In Channel Islands Harbor, sea bass have a place to grow

Thousands of juvenile white sea bass are nestled away in a Channel Islands Harbor dock where they’re given a fighting chance at maturity.

Nets and fencing protect them from predators. Regular feedings help them grow. Volunteers check on them daily, take note of their behavior and clean their two pens.

But all the precautions and amenities can’t protect them from water toxicity that flows into the harbor after most rain storms.

In November, the facility ― called a grow-out pen — received about 8,300 sea bass as part of the state-funded Ocean Resources Enhancement and Hatchery Program.

That number had been diminished to less than 4,000 by the end of December due to heavy rainfall that pelted Ventura County that month, said Frank Sullivan, the Channel Islands Harbor pen operator.

The ocean program started in 1982 and focused on California halibut and white sea bass, said Valerie Taylor, the state's Department of Fish and Wildlife program coordinator.

By 1990, the reported number of halibut caught by anglers had started to rebound, but sea bass continued to decline. As a result, researchers began solely concentrating on sea bass, Taylor said Monday.

The program helps researchers determine the feasibility of strengthening fish populations along the California coast through the use of hatchery raised stock, Taylor said.

Funded through sport and commercial fishing licenses stamped for ocean use, the program has a $1.85 million budget this fiscal year, which ends on June 30, Taylor said. Funds cover the hatchery costs and research.

The state provides the Oxnard facility with the fish and medical support, but Sullivan and his crew rely on volunteer hours and fundraisers to run the day-to-day operations.

The Channel Islands grow-out pen typically runs on $1,500 to $2,000 each year, said Sullivan who has been with the local facility since 2004. The Oxnard facility opened in 1992, 10 years after the state program launched.

Located near the Channel Islands Sportfishing building, the small facility is covered with a canopy to keep the water cool. Underwater nets attached to two docks to create three pens, but only two are currently in use.

Resource 'we've been enjoying'

Sullivan is one of 10 regular volunteers who care for the fish. But if he puts a call out for help on social media, he gets upward of 20 to 30 volunteers.

Some are conservationists who have never held a fishing pole, but most are avid anglers.

"We're interested in giving back to the resource that we've been enjoying," Sullivan said.

A hatchery owned and operated by Hubbs-SeaWorld Research Institute in Carlsbad provides 4- to 6-inch sea bass to 13 grow-out facilities in Southern California, according Fish and Wildlife.

When it comes time to release the fish in the spring, the sea bass are about 8 to 10 inches long, Sullivan said. Volunteers wait for a moonless or overcast night when the current is receding from the harbor. Then they drop the nets and release the stock.

The darkness and tide gives the young fish a head start on ocean predators.

It’ll take another three to five years in the wild for the sea bass to reach the legal take limit of 28 inches, Taylor said.

A fish raised in Channel Islands Harbor in 1997 was recaptured in 2009 and weighed about 33 pounds, Sullivan said in an email. Two more raised in 1997 were captured in 2002 near Catalina Island and weighed about 10 and 18 pounds.

Officials are able to identify the fish by through a magnetic tag in gill.

While the stock regularly die in captivity, the number of deaths jumps up from one or two per day to hundreds after a storm.

“It puts chemicals in the water that aren't usually there,” Sullivan said referencing the trash and runoff the flows into the harbor.

Sullivan said about 75% of the fish raised in the local facility typically survive captivity. Less than half will be released this year.

Following the December storms, fish continued to die off for weeks. It wasn’t until scientists treated the pens with peroxide that deaths started to taper. Volunteers also fed the stock medicated pellets to help them recover.

While the county received heavy rainfall earlier this month, Sullivan said Friday he hasn’t seen significant deaths. It could mean the peroxide and medication are having lasting effects. Or that volunteers haven’t been able to find the carcasses.

When they die, the sea bass fall to the bottom of the pen where they are hidden by the water’s depths and shadows, Sullivan said. The carcasses are then collected by the volunteers.

A total of 2.7 million white sea bass have been released during the 41 years the program has been operating, according to state figures. As of 2022, the Channel Island Harbor pen released about 253,600.

To volunteer with the local replenishment effort, reach out to Sullivan at fransull@charter.net.

Brian J. Varela covers Oxnard, Port Hueneme and Camarillo. He can be reached at brian.varela@vcstar.com or 805-477-8014. You can also find him on Twitter @BrianVarela805.

This article originally appeared on Ventura County Star: Sea bass growing at Channel Islands Harbor part of state program