Under the Surface of

Morro Bay

This web guide highlights most common species found in Morro Bay. Scroll through the photos to learn more about the bay and what lives under its surface.

Morro Bay is a small estuary located just west of San Luis Obispo, on California's Central Coast, where Los Osos and Chorro creeks mix with the saltwater of the Pacific Ocean. Known for its wildlife, especially sea otters, Morro Bay is one of 28 estuaries nationwide designated by the Environmental Protection Agency as a critical to the economic and environmental health of the nation. In the past, Morro Bay was dominated by eelgrass, which formed the basis of the bay’s ecosystem. But in recent years, the eelgrass has declined drastically.

In 2017-2018, Cal Poly San Luis Obispo student Iliana Arroyos (supervised by Jennifer O'Leary, then a professor at Cal Poly and California Sea Grant extension specialist) set out to document the species that make their home in the bay, in order to draw attention to the rich ecosystem that lies hidden under the water’s surface. She captured photographs of the marine life in Morro Bay and researched their natural history as part of her senior project.

In order to find specimens to photograph, she walked along the shores of the bay, keeping an eye out for animals and plants, and used crab traps and fish seining to collect species from underwater. She also tagged along with professors collecting data for research projects, who allowed her to take photos of their samples. All animals were released once recorded and photographed.

Explore the diversity of Morro Bay through the photos and descriptions below!

Photos, text, and research by Iliana Arroyos. Reviewed by California Sea Grant Extension Specialist Jennifer O'Leary.

Published by California Sea Grant, 2018.