Fish numbers have increased 329% in four years off the PV Peninsula thanks to new reef – Daily Breeze

The Palos Verdes Reef Restoration Project, which transported tons of rock from Catalina Island to the peninsula’s coast to create a natural reef, has continued to thrive nearly four years after its construction, according to a newly released report.

Giant kelp forests are maturing and fish numbers have reportedly increased by the tons, according to an annual report published this month by the Southern California Marine Institute and Occidental College’s Vantuna Research Group.

Over a period of about four months in 2020, nearly 53,000 tons of rock was moved from two quarries on Catalina Island to the coast of the Palos Verdes Peninsula, where landslides had decimated reefs for decades, to create habitat for marine life and to promote recreational fishing. possibilities.

According to scientists, this was the first restoration project in California to replace reefs with the same material that formed the original reefs.

Daniel Pondella, director of the Southern California Marine Institute and Vantuna Research Group, said in an interview on Thursday, April 25, that marine life began to increase much faster than they expected — and that has continued with some additional positive results.

The project, Pondella said, has not only increased the number of fish around the reef, but also “throughout the study area.”

“Imagine a halo effect that includes both the soft bottom, or sand, around the reefs,” he said, “the number of fish there has increased dramatically, and then all the natural reefs, which are literally a few feet away. ”

Overall, Pondella says, there has been a 329% increase in “fish biomass density,” or 7.86 tons, since just before the 62-acre project was built.

“It’s a huge amount, statistically or biologically, or even just in terms of actual numbers,” Pondella said. “It’s extraordinary.”

The Southern California Marine Institute is involved in the research as the permit and lease holder for the artificial reef and is in charge of the project. The Vantuna Research Group also contributed to the reef design and studies related to the project.

The design of the project, Pondella said, was aimed at replenishing “commercial and recreational species that are economically important.” These include kelp bass, sand bass, California sheepshead and vermilion rockfish.

“We’re actually seeing that across the board,” Pondella said of the increase in these species.

The peninsula’s land has been shifting for centuries, evidenced by the landslides that have buried the reefs, but also by the recent land movements that have red-flagged houses and created other problems on the hillside.

Recognizing this history, Pondella said, the reef was designed to be “resistant and resilient in the face of the sedimentation challenges we see.”

And it worked. “Not a single funeral took place,” Pondella said.

The restored reef was placed on top of the reef covered by landslides. The two reefs are separated only by a “thin layer of sand between a few centimeters to less than a meter,” Pondella said.

“We’ve seen the base of the reef and the currents and the waves scouring and part of that historic reef is now exposed to an area of ​​I think an acre,” Pondella said. “So we see that it is not getting worse, but even better. And this is only one year of data, so hopefully that trend will continue.”

The discovery of DDT and related chemicals, as well as World War II munitions, off the coast of the peninsula in recent years has scientists concerned about the impact of these harmful chemicals on the area’s ecosystem.

The reef project, meanwhile, is part of the National Oceanic and Atmospheric Administration’s Montrose Settlements Restoration Program to “restore fish and habitats,” according to this month’s report.

The long-defunct Montrose Chemical Corporation, located in an unincorporated area of ​​Los Angeles County near Torrance, reportedly legally dumped the synthetic insecticide DDT and other toxic chemicals into the Pacific Ocean for decades until it was declared illegal in 1972. forbidden.

Montrose closed a decade later, but the company was hit with a $140 million settlement by federal agencies for dumping those harmful chemicals into the ocean.

The Palos Verdes Reef Restoration Project was funded in part by that settlement with Montrose.

The past dumpings are a “serious issue,” Pondella said, but are considered outside the zone of their work on the restored reef.

“You don’t want to design a reef that’s going to be fished and have fish that have a lot of DDT and (other man-made chemicals) and other problematic substances,” Pondella said. “So we specifically tested that in advance.”

Currently, according to Pondella, there are no plans to expand the restoration project along the peninsula, but it will be used as a model for future major infrastructure projects, such as offshore wind farms.

“The idea is that when you build a project, you use the best science possible so that you not only create the infrastructure that we need to protect the coastline,” Pondella said, “but you also use the science to ensure that the way the project is built, it creates a positive impact on the environment.”