— Squid are part of ocean’s core food web; in 2014, California sardines crashed

In recent years scientists have gained a deeper understanding of sardines’ value as “forage fish,” small but nutrition-packed species such as herring and market squid that form the core of the ocean food web, funneling energy upward by eating tiny plankton and being preyed on by big fish, seabirds, seals and whales.

From the Los Angeles Times
January 5, 2014
By Tony Barboza

The sardine fishing boat Eileen motored slowly through moonlit waters from San Pedro to Santa Catalina Island, its weary-eyed captain growing more desperate as the night wore on. After 12 hours and $1,000 worth of fuel, Corbin Hanson and his crew returned to port without a single fish.

“Tonight’s pretty reflective of how things have been going,” Hanson said. “Not very well.”

To blame is the biggest sardine crash in generations, which has made schools of the small, silvery fish a rarity on the West Coast. The decline has prompted steep cuts in the amount fishermen are allowed to catch, and scientists say the effects are probably radiating throughout the ecosystem, starving brown pelicans, sea lions and other predators that rely on the oily, energy-rich fish for food.

If sardines don’t recover soon, experts warn, the West Coast’s marine mammals, seabirds and fishermen could suffer for years.

The reason for the drop is unclear. Sardine populations are famously volatile, but the decline is the steepest since the collapse of the sardine fishery in the mid-20th century. And their numbers are projected to keep sliding.

One factor is a naturally occurring climate cycle known as the Pacific Decadal Oscillation, which in recent years has brought cold, nutrient-rich water to the West Coast. While those conditions have brought a boom in some species, such as market squid, they have repelled sardines.

If nature is responsible for the decline, history shows the fish will bounce back when ocean conditions improve. But without a full understanding of the causes, the crash is raising alarm.

An assessment last fall found the population had dropped 72% since its last peak in 2006. Spawning has taken a dive too.

In November, federal fishery managers slashed harvest limits by more than two-thirds, but some environmental groups have argued the catch should be halted outright.

“We shouldn’t be harvesting sardines any time the population is this low,” said Geoff Shester, California program director for the conservation group Oceana, which contends that continuing to fish for them could speed their decline and arrest any recovery.

The Pacific sardine is the ocean’s quintessential boom-bust fish. It is short-lived and prolific, and its numbers are wildly unpredictable, surging up and down in decades-long cycles in response to natural shifts in the ocean environment. When conditions are poor, sardine populations plunge. When seas are favorable, they flourish in massive schools.

It was one of those seemingly inexhaustible swells that propelled California’s sardine fishery to a zenith in the 1940s. Aggressive pursuit of the species transformed Monterey into one of the world’s top fishing ports.

And then it collapsed.

By mid-century sardines had practically vanished, and in the 1960s California established a moratorium on sardine fishing that lasted 18 years. The population rebounded in the 1980s and fishing resumed, but never at the level of its heyday.

Since the 1940s scientists have debated how much of the collapse was caused by ocean conditions and how much by overfishing. Now, researchers are posing the same question.

“It’s a terribly difficult scientific problem,” said Russ Vetter, director of the Fisheries Resources Division at NOAA’s Southwest Fisheries Science Center.

Separate sardine populations off Japan, Peru and Chile fluctuate in the same 50- to 70-year climate cycle but have been more heavily exploited, Vetter said. West Coast sardines are considered one of the most cautiously fished stocks in the world, a practice that could explain why their latest rebound lasted as long as it did. The West Coast’s last sardine decline began in 1999, but the population shot back up by the mid-2000s.

In recent years scientists have gained a deeper understanding of sardines’ value as “forage fish,” small but nutrition-packed species such as herring and market squid that form the core of the ocean food web, funneling energy upward by eating tiny plankton and being preyed on by big fish, seabirds, seals and whales.

Now, they say, there is evidence some ocean predators are starving without sardines. Scarcity of prey is the leading theory behind the 1,600 malnourished sea lion pups that washed up along beaches from Santa Barbara to San Diego in early 2013, said Sharon Melin, a wildlife biologist at the National Marine Fisheries Service.

Melin’s research indicates that nursing sea lion mothers could not find fatty sardines, so they fed on less nutritious market squid, rockfish and hake and produced less milk for their young in 2012. The following year their pups showed up on the coast in overwhelming numbers, stranded and emaciated.

We are likely to see more local events like this if sardines disappear or redistribute along the coast and into deeper water,” said Selina Heppell, a fisheries ecologist at Oregon State University.

Biologists also suspect the drop is hurting brown pelicans that breed on California’s northern Channel Islands. The seabirds, which scoop up sardines close to the ocean surface, have shown signs of starvation and have largely failed to breed or rear chicks there since 2010.

Brown pelicans were listed as endangered in 1970 after they were pushed nearly to extinction by DDT, which thinned their eggshells. They were taken off the list in 2009 and now number about 150,000 along the West Coast.

Though pelicans have had more success recently in Mexico, where about 90% of the population breeds, environmental groups think the lack of food at the northern end of their range could threaten the species’ recovery.

Normally, pelicans and sea lions would adapt by instead gobbling up anchovies. But aside from an unusual boom in Monterey Bay, anchovy numbers are depressed too.

“That does not bode well for everything in the ocean that relies on sardines to get big and fat and healthy,” said Steve Marx, policy analyst for the Pew Charitable Trusts, a nonprofit that advocates for ecosystem-based management of fisheries.

Fishermen also attest to the scarcity.

The West Coast sardine catch oscillates with the market and was valued at about $14.5 million in 2013, according to the National Marine Fisheries Service. But California fishermen pulled in just $1.5 million worth of sardines last year, preliminary data from state Department of Fish and Wildlife show.

Just a few years ago, Hanson, the sardine captain, didn’t have to travel far from port to pull in nets bulging with sardines.

Not anymore. If his crew catches sardines these days, they are larger, older fish that are mostly shipped overseas and ground up for pet or fish food. Largely absent are the small and valuable young fish that can be sold for bait or canned and eaten.

Still, when he embarked for Catalina Island on a December evening, Hanson tried to stay optimistic. “We’re going to get a lot of fish tonight,” he told a fellow sardine boat over the radio.

After hours of cruising the island’s shallow waters, the voice of another boat captain lamented over the radio, “I haven’t seen a scratch.” So the Eileen and other boats made an about-face for the Orange County coast, hoping to net sardines in their usual hideouts.

No such luck.

By daybreak, Hanson was piloting the hulking boat back to the docks with nothing in its holds.

tony.barboza@latimes.com

http://articles.latimes.com/2014/jan/05/local/la-me-sardine-crash-20140106

Posted under Fair Use Rules.

Advertisements

As Pacific sardine collapse worsens, scientists worry about ecosystem ripple

Researchers can’t tell exactly what’s driving the die-off…”Those ocean life patterns are just not working the way they have in the past,” said Michael Milstein, a spokesman for the National Oceanic and Atmospheric Administration.

From the Oregonian

By Kelly House | The Oregonian/OregonLive
Email the author | Follow on Twitter
March 10, 2016

Charts on website

Nearly a year into a West Coast sardine fishing ban enacted to protect the collapsing population, the fish formerly worth more than $8 million to Oregon’s economy have shown no signs of a comeback.

New federal research indicates numbers of the small, silvery, schooling fish have plummeted further than before the fishing moratorium, dashing any hope of lifting it in 2016.

With the current sardine population hovering at 7 percent of its 2007 peak, fishermen now say they expect to wait a decade or more to revive the fishery.

“I don’t want to take a pessimistic view, but I would think we’ll be shut down until 2030,” said Ryan Kapp, a Bellingham fisherman who advises the Pacific Fishery Management Council on sardines and other fish.

Sardines aren’t struggling in isolation. Other fish near the bottom of the marine food web, such as anchovies and herring, are also down. The shortage of sustenance is rippling upward to create crises for predator species from seals to seabirds.

Researchers can’t tell exactly what’s driving the die-off, nor how long it will last. Some say the crash can be attributed to cyclical boom-and-bust population dynamics sardines have always exhibited.

Others argue overfishing played a role, driving sardine populations down too far and too fast to blame it on a natural population flux.

Then there’s the unavoidable presence of the “warm blob,” a lingering mass of overheated water that for more than two years has wreaked havoc on sea life off the Pacific coast.

Those ocean life patterns are just not working the way they have in the past,” said Michael Milstein, a spokesman for the National Oceanic and Atmospheric Administration, the federal agency that tracks sardine numbers. “There’s a feeling that a lot of this is environmentally-driven.”

RIPPLES IN THE FOOD CHAIN

The Pacific fishery council’s rules call for a fishery shutdown if the total weight of adult sardines falls below 150,000 metric tons. When the population fell below that threshold last spring, council members scrambled to enact a midseason shutdown.

Federal scientists last month estimated sardine biomass has dropped below 65,000 tons this year.

Even with fishing pressures lifted, sardines could struggle to bounce back in an ocean devoid of their main food source. The lipid-rich coldwater plankton that sardines like to eat have become scarcer in West Coast waters, replaced by tropical species with less appeal to the region’s predators. Scientists suspect the warm blob is causing the plankton shift.

Without that food source, “the whole system can suffer,” said Kerry Griffin, who manages sardines for the Pacific Fishery Management Council.

The end result is ominous for more than just fishermen. Oily sardines are a key food source for larger ocean-going animals. As that option becomes scarce, predators switch to less-nutritious food options and can end up starving.

Scientists believe that chain reaction is already playing out in a big way. A group of National Oceanic and Atmospheric Administration researchers last week released a study linking the sardine collapse to the surge in starving sea lion pups washing ashore along the California coast. The scientists who authored the study say they expect the mass starvation that stranded 3,000 pups last year to continue as long as forage fish numbers remain low.

Similar phenomena have been observed among other species that target small schooling fish for food. Brown pelicans are failing to breed, dead Guadalupe fur seals are washing ashore in California, undersize salmon are returning to Canadian spawning grounds and seabirds are washing ashore weakened or dead on the Oregon coast.

OVERFISHING?

Environmentalists for years warned that a sardine collapse was imminent. Now they have begun lobbying to get more conservative harvest policies in place before the fishery reopens.

Research shows that overfishing intensifies the cyclical downturns of sardines and other small fish, and ocean conservation groups argue current West Coast standards are too permissive to prevent overfishing.

Ben Enticknap, a Portland-based campaign manager for the international conservation group Oceana, said the group is pushing the council to adopt new standards that would trigger a fishing ban once the sardine stock drops below 640,000 metric tons. That trigger point is more than four times higher than the current level.

The group is also lobbying for a rule to prohibit fishermen from hauling in more than 15 percent of the adult population in a given season. In the final years of harvest before last year’s shutdown, fishermen caught as much as 28 percent of the adult sardines in the water.

“Fundamental flaws in management have to be fixed, or this crash will be repeated in the future,” Enticknap said.

CAUTIOUS OPTIMISM

Although the overall results of this year’s sardine count were discouraging, scientists say there’s a glimmer of hope.

Several years of poor reproduction helped drive down the sardine population. In their latest trawl, scientists saw evidence that 2015 was a good spawning year.

It’s too soon to tell whether the reproductive success signals a turning point.

“There are some potentially positive signs there,” Milstein said, but in order to boost population counts, “the young need to survive long enough to make it into the mature population.”

–Kelly House

khouse@oregonian.com
503-221-8178
@Kelly_M_House

http://www.oregonlive.com/environment/index.ssf/2016/03/as_pacific_sardine_collapse_wo.html

Posted under Fair Use Rules.