Coronado installs two buoys to study and track sharks

One of two “shark buoys” recently installed off the coast of Coronado Island.
One of two “shark buoys” recently installed off the coast of Coronado Island. | Photo via City of Coronado

There’s some-fin cool happening in Coronado: the city has teamed up California State University Long Beach’s Shark Lab to install two new, state-of-the-art buoys off the coast to track + study local shark populations. Let’s dive into how this works, with a little help from Coronado Lifeguard Capt. Sean Carey.

What do the buoys do?

The buoys are outfitted with solar-powered receiver technology that detects sharks that have been tagged by researchers. The tech is used to better understand shark behavior patterns

“Anytime a tagged shark passes within about 500 meters of one of these buoys, the buoy is going to record the detection — and it’s going to tell us which shark it was, based on that tag number,” Carey explained.

The data is recorded by the lab and shared with Coronado lifeguards in real-time via an online database + app that sends alerts.

The buoys are monitored by researchers with the Shark Lab at CSULB
The buoys are monitored by researchers with the Shark Lab at California State University Long Beach. | Photo via City of Coronado

Where are the tagged sharks + buoys?

Over the past seven years, the Shark Lab has tagged 175+ white sharks with active transmitters from Morro Bay to San Diego. In November 2020, researchers began a 3-month process to tag seven sharks in Coronado. Carey said those sharks have all since scattered, with two of them migrating north to Del Mar.

Since the Coronado buoys were installed, there have been no shark detections. Carey said it’s hard to say why the tagged sharks have moved away, but thinks it may have to do with a diminished stingray populationtheir favorite food source. This doesn’t mean there aren’t sharks in Coronado, though — just not the tagged ones right now.

In San Diego County, these bright yellow buoys have only been installed at two beaches: Del Mar and, as of last month, Coronado.

Carey said the Coronado buoys were installed between 300-400 yards offshore, depending on the tide, “well beyond where the surfers are catching waves.” One is in front of the city’s main lifeguard tower, while the other is off the southern end of Hotel del Coronado. These two locations were chosen because they span most of the area.

“We have almost the entire beach covered,” Carey added.

The other buoys in the Shark Lab’s California network are off Carpinteria, Long Beach + Huntington Beach.