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It happened on January 1, 1997. As in previous years, this New Year's morning brought the annual assessment and subsequent realization that there was definitely more of me to love and behold. Like all
compelling issues confronting me, I formulated a plan of attack. A resolve of healthy activity for mind, body, and spirit. I loaded the long board into the trusty Woody and headed for Maverick's. Surveying the conditions, I slurped
on black coffee. Two words entered my mind: Surf's Up. |
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"You've got a deal, Oscar Knows," SOB promised. With that he slid his goggles down over his eyes.
"Pretty cool, huh, OK Man? A couple of years ago down in Santa Cruz I was a spectator to the life guard competitions by the wharf. You know, the competition where all the young hard-body humans compete to get their water
safety instructor badges. All sorts of great gear comes flying off as they go splashing around that old pier. I spotted these goggles on the bottom -- like they say, finder's keepers! All I know is I got a great pair of goggles and
someone named Jessica D hit the finish line with some real bloodshot eyes." |
Sewage May Be Harming Sea Otters |
Researchers are starting to compile evidence that land runoff or sewage spills may be harming sea otters, possibly even reducing their numbers. And, the researchers warn, otters are a "sentinel species" that can indicate wider harm done to their environment.A recently completed study, funded by a Pacific Grove sewage-spill fine, found several types of bacteria and parasites in otters that are similar or identical to those that cause gastrointestinal disease in humans. One of the study's authors says it's "highly unlikely" that the bacteria and parasites found in the otters originated in the sea, although researchers say they haven't yet found a "smoking gun" linking the presence of those pathogens in otters to sewage spills or coastal runoff. |
Human gastrointestinal diseases found in species |
The study, conducted in 2000-2001 by researchers with the Monterey Bay Aquarium, the state Fish and Game Department's Marine Wildlife Veterinary Care and Research Center in Santa Cruz and the University of California at Davis' School of Veterinary Medicine, analyzed 40 samples of otter feces, mostly from Monterey Bay, to seek direct evidence of pathogens also found in humans and domestic animals from cats to cows. It found many, several detected for the first time in otters.Over the past several years, examinations by the research center of otter corpses found along the Central Coast had implicated infectious diseases in more than 40 percent of those deaths, the study summary said. That's "a very high percentage for a wild animal," said David Jessup, Fish and Game senior wildlife veterinarian and supervisor of the research center.Jessup said "diseases appear to be the big cause" for sea otter population declines in recent years. According to census numbers compiled by Friends of the Sea Otter, a Monterey-based advocacy and education group, California sea otters have dropped from mid-1990s highs of close to 2,400 to about 2,000. The California sea otter is found in coastal waters from Half Moon Bay to near Santa Barbara.Preliminary data had suggested that some of the deaths from infectious diseases were caused by bacteria and parasites found in humans and domestic animals. The recently completed study was undertaken as a first step in seeking a definitive link.Researchers involved in the study are careful to say that further studies are needed to establish whether the pathogens found in otters originated from human or domestic-animal waste, spilling into the sea from sewage or runoff from storm drains and agricultural land. But the study demonstrates the need for further and more elaborate research, they say. |
"We simply were looking at whether pathogens associated with human gastrointestinal illness are found in sea otters," Jessup said. "They are." |
Whether there's a definitive link is a question "we want an answer to," said Monterey Bay Aquarium veterinarian Michael Murray, another of the study's five collaborators/authors. Researchers are now seeking funding for studies involving more advanced techniques, such as DNA comparisons, to pinpoint the source of pathogens found in the otters."Circumstantially there seems to be a relationship" linking the pathogens to human sources, Murray said. "We need more of a smoking gun."The city of Pacific Grove contributed $35,000 for the study just completed, which covered about 90 percent of its cost, Jessup said. That funding came from a $70,000 fine the city was assessed by the Monterey Regional Water Pollution Control Agency for a spill two years ago that dumped 70,000 gallons of sewage into Monterey Bay. In paying the fine, Pacific Grove Public Works Director Stephen Leiker said the city had the option of directing it to state Supplemental Environmental Program projects, instead of having it go into a larger statewide pool."I would rather have the money the city contributed to go to something that could be productive at a local level, especially as it impacts the (Monterey Bay) sanctuary and its health," Leiker said.The full implications of the study go beyond sea otters, affecting the near-shore marine environment as a whole - which means that humans using the sea for recreation and seafood may find that what they've been putting into the sea could come back to harm them. |
"If (otters) pick it up, we have the potential of picking it up as well, because we share the neighborhood," Murray said. |
Otters are a convenient way of getting at the bigger picture because they are an excellent sentinel species. To help stay warm in cold seas they eat 25 percent of their body weight a day in clams, crabs, snails, starfish, abalone and 40 other marine animals. That makes them a "bio-accumulator" of their environment, Murray said.So what shows up in otters is likely common to that environment. Like the canary in the coal mine that will die from poison gas before humans detect it, a sick otter may indicate a sick ecosystem.And prominent scientists though they are, the study's researchers are aware of the sentimental attachment many people have for the otter, the Central Coast's unofficial mascot."All of us have a feeling that otters are aesthetically pleasing and important from a conservation perspective for Monterey Bay and the Pacific Ocean, (but) we also feel they are a very effective sentinel species that allows us to gauge the health of the near-shore marine ecosystem," Jessup said. "They're doing us a tremendous service." |
Here are pathogens found for the first time in otters and that are found in the feces of infected humans, with information on them from the U.S. Food and Drug Administration and the Centers for Disease Control. |
Cryptosporidium, a single-celled protazoal parasite found in two otter feces samples. It is also common in the intestines of people and herd animals, domestic and wild, and causes a disease called cryptosporidiosis that 80 percent of North Americans have had at one time or another, characterized by diarrhea, abdominal cramps, fever and dehydration. It generally lasts two to four days in people with healthy immune systems but can be long-lasting and life-threatening for AIDS patients.- Giardia lamblia, another protazoal parasite, found in one otter feces sample. Found in humans, dogs and cats, mostly commonly from drinking contaminated water. The intestinal illness usually lasts one to two weeks for those with healthy immune systems. - Salmonella, a bacteria found in a dead otter in Santa Barbara County - the otter had suffered from "explosive diarrhea" before death, according to the study. Humans usually get salmonellosis from spoiled or undercooked foods, especially eggs, and symptoms can be severe. - Plesiomonas shigelloides, a bacteria humans get from water-borne sources and that also occurs in many animals. Causes gastroenteritis. Found in seven of the 40 otter feces samples.- Clostridium perfringens, an anaerobic bacteria found in eight of the otter feces samples. People get it from food poisoning, and it causes distress that generally lasts 24 hours.- Camplyobacter, the most common bacterial cause of diarrheal illness in the United States. The illness typically lasts a week for those with healthy immune systems. Found in one otter feces sample. |
If trouble is ahead for the sea otter, it won't be the first time. |
Heavily hunted for their luxuriant fur in the 1800s, sea otters were thought to be gone forever from the California coast by the early 20th century until a group of about 300 was unexpectedly found 13 miles south
of Carmel in 1938.Today's population is descended from that group, and slowly grew to the peak of about 2,400 in the mid-1990s. However, a "low genetic variability" may make them more susceptible to diseases and
environmental changes and may contribute to their slow growth since the 1930s, said Matt Rutishauser, science director for Friends of the Sea Otter.Before the hunters arrived, about a million sea otters lived along the coast from
Baja California up to Alaska and over to Russia and Japan. The survivors have formed three subspecies isolated from each other - the southern, or California, the Alaskan and the Russian.The California sea otter was placed on the
Endangered Species list in 1977, classified as "threatened." In addition to its role as sentinel, otters are considered a "keystone" species that plays a vital role in ecosystem balance by eating sea urchins and
other animals that graze on kelp. By helping enhance kelp forests, otters indirectly foster growth of fish stocks that associate with kelp.The study just completed "really illustrates the link between the land and the
near-shore ocean environment," Rutishauser said. "They found human pathogens in sea otters, and they came from a terrestrial source of some kind. |
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Mysteries of the Animal World: Sea Otters... ``They're Dying" |
Scientists at UC Davis revealed Tuesday that the health of California's sea otter population is even more tenuous than previously thought -- and almost certainly worsened by polluted ocean waters, including contamination from the feces of the ordinary house cat. The most common parasite besieging California sea otters is Toxoplasma gondii, a new study shows, and the otters afflicted with it were four times more likely to die in shark attacks as uninfected animals. The cat is the only animal that sheds Toxoplasma cysts in its feces. "Just like any organism, sea otters can get sick from their environment, and that's what's happening here," said Christine Kreuder, a veterinarian, graduate student of epidemiology at UC Davis and co-author of the groundbreaking study released Tuesday. Unexpectedly, the study also found that -- aside from the parasites, sharks and whirling boat propellers plaguing them -- the otters are suffering from high levels of heart disease. Nearly Two-thirds of the Otters Died of Disease UC Davis scientists, along with researchers at the state Department of Fish and Game, analyzed autopsy results of 105 dead otters retrieved from February 1998 through June 2001. The study found that: -- Thirteen percent of the animals died of heart disease, a previously unknown cause of mortality in this species. -- Nearly two-thirds of the otters died of disease, an alarmingly high number given that 47 percent of the dead creatures were between the ages of 4 and 9 years -- the prime of life for otters and their peak years for breeding. -- About 38 percent of the diseased animals suffered from parasitic infections that can invade the brain and cause seizures, blindness and other neurological ills. SWOLLEN HEARTS While previous studies have found high disease rates among California otters, Kreuder's study is the first to identify heart disease as a significant cause of death. Study co-author Melissa Miller, who conducted the necropsies on the subject animals, found a number of inflamed, enlarged and discolored hearts -- evidence of congestive heart failure. "This is brand new and a mystery," Kreuder said. "Part of my work now is to find the underlying causes, which may be pathogens or nutritional deficiencies. " Previous studies have shown a strong link between contaminated cat poop and dead sea otters, and this study appears to confirm what researchers have suspected: Parasite-ridden otters may die disproportionately from shark attack and boat strikes because they are too impaired to stay out of harm's way. "They are at a severe disadvantage neurologically," Kreuder said. "The (infected otters) shake and twitch, which may attract the sharks' attention. And they may be less likely to stay in protected areas where they can avoid shark interactions." Oddly, the sharks do not appear to be eating the otters they kill. "They appear to be checking them out, in the way sharks do, with a little nip," Kreuder said. "But a little shark nip is major damage to a little sea otter. |
The study does not directly address the unusual number of dead otters found on state beaches this winter and spring -- 100 since Jan. 1 -- but may hold ominous clues to the cause of their demise. Many of this year's victims also have been animals in their prime breeding years, and a large proportion were suffering from infectious disease. The fact that the population now numbers only about 2,000 and is waning, even with a ban on hunting and other protections, is worrisome -- and seems to indicate that incremental pollution, overfishing and other human pressures are enough to threaten the otters' survival. "I don't believe we are going to find a single excuse," said Mike Murray, chief veterinarian for the Monterey Bay Aquarium. "It's likely that we're going to find resource limitations on top of contamination on top of pathogen pollution on top of some other factor." The study fingers the Morro Bay area and the southern end of Monterey Bay as having clusters of suspicious sea otter deaths, giving researchers a starting point to investigate environmental conditions that may contribute to the incidence of disease. The study's highest value may be in helping clarify where research should focus. For example, Toxoplasma gondii -- the same parasite that can cause pregnant women to miscarry -- is spread by exposure to cat feces, and the Sarcocystis neurona parasite through opossum feces. Otters most likely contract Toxoplasma gondii by eating bivalves that filter the floating cysts from contaminated seawater. But so far, nobody knows for sure how feces from these nonnative, land- living animals are washing into the coastal waters in such deadly abundance. No one can yet say what cat owners should do to avoid contributing to the problem or what role feral cat colonies may play. "That is where research is going to be in the future," Kreuder said. "We have to trace it to its source." TAINTED CRABS Solving the problem presented by another killer parasite, acanthocephalans, commonly known as the thorny-headed worm, will require a vastly different approach. Acanthocephalans is a bird parasite that spends part of its life cycle inhabiting tiny sand crabs. Sea otters pick up the worms when they eat the crabs, and the worms hatch inside them and can burrow through their intestinal walls, causing fatal infections. Sand crabs, however, are not a normal part of the sea otter diet -- leading scientists to wonder why the otters are turning to this dangerous food source. Before they were hunted to near extinction, this part of the California coast was home to an estimated 20,000 otters, which raises the question: Is the ocean environment now so depleted by overfishing and pollution that it can't even support one-tenth of the historic population? Research now under way will compare wild otters' current diets with a similar study conducted in the 1980s, when the population was growing. ``What We're Doing Now Will Determine Whether The Sea Otter Population Turns Around" The new tasks facing scientists appear distinctly less enjoyable than previous research, which largely focused on saving stranded otters, nursing them to health and returning them to the wild. Those efforts, intended to save the species in the event of an oil spill, are still crucial. "Bottle-feeding a cute little pup is way easier than opening a dead carcass, " said Dave Jessup, a senior wildlife veterinarian with the Department of Fish and Game. "No way around it. There's nothing cute about a stinky dead animal. "But what we're doing now will determine whether the sea otter population turns around and increases or whether it continues to drop and become seriously depleted," Jessup said. "If we don't figure out what is killing prime-age adults in their reproductive years, then saving all the stranded pups is not going to save the population." THE OTTER CENSUS A study released Tuesday showed that nearly half the southern sea otters found dead from February 1998 through June 2001 were in their prime breeding years - a fact that has ominous implications for the species' ability to rebound. 1982: 1,346 1995: 2,139 Peak: 2,377 Significant clusters of sea otter casualties from 1998 to 2001. |
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Habitat: Found near shore in shallow waters, generally 115 feet deep or less. Kelp beds are the ideal environment for otters. Diet: Carnivores. Feed on marine invertebrates such as abalone, clams, sea urchins, crabs, barnacles, snails, squid, octopuses, chitons, worms and sea stars. Otters eat 20-25% of their body weight each day to maintain their high metabolism. Behaviors: Use tools for feeding; spend hours each day grooming, which keeps the fur waterproof by coating it with oil from the skin; strong sense of smell; excellent eyesight in and out of water. Male and female sea otters usually segregate into separate groups. Predators: After being hunted nearly to extinction in the early 1900s, sea otters became a protected species. Now their biggest threats are from sharks and birds and a degraded environment. Reproduction: Females reach sexual maturity at 3-5 years; males at 5-6 years. Male sea otters mate with several females throughout the year, usually bonding with one female for 3-10 days. A single pup is born to the female a year after breeding. Twins are rare. Pups weigh 5 pounds at birth and are born with a fuzzy coat that prevents them from sinking. The mother cares for her pup up to a year after its birth. Sources: |
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