Shrinking size threatens species' ability to reproduce
By DAVE DOWNEY
Sunday, May 10, 2009
As environmentalists and fishermen spar over what proportion of coastal Southern California waters should be protected as a sort of ocean wilderness, scientists say one thing is clear: The marine environment along San Diego and nearby counties is far from pristine.
"There's been growing concern within the state and the region about the overall health of the near-shore ecosystems, partly due to over-exploitation, partly due to habitat loss and partly due to pollution," said Charlie Wahle, a senior scientist for the federal government in Monterey.
That concern has spawned a campaign to redesign and expand a system of state reserves all along California's 1,100-mile-long coast.
For the past several months, the state has been focusing its efforts on Southern California between Santa Barbara and the U.S.-Mexico border. And debate is heating up among fishers, divers, environmentalists, scientists, public officials and others over how much of the ocean should be fenced off from fishing and other activities to boost declining populations of marine animals.
Whatever the result of that debate, several signs suggest that not all is well.
Hard to find
Rockfish populations collapsed during the 1990s and are struggling to recover today, scientists say. Four species of rockfish are common in Southern California, including the cowcod, bocaccio and canary, and less than one-quarter of their original populations remain, according to a state report.
Not only are numbers down for rockfish and other groups of species, the fish are half as big as two decades ago, scientists say.
Conditions are particularly dire for the seven species of abalone in Southern California, where the soft-shelled animals used to be plentiful.
Kate Hanley, marine conservation director for the environmental group San Diego Coastkeeper, said, "If you talk to an old-timer around here, you'll find that you used to be able to just walk along the shore of La Jolla and scoop up an abalone and have it for dinner."
Abalone are hard to find now.
Populations of all the abalone species have declined to tiny fractions of what they were, said Ed Parnell, a marine ecologist who conducts research for UC San Diego's Scripps Institution of Oceanography, in a telephone interview last week.
And the situation is so dire for one species ---- the black abalone ---- that it was declared by federal officials in January to be in danger of going extinct.
"Black abalone are all gone off San Diego," Parnell said. "They've been hit by both overfishing and disease."
On the rebound
At the same time, not all is lost, he said: "Many species are doing pretty well offshore here."
Parnell said that kelp bass and sand bass are still common, for example.
And a state report last fall said the population of giant sea bass, which plummeted last century largely as a result of overfishing, has rebounded since the state banned fishing with gill nets in 1994. But it is still well below historical numbers.
The plight of California's near-shore animals was the driving force behind a new state law passed a decade ago, calling for a complete overhaul of the state's existing, fragmented system of marine protected areas. Such places restrict or ban harvesting of marine life.
It has taken a long time for the project to get off the ground, however. State officials launched an effort to retool the system several years ago, only to have it collapse amid a groundswell of opposition from the fishing industry. Stunned fishermen protested when officials abruptly announced they planned to substantially expand marine protected areas off La Jolla and Point Loma, and to create one off Camp Pendleton Marine Corps Base.
A marine protected area is much like the wilderness area and habitat conservation plan on land, in which human activities are restricted to protect a variety of wildlife. The focus is waters the state has control over ---- from the shore to three miles out.
Closed to fishing
Despite the earlier disaster, the state is at it again.
But this time, fishers were brought in at the front end. Rather than leaving them in the dark and letting them react to someone else's plan, state officials invited fishers to sit on a regional stakeholder group of more than 60 people representing ocean users, environmentalists, scientists and others. The group is preparing to refine a set of draft proposals for a new system of reserves in Southern California later this month.
The state successfully used that strategy to design marine protected areas in Central and Northern California. But observers say it will be much more difficult to carve out an acceptable compromise in the heavily populated, heavily fished southern part of the state.
Nevertheless, the state Department of Fish and Game is aiming to deliver a plan by fall through something called the Marine Life Protection Act Initiative. In the meantime, this summer promises to be a hot one ---- at least in terms of debate over the merits of fencing this or that section of state waters off from fishing.
In San Diego County, say scientists and fishers, the biggest fight again is expected to focus on La Jolla and Point Loma. And there may be a move to close waters off the North County coast near Encinitas and Solana Beach, they say.
As for Camp Pendleton, the military has made a pitch to leave that area open to avoid conflict with amphibious exercises.
Dave Rudie owns Catalina Offshore Products, a San Diego seafood company that harvests sea urchins. A member of the regional stakeholder group, Rudie said the state should avoid closing too-large areas because it could backfire. He said controlling sea urchin populations helps the environment by preventing the animals from devouring kelp beds.
The underwater forests of seaweed that tend to concentrate along rocky reefs is one of the local bright spots in an otherwise murky picture.
"San Diego County has relatively healthy and robust kelp systems," said Hanley of San Diego Coastkeeper.
But most fish species have declined.
"Fishermen are now catching less than half of what they caught in 1990," Hanley said. "And the fish that they do catch are 45 percent smaller."
Size is a problem for several reasons. One, said Hanley, is that large female fish produce exponentially more eggs than smaller females.
"You always want big old fat females around ---- at least in the fish world," she said.
In an underwater world with smaller females, there is less chance to reproduce, she said.
Karen Garrison, co-director of the Natural Resources Defense Council's oceans program, said size also is a huge concern for one particular species: the California sheephead.
In a curious phenomenon, all sheephead hatch as females. It is only when they get older that many develop into males.
And, so, said Garrison, as sport fishermen take large sheephead for trophies, they inadvertently thin out males, a trend that threatens the species' survival.
"They are systematically taking males out of the population," she said.
Fishing also has been blamed for the precipitous drop in the number of black abalone. But the National Oceanic and Atmospheric Administration's Fisheries Service, in placing the shellfish on the endangered species list this year, said the primary factor in the creatures' demise was the spread of a bacterial disease known as withering syndrome.
"It's clear that our management isn't adequate to keep our ecosystems in shape," Garrison said.
Rudie begs to differ.
"In the last 10 years, things have rebounded because of good fisheries management," he said.
Yes, there may be a need for more management tools, such as the reserves that are in the making, he said. But Rudie said the state must recognize the progress that has been made to date and avoid going overboard in drawing new boundaries for marine protected areas.
"The fishing groups are not against marine protected areas. We are proposing some of them," Rudie said. "We just don't want to be put out of business in this experiment."