For All the Fish, So Long?

The jumbo squid arrived off the Northern California coastline sometime around 2002. It didn’t seem unusual at the time: Every ten or twenty years the squid meander up from Central America, following warm currents and the fish they like to eat. They leave a few years later when conditions change. But this time something funny happened: They didn’t leave.

No one’s quite sure why, but for the last six years, California has had a squid problem. “Invasions have been documented throughout the past century,” John Field, a researcher for the National Oceanic and Atmospheric Administration, wrote in a recent paper, but “the spatial and temporal extent of the ongoing invasions appear to be unprecedented in the historical record.”

John McCosker, an eminent research scientist and director of the California Academy of Sciences aquatic biology program, is more blunt: “The squid are moving north, eating most everything in their path,” he says. “It’s like a horror movie.”

The squid’s encampment raises a host of unanswered questions: Does the shrinking of tuna and shark populations mean that there aren’t as many large predators to keep squid in check? Are squid reproducing here or just swimming up from more southerly breeding grounds? Will their eating habits depress local populations of commercially important fish like hake, rockfish, and smaller squid? Most glaringly: Will they ever go away?

One factor that may have prompted their invasion is the ongoing “shoaling” of low-oxygen zones in the Pacific Ocean. Parts of the ocean, particularly in warmer tropical waters, have always had a low oxygen level, but during the last decade, that zone has spread into shallower water along the West Coast. The squid appear to thrive in it—although no one’s certain why.

That’s maybe the most worrying thing about the squid invasion—the possibility that it’s a symptom of broader ocean changes that are altering the habitat for thousands of species. Scientists still lack definite proof, but recent news suggests that it’s a depressing time for ocean health: Warming. Acidification. Dying coral. Chemical and hormonal pollution. Doomed salmon fisheries. Beach-closing blooms of jellyfish.

Some scientists have even suggested that worldwide, we’re watching our oceans go backward 550 million years to the conditions of the Cambrian era, when invertebrates ruled the warm seas and bony fishes hadn’t been invented yet. Could the California squid invasion signal the dawning of the age of a warm ocean full of ill-tempered invertebrates? Or can our local back-boned species hang on, forestalling what some researchers worry may be the end of fish?

The Changing Ocean
About a year ago, Chris Harrold, the Monterey Bay Aquarium’s conservation research director, and I stopped at the aquarium’s signature exhibit, the kelp forest tank: 340,000 gallons of what you would have seen scuba diving in pretty much any kelp forest in the state—thirty years ago. “Can you see this along the coast right now?” I asked.

Harrold paused for a moment. “If you dive the offshore Channel Islands or go down along the coast of Big Sur, to areas that are remote, those are sort of de facto marine reserves because people can’t get there,” he said. “Those kelps forests would look an awful lot like this one.”

“But,” he continued, echoing a common lament among California’s fishermen and divers, “if you dive in areas that are heavily dived, like along the coast of Monterey, it would be quite a bit more sparse. The fishes would be smaller, because scuba divers and recreational fishermen can fish there. And that leads to fewer fish and generally leads to smaller fish as well.”

Others will tell you that marine life isn’t as abundant as it used to be: Fishermen who now have to boat thirty miles to find fish tell stories of friends limiting out in an evening at the dock twenty years ago. Scuba divers talk of picked-over reefs and quiet kelp forests. Free divers and spear fishermen remember rocks plated with abalone and chasing after gigantic fish like white sea bass.

To scientists like Harrold, with decades of experience studying California’s marine environment, it’s clear that the Pacific Ocean is changing. But measuring how much, and which of these changes are normal, cyclical events and which are our fault, he says, “is just a very difficult nut to crack.”

The ocean, and the Pacific in particular, is always under stress. There are dramatic events like El Niño, as well as cyclical fluctuations in currents, temperature, oxygen levels and nutrient upwelling and that’s not even the half of it. “There are so many [factors] that we know,” Harrold says, “and we don’t even know how many we don’t know.”

Here’s what we do know: The ocean is warming, but what portion of that is random fluctuation and what’s long-term change is hard to say, particularly locally. Worldwide, the ocean is becoming more acidic, as the water takes carbon dioxide out of the air and turns it into carbonic acid. Its pH has dropped about a point, which scientists suspect is bad for coral reefs and shelled animals like mussels and oysters, because even a slight change is damaging to their shells.

Meanwhile, polluted water runoff from cities and farms has carried nitrogen and phosphorous out into the ocean, where, along with carbon dioxide from the air, it’s gobbled up by algae and bacteria that quickly suck up all the oxygen in an area, leading to red tides—giant algae blooms—and low or no-oxygen seas. The most famous example is the 20,000-square-kilometer “dead zone” at the mouth of the Mississippi River that appeared in the 1950s and has yawned out ever since.

These factors are leading towards huge changes in the function and constitution of the ocean. Still, it’s a big, resilient place, and since most of the human-caused ocean changes result from accommodating 21st century human needs—feeding and clothing ourselves, getting around—it’s likely we won’t stop without proof that we’re doing great harm. Unfortunately, it’s just as likely the damage won’t be completely evident until it’s done. Given how we rely on a healthy ocean, it isn’t a great place for conducting uncontrolled experiments.

“I don’t know if anyone can tell you if we’ve gone past the point of no return on any particular parameter, but I’m sure almost every scientist could tell you there are points of no return,” Harrold says. “We just don’t know where they are. And we may not find them until we’re there. That’s what’s scary.”

The Missing Salmon
Not long after I met with Harrold, I visited a longtime recreational fisherman who was selling his boat. He couldn’t fish for salmon—once the main reason to fish in California—because the population has entirely collapsed, leading authorities to ban salmon fishing for the last two years. For many Californians, this record low has been one of the most compelling pieces of evidence that fish are in trouble. But how much is the changing ocean behind the salmon’s disappearance?

A clue surfaced in the mid-1990s, when the National Marine Fisheries Service received a petition asking it to list Puget Sound salmon as an endangered species. The NMFS responded with a 1998 report reviewing the status of all salmon species throughout the western United States. Among them were the Central California salmon known as fall-run Chinook.

At the time, the fall-run Sacramento River Chinook appeared to be in good shape, with numbers possibly approaching historic highs. But many of the report’s authors felt those numbers were misleading. While the salmon weren’t immediately in danger of extinction, the report concluded, they were “likely to become so in the foreseeable future.”

Those danger signs weren’t enough to convince politicians to protect the salmon. “Back then there were a million fish, and squaring that with the idea they might go extinct, it just wasn’t possible,” says fisheries service biologist Steve Lindley, one of the report’s co-authors.

Almost exactly ten years later, the population collapsed. More than a million salmon once swam up the Sacramento River every year to spawn. As recently as 2006, there were hundreds of thousands. By the fall run of 2008, there were only 66,000.

That year, for the first time ever, the fisheries service closed the salmon fishing season throughout California. Conditions didn’t improve this year; the economic damage for 2008 has been estimated at more than $250 million and thousands of jobs. “We are feeling a bit vindicated,”  Lindley says.

Lindley, still at the NMFS, was the lead author of a recent report analyzing the salmon collapse and its causes. His report, much like his review a decade ago, portrays a species ill-equipped to deal with environmental change. Salmon have low genetic variability because almost all of them come from hatcheries. Those that don’t must make do with spawning habitat degraded by water pumping, development, pollution, and the arrival of invasive species like overbite clams. While none of these problems individually precipitated the collapse, they made the salmon’s existence precarious enough that a random change in ocean conditions could. It was left to Lindley and his NMFS colleagues to figure out where that change had occurred.

Their conclusion: In 2004 and 2005, the current off California, which usually drives a strong upwelling of cold, nutrient-rich water, shifted, resulting in warmer water and changes in the food chain. Scientists watching the ocean that year noticed seabirds abandoning their Farallon Islands nests, emaciated gray whales, and sea lions swimming far offshore to find food. For that year’s doomed young salmon, the water warmed, and their favorite prey disappeared, just as they entered the ocean. Many starved to death, never returning to the river to spawn.

Ocean conditions returned to “normal” in 2006, so Lindley’s report predicts that the salmon population will probably rebound next year, and even more the year after. But while Lindley doesn’t believe the salmon face immediate extinction, he does think they face a problem with diminishing returns. Without environmental changes, such as improved spawning habitat and water flow, and reduced hatchery production to allow for greater genetic diversity, there are likely to be more of these boom-and-bust cycles as ocean conditions fluctuate.

After each bust, the recovering population will likely get a little smaller and a little more vulnerable. It’ll be like looking at a peak-and-valley line, with each peak a little lower and each valley a little deeper. “It’s just getting lower and lower, and eventually it’s going to crash,” Lindley says.

The Blooming of Jellyfish
Jeremy Jackson, an eminent marine scientist at the Scripps Institution of Oceanography, has looked into the future and predicted the “rise of slime”—the end of vertebrate fish and a dawning era of microbes, algae, and jellyfish. In some parts of the world there do appear to be more jellyfish than there once were. The Mediterranean, where jellyfish seem to have all but displaced fish, is a favorite apocalyptic case study, but around the world, from Puerto Vallarta to Phuket, jellies’ stinging tentacles regularly close beaches.

Jellies’ success has been attributed, in part, to humans: Overfishing has reduced their predators and competitors, farm runoff has created low-oxygen dead zones favorable to jellies because, unlike fish, they don’t need much oxygen to move around, and ocean warming appears to foster their favored planktonic prey while harming the plankton that fish prefer. The Mediterranean in particular has lent itself to slime’s rise: As an enclosed sea, it’s more susceptible to the unholy trinity of water pollution, invasive species, and overfishing.

Algae and microbes thrive in similar conditions, especially in polluted runoff areas. They so rapidly consume the water’s oxygen that their massive blooms leave giant dead zones. Fish swim in…but don’t swim out.

Nothing seems to inspire hyperbole quite like microbes and jellyfish. Daniel Pauly, a fisheries scientist at the University of British Columbia, has said that with oceans turning into a microbial soup, his kids will tell their kids, “Eat your jellyfish!” A similarly bleak report in the journal Trends in Ecology and Evolution earlier this year, written by an international team of scientists from Australia, Africa, and America, was titled “The Jellyfish Joyride.”

But while the idea of a future ocean so thickly filled with creeping jellies that you could walk across them may get scientists giddy, locally, we’re doing okay. “I’m not prepared to say we’ve seen a jellyfish increase,” says Steve Haddock, a jellyfish expert at the Monterey Bay Aquarium Research Institute. “I don’t think there’s any quantitative evidence that shows that.”

After all, he points out, jellyfish come in a huge variety of types, sizes, habits and politeness levels—there are hundreds of species—and they’re probably just as fragile as other parts of the ecosystem. Haddock has read news stories from India, where researchers are worried about jellies disappearing because they are the main food source for endangered turtles, and from China, where researchers are seeding the ocean with jellyfish to ensure a continued viable jelly fishery.

In fact, counting how many jellyfish are actually out there is tricky. That’s the thing about studying jellyfish:
It’s hard. Or rather, too soft. Those much-maligned slime are tough to capture, tag and track, or even find. Jellies live out of the view of remote sensing equipment and don’t show up much in the fossil record.

Researchers resort to approaches like counting them from airplanes, but you can guess at the uncertainties involved in doing that. And even though jellyfish blooms seem startling, they, too, are cyclical. Haddock says he’s seen reports of a massive jelly bloom that closed fisheries in the North Sea, off the coast of Holland—except that this one occurred in the 1700s. Huge blooms have similarly been recorded in the Mediterranean going back a hundred years.

But what is not part of the cyclical pattern, Haddock says, is the arrival of invasive species. Humans are quite talented at doing the Johnny Appleseed thing—ocean-going ships that carry ballast water transplant critters all over the world, including introducing jellyfish to areas where they’ve bloomed like crazy, along with other species that have paved the way for native jellyfish to go nuts. “Anything you do that throws off the balance of the ecosystem is going to have these kind of cascading and probably unanticipated effects,” Haddock says.

Nevertheless, he’s not worried about the rise of slime: “I don’t go into the ‘destroy all evil jellyfish’ camp—they’re kind of part of the ecosystem.” But, Haddock says, “I am worried that when I go scuba diving there’s no big fish, and everything’s totally picked over, and the environment is obviously being degraded by human activity.”

Which raises another question: How overfished is California?

The Plight of the Bony Fish
Overfishing has been rightfully blamed for many of the ocean’s ills. Books like The End of the Line or The Empty Ocean report that the North Atlantic has been picked clean, and that governments in Europe, Africa, and Asia have denied or delayed action while maximizing their harvest to the point of collapse. In California, the question of overfishing is more nuanced—it depends on the species.
First, though, what counts as a California fish?

It’s a surprisingly complex question. There are around one thousand different kinds of fish off the
Pacific Coast, most sharing the common characteristics of the animals that have lived here for the last 500 million years: backbones, gills, scales—although there are some exceptions.

Yet California-specific fish—the kinds you see in aquarium kelp forest tanks—vary wildly. There are native
fish everyone recognizes: salmon, rockfish, halibut, white sea bass, and bright orange garibaldi (the state marine fish, which, despite its diminutive size, is one of the most aggressive creatures in the sea). There’s the stuff the food chain is made of—mackerel, sardines, anchovies, pollock, hake. Then there’s the kind no one except marine biologists doing dissertations have ever heard of—infinite varieties of perch, smelt, gobies and things with funny names like the shortspine thornyfish (also known as the “idiotfish”).

To survey the health of every kind of fish in the ocean would be impossible, but the numbers for one kind of native fish tell a compelling story. Commercial fishing drove the state’s smaller, near-shore fish species, like rockfish, to record lows in the early 1990s. Fishermen took more than 16,700 tons of rockfish in 1991, the peak fishing year since the National Marine Fisheries Service started keeping data in 1950, when the commercial haul was only 3,700 tons.

But things have turned around since the ‘90s, thanks to stricter regulations. Bottom trawling—dragging a net across the seafloor and pulling up everything in it—is banned here. (The US government bans trawl-fishing in West Coast federal waters, as well.) The state has a number of no-fishing marine reserves; regulators are now working on a funding-and-controversy-plagued, but visionary, network of reserves that would be as effective a plan as any at conserving local species. As for the rockfish, the commercial haul in 2007 was only 640 tons. Today, scientists say, groundfish populations—fish, like the rockfish, that live near the bottom in the coastal zone, in roughly ten to one hundred feet of water—appear to be doubling or even tripling.

This is good news—but it only applies to species whose habitat is covered by California or US regulations.
The news for the globetrotting species that visit our waters like tuna, swordfish, and sharks is extremely bad. Bluefin tuna, for example, which can swim back and forth between California and Japan in months, are on the sushi boat to extinction. It’s simply impossible to convince a tuna or shark to stick around in California where the weather’s nice and the fishing regulations severe.

So while the outlook for open-ocean fish is dire, for California’s kelp forest natives, it isn’t too bad. “As long as we’re fishing, and continuing to impact the ocean through warming and other things, it’s not going to be pristine,” says John Field, a researcher at NOAA’s Southwest Fisheries Center, of the possibility that the coastline will return to the aquarium-like conditions that people remember. “But certainly in reserve areas things should look as close to pristine as possible.”

The Squid Invasion
In 2005, Field was out in Monterey Bay doing population surveys of shortbelly rockfish—or at least he was trying to, but his nets kept coming up filled with squid. Field wondered what the squid were eating, so he cut a few open and, sure enough, they’d been dining on shortbelly rockfish. “I thought, ‘Well, new source of mortality,’” Field says. “I’d better study this.”

The squid invasion is an international concern: They moved north from their traditional home off Central America, and south, too, into Peru and Chile. Many Chilean fishermen blame the squid for a hugely reduced catch of hake, and Field would like to know whether that’s true, and to what extent that applies up here as well. (Hake are an important and declining fishery in California.) There’s also recent, intriguing work done with remote hydroacoustic sensors showing that squid are chasing hake and changing their schooling behavior.

Squid may be bothering other species, as well. Although Field doesn’t think it likely that a squid could catch an adult salmon, researchers have discussed—and found plausible—the idea that marauding squid could disrupt salmon schools.

But the squid have predators—sharks, billfish, and tuna may benefit from the invasion. “There’d be winners and losers,” says Field. “Shortbelly rockfish and hake might be on the losing end, and sharks and marine mammals might be on the winning end.”

There’s a qualifier on that, though: It takes a big tuna to catch a big squid, and big tuna are increasingly
scarce. Sharks, tuna, and billfish have been fished to the point where there aren’t many big ol’ honkers around—and that may be one reason the squid are here in the first place.

Are squid here to stay? Settling in to raise a family constitutes a bad sign, but no one’s sure if that’s happening yet. Louis Zeidberg, a postdoctoral researcher at the Hopkins Marine Lab, spent the last year searching for squid babies and actually tried breeding them using in vitro fertilization. He hasn’t had any luck at the water temperatures commonly found in Northern California. “We have been able to do in vitro fertilization at 17 degrees [Celsius], maybe even 15, but I don’t think we’ve been able to do it at 12, which is a typical temperature up here,” Zeidberg says. “However, we are still refining our techniques for fertilization. It’s not a rule-out yet.”
T

he other conundrum is why the squid invasion appears to correspond with the expansion of the low-oxygen zone off of California’s coast. Technically, squid should do worse in those areas—scientists have always thought that squid need more oxygen than fish. But Zeidberg said recent tagging data indicates that instead of swimming willy-nilly after prey, the squid are swimming straight up out of the low-oxygen zone, and then gliding down through the water column—a energy-saving movement, like a human swimmer coming up to breathe and then drifting downward to conserve air—allowing them to thrive in low-oxygen water. Most fish, on the other hand, can’t swim in those zones very well, so the prey there is off-limits; fish that do swim through are often sluggish from lack of oxygen and can become prey themselves.

The squid have long followed the movement of the low-oxygen zone, but it’s changed shape in the last decade, covering more shallow water throughout the eastern Pacific Ocean. It’s happened before, most recently in the 1950s and 1960s. This time, though, the zone appears to be slightly larger. And that’s a reason to worry: Even though many of the events that are fostering the squid’s rise are normal and cyclical, they’re happening with increased intensity, or lasting longer.

“We are noticing very subtle signs everywhere that indicate that things aren’t in balance the way they used [to be],” Zeidberg says. “Maybe the squid’s only going to be here for ten years. But if the typical predator load and typical oxygen levels were in existence the way they were in the 1930s, they should’ve only been here for two years instead of ten. We see these little subtle examples that are pretty indicative of a low level of health for the Earth’s ecosystem. And [the evidence] is not going to be very straightforward until things are really bad.”

The End of Fish?

So here’s the big question. Fish: screwed, or not?

There’s good news: Salmon are expected to—at least temporarily—recover from their collapse. Habitat restoration in the Sacramento River and Delta could help ensure their survival. Groundfish are recovering. California can protect the marine environment and address the acidification and warming issues that go hand-in-hand with climate change. Even the squid invasion may not be the end of the world for fish—or at least for the kinds big enough to bite back.

But big-picture marine scientists are more pessimistic about ocean health and the future of fish than you might imagine. “The ocean you and I inherited was probably better than what we will leave for our children, or grandchildren,” says John McCosker of the California Academy of Sciences, “However, it’s not too late.”

McCosker says the best reason for optimism is that President Obama appears to have placed greater value on the work of scientists, which means that government will more carefully weigh the probable outcomes of our actions— like the “rise of slime” Jeremy Jackson warns about. (For his own part, McCosker has predicted that in Europe and Asia, hit worse by overfishing and jellyfish/microbe takeovers, “the future is muck.”) The Obama administration’s NOAA administrator, Jane Lubchenco, is a marine scientist who’s well-respected by her peers, and McCosker, Chris Harrold and others said they hope the change will mark the end of political interference with ocean science.

But even if Obama’s administration makes changes, the ocean moves slowly, and it may take years before its health improves. For endangered species, “years” is a long time to wait. “I’m hoping that nothing will go extinct in the meantime,” McCosker says. Chris Harrold doesn’t believe that this is the end of fish, but he’s not entirely optimistic either. “Fishes have been around for 500 million years,” he says. “I’ve got to think that humans would go extinct long before fishes or other marine life would. But there are some very disturbing trends, and I don’t think anybody can extrapolate where these trends will take us, because
the ocean is just too complicated.”

Meanwhile, as the conservation research director at one of the world’s largest aquariums—a place that has introduced millions of visitors to the idea of healing the ocean—Harrold has to find a way to keep the customers upbeat. “What hope can we give people?” he asks. “I guess I do believe that the damage that we’re doing is reversible. But the trend and our behavior is not yet there.”


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