Monterey Bay White Sharks

Recently two dead whales have washed up on our local beaches here in central California, one in Watsonville on Sunset State Beach and the other right here on the beach at Hopkins marine station in Pacific Grove. These incidents while sad also highlight the important role whales play in marine food webs.

While white sharks predate on smaller marine mammals like sea lions and elephant seals they don’t typically hunt whales, but they will scavenge on whale carcasses. When a whale dies their bodies float and become a massive food source drawing in animals from all around the surrounding area including white sharks and other shark species. The sharks will feed on the main body of the whale, usually avoiding the pectoral fins and flukes. The whale’s body will eventually lose buoyancy as it is consumed and decomposes and it will then sink to the bottom of the ocean floor where it will become a food source for scavenging deep sea species.

To learn more about white shark foraging on whale carcasses check out the following article: https://doi.org/10.1016/j.gecco.2019.e00655

Photo credit: Andrew Read and Jeff Milisen

Happy World Ocean Day! 🌊🦭🪼🪸🐠🐟🐙🦀🦈

While every day is World Ocean Day for our Monterey Bay White Shark team we hope you are spending today celebrating our incredible oceans and all of the amazing life they support!

Oceans cover over 70% of our planet and are vital for global health. They are home to a diverse group of plants and animals that make up the many marine ecosystems we see across our planet. They also help regulate our global climate system, produce much of our oxygen, and provide key resources for billions of people. But our oceans, and their inhabitants, face a rising number of risks from warming climates, pollution, and overfishing among many others.

So how can you help?
1. Spend time in your local environment, even if you don’t live near a beach visit a local state or national park and learn about your local watershed and how it connects back to the ocean

2. Support sustainable seafood practices and buy sustainably harvested fish

3. Participate in a local beach cleanup

4. Reduce your daily single use plastic consumption

5. Support research and conservation groups like ours working to understand and protect our oceans and their wildlife

Today UCSC Costa Lab undergraduate Anna Ortiz presented her poster on her project studying predator bites on elephant seals! Anna looked at over 100 observations of predator bites on elephant seals and created a standardized database to document these observations!

Swipe to see first a bite from a white shark and swipe once more for a bite from an orca.

Seal pictures taken by researchers at Año Nuevo under NMFS permit No. 28742

Did you know?

June is sea lion pupping season!!

Most California sea lion pups are born during the first few weeks of June. After nearly a year of pregnancy, mothers return to breeding colonies to give birth and nurse their pups. Though most adult white sharks aren’t in California in June, they will be in a few months, right when the sea lion pups will begin swimming.

Studying white sharks also means understanding the ecology of the marine mammals they interact with, like California sea lions.

Pictures: Dan Costa (with zoom lens)

Meet Daphne Shen! Daphne is a member of the Costa Lab at UCSC. She is critical to our pinniped fieldwork, including tagging California sea lions and northern elephant seals. Daphne recently completed her masters degree studying how exposure to a predatory acoustic stressor affected northern elephant seal dive behavior!

Did you know? White sharks in the Monterey Bay National Marine Sanctuary () come in all shapes and sizes! Our recent paper provides the first aerial body condition estimates in free-swimming white sharks, quantifying their relative girth. 🦈 Link in bio to read more!