Ocean Sanctuaries Are a Boon for Fish, Seabirds, and Marine Mammals

Ocean Sanctuaries Are a Boon for Fish, Seabirds, and Marine Mammals

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As we reach the northernmost point of our boat trip, eight miles from our launch, we’re greeted by a raucous cacophony of barks, belches, growls, and harps emanating from the congregation of seals and sea lions on the rocks surrounding the St. George Reef Lighthouse, some seven miles offshore. At least 30 humpback whales swirl around us, their mighty bodies generating waves that rock our cozy, 21-foot boat, making it feel downright inadequate. Strong cuts the engine, and for nearly an hour we take in the heaves and blows and the lunges and crashes of breaching whales, some close enough to our boat that we can see barnacles clinging to their flippers. Upwelling from the California Current, a cold-water conveyor belt that extends from southern British Columbia down to Baja California, draws decaying organic matter and nutrients such as nitrate and phosphate from deep water and delivers them to these shallow, near-shore waters. This, in turn, drives the bounty of phytoplankton, krill, and fish on which the whales beneath us are feeding.

Amid the bustle, the seabirds busy themselves around us. A handful of potato-sized Cassin’s auklets skid across the surface, bouncing and surfing on the calm sea. Two marbled murrelets, federally listed as a threatened species, bob on the water and then dive for a meal of bite-sized krill, sardines, or Pacific herring. A lively conversation of throaty caws and shrill chirps ensues between a common murre father and his nearly fledged chick. This chatter is “a vital lifeline before the chick can feed itself,” says Strong. 

During the spring breeding season, Brandt’s cormorants and common murres pack tightly together, forming salt-and-pepper-hued blankets of nesting colonies, tens of thousands of birds thick. “It’s spectacular, especially on islands like [Castle Rock], where full hillsides are completely covered,” says Strong. From a distance, he says, “you feel like you’re looking at a busy street, or a concert of people. You forget, looking through a scope, how small the birds are.”

For the rest of the year, seabirds are less visible to us, with islands like Castle Rock quieting down like resort towns in the off-season. The birds spend the majority of their lives at sea, linked to land only long enough to raise their young. “If they could hatch eggs on the water surface, they’d never touch land,” says Jensen. “The choke point in their survival is their ability to come onto land and be undisturbed, have their young, and then get back out onto the ocean.”

Seabirds are inextricably linked to the marine ecosystem; they’re near the top of the food chain, consuming 20 percent to 30 percent of pelagic fish production. Although they don’t provide direct services to humans, their role as ecological sentinels is clear. “They’re like a smoke detector,” says Jensen.

Periodically fish populations will falter or crash for reasons that aren’t well understood, and seabirds mirror these changes. In 2009, on Southeast Farallon Island near San Francisco, Brandt’s cormorants had the lowest breeding population ever recorded there, according to a 2010 report by nonprofit PRBO Conservation Science. It concluded that depleted numbers of anchovies and other forage-fish species led to the low breeding success of Brandt’s cormorants and common murres. A 2006 study by University of California-Berkeley researchers attributed the declining populations of marbled murrelets to the collapse of Pacific sardine fisheries in the late 1940s and the depletion of other central California fisheries. That, in turn, led murrelets to fish lower on the food web and hindered their reproductive success.

The northern fisheries I’m visiting are considered relatively healthy compared with those on the Southern California coast, where development and fishing pressures are much higher. Some fishermen argue that fish stocks are flourishing in Northern California waters and that the MLPA regulations are unnecessary. Long-term data are limited, but the area is home to several National Marine Fisheries Service “species of concern”—species whose numbers are reduced but for which there’s too little information to list as threatened or endangered—such as bocaccio, yelloweye, and canary rockfish.

 

On the north coast, fishing for some species is already restricted to May through mid-September. Foul, unpredictable weather further limits the number of viable fishing days. So it’s natural that additional restrictions would cause friction, especially given that the process required people with competing interests—commercial and recreational fishermen, Native Americans, scientists, and conservationists—to agree on which areas should be protected.

After months of discussion and compromise, they came to an agreement. In late 2010 all 31 stakeholders, as well as the team of 21 scientists, supported the plan. In the final scheme, 5 percent of the north coast region has complete protection and 12 percent has partial protection, with limited fishing, including in some key rockfish habitat. The proposal was adopted, unchanged, by the state, and the regulations will take effect in early 2013.

Magazine Category

Author Profile

Amanda Mascarelli

Amanda Mascarelli is a freelance journalist specializing in science, health and environmental issues. Her work appears in publications such as Audubon, Nature, High Country News, Los Angeles Times, Science News for Kids, The New York Times, and others

Type: Author | From: Audubon Magazine

Comments

Ocean sanctuaries, seabirds and forage fish

Editor:
The topic of "forage fish" is a hot one, what with Oceana suing the National Marine Fisheries Service over their management of such organisms and the recent major study funded by Lenfest Foundation. The importance of the topic comes out in the article by Amanda Mascarelli "Life Insurance" (July-August 2012), which provides details on the marine reserves being established along the California Coast through the Marine Life Protection
Act (MLPA). This is cutting edge stuff, the US actually leads the way in the establishment of marine protected areas (MPAs) that actually are marine reserves as well, e.g. the vast Papahanaumokuakea and the Remote Pacific Islands national monuments recently designated. Most of the MPAs that get announced these days allow full-scale fishing, but the growing wisdom in fisheries management has evolved to include no-take MPAs as
necessary tools in providing sustainable catches. That being said, the Life Insurance article includes some important mis-representations. Forage fish are defined as those species that are prey to seabirds, mammals and large fish throughout their entire life cycles: they are bite sized, essentially, and abundant. The California Current is somewhat unique among
similar systems in that the juveniles of rockfish were once the food web currency on which top predators, including salmon, survived and not so much the typical forage species of eastern boundary currents: anchovies, sardines etc. However, an initial miscalculation on the part of fishery managers, in which by virtue of their incredible abundance it was deemed
that rockfish had a forage fish rate-of-recruitment (turnover in a few years) when, as it later was learned (too late, rockfish fisheries now closed), they actually matured late, grew slowly and owing to episodic reproduction needed to live upwards of 100 years for their stocks to
persist. They produced their abundant young, perhaps to be eaten (!), somewhat similar to Atlantic cod (now also gone). The article does touch on this --- the large, most fecund rockfish need to return --- but it should be emphasized that these MLPA reserves, while critical to rockfish recovery, benefitting both human and natural predators alike as well as
the ecosystem, will do little for the highly mobile "forage fish" like sardines, anchovies and krill. A school of anchovies can move through one of these MLPA reserves in a matter of hours. Moreover, the article repeatedly and specifically mentions sardines as important to coastal seabirds (e.g. caption to opening image) when in fact the sardines that occur in coastal waters are larger than most of the seabirds. Certainly a pelican can down an adult sardine but in no way are these fish important to murres, murrelets or cormorants as the article claims. To find small sardines one must travel to the outer reaches of the California Current where the species spawns, often more than one hundred miles from shore, and where these bird species and many mammals are absent (maybe the sardines "know" this, evolutionarily speaking). In the quest for better ecosystem based management, something that the Audubon Society champions, it is important that we have our facts right before we present our arguments in favor of spatial protection of marine resources.

David Ainley
Sausalito, California

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