The Good, the Bad, the Ugly: Historic Fish Die-Off at Malibu Lagoon – Multiple Causes Could Be to Blame.

By Steve Woods

Unfortunately, the good news of a thriving Lagoon Ecosystem is being followed by the horrible news of a historic Mullet die- off in all parts of the Malibu  Lagoon.

In a few short days from August 22-25 thousands of mature adult Mullets have floated belly up dead in the creek near Serra Retreat, north of the PCH bridge to the Adamson House and over to the newly restored channels of the Malibu Lagoon.

Sadly, hundreds more mullet can be seen jumping airborne gasping for air or gathered in the shallows near the ocean side of the sand berm trying to breathe air that they cannot get in the water or slowly rolling in circles in a slow suffocating death.

The cause of the die off is still unknown but a biologist from the Resource Conservation District of Santa Monica were immediately notified and arrived with extra data sensor probes to test dissolved oxygen and temperature levels along with taking a few dead fish for autopsies.

Rosi Dagit, senior Fish Biologist for the Santa Monica Mountains, is on vacation in a remote mountain area without cell service and no doubt will be saddened with the news upon her return next week.

According to several of her associates and environmental scientist from State Parks, have relayed to California State Parks District Superintendent Craig Sap that the initial theories suggest that all depths of the water column had dangerously high temperatures at about 28 degrees Celsius or 82 degrees Fahrenheit and though the day time dissolved oxygen levels were marginal, the night time levels may have dropped to dangerous levels. Mark Abramson, Senior Watershed Advisor for the The Bay Foundation, stated that the general rule is, “The warmer the water the less oxygen that fish have to compete for.”

This event is the biggest fish die off since 2009 and is much bigger than the mullet die offs of the late 70’s ,,,Craig  Sap said this was the largest he could recall seeing in his years working for the state and added  “I’ve seen—not to this degree—but historically, I’ve seen this happen before. I can’t recall how long ago, but I’ve seen some die-offs,”

I walked around the lagoon with one of the senior fish monitors, Jayni Shuman, who collects fish samples on a regular basis, and we both were horrified by the unfortunate morbid event and in disbelief of the sheer numbers of Mullets  that were dead or dying but noticed that no other populations of native species seemed affected nor did it appear that younger smaller Mullet were dying.

Though the fish net monitoring program does collect and net samples of fish at specific locations around the lagoon and has recorded samples of smaller fish like the endangered Tidewater Gobies, Smelt, Pronghorn Sculpin etc., the team rarely ever netted the large mature Mullets, so no one really knew how many were in the lagoon.

It is obvious that the lagoon supports a large healthy population of mature mullet because many are visibly witnessed jumping and swimming around the shorelines but no one could have imagined that the lagoon was supporting such unprecedented massive numbers of them. Some guesses of floating dead Mullets were as high as 3-5 thousand and how many have survived is unknown but many are still being seen swimming around the floating dead.

Will they all die in short time? The die off event may have been the perfect storm of one of the hottest summers in Malibu history combined with the largest mullet populations in lagoon history all competing for a dwindling oxygen supply.

One fish biologist added that another factor cannot be ruled out, yet with a possibility that the mullet may have been involved in an exhaustive mating activity and when they do, they crowd together tightly to inseminate their mates which may have depleted or reduced their oxygen needs.

Could there have been a toxic waste dumped near the lagoon ? Did Tapia accidentally discharge a toxic load of sewage into the creek up stream? Was the city’s new sewage plant pipes being tested or have a malfunction? Are Colony septic systems still leeching dangerous levels of untreated human waste, toxic household cleansers or flushed pharmaceuticals into the subterranean lagoon hydraulics?

Until the test come back, the initial guesses are inconclusive.  With the historic number of consecutive days of above average hot days in a row heating the water in the lagoon this summer,  it appears to be the root cause but perhaps other factors also added to the deadly stress With thousands of dead mullets that are in a rotting state of decomposition and about to send out a strong stench to the surrounding visitors and residents the question remains.

What to do ? Talks have started with State Park officials whether to let the fish naturally rot back into the natural food chain or hire a contractor to clean out the rotting fish.

Would the dead fish create a toxic stew which could negatively impact the other native species, or would the natural nutrients be a benefit to the food chain much like Salmon that die after they spawn?  Could it cause a human health problem or just a nasal/visual nuisance ? No doubt nearby residents will complain but how will State Parks balance human annoyance with letting nature takes its natural course?

The Malibu Times added some speculation, “locals have raised concerns over alleged failures in the project,  one common complaint is the lack of breeches in the lagoon, meaning lagoon water is not mixing with ocean water.”

All Southern California wetlands and lagoons have a dry season closed berm condition, and a wet season open berm condition when rains naturally break through the sand berm to the ocean.

Lagoon species have evolved and depend on the two distinct open and closed seasonal conditions. Fish and Wildlife will not sign off or condone the out of season breeching of the lagoon to save the non-native Mullets at the expense of the endangered native species in the lagoon which are very adaptive to extreme conditions. It is known that open season tidal circulation creates healthy water quality, but if the lagoon were to prematurely breech during closed berm conditions that thousands of fish would perish due to salt water inundation and a premature man-made breech would flush fresh water into the tide pools also killing most the tide pools creatures.

If you google Mullet die-offs you will find that these unfortunate events are fairly common due to natural environmental changes and the impacts of human pollution.

Over the next several weeks this historic Mullet die off will be investigated by scientist collecting data from the sensor probes at the monitoring stations and the fish autopsies to determine the main cause and possibly any other contributing causes.

Cece Woods

The Current Report Editor in Chief Cece Woods started The Local Malibu, an activism based platform in 2014. The publication was instrumental in the success of pro-preservation ballot measures and seating five top vote-getters in the Malibu City Council elections.

During the summer of 2018, Woods exposed the two-year law enforcement cover-up in the Malibu Creek State Park Shootings, and a few short months later provided the most comprehensive local news coverage during the Woolsey Fire attracting over one million hits across her social media platforms.

Since 2020, Woods was the only journalist reporting on the on-going public corruption involving former L.A. Metro CEO Phil Washington. Woods worked with Political Corruption expert Adam Loew, DC Watchdog organizations and leaders in the Capitol exposing Washington which ultimately led to the withdrawal of his nomination to head the FAA.

Woods also founded Malibu based 90265 Magazine and Cali Mag devoted to the authentic southern California lifestyle.

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