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The California Sea Otter: Between a Rock and a Hard Place
by Robin Meadows

When it comes to protecting sea otters off the central coast of California, the U.S. Fish & Wildlife Service is damned if it does and damned if it doesnt. By federal law, sea otters must be kept out of most of the states southern coastal waters. But doing so may imperil this threatened species, which, after years of increase, is now declining for unknown reasons.

Sea otters (Enhydra lutris) once ranged all along the Pacific Rim from northern Japan to Baja California, Mexico. Hunted for their luxuriant fur, the otters plunged from as many as 300,000 individuals before intensive harvesting began in the mid-1700s to only 1,000 to 2,000 in 13 small populations by about 1900. When they were finally protected under the 1911 International Fur Seal Treaty, sea otters were thought to be extinct in California.

Then in 1914, 32 sea otters were discovered along the states central coast near Big Sur. The California sea otter population has since grown, albeit slowly, to about 2,000 and its range has inched toward the southern coasts shellfish-rich waters. Therein lies the heart of problem: Sea otters and the shellfish industry are both after the same preyand the otters are not subject to industry regulations. Because sea otters lack the blubber that helps other marine mammals keep warm in the cold ocean water, they have to eat a lot. A single adult male, which weighs about 65 pounds, can go through 20 pounds of abalone, sea urchins, and other shellfish in just one day. Sea otters are such efficient predators that once they move into an area, they can strip it bare of large, accessible shellfish. "The before and after is really a shock," says sea urchin harvester Bruce Steele. "Its hard to comprehend how they can take so much so fast."

Biologists reply that southern Californias shellfish levels are artificially high. They argue that the only reason these coastal waters are so shellfish-rich is that the otters were wiped out there decades ago. Now that the otters are returning, the shellfish populations are merely dropping back to their historical levels.

The conflict between Californias sea otters and shellfishermen last came to a head during the early 1980s. At that time, the biggest threat to the otters was oil spills. The U.S. Fish & Wildlife Service (USFWS) decided to minimize that threat by establishing new colonies in the sea otters historic range. Biologists thought the best bet for a new colony was San Nicolas Island, which lies 60 miles off Los Angeles. But shellfishermen went ballistic at the thought of reintroducing the sea otter into what they saw as their prime fishing grounds.

To appease the shellfish industry, in 1986 the USFWS agreed to set up a "no-otter zone" along the south coast of the state in exchange for establishing a colony at San Nicolas Island. At the time, the compromise seemed like a win-win plan: The shellfishermens livelihood was guaranteed and the otters gained a hedge against being wiped out in the event of a huge oil spill.

But trouble began right away. Although the waters off San Nicolas Island support plenty of shellfish and seem like a perfect place for sea otters, to the bewilderment of biologists the re-introduction of sea otters to San Nicolas has been a complete flop. Between 1987 and 1991, about 140 otters were moved from the main central coast population to the island and at least 50 pups have been born there. But even so, the number of sea otters living at the island has never been higher than 20 since the initial relocation. "Its a huge mystery," says Ventura-based USFWS biologist Steve Alcorn. "For whatever reason, it just hasnt worked."

Five years into the effort to establish a new sea otter colony at San Nicolas Island, biologists learned that there was a second big problem with the plan. Even if the new colony was a complete success, it still wouldnt be enough to protect the species from catastrophic oil spills. The 1992 Exxon Valdez spill killed thousands of Alaskan sea ottersmore than the total California populationand spread more than 400 miles in a month. An oil spill this size could reach the otter populations both along the central coast and at San Nicolas Island.

Furthermore, the USFWS plan to maintain a no-otter zone is easier to do on paper than in real life. Finding and capturing sea otters in the open ocean is extremely time-consuming and expensive. Efforts to remove ten otters reported in the no-otter zone included four week-long boat tripsand even then only two of the otters were caught. Maintaining the no-otter zone in 1992 cost nearly $10,000 per otter captured.

In light of all these problems, last year the Sea Otter Recovery Team, a ten-person advisory panel, recommended ditching the plan to establish new colonies, which would also mean ditching the no-otter zone. Instead, the team recommended allowing the main population to expand naturally along the southern coast.

To the consternation of the shellfish industry, thats just what is happening now. The main population has been expanding steadily along the coast and, as of January 1999, about 150 otters have moved south into the former no-otter zone.

The shellfish industry is accusing the USFWS of breaking its promise to protect their livelihood by maintaining the no-otter zone. The Santa Barbara-based California Seafood Council warns that reneging on this deal will further erode trust in government, and some fear that this could sour efforts to reintroduce predators elsewhere. For instance, USFWSs otter flip-flop could strengthen ranchers opposition to reintroducing gray wolves to the Yellowstone area.

But USFWS biologists say they have no choice. For one thing, moving otters out of the zone probably wouldnt do any good. Biologists now know that moving sea otters is usually a waste of time. "They have strong homing instincts and can navigate accurately back to their capture location over hundreds of miles," says Sea Otter Recovery Team member Katherine Ralls, a National Zoo research zoologist. "We shouldnt move them because many of them will just come back."

More important, moving sea otters from the no-otter zone could harm the species chances of survival. After a decade of steady growth, the California sea otter has declined for four years in a row. The spring count has dropped 12 percent, from nearly 2,400 in 1995 to fewer than 2,100 in 1999. Biologists fear that maintaining the no-otter zone would jeopardize the species further. Capturing and relocating otters is so hard on them that about five percent die, and the population simply cant afford any more losses, says Alcorn.

The USFWSs foremost concern is figuring out why the California sea otter population is declining. In theory, reasons could include fewer pup births, more otters dying of disease, and more otters drowning in fishing gear. Biologists have ruled out the first two possibilities because otter rates of reproduction and deaths due to disease have long been constant.

Although there is no solid link, the California sea otters recent decline does correlate, however, with an increase in fisheries along the central coast. Based on preliminary data, the National Marine Fisheries Service estimates that fishery-related sea otter losses have increased from very few in 1995 to almost 50 in 1998. "Losses of this magnitude would significantly impact sea otter population trends," write Jim Estes and Brian Hatfield of the Biological Resources Division of the U.S. Geological Survey in "Population Status of the California Sea Otter," a 1998 report prepared for the USFWS. They caution that more research is needed to determine whether the increase in fisheries really is harming the sea otters.

While disease is not a factor in the recent decline, it could be detrimental to the California sea otters long-term prospects. Analysis of otter carcasses found cast on beaches since 1992 shows that nearly 40 percent died of infectious diseases such as encephalitis and peritonitis. This high rate of disease could help explain why there are only about 2,000 California otters despite nearly 80 years of protection. The California population has grown only a fourth as fast as the Alaska population (about five percent versus up to 20 percent per year), even though the two populations reproduce at similar rates.

Due to the precariousness of the California sea otter, the USFWS wants to follow the Sea Otter Recovery Teams advice and let the main population expand along the southern coast. But abandoning the plan to establish new colonies in exchange for maintaining the no-otter zone is no simple matter. The California sea otter falls under the jurisdiction of a welter of sometimes-conflicting laws, from the Endangered Species Act to the Marine Mammal Protection Act.

California sea otters even boast their very own law: Public Law 99-625, which Congress passed to authorize the USFWS to establish new colonies. This law also requires the service to maintain the no-otter zone. But there is a final twist: If the new colony at San Nicolas Island is declared a failure, the USFWS must remove all sea otters from both the island and the no-otter zone.

Navigating through all these laws could take until spring 2001and thats if all goes smoothly, says the USFWSs Alcorn. Chances of that are slim. "Weve heard rumbles of a lawsuit from shellfisheries," he says.

Still, the USFWS is undeterred. "Our position is that we dont want to move them because the population is in decline," says Alcorn. "Theres a huge conflict between the Endangered Species Act and the Public Lawbut we think the ESA trumps the Public Law."

ZooGoer 28(6) 1999. Copyright 1999 Friends of the National Zoo. All rights reserved.

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