Santa Monica Bay turns pink in the name of science, ocean health

Santa Monica Bay turns pink in the name of science, ocean health

September 16, 2025 12:39 PM
by City of Santa Monica

Header photo courtesy of UCLA Coastal Flood Lab and The Bay Foundation.

If you noticed a pink hue in the ocean on Monday morning, along with several media crews on the Pier, a drone, and a boat with a dancing pink octopus, you may have wondered what was going on.

With the support of the city, researchers from the UCLA Samueli School of Engineering, in collaboration with The Bay Foundation, released non-toxic fluorescent rhodamine water tracer dye into the ocean to study how the Santa Monica Breakwater influences ocean circulation.

The dye, which has been used by researchers for many years to understand water movement, created a pink streak in the ocean near the breakwater before dispersing naturally, and its movements are now being tracked by special buoys the researchers placed in the waters around the Pier.

Though this type of experiment has been conducted in several locations, it was a first for Santa Monica. The experiment builds on years-long efforts by the city of Santa Monica, coordinating with key partners, to address ocean water quality beneath the Pier and advance key initiatives supporting sustainability and coastal health. 

These efforts have included:

• Capturing and diverting urban runoff and rainwater from the nearby downtown area as part of the 2018 Clean Beaches Project.
• Implementing the Sustainable Water Infrastructure Project (SWIP), which also captures stormwater, diverting urban runoff and stormwater pollution away from the Santa Monica Bay.
• Installing new bird netting beneath the pier in August 2023 and prohibiting the distribution of food to birds and animals at beaches and on the Pier.
• Restoring beach dunes to build ecological and coastal resilience.
• Working with Heal the Bay this year to convene a pier water quality task force to bring together a diverse group of experts to find solutions to this issue.

As part of the current experiment, the researchers will return three more times, twice from Sept. 22-24 and again on Sept. 30, to release additional tracer dye once they've learned more about the circulation patterns.  

Authored By

City of Santa Monica

Categories

Beach, Programs, Sustainable and Connected