Join us for the first
Hawai‘i Intertidal Bioblitz!
During the months
of March, April, and May 2021
at rocky intertidal sites statewide
Sunday April 25th

Join Oceania and friends as we survey the Hawaiian intertidal in spring 2021! 

A bioblitz is a citizen-science effort to record as many species within a designated location and time period as possible.

How to participate:

  • During the months of March, April, and May 2021 go to any rocky intertidal area in Hawai‘i and take pictures of the organisms you see—limu (algae), invertebrates, and fish!

  • Use iNaturalist—download the app and make your own account.

  • Click here for directions on how to use iNaturalist for the Hawai‘i Intertidal Bioblitz. 

  • Link your pictures to the project "Intertidal of Hawai‘i". 

  • To see the most intertidal organisms, head to the beach on a low tide. 

    • When is low tide? Go to NOAA's Tide Predictions site. Click on the location closest to your area. Search for the date(s) you are interested in.

    • The lower the low tide (the more negative the number), the better for tidepooling! ​

  • Use the Field Guide to Hawai‘i's Coastal Organisms to help you identify your finds! A PDF of the guide is here, or you can purchase laminated copies.


With appropriate support from adults, this bioblitz is appropriate for ages 5+.

Volunteers will be at the following locations on O‘ahu on April 25th to facilitate the use of iNaturalist, help with identifications, and share information about the intertidal!

  • A limited number of free laminated identification guides will be available until supplies run out. 


Socially-distanced event—please wear a mask! 

Diamond Head Beach: 8:00 am to 10:30 am

Maili Beach: 8:00 am to 10:30 am

  • Parking lot entrance off Farrington Hwy directly across from 7-11 (87-731 Farrington Hwy, Waianae). The intertidal site is directly in front of the parking lot.


Sandy Beach: 8:00 am to 10:30 am

  • Park at bathroom closest to Makapu‘u Lighthouse (northernmost bathroom) of the Sandy Beach Parking Lot. The intertidal site is located just north of furthest end of the parking lot. 

Safety First

  • Wear closed-toed shoes to protect your feet and reduce the possibility of slipping (e.g., reef walkers, tabis, water shoes, old sneakers). 

  • Take turns with a buddy to watch the ocean and keep your knees bent to stabilize yourself. 

  • Do not put your fingers into holes or crevices. Although most intertidal organisms are harmless, some may bit, pinch, or sting. 


Respect the Environment​

  • Please show respect. Hawai‘i's coasts are 'ocean gardens' tended by local communities who have intimate knowledge of these places. This scientific knowledge is the result of kilo, careful observation, by generations of Native Hawaiians. 

  • When picking algae, leave the holdfast (where it is attached to the rock) so the algae will grow back. Do NOT pick algae from limu-protected areas (e.g., Diamond Head Beach Park this year!). 

  • The intertidal is a place that many organisms call home. Respect their space by replacing overturned rocks and being mindful of your footsteps. 

  • If you handle organisms, keep them wet, treat them gently, and return them to where you found them. 

  • Most wild organisms do not fare well in tanks. Snap and picture and leave your favorite critters at the beach.​

FREE limu resource: Request physical copies here of Hawai‘i Sea Grant's magazine Ka Pili Kai issue called Limu: Gifts from the Sea


Contact Joanna Philippoff ( for more information.


If you are an LCC or WCC student contact Anuschka Faucci (