California Biodiversity Day 2025

Oct 17, 2025

Leah Gardner, Senior Environmental Scientist (Specialist) – Vegetation Management, Natural Resources Division
Dena Spatz, Senior Environmental Scientist (Specialist) – Wildlife Management, Natural Resources Division
Erika Delemarre, State Park Interpreter II – MPA & Coastal Programs Coordinator, Interpretation and Education Division

Photograph of a child holding up a mask obscuring their eyes; the mask is in the shape of glasses and features an illustration of a woodland scene in one lens, the words "Calfiroani biodiversity Day" in the other lens, and an illustration of a Monarch Butterfly atop it.

And the award for the park with the most species for California Biodiversity Day 2025 goes to…

McArthur-Burney Falls Memorial State Park!! A small but mighty team of 10 staff and volunteers recorded a whopping 289 unique species in their park from September 6 – 14 in celebration of California Biodiversity Day, unseating the reining 2024 champions, Point Lobos State Natural Reserve! McArthur-Burney Falls Memorial State Park was competing with 60 other parks who joined the annual challenge to capture a detailed snapshot of the amazing biodiversity within our park system.

Photograph of 10 adults and 1 child standing in front of a tall waterfall and several tall conifer trees.

Bioblitz team at McArthur-Burney Falls Memorial State Park, California Biodiversity Day 2025.

Last year’s winner, Point Lobos State Natural Reserve held a close second place. They recorded 283 species, with more than 50% of the observations photographed by volunteer SCUBA divers participating in an underwater bioblitz coordinated by State Park Interpreter I and Dive Team Member, Ashley Wemp. The divers recorded amazing underwater life including rockfish, sea stars, sea snails, anemone, tunicates, nudibranchs, all kinds of algae, and so much more.

Coming in third place was Folsom Lake State Recreation Area, with 253 species. Their week of events included an invitation to participate in an innovative water hyacinth removal paddling program to reduce an invasive species from the lake surface by from kayaks.

Grid 3x2 grid pf photos depicting various aquatic species at close range.

Marine life observed at Point Lobos State Natural Reserve, including multiple species of nudibranchs. Photos in iNaturalist by ©divebuddy and ©scsb01.

Honorable mention goes out to the efforts of the North Coast Redwoods District which pitted their northern sector against their southern sector in an intradistrict competition. The northern group of 12 parks won with 312 species – including the infamous banana slug, which was the most common species observed. Altogether, the district captured an outstanding 1,248 observations that identified 540 unique species!

In total, State Parks hosted nearly 100 events in 70 different park units for California Biodiversity Day. In addition to bioblitzes, nature walks, and restoration activities engaging visitors with the nature of parks, the PORTS Program connected K-12 students in classrooms across California with our state’s incredible biodiversity. A weeklong schedule of twelve PORTScasts reached 4,745 students with these highlights:

The Bears of California program had the highest attendance, with 896 participants.
A close second was Mysteries of the Octopus at Crystal Cove, which engaged 790 participants.
An additional PORTSCAST livestreaming from Pt. Lobos was held at CNRA headquarters featuring the new van, “VANNIE Devito” and garnered approximately 100 people who enjoyed ice cream goodies for their attendance.

Extremely close-up photograph of a small disc-shaped gall and an approaching small spider, all on one lobe of an oak leaf.

A disc gall wasp found on an Oregon Oak tree and accompanied by a spider, one of many biodiversity discoveries during McArthur-Burney Falls Memorial State Park’s California Biodiversity Day bioblitz. Photo in iNaturalist by ©Chaye Vail.

Since its inception in 2019, California Biodiversity Day has grown into a week of activities and events fostering nature discovery across the state. State Parks interpretive and natural resources staff have continued to combine forces to create engaging and memorable experiences for visitors in parks. In addition to the events planned and hosted by the Department, partners such as California Department of Fish and Wildlife, California Academy of Sciences, National Audubon Society, California Native Plant Society, and numerous local non-profits hold Biodiversity Week events across the state. In 2025, dozens of partners spanning the state hosted a record-breaking total of 220 events from Sept. 6-14, recognizing and documenting our state’s wide variety of unique and amazing life and ecosystems.

A special THANK YOU to everyone who hosted, supported, or participated in this year’s events. We’ll celebrate again next September! Save the dates for Sept 5 – 13, 2026!

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