STURGEON - CASPIAN SEA

Transcription

1 STURGEON - CASPIAN SEA Huso huso (Beluga Sturgeon), Acipenser stellatus (Stellate Sturgeon), Acipenser gueldenstaedti (Russian Sturgeon), Acipenser persicus (Persian Sturgeon), Acipenser nudiventris (Ship Sturgeon) Sometimes known as European Sturgeon (Beluga Sturgeon), Giant Sturgeon (Beluga Sturgeon), Great Sturgeon (Beluga Sturgeon), Osetra caviar (Russian Sturgeon, Persian Sturgeon), Sevruga caviar (Stellate Sturgeon), Starry Sturgeon (Stellate Sturgeon) SUMMARY With a lifespan up to 100 years, Beluga Sturgeon are naturally vulnerable to fishing pressure. Poor management, overfishing, pollution, and habitat destruction have contributed to severe population declines of this and other Caspian Sea Sturgeon species. The high value of caviar has posed a major obstacle to stemming illegal trade in caviar. Criterion Points Final Score Color Life History Abundance Habitat Quality and Fishing Gear Impacts Management 0.50 Bycatch 1.50 Final Score 0.80 Color

2 LIFE HISTORY Core Points (only one selection allowed) If a value for intrinsic rate of increase ( r ) is known, assign the score below based on this value. If no r-value is available, assign the score below for the correct age at 50% maturity for females if specified, or for the correct value of growth rate ('k'). If no estimates of r, age at 50% maturity, or k are available, assign the score below based on maximum age Intrinsic rate of increase <0.05; OR age at 50% maturity >10 years; OR growth rate <0.15; OR maximum age >30 years. Historically, most of the world's Sturgeon were caught in Russia, Kazakhstan, Azerbaijan and Iran, with the remainder coming from China, Romania, the United States, Canada and other nations (Speer et al. 2000). The species that reside in the Caspian Sea are Beluga, Russian, Stellate, Persian and Ship Sturgeons (Speer et al. 2000). There are no estimates of intrinsic rate of increase for these species, and only some values of the other factors were available for the different species. Beluga Sturgeon: k = 0.1, age at maturity is years, and maximum age is 100 years. Stellate Sturgeon: k = 0.06 and age at maturity is 9 years. Ship Sturgeon: k = , maximum age is 30. Russian Sturgeon mature at 11 years (Fishbase 2004) Intrinsic rate of increase = ; OR age at 50% maturity = 5-10 years; OR a growth rate = ; OR maximum age = years Intrinsic rate of increase >0.16; OR age at 50% maturity = 1-5 years; OR growth rate >0.30; OR maximum age <11 years. Points of Adjustment (multiple selections allowed) Species has special behaviors that make it especially vulnerable to fishing pressure (e.g., spawning aggregations; site fidelity; segregation by sex; migratory bottlenecks; unusual attraction to gear; etc.). Caspian Sea Sturgeon spawn in the rivers that feed into the Caspian Sea. Larvae migrate to the sea, where they live until they mature. Mature females migrate back to their river of origin (Speer et al. 2000), and are easily targeted on their journey up-river Species has a strategy for sexual development that makes it especially vulnerable to fishing pressure (e.g., age at 50% maturity >20 years; sequential hermaphrodites; extremely low fecundity). Spawning is infrequent. Beluga Sturgeon spawn only once every 3-4 years (Billard and Lecointre 2001). Persian Sturgeon spawn every 4-6 years (CEP 2004). Ship Sturgeon

3 spawn every 2-3 years (CEP 2004). Stellate Sturgeon females spawn every 3-4 years. Russian Sturgeon males spawn every 2-3 years, and females every 5 years (Billard and Lecointre 2001) Species has a small or restricted range (e.g., endemism; numerous evolutionarily significant units; restricted to one coastline; e.g., American lobster; striped bass; endemic reef fishes). These species are all restricted to a small range, mostly in the Black and Caspian Seas, and a few are found in the Azov Sea (Fishbase 2004) Species exhibits high natural population variability driven by broad-scale environmental change (e.g. El Nino; decadal oscillations) Species does not have special behaviors that increase ease or population consequences of capture OR has special behaviors that make it less vulnerable to fishing pressure (e.g., species is widely dispersed during spawning) Species has a strategy for sexual development that makes it especially resilient to fishing pressure (e.g., age at 50% maturity <1 year; extremely high fecundity) Species is distributed over a very wide range (e.g., throughout an entire hemisphere or ocean basin; e.g., swordfish; tuna; Patagonian toothfish) Species does not exhibit high natural population variability driven by broad-scale environmental change (e.g., El Nino; decadal oscillations) Points for Life History

4 ABUNDANCE Core Points (only one selection allowed) Compared to natural or un-fished level, the species population is: 1.00 Low: Abundance or biomass is <75% of BMSY or similar proxy (e.g., spawning potential ratio). Although there are no estimates of BMSY, abundance of Sturgeon in the Caspian Sea is well below historic levels. Beluga is on the decline in the Black Sea. In the Danube River, the last major spawning river for Beluga in this region, the species is considered vulnerable in the lower reaches, critically endangered in the middle reaches, and extirpated from the upper reaches. Beluga is on the verge of extinction in the Sea of Azov (Caviar Emptor 2004b). In the 1980s, the abundance of Beluga Sturgeon in the Caspian sea was over 18 million individuals. In 1999, abundance had dropped to 8 million individuals, according to the Caspian Environment Programme (2004). Some groups estimate that this value is even lower (Anon. 2004). Abundance of Stellate Sturgeon decreased from 30.1 million individuals in 1991 to 13.9 million individuals in 1999 (CEP 2004). Abundance of Russian Sturgeon in the Caspian Sea declined to 29.2 million specimens in 1999, as compared with 60.5 million specimens in 1978 (CEP 2004). Hatchery-reared fish are being released into the wild to supplement wild populations. For example, about 30% of the Stellate Sturgeon in the Caspian Sea and all in the Sea of Azov were hatchery born in the early 1990s; and a full 96% of Beluga Sturgeon in the Volga River in 2001 were thought to be from hatcheries (CITES 2000). These restocking programs are not successfully replenishing natural or sustainable populations of Sturgeon in the region, nor are hatchery-born fished considered an adequate replacement for healthy wild populations Medium: Abundance or biomass is % of BMSY or similar proxy; OR population is approaching or recovering from an overfished condition; OR adequate information on abundance or biomass is not available High: Abundance or biomass is >125% of BMSY or similar proxy. Points of Adjustment (multiple selections allowed) The population is declining over a generational time scale (as indicated by biomass estimates or standardized CPUE). The populations of these species have been declining. Catches in the late 1990's were about 1,000 tons per year, compared with over 20,000 tons per year in the late 19th and early 20th centuries (Speer et al. 2000). The number of Beluga Sturgeon entering Russia's Volga River to spawn dropped from 26,000 annually during to 7,000 in the

5 period. One source indicates that during , an average of only 2,800 individuals were observed (Caviar Emptor 2004b). CITES quotas for Sturgeon catch and caviar export have progressively been lowered since listing Sturgeons under Appendix II as species that may become threatened with extinction if trade is not strictly regulated. The only species for which quotas increased was Persian Sturgeon (CITES Quotas 2003) Age, size or sex distribution is skewed relative to the natural condition (e.g., truncated size/age structure or anomalous sex distribution). Populations of these Sturgeon species have distorted age distributions. For example, there has been no catch of Stellate females over 25 years old or males over 21 years in recent years (CEP 2004). A survey conducted in 2002 by the Caspian Environment Programme (CEP) found only 28 Sturgeon over the entire survey region, of which 85 percent were immature (Caviar Emptor 2004a). Data presented in Billard and Lecointre (2001), indicate that longevity of Sturgeon is presently lower than historical life spans. For example, Beluga Sturgeon can live to over 100 years old, and currently their longevity is estimated at Species is listed as "overfished" OR species is listed as "depleted", "endangered", or "threatened" by recognized national or international bodies. The World Conservation Union (IUCN) lists all 5 of these species as 'Endangered' (IUCN 2003). In April, 2004, the U.S. listed beluga caviar as 'Threatened with Extinction' as defined by the Endangered Species Act (Fed. Reg. 2004). All Sturgeons are listed under Appendix II of CITES as species that may become threatened with extinction if trade is not strictly regulated (2004) Current levels of abundance are likely to jeopardize the availability of food for other species or cause substantial change in the structure of the associated food web The population is increasing over a generational time scale (as indicated by biomass estimates or standardized CPUE) Age, size or sex distribution is functionally normal Species is close to virgin biomass Current levels of abundance provide adequate food for other predators or are not known to affect the structure of the associated food web Points for Abundance

6 HABITAT QUALITY AND FISHING GEAR IMPACTS Core Points (only one selection allowed) Select the option that most accurately describes the effect of the fishing method upon the habitat that it affects 1.00 The fishing method causes great damage to physical and biogenic habitats (e.g., cyanide; blasting; bottom trawling; dredging) The fishing method does moderate damage to physical and biogenic habitats (e.g., bottom gillnets; traps and pots; bottom longlines). Riverine beach seines and fixed nets are used to harvest Sturgeons (CEP 2004). The only legal method to catch fish in the commercial fishery is a 'sweep net,' which is a bottom net which is stretched across the river, and hauled in several times a day (Speer et al. 2004; CITES 2000). In Iran, gillnets are used at the mouths of the river, and scientific trawl surveys may contribute to catch (Anonymous, pers. comm. 2004) The fishing method does little damage to physical or biogenic habitats (e.g., hand picking; hand raking; hook and line; pelagic long lines; mid-water trawl or gillnet; purse seines). Points of Adjustment (multiple selections allowed) Habitat for this species is so compromised from non-fishery impacts that the ability of the habitat to support this species is substantially reduced (e.g., dams; pollution; coastal development). Caspian Sturgeon historically spawned in the Volga, Ural, Kura, Terek and Sulak rivers, but dams have since been constructed on all but the Ural River. The Ural River is now the only river where Sturgeon reproduce naturally, without the aid of hatchery-bred fish. The construction of the Volgograd dam has blocked about 85% of the spawning ground on the Volga River, which was historically the most important river for Caspian Sea Sturgeons. In addition to dams, pollution from coastal development and industry has substantially impacted water quality in the Caspian Sea (Speer et al. 2000). Levels of organochlorine (PCB's, DDT, etc.) were found to be high in all species of Sturgeon in the Caspian Sea (Caviar Emptor 2004b) Critical habitat areas (e.g., spawning areas) for this species are not protected by management using time/area closures, marine reserves, etc. Critical habitat areas are not protected (Speer et al. 2000; Speer, pers. comm. 2004).

7 -0.25 No efforts are being made to minimize damage from existing gear types OR new or modified gear is increasing habitat damage (e.g., fitting trawls with roller rigs or rockhopping gear; more robust gear for deep-sea fisheries) If gear impacts are substantial, resilience of affected habitats is very slow (e.g., deep water corals; rocky bottoms) Habitat for this species remains robust and viable and is capable of supporting this species Critical habitat areas (e.g., spawning areas) for this species are protected by management using time/area closures, marine reserves, etc Gear innovations are being implemented over a majority of the fishing area to minimize damage from gear types OR no innovations necessary because gear effects are minimal If gear impacts are substantial, resilience of affected habitats is fast (e.g., mud or sandy bottoms) OR gear effects are minimal Points for Habitat Quality and Fishing Gear Impacts MANAGEMENT Core Points (only one selection allowed) Select the option that most accurately describes the current management of the fisheries of this species Regulations are ineffective (e.g., illegal fishing or overfishing is occurring) OR the fishery is unregulated (i.e., no control rules are in effect). Local management agencies around the Caspian Sea have not been effective at Sturgeon conservation efforts (Caviar Emptor 2004a; Speer, pers. comm. 2004). In addition, illegal fishing is occurring on a large scale. In 2000, the U.S. Fish and Wildlife Service estimated that half of the world's caviar trade was illegal (Speer et al. 2000). There are no coordinated plans in place, and no sustainability goals. There are export limits in place, but they account for only 10% of actual exports (Speer, pers. comm. 2004).

8 CITES has implemented two bans on caviar exports from the Caspian Sea, for 6 months in 2001, and for 3 weeks in Neither of these bans has had any conservation impact, as Sturgeon are a long-lived species that will require many years to recover (Caviar Emptor 2004a). Despite listing Beluga Sturgeon as threatened, the U.S. Fish and Wildlife has not implemented a ban on imports of Beluga caviar (Caviar Emptor 2004a). On September 1, 2004, CITES again halted global trade of most caviar, including Beluga Sturgeon (Caviar Emptor 2004c). Whether this ban will lead to a recovery of Sturgeon populations remains to be determined, depending on if the ban is well enforced, and if it remains in place for long enough to allow recovery Management measures are in place over a major portion over the species' range but implementation has not met conservation goals OR management measures are in place but have not been in place long enough to determine if they are likely to achieve conservation and sustainability goals Substantial management measures are in place over a large portion of the species range and have demonstrated success in achieving conservation and sustainability goals. Points of Adjustment (multiple selections allowed) There is inadequate scientific monitoring of stock status, catch or fishing effort. The five range States of the Caspian Sea have committed to cooperating on research and assessment efforts. They are supposed to develop an internationally acceptable stock assessment and monitoring system and a transparent, robust and internationally acceptable method for deriving catch and export quotas from stock monitoring data (CITES 2003). There is major discrepancy between the results analyzed by the fishing nations and used to determine quotas, and the analysis by conservation organizations (CITES 2003; Caviar Emptor 2004a). Current assessments are considered to be flawed (Speer, pers. comm. 2004) Management does not explicitly address fishery effects on habitat, food webs, and ecosystems This species is overfished and no recovery plan or an ineffective recovery plan is in place. These species are overfished, but there are no recovery plans in place (Speer et al. 2004) Management has failed to reduce excess capacity in this fishery or implements subsidies that result in excess capacity in this fishery.

9 +0.25 There is adequate scientific monitoring, analysis and interpretation of stock status, catch and fishing effort Management explicitly and effectively addresses fishery effects on habitat, food webs, and ecosystems This species is overfished and there is a recovery plan (including benchmarks, timetables and methods to evaluate success) in place that is showing signs of success OR recovery plan is not needed Management has taken action to control excess capacity or reduce subsidies that result in excess capacity OR no measures are necessary because fishery is not overcapitalized Points for Management BYCATCH Core Points (only one selection allowed) Select the option that most accurately describes the current level of bycatch and the consequences that result from fishing this species. The term, "bycatch" used in this document excludes incidental catch of a species for which an adequate management framework exists. The terms, "endangered, threatened, or protected," used in this document refer to species status that is determined by national legislation such as the U.S. Endangered Species Act, the U.S. Marine Mammal Protection Act (or another nation's equivalent), the IUCN Red List, or a credible scientific body such as the American Fisheries Society Bycatch in this fishery is high (>100% of targeted landings), OR regularly includes a "threatened, endangered or protected species." 2.00 Bycatch in this fishery is moderate (10-99% of targeted landings) AND does not regularly include "threatened, endangered or protected species" OR level of bycatch is unknown. The level of bycatch is unknown (Speer, pers. comm. 2004) Bycatch in this fishery is low (<10% of targeted landings) and does not regularly include "threatened, endangered or protected species."

10 Points of Adjustment (multiple selections allowed) Bycatch in this fishery is a contributing factor to the decline of "threatened, endangered, or protected species" and no effective measures are being taken to reduce it Bycatch of targeted or non-targeted species (e.g., undersize individuals) in this fishery is high and no measures are being taken to reduce it. While there are no precise estimates of bycatch, a large number of males, juveniles, and other fish species are taken in the nets (Speer, pers. comm. 2004) Bycatch of this species (e.g., undersize individuals) in other fisheries is high OR bycatch of this species in other fisheries inhibits its recovery, and no measures are being taken to reduce it. There is insufficient data available to determine this The continued removal of the bycatch species contributes to its decline. The take of male and juvenile Sturgeon contributes to the decline of the species (Speer, pers. comm. 2004) Measures taken over a major portion of the species range have been shown to reduce bycatch of "threatened, endangered, or protected species" or bycatch rates are no longer deemed to affect the abundance of the "protected" bycatch species OR no measures needed because fishery is highly selective (e.g., harpoon; spear) There is bycatch of targeted (e.g., undersize individuals) or non-targeted species in this fishery and measures (e.g., gear modifications) have been implemented that have been shown to reduce bycatch over a large portion of the species range OR no measures are needed because fishery is highly selective (e.g., harpoon; spear) Bycatch of this species in other fisheries is low OR bycatch of this species in other fisheries inhibits its recovery, but effective measures are being taken to reduce it over a large portion of the range The continued removal of the bycatch species in the targeted fishery has had or will likely have little or no impact on populations of the bycatch species OR there are no significant bycatch concerns because the fishery is highly selective (e.g., harpoon; spear) Points for Bycatch

11 REFERENCES Anonymous. Personal Communication. July Billard, Roland and Guillaume Lecointre. Biology and conservation of Sturgeon and paddlefish. Reviews in Fish Biology and Fisheries 10: 355 C392, 2001.Kluwer Academic Publishers. Printed in the Netherlands. Caspian Environment Programme. Caspian Sea Biodiversity Database. Online at: Accessed 2 August Caviar Emptor. 2004a. Protecting Endangered Beluga Sturgeon: Timeline. Available online at: July, Caviar Emptor. 2004b. Current Status of Beluga Sturgeon: Summary of Scientific Literature. Available online at: Accesed July 30, Caviar Emptor. 2004c. Breaking News: Wildlife Officials Shut Down Global Caviar Trade. Available online at Accessed 2 September, Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). UNEP-WCMC. 2 September, UNEP-WCMC Species Database: CITES-Listed Species Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Caspian Sturgeon Catch and Caviar Export Quotas for Available online at: Accessed 2 September Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Current Trends in the Huso huso fishery in the Caspian Sea and the Beluga Catch and Export Quotas for Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Sixteenth Meeting of the CITES Animals Committee Shepherdstown (United States of America) December Federal Register: Final Determination of Threatened Status for the Beluga Sturgeon (Huso huso). April 21, Volume 69, Number 7. Available online at: Accessed July 30, Fishbase Available online at IUCN IUCN Red List of Threatened Species. Downloaded on 29 July 2004.

12 Speer, Lisa (Natural Resources Defense Council), Liz Lauck and Ellen Pikitch, Ph.D. (Wildlife Conservation Society), and Susan Boa, Lisa Dropkin and Vikki Spruill (SeaWeb). The Decline of the Caspian Sea Sturgeon and the Road to Recovery. December 2000 Speer, Lisa. National Resources Defense Council. Personal Communication. 2 August 2004.