[Posted by Chuck Almdale]

Long time frequenters of Malibu Lagoon well-remember the big die-off of Jumping Mullet back in August 2018. I’m not sure if anyone ever determine the exact reason(s) why 3,000-5,000 died in the lagoon, although the primary suspect was uncommonly warm air temperatures common in August, plus very warm temperatures in the lagoon itself. Warm water can’t hold as much oxygen as can cooler water. As I wrote then:

Some tests were taken that day: dissolved oxygen was 3-5 milligrams per liter, described as “… isn’t great, but also isn’t below the critical thresholds.” Water temperature was high: about 28°C (83-84°F). This was not good, as according to FishBase the maximum temperature limit for Mugil cephalus is 24°C (75°F). Many mullet were still jumping frequently in the lagoon. Mullet were seen “roiling the water” as far as ½ mile up Malibu Creek.

Something possibly similar seems to be going on in the Ballona Lagoon, that long narrow body of water on the east side of the Venice “peninsula.”

This was announced on the Los Angeles birders listserve https://groups.io/g/LACoBirds/ by alert Venice resident Ursula Heise on Tuesday, 13 Aug 2026, when she wrote in:

Just got back from going along Ballona Lagoon/Strongs Drive in Marina Del Rey. There are hundreds of dead fish floating from the ocean toward the Venice Canals: large and small, all kinds of species. Does anybody have info on what’s happening? Or how to report it to LA County Beaches and Harbors? I went to their website, and there seems to be no link to report an environmental issue that also has one concerned about the birds in the area (lots of egrets this morning). Thanks for any help.

Perhaps LA County Beaches might install a prominent link on their website redirecting people to the proper location to report a Beach & Harbor problem if they wish to have nothing to do with it?

One birder replied that such reports can be made to the California Dept. of Fish & Wildlife: https://wildlife.ca.gov/Conservation/Laboratories/Wildlife-Health/Monitoring/Mortality-Report

Another birder wrote that such events can be reported to Los Angeles County Environmental Protection Agency at: 888-700-9995, or by dialing 211 for the National Hotline Service available 24/7, linking people with local community, health and human service agencies. Santa Monica Bay Audubon Society has information at https://smbasblog.com/bird-rescue/ for Bird & Marine Mammal Rescue & Tags.

I contacted Ms. Heise, who was kind enough to supply the photograph below and brief explanatory text. She explained that she’d been running, had no camera, and was stunned to so many dead fish. Other local people she asked knew nothing about it. She went home and returned around 9:45 am with her phone camera, saw that there were “noticeably fewer fish” and only one of the larger fish, but took the photo which is “…not great, but you can see that there are a number of small fish and one midsize one.”

At around 9 am on Thursday, 8/13/26, I observed hundreds of dead fish drifting down the canal along the Esplanade/Strongs Dr. [just south of Washington Blvd. between Anchorage and Jib Sts.] in Marina Del Rey from the Ballona Lagoon north toward Washington Blvd. and the Venice Canals. The fish included very small fish, sardine-sized fish, several large flatfish (halibut or flounder?) and at least one large round fish that looked like a catfish (which it was not, of course, but that was the rough shape and size). None of the pedestrians and utility workers had realized the issue except for one elderly woman, who planned to notify Beaches and Harbors. Upon return 45 minutes later, the number and size of fish had diminished, but there was still a steady flow of dead fish in the same direction. I spoke to representatives of CA Fish and Wildlife (a woman named Karen) and to someone at Heal the Bay.
—— Ursula K. Heise, Venice

If anyone learns anything additional, let me know and I’ll update this post.

Surface Water Temperature chart NOAA Fahrenheit Link. Temperatures in Santa Monica Bay are currently over 70°F.