Withering Syndrome
Will the Fish and Game Commission
allow renewed shipments of infected abalone into northern California
under an endorsement from the Department of Fish and Game?
As of February 2000, the answer is YES!!!
By March 2000, the answer is back to no.
Then, in May 2000, we're back to YES!!!
What are abalone?
Abalone is the common term for marine mollusks (sea snails) that are highly valued as a seafood delicacy worldwide. California coastal waters are populated by five commercially and culturally valuable abalone species: red, black, green, pink, and white abalone. These species share overlapping natural ranges encompassing most of the coastline of the State of California and much of the West Coast of Mexico's Baja California. Other regions of the world host different abalone species.
Not very many years ago, abalone carpeted the bottom of near shore waters from Mexico to Oregon wherever sandy bottom gives way to the rock habitat preferred by abalone. This is largely still the case north of San Francisco where commercial harvesting and recreational harvesting while using SCUBA equipment have been prohibited for more than 50 years. But south of San Francisco, seemingly inexhaustible supplies of abalone have been steadily whittled away over the past 150 years. In 1993 and 1997, indefinite moratoriums were imposed on the harvesting of abalone from all California waters south of San Francisco. These moratoriums followed catastrophic declines in the populations of all five species.
North of San Francisco, where only red abalone is commonly found, one of the world's premier abalone fisheries continues to thrive. An estimated 40,000 individuals participate each season in a recreational fishery that is valued at $20,000,000 per year. Commercial harvesting north of San Francisco has been prohibited since the 1950s.
Red abalone is also the focus of numerous aquaculture operations along the California coast.
What is Withering Syndrome?
In 1985, commercial abalone divers working the near-shore waters of Santa Cruz Island off southern California reported finding large numbers of sick and dying abalone. Initially limited to black abalone, affected animals were severely shrunken inside their shells. These weakened animals could not maintain their normal grip on the rock substrate and large quantities of empty shells indicated that massive die-offs had occurred in place. The term "Withering Syndrome" was coined to describe this malady: progressive atrophy of the foot muscle, weakness, weight loss, lethargy, little response to touch and eventual starvation. Within a few years, Withering Syndrome was found to have spread to animals along the entire California coastline south of Pt. Conception and into Mexico. Worse, the malady was found to affect green, pink, and red abalone as well as blacks.
In 1998, Dr. Carolyn Friedman determined that Withering Syndrome is the terminal phase of a bacterial infection. Once animals exhibit the visual signs of Withering Syndrome, they are doomed to expire within a few months.
How Bad is Withering Syndrome?
Withering Syndrome is 100% fatal. Once an animal displays the overt symptoms of Withering Syndrome, it will die within a few months.
Withering Syndrome is responsible for reducing southern California's populations of black abalone by more than 99% throughout its range. Black abalone was recently added to the list of candidate species for endangered status under the Endangered Species Act and some scientists close to the situation believe green abalone will follow suit.
Withering Syndrome has also been found in pink, green, and red abalone. The impact of Withering Syndrome on these species is unclear in southern California where an intense recreational and commercial fishery existed until it was closed on an emergency basis in 1997. By then, almost all concentrations of these species in southern California had been eliminated and arguments continue to this day as to whether this was the result of human harvesting pressure, disease, or other causes. Southern California currently has only a few relatively dense, localized populations of red abalone; most notably, San Miguel Island. A 1997 survey at San Miguel Island found Withering Symptoms in about 5% of the red abalone examined at some locations. The 1999 survey at San Miguel Island discovered a dramatic decrease in numbers of abalone at Cyler Harbor and high numbers of fresh shells indicated significant mortality of abalone, suggestive of Withering Syndrome.
The impact of Withering Syndrome on wild red abalone is only now beginning to receive attention and closer scrutiny. Developments in southern California suggest that the causative agent of Withering Syndrome may be as devastating over time to red abalone as it has proven to be for black abalone.
Has Withering Syndrome been found in northern California?
No.
What causes Withering Syndrome?
The massive die-offs of black abalone led directly to the 1993 closure of that fishery for the entire State of California. It also motivated basic but limited research to determine the cause of Withering Syndrome. After years of difficult work, the foremost researcher in this area, Dr. Carolyn Friedman of the Bodega Marine Lab, was able to identify the causative agent for Withering Syndrome as an "RLP-like Procaryote" (RLP); that is, a newly discovered bacteria. The RLP bacteria infect the digestive system of the animal. When sufficiently developed, the effect is that the animal slowly starves to death even in the presence of an abundant food supply. Withering Syndrome is the terminal stage of an RLP-infection where the effects of starvation are visibly apparent.
Has RLP been found in northern California?
Yes. RLP has been found in northern California aquaculture facilities and at two locations in the wild.
In 1998, the California Department of Fish and Game (CDFG) came to two realizations: that RLP was the likely cause of Withering Syndrome and that CDFG had been authorizing the transfer of RLP-infected abalone from southern California to northern California aquaculture facilities. Inspection of animals from California's aquaculture facilities quickly confirmed RLP-infested facilities from southern California nearly to the Oregon border.
Starting in 1998, CDFG began limited surveys of wild abalone populations to determine the rough geographical distribution of RLP. Those surveys found that wild abalone as far north as the San Mateo coast were infected with RLP that had progressed to Withering Syndrome. North of San Francisco, two of six sites surveyed were found positive for RLP in wild red abalone.
Can RLP be eliminated from an infected abalone?
No.
Treating infected abalone with antibiotics can reduce the intensity of the infection but does not eliminate it. This is a hopeful development for aquaculture operations but has no practical application for wild abalone populations.
Does RLP always lead to Withering Syndrome?
Maybe.
There are some hopeful indications that RLP-infected abalone may not develop Withering Syndrome. Over a period of seven months, RLP-infected red abalone kept in a laboratory in 15° C/58° F water did not develop Withering Syndrome. Extrapolation of the laboratory results to the natural conditions along California's north coast offers some cause for optimism but have not been verified as yet.
Laboratory experiments are strongly suggestive that Withering Syndrome develops faster and is more virulent if RLP-infected animals are stressed by elevating the temperature of the water they are held in. One experiment, for example, stressed RLP-infected red abalone by increasing water temperatures 4° C/7° F. A control group obtained from the same source was kept in water maintained at the same temperature (15° C/58° F) in which all the animals were raised. Over the seven-month period of this experiment, the abalone kept in warmer water developed Withering Syndrome while the control group did not.
Being one of the few laboratory experiments using red abalone, the results of this experiment suggest some hopeful possibilities. Specifically, that colder water may offer intrinsic protection against the development of Withering Syndrome. Limited anecdotal evidence exists that supports this hopeful prospect. But before embracing this theory as a cornerstone for resource management decisions, other questions need to be answered.
Near-shore ocean temperatures along the California coast from Oregon to San Miguel Island south of Pt. Conception vary surprisingly little most of the time and they average some few degrees lower than those used in the experiment described above. Yet Withering Syndrome was found in up to 5% of the red abalone surveyed at San Miguel Island in 1997. 1999 surveys of the same areas revealed dramatic decreases in red abalone populations possibly attributable to Withering Syndrome.
In response to the spread of Withering Syndrome, the CDFG only began underwater surveys off central and northern California in 1998. Fewer than a dozen sites have been surveyed so far and many of those were completed south of San Francisco. So far, Withering Syndrome has been found in the wild off the San Mateo coast just to the south of San Francisco.
Everyone close to the situation is hopeful that an as yet undetermined combination of factors will spare northern California's red abalone. Over the next few years, the situation will become much clearer. Until then, less than conservative management changes cannot be justified.
How was RLP introduced to northern California?
Currently available data indicates that RLP was introduced to northern California by human activities associated with aquaculture. Of the two northern California locations found to be positive for RLP, both have a history of out-plantings using seed abalone from aquaculture facilities later discovered to have been infected with RLP. The Crescent City site is additionally located close to an RLP-infected aquaculture production facility discharging raw effluent into the ocean.
In contrast, four other locations north of San Francisco have been surveyed without finding RLP. Two of those locations (the Bodega Bay Marine Lab reserve and Seven House Cove near Caspar) were out-planted in 1995 as part of the same experiment as the Van Damme out-planting. A third site close to a marine laboratory now known to be holding RLP-infected abalone was also negative for RLP in the 38 abalone sampled. The final site, Shelter Cove, is far removed from out-planting and aquaculture production activities.
Based on the best available information today, it is hard to imagine natural mechanisms that account for the location and distribution of RLP off northern California as it has been mapped to date. CDFG is planning to expand the number of survey sites in 2000 and it is possible that naturally occurring RLP will be found off northern California. It should be understood, however, that the opposite can never be proved. That is, it is impossible to prove that RLP does not occur naturally short of testing every single wild abalone. Collecting additional data that yields negative results simply reduces the statistical likelihood of RLP occurring naturally. In pursuit of this numbers game, it should also be noted that testing for RLP requires that the animal be destroyed to obtain the necessary tissues.
How has CDFG responded to the RLP Discovery?
In August 1998, CDFG banned shipments of RLP-infected abalone seed from southern California to facilities north of Carmel, the northernmost appearance of Withering Syndrome. CDFG also began in-water sampling of wild stocks to determine the distribution of Withering Syndrome and RLP in the wild. When Withering Syndrome was found in wild abalone as far north as the San Mateo coastline, the ban was changed to allow RLP-infected abalone to be transferred to any facility located south of San Francisco.
What does the current ban mean?
The current ban, established in August 1998, prohibits transfers of RLP-infected abalone to facilities north of San Francisco. Transfers of uninfected abalone have continued unaffected.
California's abalone aquaculture industry is supplied with seed (baby abalone) stock from two or three specialized aquaculture facilities based in southern California. The receiving facilities feed and maintain the seed abalone over the few years it takes for them to grow to marketable size. The southern California sources for seed abalone are infected with RLP. Transmission of RLP to seed abalone occurs when they reach a certain minimum size. In order to obtain uninfected seed, the Crescent City operation has been limited to acquiring the seed smaller than that minimum size.
Who benefits from importing infected abalone to northern California?
A single aquaculture operation, Abalone International, stands to benefit financially if the current ban is lifted.
The number of abalone aquaculture facilities has dwindled to that single operation located in Crescent City. The owners of Abalone International are reporting that the current ban has resulted in a 26-month production gap that needs to be filled with RLP-infected seed abalone.
Who supports Abalone International in this matter?
In addition to the Crescent City operators, aquaculture industry representatives and CDFG scientists and managers who work closely with the aquaculture industry are pushing for renewing shipments of RLP-infected abalone to northern California. Reports of financial hardship for Abalone International appear to be the underlying motivation for supporting renewed shipments of infected abalone into northern California.
In consideration of that well-intentioned motivation, it is worth noting that the ban is less than 18 months old and would have initially imposed only a very minor production gap. In order to account for the claimed 26-month gap, one possible explanation involves the stated intent of the Crescent City operation to expand their production capacity. If those plans require increasing current shipment levels sooner than it takes uninfected seed to grow to market size, the need to import infected seed becomes apparent. A 26-month production gap also begins to make sense. It also suggests that claims of financial hardship related to the current ban are based to some degree on missed opportunity costs.
What is the justification for lifting the ban?
In January 2000, a panel of CDFG and University of California scientists was convened for a panel discussion facilitated by CDFG managers. Two goals were on the agenda. The first goal was to "recommend to the Department of Fish and Game's Director a reasonable course of action, based on best available scientific information, that will prevent human activities from aggravating impacts or increasing the geographic distribution of a bacteria that cause withering syndrome in abalone".
Astonishingly, the management action recommended was to renew shipments of RLP-infected abalone to northern California. Motivated by the financial difficulties reported by Abalone International, the panel felt that California's northern coastal waters had been exposed to RLP since at least the mid-1990s and that any problems with Withering Syndrome should have already shown up in that time.
Why is renewed shipments of infected abalone a bad idea?
Lifting the current ban indisputably increases the risk of Withering Syndrome spreading throughout northern California's premier abalone fishery. What is disputed is how the risk is increased and whether widespread RLP represents a likely threat to the north coast natural resource. Proponents of lifting the ban are optimistic on both counts.
Opponents point out that RLP has been recognized as a threat for less than two years and efforts to quantify the degree of threat have only recently begun. Available information in 1999 led to a recommendation from the CDFG Aquaculture Disease Committee to destroy all aquaculture and wild abalone in the Crescent City area. Less than a year later, the addition of very little new information is being used by that same committee to not only reverse last year's recommendation but to advocate renewed shipment of RLP infected stocks to the same area. Such a dynamically changing body of scientific knowledge begs cautious and unhurried application.
Additionally, the scientific panel recommending that the ban be lifted qualified that recommendation with the requirement that a monitoring program be in place capable of detecting the spread of RLP from the Crescent City to the south. Unfortunately, methods needed for effective monitoring have not yet been developed nor has a source of funding been identified to start that development.
This opposition would not warrant overbearing consideration were it not for the stakes. Northern California's abalone resource contributes $20,000,000 annually to coastal communities and the state's economy. Much more important than any economic contribution, that unique resource is a cultural heritage offering recreational experiences enjoyed by a broad sweep of California's citizens. This year's crop of underdeveloped scientific hypotheses emerging from last year's miscalculations is no basis for the risks being suggested.
Who opposes lifting the current ban?
The California scientific community involved with abalone and aquaculture is quite small. Within that community there are strong sentiments on both sides. Contact information for most of the scientists and aquaculture managers involved has been included at the end of this document.
In terms of northern California's recreational abalone harvesters, opposition to a lifting of the current ban is passionate and all but unanimous.
Won't northern California's colder water offer some protection from Withering Syndrome?
A very iffy maybe.
Some members of the scientific community are convinced that the lack of confirmed finding of Withering Syndrome in north coast abalone populations is evidence that the RLP-infected abalone do not succumb to Withering Syndrome in cold water conditions. There is also limited supporting evidence that cold conditions inhibit the spread of the infection.
On the other hand, San Miguel Island in the southern Channel Islands near Santa Barbara is known for a cold water regime. Lying outside the protection of the Southern California Bight, San Miguel is exposed to severe weather and the same cold water currents of the central coast. Water temperatures there range from 42° -55° F/6° -13° C. Despite the cold water environment, up to 5% of the wild populations of red abalone during a 1997 survey of San Miguel Island displayed symptoms of Withering Syndrome. Water temperatures prevalent in the north coast are only slightly colder that the conditions which predominate at San Miguel Island. Given the similarities between the north coast and San Miguel, can there be assurances that the scientists are correct in their assumptions? Serious room for doubt remains.
The responsible pathogen is a bacterium, a kingdom which has been shown to possess the greatest range of tolerance to living conditions of any life on the planet. Bacteria have been shown to be able to live in freezing ice as well as the extreme temperatures found in geothermal vents on the ocean floor. They have demonstrated an ability to develop tolerances to the most potent of our antibiotics. Is it wise or prudent for our resource managers to place the last remaining reserves of harvestable excess at risk based on information as poorly developed as our current understanding of RPL and Withering Syndrome?
Isn't Van Damme a greater threat?
Evidence exists to argue strongly either way.
One of sixty abalone tested from Van Damme State Park was found to be infected with RLP. Discounting the possibility of a false positive result, the presence of RLP at Van Damme is believed to be the result of a single out-planting five years ago. At two other locations that were out-planted at the same time as Van Damme using the same source for seed abalone, RLP has not been found. Maybe RLP has disappeared from the other two locations and will naturally disappear from Van Damme in time. Or, equally plausible, Van Damme is ground zero for a Withering Syndrome epidemic started in 1995 that will destroy northern California's red abalone resource. Either a lot of years or a lot of science is needed before we'll know which way things are going to develop at Van Damme.
The Crescent City situation is entirely different. It involves first renewing and then maintaining an ongoing source for RLP introduction into the ocean environment. Any possibility of RLP naturally disappearing from waters off Crescent City is effectively eliminated.
The two situations represent considerably different relative risks that can only be compared superficially.
Won't Crescent City's geographical location protect northern California's wild stocks to the south?
Maybe.
The natural environment surrounding Crescent City isn't the best abalone habitat. It's physically located beyond the northern extreme of what many consider the "prime" abalone resources of northern California. Divers surveying for abalone couldn't find a single abalone in waters shallower than 35' along 15 miles of coastline immediately to the south of Crescent City. Though by no means conclusive, this would suggest that there aren't many abalone to serve as a conduit between the infectious populations of red abalone in the Crescent City area to the denser populations to the south.
On the other hand, Withering Syndrome that initially appeared at Santa Cruz Island spread quickly to other islands and the mainland coast across a deep-water channel tens of miles wide. If the spread from Santa Cruz Island occurred without human intervention, it would strongly suggest that RLP has been transmitted through the water column over very long distances without any intermediate hosts. With prevailing southern currents off the Crescent City area, this would bode poorly for the dense abalone populations in the path of those currents.
Where did RLP come from and how did it spread?
Both answers are unknown.
Withering Syndrome appeared full-blown at Santa Cruz Island in 1986 and soon thereafter was found at Anacappa Island. Within a very few years, it was detected throughout southern California's offshore islands and along the mainland north to Pt. Conception. It was also found at Diablo Canyon north of Pt. Conception in the warmer water effluent plume of a nuclear reactor. It took until 1999 before RLP were verified as the cause of Withering Syndrome. As a result, investigation of where the bacteria originated has only recently begun.
The spread of RLP to the north coast by aquaculture-related activities might offer a useful clue in how RLP spread quickly throughout southern California. The north coast example suggests the possibility that out-plantings of red abalone into the wild from infected aquaculture facilities inoculated large areas of the offshore islands and mainland coast of southern California over a relatively short period of time. This would account for the appearance of Withering Syndrome over a large geographical area in just a few short years.
There are other alternatives to account for the rapid appearance of Withering Syndrome over most of southern California. Those alternatives would include the possibility of transmission through the water column over long distances without intervening populations of abalone. This particular alternative would be particularly unsettling applied to northern California and the continuous introduction of RLP into the natural environment by the Crescent City aquaculture operation.
Could RLP be naturally occurring in California Waters?
Unlikely but remotely possible.
Sampling of wild abalone at Shelter Cove, Caspar, and at the Bodega Marine Lab did not reveal the presence of RLP in those wild stocks. Totaling more than 180 animals, this is a large enough sample to offer a relatively high degree of confidence that RLP does not naturally occur in northern California. That said, it is statistically impossible to ever prove that RLP does not occur naturally in northern California waters without testing every single animal.
If RLP does not occur naturally in northern California, it's unlikely to occur naturally in southern California. But, again, where it came from is not known.
What should be done?
The current ban on transferring RLP-infected abalone from southern California to northern California should be maintained.
CDFG efforts to collect samples from wild abalone should be accelerated over the next six months. If it can be statistically demonstrated that RLP is naturally occurring off northern California, lifting the current ban on importing RLP could be better justified.
Before renewing imports of RLP-infected abalone, a monitoring system that can detect the spread of RLP from a localized point source system needs to be developed and deployed. This monitoring capability was a required component in the recommendation to lift the current ban that emerged from the January 2000 scientific panel.
If a change to less conservative management is motivated by a financial crisis, the facts of that crisis should be fully revealed and understood by those responsible for authorizing increased risk to the wild stocks.
Most or all of the abalone aquaculture facilities along California's coast are dumping RLP infected effluent into the open ocean. Keeping in mind that these are pathogens associated with killing 99% of entire species in less than a decade, the need to question the lack of effluent processing appears to be a given.
Who are the participants in this issue?
University of California, Davis
2415B Tupper Hall
Davis, CA 95616
(530) 752-1034
tecarpenter@ucdavis.edu
Dr. Carpenter is an epidemiologist and professor with UC Davis' School of Veterinary Medicine. His areas of research include wild epidemiology. He participated in the January 2000 scientific panel.
University of California, Davis
Department of Animal Science
2117 Meyer Hall
Davis, CA 95616
(530) 752-7689
fsconte@ucdavis.edu
Dr. Conte is an aquaculture specialist with UC Davis' Department of Animal Science, a member of the CDFG Aquaculture Disease Committee, and is associated with the California Aquaculture Association. Dr. Conte does not support lifting of the current ban.
California Department of Fish and Game
Fish Health Laboratory
Bodega Marine Laboratory
University of California
Westside Road
P.O. Box 247
Bodega Bay, CA 94923
Dr. Friedman is the leading Withering Syndrome researcher for CDFG. She is credited with finding the causative agent of Withering Syndrome and is a top authority on Withering Syndrome as it applies to aquaculture activities. She participated in the January 2000 scientific panel and supports lifting of the current ban.
University of California, Davis
2102 Tupper Hall
Davis, CA 95616
(530) 752-3411
rphedrick@ucdavis.edu
Dr. Hedrick is an aquaculture specialist and a professor with the UC Davis' Department of Medicine and Epidemiology. His areas of research focus on the effects of infectious diseases on cultured fish and shellfish. He participated in the January 2000 scientific panel.
California Department of Fish and Game
Marine Resources Division
330 Golden Shore, Suite 50
Long Beach, CA 90802
(562) 590-5109
Pete Haaker is a CDFG marine biologist working out of southern California. He spends a lot of time in the field and has been involved in most of the survey work on Withering Syndrome in southern California waters.
fhenry@dfg2.ca.gov
Frank Henry is the CDFG marine manager for northern California.
Abalone International
Crescent City, CA
abaloneint@earthlink.net
Owners and operators of the Crescent City aquaculture facility at the center of this controversy.
djohnston@dfg.ca.gov
DeWayne Johnston heads the Marine Region for the California Department of Fish and Game. DeWayne is responsible for recommending the Marine Region position to the Director of Fish and Game.
California Department of Fish and Game
Marine Resources Division
19160 S. Harbor Blvd.
Fort Bragg, CA 95437
(707)964-7298
Kon Karpov is a senior marine biologist for CDFG based in Fort Bragg. Kon is the foremost expert on northern California's wild abalone resource.
Professor of Zoology
Department of Biological Sciences and Marine Science Institute
University of California, Santa Barbara
Santa Barbara, CA 93106
Dr. Kuris has participated in studies of exotic species introductions to California's marine environment. Most notably in this context, Dr. Kuris was one of the primary researchers involved in studying the Sabellid Polychaete introduced to California through the abalone aquaculture industry's importation and handling of South Africa native abalone.
University of California, San Diego
Scripps Institution of Oceanography
9500 Gilman Drive
La Jolla, CA 92093
(858) 534-2059
Dr. Tegner is among the most respected marine researchers in the world. Her area of specialty is near-shore ecology and she's produced a substantial body of research material specific to abalone. She participated in the January 2000 scientific panel.
Who compiled this information?
Rocky Daniels
P.O. Box 3801
Santa Rosa, CA 95401
707-824-5854
norcadiver@sonic.net
http://www.sonic.net/~rocky
As a northern California recreational abalone diver, my enjoyment of the resource has unwittingly lead to direct involvement in various abalone resource issues. At present, I am one of the two northern California representatives to the Recreational Abalone Advisory Committee appointed by the Director of Fish and Game. I am also a director and the vice-president of the Sonoma County Abalone Network. The latter role, in particular, has me involved in organizing and participating in projects that include hundreds of opportunities each year to exchange ideas with recreational abalone harvesters, marine biologists, game wardens, park rangers, state life guards, and prosecutors.
norcadiver@sonic.net