply in the Arctic was low.<\/p>\n\n\n\n

Over the past few years, however, we have documented large numbers of gray whales in the waters of San Francisco Bay \u2013 and an alarmingly high mortality rate<\/a>.<\/p>\n\n\n\n

\"A
Scientists with the Marine Mammal Center talk with beachgoers about a dead juvenile gray whale that washed up on the shore north of San Francisco. Justin Sullivan\/Getty Images<\/a><\/figcaption><\/figure>\n\n\n\n

What\u2019s killing the whales<\/h2>\n\n\n\n

San Francisco Bay is a busy urban waterway<\/a>, with high-speed ferries, cargo ships, commercial fishing vessels and recreational watercraft<\/a>. That makes it a dangerous place for slow-moving whales.<\/p>\n\n\n\n

To monitor the gray whales, we conducted research surveys and collected photographs from whale-watching naturalists and community members who spotted whales in the bay. Gray whales have unique mottling patterns and markings on their sides and tails, some of which they\u2019re born with and others they have accumulated over time.<\/p>\n\n\n\n

\"A
Whales have unique markings, including some scars. This whale, known as Denali, was spotted lifting its rostrum above the water near San Francisco\u2019s Crissy Field. It later died after being struck by a vessel. Darrin Allen \u00a9 The Marine Mammal Center<\/a><\/figcaption><\/figure>\n\n\n\n

We found that from 2018 to 2025, 114 individual gray whales visited San Francisco Bay<\/a> for varying lengths of time, but very few of these whales were repeat visitors from year to year. This may be due, in part, to the high mortality rate in the bay.<\/p>\n\n\n\n

At least 18% of the whales<\/a> that we documented alive in San Francisco Bay from 2018 to 2025 later died in the area, and evidence suggests the mortality rate is actually higher.<\/p>\n\n\n\n

Of the 70 dead whales included in this study, 30 of them had evidence of trauma<\/a> associated with being hit by ships, but many other whales that died there couldn\u2019t be reached to be examined. We also documented several living whales with injuries caused by vessels. Those injuries have the potential to affect a whale\u2019s ability to thrive.<\/p>\n\n\n\n

\"A
A gray whale known as Ladybug swims in San Francisco Bay. The whale was later found dead there. Josephine Slaathaug \u00a9 The Marine Mammal Center<\/figcaption><\/figure>\n\n\n\n

The whales aren\u2019t recovering this time<\/h2>\n\n\n\n

Since 2016, the overall eastern North Pacific gray whale population has fallen by more than half<\/a>, likely driven by the decline in the food<\/a> the whales rely upon. Rising ocean temperatures and diminishing levels of sea ice are affecting both the quality and availability of the gray whales\u2019 prey, which include crustaceans they scoop up as they dive along the seafloor.<\/p>\n\n\n\n

When the eastern North Pacific gray whales suffered major die-offs in the past, including in the 1990s and early 2020s, the population rebounded. But the extremely low numbers of calves<\/a> in recent years suggest the gray whales aren\u2019t recovering as quickly this time, and that worries scientists<\/a>.<\/p>\n\n\n\n

Some subgroups of eastern North Pacific gray whales, including the Pacific coast feeding group<\/a> and North Puget Sound whales, known as the Sounders<\/a>, feed in alternative areas south of the Arctic. The Sounders capitalize on very specific prey \u2013 ghost shrimp \u2013 in Puget Sound. When food is more scarce in the Arctic, they stay longer there and are often joined by other whales from the general population. While some researchers initially believed the whales entering the bay were from these groups, we found that wasn\u2019t the case<\/a>.<\/p>\n\n\n\n

Vessel strikes also aren\u2019t unique to San Francisco Bay. Two gray whales were found dead on the Oregon coast in April 2026, both malnourished and one with evidence of a ship strike<\/a>. A malnourished young gray whale also died after swimming about 20 miles<\/a> up the Willapa River in Washington state, reflecting the struggle as this population of gray whales searches for food across their migratory range.<\/p>\n\n\n\n

What can be done to help the whales?<\/h2>\n\n\n\n

Other large whale species facing similar threats have been helped by management strategies, such as seasonal slow-speed zones during migration periods that go into effect when whales are present.<\/p>\n\n\n\n

When vessels slow down to speeds of 10 knots or lower, studies show that can reduce the risk of vessel strikes<\/a> by allowing more time for whales to get out of the way, or for captains to detect them and alter their course.<\/p>\n\n\n\n

The National Oceanic and Atmospheric Administration has in recent years issued requests for ships to voluntarily<\/a> reduce their speed to 10 knots in the Pacific Ocean off Monterey and San Francisco, but the limits haven\u2019t been mandatory and typically haven\u2019t started until May 1. The Port of Oakland<\/a> also encourages shipping companies to keep their speed under 10 knots, but it\u2019s also a recommendation, not a requirement.<\/p>\n\n\n\n

More education<\/a> to help boat operators learn how to avoid hitting whales, along with tools such as thermal cameras, could help reduce vessel strikes in San Francisco Bay.<\/p>\n\n\n\n

As the population struggles to adapt to environmental changes, San Francisco Bay may look like an attractive feeding ground to nutritionally stressed or hungry whales. We hope our research and data from across the region will help marine resource managers and policymakers find ways to protect the whales that share this busy urban waterway.<\/p>\n\n\n\n

Josie Slaathaug<\/a>, Graduate Student in Marine Biology, Sonoma State University<\/a><\/em> and Daniel Crocker<\/a>, Professor of Marine Biology, Sonoma State University<\/a><\/em><\/p>\n\n\n\n

This article is republished from The Conversation<\/a> under a Creative Commons license. Read the original article<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"

Josie Slaathaug, Sonoma State University and Daniel Crocker, Sonoma State University At least six gray whales have died in San Francisco Bay from mid-March to early April 2026. These deaths follow a pattern over the past few years, and they are raising concerns among marine biologists like us that 2026 is becoming another dangerous year […]<\/p>\n","protected":false},"author":56,"featured_media":42248,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1862,10,118,3410,15533],"tags":[1554,272,885,891,886,860,2057,954,2800,4179,8708,4337,17650,4887,5417,10482],"_links":{"self":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/42247"}],"collection":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/users\/56"}],"replies":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/comments?post=42247"}],"version-history":[{"count":1,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/42247\/revisions"}],"predecessor-version":[{"id":42249,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/posts\/42247\/revisions\/42249"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media\/42248"}],"wp:attachment":[{"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/media?parent=42247"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/categories?post=42247"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.lifeandnews.com\/articles\/wp-json\/wp\/v2\/tags?post=42247"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}