Sea Otter Surveys Get a High-Tech, COVID-Safe Update for 2021

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After a 2020 cancellation of the annual sea otter census, the count was back on for 2021.

WERC scientist Joe Tomoleoni surveying for southern sea otters

USGS wildlife biologist Joe Tomoleoni surveys sea otters along the California coast.

(Public domain.)

Happy Sea Otter Awareness Week! 

Since 1982, the USGS has conducted annual sea otter censuses along the California coast in partnership with the US Fish and Wildlife Service, the California Department of Fish and Wildlife, Monterey Bay Aquarium, and other partners. The census has been completed every year except for 2011, when weather conditions prevented the completion of the surveys, and in 2020, when survey was cancelled due to COVID-19, out of caution for the safety of researchers and wildlife in the early days of the pandemic. This past spring, the sea otter census was back on—but with some changes to make them more COVID-safe. 

The sea otter census has two parts: surveys taken along the shore in accessible areas, and surveys conducted from a small airplane. For 2021, surveys taken from shore were completed while maintaining social distancing, but social distancing isn’t possible in a tiny airplane, so the usual airplane counts were cancelled and replaced with aerial photo surveys. In this approach, instead of people counting otters directly from the plane, the plane is outfitted with sophisticated digital cameras linked to computers that capture thousands of high-resolution digital photographs of the ocean surface and coast. Since there are so many photos, the researchers will use artificial intelligence to assist with counting sea otters in the images. 

This aerial survey approach was adapted from another USGS marine ecology project developed prior to the pandemic to survey seabirds and marine mammals (learn about it here).

From schools to businesses to government agencies counting sea otters, technology has helped people adapt to the COVID-19 era. 

Learn more about the annual sea otter census here.

A kelp bed viewed from above, with two sea otters just visible next to each other amid the kelp

Zoomed image of two Southern Sea Otters (Enhydra lutris nereis) in a kelp bed, photographed from the air during aerial surveys for seabirds and marine mammals in 2020. The method was adapted for the 2021 sea otter census 

(Credit: Laney White, USGS Western Ecological Research Center. Public domain.)

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