The California coast is experiencing a shocking increase in marine mammal emergencies. Since the beginning of June, almost 400 animals have been observed stranded or sickened. Woodrow is one of the sea lions currently being treated and evaluated by the veterinary staff at the Marine Mammal Center. He’s doing well now, but undergoing close monitoring and treatment. Marine biologists, ecologists, and conservationists alike are deeply alarmed. Even worse, they are dealing with a record-breaking eruption of contagion and death among these fearful beings.
The Marine Mammal Center, in collaboration with many partners, has carefully recorded marine mammal health trends since the 1980s. This year has become particularly grim. Leptospirosis This year our leptospirosis outbreak has begun much earlier than what’s considered the norm. Tragically, experts are now cautioning that 2023 may be the most consequential year for marine mammals, with the total number of impacted animals exceeding any prior recorded events.
Rising Disease Outbreaks
Leptospirosis is a horrible bacterial infection that routinely kills 66% of its victims. Indeed, this concerning development represents the most significant threat to U.S. marine mammal health in decades. Katie Prager, a disease ecologist at UCLA, reminds us that the first recorded outbreak was not until 1970. The disease has reappeared in waves ever since. This year’s outbreak is more concerning for its timing and severity.
In a similar outbreak in 2011 and 2018, the public helped to rescue just under 300 animals. This new reality has severely affected the number of sick sea lions. That surge is flooding organizations such as the Marine Mammal Center. This year’s challenges are compounded by an unprecedented number of whale entanglements reported from San Diego to Crescent City, further straining the already-ragged network of volunteers who receive dozens of rescue calls daily.
“It’s been a brutal year. … It’s been hard on the animals. It’s been traumatic for the volunteers. It’s a lot.” – Rulli
Environmental Factors at Play
Ecologists such as Jamie Lloyd-Smith from UCLA are examining how changing ocean conditions could relate to the rise in disease occurrences among marine mammals. He appreciates the continued work by others to explore these connections. The rate, scale and scope of environmental change we face today is unprecedented and overwhelming.
“We’re trying to build our understanding of how ocean conditions relate to the occurrence of disease. But it’s a work in progress. And the world is changing quickly underneath our feet,” – Jamie Lloyd-Smith
Climate change, pollution, and overfishing are quickly shifting our marine ecosystems. Researchers are becoming more concerned that this threatens the health and survival of marine mammals. The recent surge in diseases like leptospirosis and domoic acid toxicity, where more than 2,100 animals fell ill during a historic outbreak, serves as a reminder of the precarious state of marine biodiversity.
The Bigger Picture
Unfortunately, the plight of marine mammals is not limited to California’s coastline. In recent months, the most ever dead gray whales have been discovered in the San Francisco Bay Area. This disturbing increase reflects a larger catastrophe plaguing these magnificent animals across their range. Humpbacks and gray whales are becoming ensnared in commercial fishing equipment at unprecedented and unacceptable levels. It is now contributing to 100,000 more deaths annually and recovery from all disasters much more difficult.
It’s why organizations like the Marine Mammal Center work around the clock to solve these crises. In the process, their volunteers and staff face increasing pressure, emotional toll. The health crises affecting these animals illustrate the link between human activity and the health of the environment. This is a wake-up call — policymakers and conservationists need to act now to protect our marine ecosystems. Their hard work is all that stands between vulnerable species and extinction.