Science for a Blue Planet

Featuring cutting-edge work, discoveries, and challenges of our scientists, our partners, and the larger conservation science community.

King Tide Crystal Ball

Written by Megan Elrod, Point Blue San Francisco Bay Biologist

A King Tide of today could provide a glimpse of the normal daily tides of the future. We can think of them as one of nature’s “crystal balls.” For those unfamiliar with the phenomenon, a “King Tide” is a regular, predictable occurrence where the sun, moon, and Earth align in such a way that creates a strong gravitational pull that results in unusually high tides and often flooding events. As sea levels rise, the King Tides will get higher and higher which is an issue in itself, but we can look at today’s King Tides as a potential snapshot of what we should plan for every day in the future. That’s where you come in!

Black Rail in tidal marsh habitat by Julio Molero, Flickr Commons

Bay Area organizations, including Point Blue and its San Francisco Bay Program, invite you to document and visualize where the birds go during the King Tides this year.  Our next King Tide will occur Sunday, December 13th through Tuesday, December 15th, 2020. Take a walk along a San Francisco Bay trail, record the birds you see and submit your list and photographs. Your bird list (photos and descriptions encouraged!) can be submitted to eBird where Point Blue scientists can access the lists from your King Tide survey. Photos of the flooded trails can be submitted on the California King Tides Project website

Many of Point Blue’s tidal marsh study sites are part of public open spaces owned and managed by partners that Point Blue works closely with. Trails and outdoor activities abound and we’re lucky to have them out our backdoors.

Visit these Point Blue Tidal Marsh Study Sites with public bay trails:

Students restoring habitat off the levee path at Shollenberger marsh in Petaluma, CA. Photo by Lishka Arata/Point Blue.

Along with our long-term, scientific monitoring of bird communities in these habitats, our STRAW (Students and Teachers Restoring A Watershed) Program engages local communities to plant, plan, and restore for the future. Not all tidal marsh edges are created equal, and STRAW enhances these very important areas in the Bay. They are also a great place to document the King Tide – how much of the restoration is flooded during this high tide? What creatures are hiding there? You can help us understand how to better ensure safe homes in the future, for the birds and people that live at the Bay edge. But please, remember to keep your distance and let the birds shelter safely during high tides. We all need to give each other extra space during these tough times – our feathered community members included. Here are some STRAW restoration locations to visit and document what you see (sign up for eBird to submit your bird list and let us know what you see!).

Visit these STRAW restoration sites:


Always remember respect and safety first.

It is extremely important to not interfere with wildlife during a King Tide. Getting too close can have grave negative consequences during this vulnerable time, you should give extra space to any birds you see trying to take cover and do not flush. Stay on dry trails – do not go into the marsh or wade through flooded areas just to get the shot! We also strongly encourage you to check and follow your local COVID-19 public safety guidelines.

Want to know more about our restoration and monitoring work in the flood zones around the San Francisco Bay? Explore our transition/flood zone and shorelines web pages.