Beluga Sturgeon in Caspian Sea Reclassified as 'Critically Endangered'

The International Union for the Conservation of Nature (IUCN) formally announced the reclassification of beluga sturgeon in the Caspian Sea as "critically endangered" on its Red List on March 18, providing strong evidence that fishing and international trade should be halted and a stock-rebuilding plan should be initiated immediately. Beluga sturgeon populations have been decimated in part due to unrelenting exploitation for black caviar -- the sturgeon's unfertilized eggs -- considered the finest in the world.

"For those of us who have been involved in studying the rapid decline of this species over the past several decades, this reclassification of beluga sturgeon is of great significance and relief," said Dr. Ellen Pikitch, Professor and Executive Director of the Institute for Ocean Conservation Science at Stony Brook University. "However, of even greater significance is the IUCN reclassification of many sturgeons, which shows them to be among the most imperiled animals on earth. A higher percentage of sturgeon species were designated as critically endangered than any other group of species assessed, including other fish, mammals, reptiles, amphibians and plants."
Dr. Pikitch has led scientific efforts to highlight the seriously depleted status of the beluga sturgeon and to secure protection for the species for more than a decade. Dr. Pikitch was one of the petitioners of the U.S. Fish and Wildlife Service (USFWS) seeking listing of the species under the U.S. Endangered Species Act (ESA). Beluga sturgeon were listed under the U.S. ESA in 2004, and imports of its products into the United States have been banned since 2005.
The Institute for Ocean Conservation Science at Stony Brook University contributed significant new scientific information on several species of sturgeon to the newly released IUCN Red List sturgeon assessment. Dr. Ellen Pikitch, Executive Director, and Dr. Phaedra Doukakis, Senior Research Scientist with the Institute for Ocean Conservation Science are members of IUCN's Sturgeon Specialist Group (SSG).
They recently co-authored, along with other U.S. and Kazakhstani scientists, the results of a study of Caspian Sea beluga sturgeon of the Ural River. The results, which were published online this month in the journal Conservation Biology, suggest that conservation strategies for beluga sturgeon should focus on reducing the overfishing of adults rather than heavily relying upon hatchery supplementation and also demonstrate that current harvest rates in the fishery are four to five times higher than those that would sustain population abundance.
"This study only adds more credence to the reclassification of beluga sturgeon as 'critically endangered,' and underscores the need for swift, international protection to help them stave off extinction," said Dr. Pikitch. "And, the new IUCN assessment demonstrates that almost all of the 27 sturgeon species need enhanced protection since conservation measures to date have not been sufficient to ensure the recovery and long-term persistence of these valuable and ancient fish."
Drs. Pikitch and Doukakis presented their latest findings, as well as an overview of status and trends of global sturgeon fisheries, at a meeting during the 15th meeting of the Conference of Parties to CITES in Doha, Qatar. Also presenting were Dr. Kent E. Carpenter, IUCN Global Marine Species Assessment Director, on the reclassification of the sturgeon species, and Dr. Volker Homes, Species Conservation Section Director, WWF Germany and TRAFFIC, on caviar trade and labeling.
The study is entitled, "Management and Recovery Options for Ural River Beluga Sturgeon."

Fishery Management Practices for Beluga Sturgeon Must Change, Experts Urge

A first-of-its-kind study of a Caspian Sea beluga sturgeon (Huso huso) fishery demonstrates current harvest rates are four to five times higher than those that would sustain population abundance. The study's results, which will be published in an upcoming issue of the journal Conservation Biology, suggest that conservation strategies for beluga sturgeon should focus on reducing the overfishing of adults rather than heavily relying upon hatchery supplementation.

The quantitative analysis was conducted through an unprecedented collaboration of scientists from the United States and Kazakhstan. Data used in the study were collected in the Ural River, the only remaining Caspian Sea river where beluga sturgeon reproduce unhindered by dams.
"This is the first time that anyone has calculated sustainable harvest limits for Caspian Sea beluga sturgeon and compared them to present fishing pressure," said Dr. Phaedra Doukakis, Senior Research Scientist with the Institute for Ocean Conservation Science at Stony Brook University and lead author of the study. "We can finally attach numbers to what people have suspected -- that current management of Caspian Sea sturgeon fisheries will not prevent further population decline. We hope that this study provides the evidence needed to shift mindsets and management practices," added Dr. Doukakis.
Populations of beluga sturgeon have declined by nearly 90 percent in the past several decades due to the high demand for black caviar, inadequate management, and habitat degradation.
Black caviar, the unfertilized roe (eggs) of the beluga sturgeon, is the most valuable of all caviar, and can be sold for as much as $8,000 for one kilogram (2.2 pounds). There has been grave concern about increasingly dwindling numbers of this already depleted species, which has gone extinct in the Adriatic Sea and is on the brink of extinction in the Azov Sea.
The results of the analyses* conducted by the participating scientists show that fishing pressure far exceeds sustainable levels and that limiting the take of adult and subadult sturgeon will contribute more to the population growth rate as compared with hatchery supplementation.
The beluga sturgeon can live more than 100 years, and do not reach maturity until 9 to 20 years of age. The researchers found that the optimal age of first harvest is 31 years because older and larger fish produce more eggs. Conservation efforts would be much more effective than current practices if minimum size limits for fishing targeted this optimum age for first capture and if the illegal harvest of subadult fish were reduced. These fishing limits would allow the survival of subadult and adult females and would increase population productivity by ten times that achieved by hatchery supplementation, according to the study's findings.
Currently the fishery management focus for beluga sturgeon conservation is on using hatcheries to sustain the population. However, survival of hatchery-reared fish in the wild is thought to be very low. Additionally, genetic diversity may be compromised by hatchery practices, which can potentially jeopardize the long-term survival of all beluga sturgeon. Despite the potential threats posed by hatchery fish, regulatory agencies allow more fishing (higher quotas) by countries with higher hatchery output.
"This study clearly shows that reducing the mortality of wild beluga sturgeon adults is a much more effective conservation strategy than hatchery supplementation," said Dr. Ellen Pikitch, Executive Director of the Institute for Ocean Conservation Science and a co-author of the study. "Ten hatchery fish would need to be produced to achieve the same conservation benefit as preventing the kill of a single wild beluga sturgeon. It's clear that the focus of sturgeon management in the region has been misplaced and must change. A shift in practices could prevent further declines in beluga sturgeon and ultimately promote recovery," added Dr. Pikitch.
The Convention on International Trade in Endangered Species (CITES) listed beluga and most other species of sturgeon as threatened in 1998 with an Appendix II listing. However, beluga sturgeon numbers have declined by approximately sixty percent from the time of the listing through 2005 showing that existing management of beluga sturgeon fisheries has not been effective. The new research results suggest that a change in management focus is critical to stabilization and recovery of the species.
Drs. Pikitch and Doukakis will present the findings of this study and related research on the status of beluga sturgeon at a meeting they are convening on March 18, 2010 at the 15th Conference of Parties to CITES in Doha, Qatar.
*Scientists participating in the study used yield per recruit, spawning stock biomass per recruit, and elasticity analyses to make their evaluations. The first two analyses use life history parameters to determine acceptable levels of fishing mortality. The elasticity analysis uses similar parameters to pinpoint those parts of the fish's life history that contribute most to population growth. Doukakis et al. Management and Recovery Options for Ural River Beluga Sturgeon. Conservation Biology, 2010; DOI: 10.1111/j.1523-1739.2010.01458.x

Deformities in Chinese sturgeon linked to chemical

A paint chemical that is widely used in China is leaking into the Yangtze River and may be responsible for deformities and decreasing numbers of rare wild Chinese sturgeon, a study has found. In an article published in the Proceedings of the National Academy of Sciences, researchers said a significant proportion of juvenile sturgeon caught at the river had either one or no eyes, or had misshapen skeletons [<http://www.pnas.org/content/early/2009/05/25/0809434106.abstract>].Chinese sturgeon, which have existed on earth for 140 million years, are among the 1st class of protected animals in China. The slow-growing fish has an increased capacity to accumulate the paint chemical triphenyltin (TPT), which contains tin.The experts collected 2 and 3 day old Chinese sturgeon larvae from a spawning area below the Gezhouba Dam 38 km (24 miles) downstream from the Three Gorges Dam on the Yangtze River. They later hatched in a laboratory in Jingzhou city in central Hubei province where 6.3 per cent were found with skeletal deformities and 1.2 per cent had either no eyes or just one eye."Maternal transfer of TPT ... in eggs of wild Chinese sturgeon poses a significant risk to the larvae naturally fertilised or hatched in the Yangtze River," wrote the researchers, led by Hu Jiangying at the College of Urban and Environmental Sciences at Beijing University.TPT is extensively used in paints to prevent the fouling of ship hulls and fishing nets. It is also used in fungicide to treat crops in China. A derivative of TPT is also used to eliminate snails in paddy fields.Earlier studies attributed the steep decline in Chinese sturgeon numbers to loss of spawning habitat because of the construction of the Three Gorges Dam and Gezhouba Dam.More robust tests-----------------In this study, 2 adult males and 2 adult females of the Chinese sturgeon were also captured from the Yangtze River for artificial propagation and3.9 per cent of the juveniles were later observed to have malformed skeletons, while 1.7 per cent had one or no eyes. Subjecting their study to more robust testing, the researchers injected TPT into batches of eggs of the Chinese sturgeon and Siberian sturgeon."Experimental exposure of Chinese and Siberian sturgeon (eggs) to elevated TPT levels resulted in an increase in the occurrence of deformities, the rates of which were consistent with those seen in wild populations exposed to similar concentrations of the compound," they wrote."Together, these multiple lines of evidence were consistent with the hypothesis that TPT was the likely cause of the malformations observed in larvae of wild Chinese sturgeon, although other contaminants may be present that could produce similar effects."[byline: Tan Ee Lyn]--communicated by:ProMED-mail rapporteur Mary Marshall[Triphenyltin is an organotin compound and as such can cause reproductive and developmental effects in a variety of species. When these effects occur it is at a level that is almost toxic to the maternal organism. Organotin compounds are also associated with endocrine organ damage as well as damage to other sensory organisms such as the eye. While the mechanism of action is not well understood, the effects are well recognized.Toxicants are generally time and dose dependant. In this study it is not clear how long the sturgeons have been exposed, but it seems likely that it was for some lengthily period of time. Realizing that dilution is the solution to pollution, then it further enforces the theory that the time is long, despite the dose. It is also unclear how sensitive sturgeons are to this particular compound. - Mod.TGA map of the Yangtze River and the Three Gorges Dam Reservoir is available at <http://www.chinaodysseytours.com/maps/photo/yangtze.gif>. The HealthMap/ProMED-mail interactive map of China is available at <http://healthmap.org/r/00d6>. - CopyEd.MJ]

Sturgeon reappears in Baltic after century absence

A fisherman trawling off the Swedish island of Oeland netted a sturgeon from a species which had disappeared from the Baltic Sea a century ago, news agency TT reported Tuesday.Fisherman Ulf Aakerlund was at first stumped when he found the 78-centimeter (two-and-a-half-foot) fish in his nets last week."Initially I had no idea what it was. But when we looked it up on the Internet and looked in a few books we realised it was a sturgeon," he told TT.The specimen was an Atlantic sturgeon, or Acipenser oxyrhynchus, which was thought to have been extinct in the Baltic Sea since the early 1900s due to overfishing.But according to fish expert Mikael Svensson of the Swedish Species Information Centre, efforts have in recent years been made in Poland to breed sturgeon, and the specimen may have come from there."This is a good sign. It would be great if we could have this species in Swedish waters again. The sturgeon is a very special fish that doesn't resemble anything else we have in our waters," Svensson told TT.Atlantic sturgeon can grow as big as 4.5 meters (15 feet) and weigh 360 kilograms (795 pounds).The species is rare in European waters but is more common off North America's eastern coast.

UNDIAGNOSED DEATHS, STURGEON - USA (INDIANA)

What's causing the death of shovelnose sturgeon in the Wabash River is a mystery that the Department of Natural Resources (DNR), Department of Environmental Management (DEM), and scientists at Purdue University are trying to uncover। Since mid-July [2007] about 100 of the odd-looking fish have been found dead along a stretch of the Wabash from Delphi to Attica [Indiana].On 22 Jul 2007, DNR Conservation Officer, Matt Tholen, found 35 in just a mile and a half (2.4 km) near the Tippecanoe-Warren County line [in west central Indiana]. "They've been found individually. You'd find one, then 10 or 20 yards (9-18 m) down find another," Tholen said.Whatever it is seems to only affect average size sturgeons about24-32 inches (60-80 cm) in length. "We've found no small fish, and no other (species) of fish," said Tholen, who is also public information officer for District 3.Tholen and Officer Todd Pekny have taken samples of the dead sturgeon to Purdue University for testing. "They're running tests on fat tissue," Tholen said. "I've never seen anything like this and we're just waiting on the results."Shovelnose sturgeons are found in Indiana's larger rivers like the Wabash, as well as the Missouri and Mississippi rivers.Besides being a flavorful meat fish, especially when smoked, they have become more popular for their roe, or eggs, which are used for caviar.

Although larger species of sturgeon in central Asian waters at one time provided most of the world's supply of caviar, due to habitat degradation, pollution, and overfishing, smaller species like the shovelnose have been harvested for the delicacy.Shovelnose are not considered endangered at this point, but there are concerns, according to a series of studies completed in 2006 by Purdue University fisheries biologist, Trent Sutton. "The problem with sturgeons in general is that they are a long-lived fish that take a long time to reach sexual maturity," Sutton said.The shovelnose, the smallest of sturgeons, reaches sexual maturity between ages 6 and 9, and spawns every other year. Like other sturgeon species it is particularly vulnerable to overfishing because of the time required to breed and regenerate their numbers.Sutton's research found the Wabash River population appears to be stable, but his sampling uncovered few young fish in the river. "This raises a few red flags," Sutton said. "This means that either the females aren't laying eggs or that they aren't spawning at all -- both of which would have serious ramifications."But this year [2007], according to DNR Chief of Fisheries, Bill James, a spawning population was discovered in the general area of the recent deaths. To James that indicates a healthy population overall. "There was a successful spawning this spring, and shovelnose sturgeon in the Wabash are deemed a very healthy population."That is despite pressures from invasive aquatic species, fishing pressures, and transporting some sturgeon to other states to reintroduce their populations.He also explained the dead fish had no signs of obvious disease, and because the fish don't appear to have died in mass as might occur in a contaminant spill, James speculates it may be several causes."The fish that died appeared healthy and not as if their food supply was affected. It may be an incremental build up of stresses -- spawning stress, low water flows this summer, or other environmental conditions," said James.Both dead fish and live samples collected recently are being tested for comparisons, but no obvious cause has been determined yet.In the meantime Tholen said he wants the public to be aware of the unexplained sturgeon deaths. If anyone has information that may be viable to the investigation call the local Indiana Conservation Officer District #3 office at 765-447-9582, or the local sheriff's department dispatch on the non-emergency number.[Byline: Kevin Howell]

Successful Artificial Reproduction Of The European Sea Sturgeon

Despite its status as an endangered species in France since 1982 and in Europe since 1998, the last population of the European sea sturgeon has continued to decline। Today, only a few thousand individuals remain, all native to the Gironde River. In Bordeaux, researchers were rushing to build up stocks of parent fish and set up artificial reproduction methods in an attempt to produce sturgeon fry. This objective was met on June 25, 2007 at the Cemagref fish station in St-Seurin-sur-l’Isle, in the Gironde area.

Sturgeon fry under close surveillance
The parent's are part of the sturgeon stock created from young fish born in the mid 1990s and kept in captivity since that time. After more than 10 years of daily care and effort on the part of the research team, a female (Francine, born in 1994 and weighing 8.5 kg) and two males (Justin, born in 1984, 24 kg, and Emile, born in 1994, 17.6 kg) provided slightly more than 11,000 larvae.
Depending on how successful these early-stage fish are, very fragile until they begin taking on food, and limited by the mother's weight and young age, this first reproduction should provide a few thousand fry।

Part of these fish are expected to reinforce the two stocks in captivity as part of the species’ preservation and restoration programme in Europe: one in France (the Cemagref fish station at St-Seurin-sur-l’Isle) and the other in Germany (the Freshwater Institute of Berlin)। Depending on the success rearing these fry, the remainder should be released into the wild in the Garonne and Dordogne rivers, undoubtedly at the beginning of September, to sustain the wild population whose numbers are currently at their lowest.

Towards other artificial reproduction to stimulate reimplantation of the species
The last artificial reproduction dates back to 1995 : 9000 larvae and fry were released into the wild in the Garonne and Dardogne rivers, thus reinforcing the relictual population. The follow-up of the fish released during marking operations or accidental captures in the Gironde estuary and at sea, and finally during their return to the rivers where a few have been identified over the past few years, shows just how effective these measures have been.
The sturgeon in captive stocks, progressively built up since the mid-1990s, are now approaching sexual maturity. This first success in artificial reproduction of the European sea sturgeon, from fish reared in captivity, demonstrates the soundness of this solution. It compensates the absence of any natural reproduction since 1994, given the rarity of parent fish returning to the rivers for reproduction. There is now reasonable hope that the coming years will see the release of sufficiently abundant numbers to boost this last world population of the species.
Partners united in a single objective: restore and protect the species
This highly encouraging result is the fruit of more than 20 years of research conducted by Cemagref with its scientific partners (University of Bordeaux I and the Freshwater Institute of Berlin), both in the wild and in captivity. This research has been aided financially by the European Union (Life Nature), the Ministry of the Environment, the Aquitaine and Poitou-Charente regions, the Charente-Maritime and Gironde departments, and the Adour-Garonne Water Agency.
Work is currently coordinated by the WWF France within a consortium grouping (in addition to the scientific organazations) public institutions of the EPIDOR basins (the Dordogne river basin), SMEAG (the Garonne river basin) and SMIDDEST (the Gironde estuary) and the CNPMEM (National Committee for Marine Fishery and Marine Fish Rearing).
Efforts have been made to raise awareness to this situation, aiming notably at preserving the habitats used by this species and at limiting accidental capture,conditions indispenable to the restoration of the population। This work has finally benefitted from the involvement of professional and institutional organazations of the maritime and continental fisheries sector, environmental protection groups, and specific groups working towards preserving sturgeons.

Maximum level of protection for the European sea sturgeon
The European sea sturgeon, Acipenser sturio, is a species that is strictly protected by several international agreements (Convention on International Trade in Endangered Species, the Bern convention) and European directives (habitat, fauna, flora, OSPAR : Convention for the protection of the Marine Environment of the North-East Atlantic). A plan for preserving the species on the European scale is being finalized under the auspices of the Bern convention. A national plan within the national strategy for biodiversity will organize actions on the national level.
Note: This story has been adapted from a news release issued by Cemagref.