The Bay Area is a popular tourist destination for many, including gray whales. However, it has recently been discovered that coming to San Francisco can be life-threatening for these whales. In fact, researchers have reported that one in five gray whales that enter the bay die there, according to the Frontiers of Marine Science report published on April 13, 2026. For the marine mammals, this is extremely bad as their population has already faced discrepancies in recent years. To understand why these whales are even entering the waters close to San Francisco, Josephine Slaathaug, a whale biologist at Sonoma State University, and her colleagues have been studying the whales’ migration patterns for some time now.
Gray whales, also known as Eschrichtius robustus, typically migrate from the freezing waters of the Arctic down to Mexico. Along the journey, they typically eat, and while surrounding the waters of Mexico, they tend to mate and give birth before returning north to where they started. Their trips are usually nonstop, but in recent years, researchers have found that some possibly hungry whales go looking for food within the San Francisco Bay Area. This is no surprise, as it coincides with the decrease in food availability within the Arctic, which has led animals to be resourceful and find food elsewhere. However, this in turn has caused a huge die-off of whales.
Slaathaug and her colleagues have collected 100,000 photos of gray whales from 2018 to 2025 to identify the 114 specific whales that visited the Bay Area. Similarly, 70 carcasses were found in the waters near the city in that area, and 21 matched the photographed whales. This meant that 18% of the whales that entered the region died during this time period. However, researchers have reason to believe that this percentage is a severe underestimate. Many of the carcasses were too decomposed for identification, but there is a possibility that they died after entering the bay. Further examination shows that nine out of the 21 identified whales had a cause of death related to vessel strikes. This shows a possible causation for the whale deaths.
While this study primarily focuses on gray whales within the San Francisco area, it is indicative of a larger trend, as whales have been spotted in unusual areas such as off the coasts of New England, Florida, and Hawaii. Slaathaug shares that whales’ exploration of other areas isn’t necessarily a bad thing. For Arctic whales, getting comfortable in warmer waters is a sign of adaptation. However, this also leads to other risk factors, such as boats and human activity, which can be detrimental. This poses a bigger responsibility on humans to be cautious of whale activity and provide a safer space for them to be able to hunt for food. Alternatively, Slaathaug also attributes climate change to whales being unable to find food in their normal migratory patterns, which bodes a larger issue that needs to be addressed.
