Snapshot Cal Coast Logo outline of the state of CA with silhouette of animals and photo of intertidal seaweeds & a starfish

Pisaster ochraceus and tidepool diversity. Pillar Point, San Mateo County, CA


Snapshot Cal Coast is June 17-July 9! Help us document California's incredible biodiversity on your own or at a bioblitz event near you.

For two weeks every year, the California Academy of Sciences—with support from the California Ocean Protection Council, the California Department of Fish and Wildlife, and the MPA (Marine Protected Area) Collaborative Network, and many other partners—mobilizes communities from Del Norte to San Diego to make and share observations of plants, animals, and seaweeds along the California coast using the iNaturalist app. By creating a real-time, statewide snapshot of current species ranges, we're building a community of observers that provides valuable data for scientists at local, regional, and state levels, and answering targeted research questions in support of California Marine Protected Areas.


Getting started is a snap!

Close-up of a person taking a picture of tidepool animal with iPhone

Participating in Snapshot Cal Coast is as easy and fun as a day at the beach. Get started in six easy steps:

  1. Download the iNaturalist app for iOS or Android.
  2. Create an account to start making observations.
  3. Join the Snapshot Cal Coast 2023 iNaturalist project 
  4. Head to the coast on your own time or during a bioblitz to make and share observations of plants and animals you see, especially species on our "most wanted" list (see below).
  5. Observe during low tide. See NOAA's tide table to find exact times for low tides near you.
  6. Spread the word with hashtag #SnapshotCalCoast!



    Keep tidepool etiquette top of mind

    1. Observe things where you find them. Never remove animals, rocks, shells, seaweeds, or plants from the tidepools.
    2. Walk gently, taking care to avoid stepping on animals or seaweeds.
    3. Do not “roll” rocks. Animals living on the underside of rocks can only survive there.
    4. Be aware of the wildlife around you and try to minimize disturbances.
    5. Be careful! Tidepools and rocky shorelines are slippery, and tides and waves can catch you off guard. Never turn your back on the ocean.

    Most-wanted species

    In addition to documenting as many species as possible from as many places as possible, we are also interested in learning more about a handful of “most-wanted” species and groups. These include introduced species for which we have limited data on their ranges, species whose ranges are affected by changing oceanic conditions and habitat modification, and species that are affected by emerging diseases.

    Check out the iNaturalist Most Wanted Species Guide for more information.

    Native rocky intertidal species



    Snails in the genus Nucella

    Snails in the genus Tegula


    Lottia gigantea (Owl Limpet)


    Strongylocentrtus purpurartus (Pacific Purple Sea Urchin)


    Non-native species


    Watersipora Bryozoans



    Mud Snails


    Join Upcoming Bioblitz Events

    Connect with other beach-lovers at a bioblitz near you! Scheduled events are listed by county, north to south. 

    Del Norte County

    June 22 8 am - 12 pm Endert's Beach organized by Redwood National and State Parks

    July 6 8 am - 12 pm Wilson Creek Beach organized by Redwood National and State Parks 

    July 7 Point St. George organized by Tolowa Dee-ni' Nation (for information email 



    Humboldt County

    June 23  8am - 12pm Trinidad State Beach organized by California State Parks North Coast Redwoods District 

    July 2 Baker Beach organized by Trinidad Coastal Land Trust

    July 7 Sue-Meg State Park: Palmer's Point organized by California State Parks North Coast Redwoods District


    Sonoma County

    June 21 Fort Ross Cove and Sandy Beach organized by Fort Ross Conservancy 

    June 24 9am - 11am Campbell Cove organized by Stewards of the Coast and Redwoods Register Here

    San Mateo County

    June 24 Mirada Surf & Quarry Park organized by San Mateo County Parks Register Here

    July 4 6am Pillar Point Tidepools organized by California Academy of Sciences Register Here 


    Alameda County

    July 1 10 am - 2 pm Lake Merritt organized by Rotary Nature Center Friends Register Here

    July 1 3:30pm - 5:30pm Point Molate Beach Park organized by Wholly H2O Register Here

    Santa Cruz County

    June 19 Davenport Landing organized by Seymour Marine Discovery Center (Contact Dr. Allison Gong at 

    July 1 Seabright State Beach hosted by Santa Cruz Museum of Natural History

    July 5 Seabright State Beach hosted by Santa Cruz Museum of Natural History

    July 8 Seabright State Beach Seabright State Beach hosted by Santa Cruz Museum of Natural History For more information on these events contact



    Monterey County

    July 7  7:30 am The Great Tidepool (near Asilomar) organized by California Academy of Sciences Register Here 

    San Luis Obispo County

    June 24 9am - 11am Estero Bluffs State Park organized by Morro Bay National Estuary Program Register Here

    July 7 9am - 11am Hazard Reef, Montana de Oro State Park organized by Morro Bay National Estuary Program Register Here

    Los Angeles County

    July 7 8 am-Noon Leo Carrillo State Park organized by California State Parks

    Orange County

    June 17 8:30am Bolsa Chica Ecological Reserve, Brightwater Trailhead organized by USC Sea Grant Register Here

    July 7 Dana Point Headlands Beach organized by City of Dana Point Email for more information 

    San Diego County

    June 20 Coronado Central Beach organized by Coronado Public Library Register Here

    Map of California Coast

    How we are using these data?

    Observations contributed by volunteers, community, and community scientists during Snapshot Cal Coast and year-round via iNaturalist make up an increasingly large proportion of our knowledge of biodiversity over space and time on the California coast. Our team—a collaboration between the California Academy of Sciences, the California Ocean Protection Council (OPC), and the California Department of Fish and Wildlife (CDFW)—is building the capacity to use these crowdsourced community-contributed observations to understand and monitor biodiversity across California’s coastal and marine protected areas.

    Our data science efforts were initiated by Dr. Giovanni Rapacciuolo and are now led by Dr. Natalie Low and focus on developing innovative approaches and tools to translate crowdsourced community-contributed observations into meaningful indicators of biodiversity change on the California coast in support of California’s long-term MPA Monitoring Action Plan and the Ocean Protection Council's Strategic Plan. In particular, we are now focusing on mobilizing the community of volunteer naturalists, community, and community scientists to power an Early Warning and Forecasting System for biodiversity change on the California coast. This system will combine crowdsourced community-contributed observations with state-of-the-art ecological models to track key metrics of ocean and coastal health over time (e.g. distribution and abundance of native species, spread of invasive species, emergence of marine disease) and forecast changes in those metrics associated with a changing climate. This effort will provide resource managers with the tools necessary to slow or stop biodiversity loss in California’s coastal and marine habitats and will also empower community scientists to take an active role in conserving biodiversity.

    You can find out more about how we are using data contributed by the community during Snapshot Cal Coast and year-round via iNaturalist, as well as explore and interact with our findings, by visiting You can also watch the short talk by Dr. Rapacciuolo below about our data analysis efforts.