The First Mnemiopsis Advisory Group Workshop

Background:

At the Second Biodiversity Meeting, organized by the CEP in July 2000 in Almaty, Kazakhstan, the participants from the Caspian Countries discussed the issue of biological invasions and effects of exotic species in the Caspian Sea. The participants stressed the importance of further investigation of problems caused by introduced species, particularly in light of recent discovery of ctenophore Mnemiopsis leidyi (comb jelly) in the Caspian Sea. National Experts recommended to the CEP to establish a special Working Group of world-recognized experts in this field to thorough investigate the problem. In line with this recommendation, a meeting was organized on 24/25/26 April 2001 to review the problem of opportunistic settlers (with specific attention to Mnemiopsis) in the Caspian Sea and advise on possible course of actions.

The participants of the meeting agreed that the situation with Mnemiopsis in the Caspian Sea in 2000 was serious. They agreed that there is a strong need for more information on the distribution of Mnemiopsis in the Caspian Sea and its ecosystem impacts. They stressed an acute need for additional data of permanent monitoring of Mnemiopsis in the Caspian Sea, a laboratory study of Mnemiopsis’ predatory impact on the zooplankton in the Caspian Sea and an estimation of the capacity of the ctenophore Beroe ovata to serve as biological control agent for Mnemiopsis. They also recommended for the Caspian Environment Programme to establish the special Regional Advisory Group, comprised by the Mnemiopsis experts from the Caspian states and nominated by the CEP National Focal Points. Development of the Action plan for implementation y the Caspian countries, with assistance from the Caspian Environment Programme at the initial stage, was suggested to be the main goal of this Advisory Group. Members of the Group were nominated by the NFPs of the riparian states (Attachment 1).

The First Workshop of the CEP Regional Mnemiopsis Advisory Group was held in Baku, Azerbaijan, at the CEP PCU on December 3-4 2001, with the following main objectives:

• To analyze the results of the Mnemiopsis monitoring organized in Russian Federation, Azerbaijan and Islamic Republic of Iran and measurements done by Turkmenistan and Kazakhstan during the summer and autumn seasons, 2001.
• To analyze the results of the Mnemiopsis and Beroe laboratory studies conducted in the Iranian and Russian labs.
• To revise and update the action plan "Addressing the Invasion of the Caspian Sea by the Comb Jelly Mnemiopsis" taking into account the results of the monitoring and laboratory studies.

The meeting was attended by the members of the CEP Mnemiopsis Advisory Group, except Mr. E. Hosseini (Iran) and Ms Yu.Kim, who was replaced by Ms. L. Khvon, and by the regional and international experts actively involved in the Mnemiopsis monitoring and laboratory studies in the Caspian Sea region (Attachment 2).

I. Opening of the Workshop

Tim Turner, Coordinator of the Caspian Environment Programme, opened the workshop. He welcomed the participants of the meeting to the PCU and stressed the importance of the meeting in addressing one of the most important emerging environmental problems in the Caspian Sea – invasion by Mnemiopsis, along with other invasive species.

Dr. V. Vladymyrov, Scientific and Information Officer of the CEP, presented the draft agenda for the meeting (Attachment 3) and some minor changes were incorporated. Prof. H. Dumont, well-known specialist in hydrobiology, was proposed as a chairman of the workshop. The agenda and chairman were adopted.

Dr. V. Vladymyrov reminded to the participants the history of the issue (Appendix 1) and the contents of the draft Action plan prepared in May 2001 (Attachment 4) and acquainted them with the ToR of the Regional Mnemiopsis Advisory Group drafted by the PCU (Attachment 5). It was decided to discuss these documents after the expert presentations.

Dr. A. Kideys presented common methodology of the Mnemiopsis monitoring in the Caspian Sea prepared by himself and Dr. T. Shiganova (Appendix 2) and distributed to the reparian countries. He presented also the detailed monitoring plans prepared and initiated by him with the CEP support in Azerbaijan and Iran and stressed the necessity for similar plans to be prepared for Turkmenistan and Kazakhstan.

II. Present state of Mnemiopsis population in the Caspian Sea – country overview

Dr. Z. Kuliev presented the results of the Mnemiopsis monitoring in the Azerbaijan coastal waters (Appendix 3). The work started in July and is going on with financial support from TACIS. All the equipment and methodology were agreed with the CEP expert (A. Kideys), who conducted several surveys together with the Institute specialists. At all the monitoring transects the comb jelly Mnemiopsis of different sizes and age groups were found. In one occasion a biomass value of 3.2 kg/m2 was estimated off Sumgait and the next highest biomass value was over 0.5 kg/m2.

Dr. H. Negarestan presented results of recent studies conducted in Iran (Appendix 4). They were organized by the Iranian Fisheries Research Organization with a support of the CEP. The presence of the ctenophore increased in summer, and, at 20 m depth, the maximum biomass of 2.1 Kg/m² was recorded in September 2001 in Amirabad Mazandaran. In the same locations and depth the biomass at 20 m depth in November has decreased to 0.8 Kg/m². The maximum biomass in November found not to be at 20 m depth but 50 m where in Amirabad a biomass of 1.1 Kg/m² was observed.

Dr. L. Khvan summarized the situation with Mnemiopsis in the Kazakh waters (Appendix 5). Scientific Research Institute of Fishery of the Kazakhstan Republic performed surveys in August – September 2001 in the North-Eastern part of the Caspian, as well as in a coastal zone of the middle Caspian, with the aim to determine the distribution and concentration of Mnemiopsis in the territorial waters of Kazakhstan Republic. Only a few organisms were occasionally found during these surveys mostly in the form of shapeless mass. In addition, during the planned fishery monitoring the attention was paid to a possible presence of the Mnemiopsis, but none were found in this region neither in April nor in July.

Dr. F. Shakirova described the situation with Mnemiopsis in the Turkmenistan waters of the Caspian Sea (Appendix 6). There is currently no permanent monitoring in the Turkmenistan coastal zone. A sampling was only conducted in the vicinity of Turkmenbashi (cape Avaza) in the middle August 2001. It was found that the density of ctenophores ranged from 62 to 550 ind/m³, and biomass varied from 32.09 g/m³ to 215.5 g/m³. Length of the species reached 11-30 mm, with smaller individuals prevailed.

Dr. T. Shiganova presented results of the recent Russian studies of the Mnemiopsis distribution in the Caspian Sea, organized by KaspNIRKH with participation of P.P.Shirshov Institute of Oceanology RAS (Appendix 7). Surveys were performed in the Northern, Middle and Southern Caspian in June, July, August and October 2001. In June Mnemiopsis was found only in the Southern Caspian and the southern part of Middle Caspian, the highest density and biomass were estimated in the Southern Caspian with values 2005 ind/m² and 230 g/m² , respectively. In second half of July Mnemiopsis had spread throughout the whole Middle Caspian, some specimens were found in the southern part of the Northern Caspian. The average density had increased twice, reaching 1266 ind/m², and biomass rose more than 4 times, reaching 372.7 g/m². In August Mnemiopsis was distributed widely in the Northern Caspian. In the areas, where salinity exceeded 4 ‰, the average density and biomass for all Caspian Sea were maximal - 3756 ind/m² and 960 g/m², correspondingly. The density of Mnemiopsis was also considerable (3375 ind/m²) in October, but biomass had decreased to 555.9 g/m², probably due to the increasing density of small-sized specimens.

During the discussion, A. Kideys presented the results of Mnemiopsis sampling organized during the August basin wide cruise on estimation of fish stock organized by TACIS. According to these results, larger organisms were observed in the deep part of the sea. Mnemiopsis was observed at all sampling stations (the survey did not cover the Northern shallow part of the Sea).

Participants considered effects of Mnemiopsis on the Caspian Sea ecosystem in 2001 as significant, specifically its effects on zooplankton, kilka and seals.

III. Laboratory studies of Mnemiopsis and Beroe

Drs. G. Finenko and T. Shiganova presented the results of the laboratory experiments with Beroe and Mnemiopsis performed in the Iranian labs (Appendix 8). The Mnemiopsis-predator Beroe was transported from Turkish Seas to Mazandaran, Iran, to evaluate its suitability to combat Mnemiopsis problem in the Caspian Sea. Experiments show that Beroe ovata can live and grow intensively in the southern Caspian Sea at salinity of 12-13 ppt. Beroe feeding rates were quite high (up to >100% of its own body weight a day) at 21-26^oC. Daily rations and growth rates at 12.8 ppt are close to that in the Black Sea (where the salinity is 18 ppt).

Based on the physiological data, it could be suggested that in the Caspian Sea Beroe is able to ingest Mnemiopsis intensively and decrease its abundance sharply as it happened in the Black Sea. It was possible to obtain from Beroe eggs and on a few occasions larvae, but larval development experiments were not successful in the laboratory. However, it is still possible that successful development may take place in field conditions.

Different physiological characteristics (feeding, respiration rates and fecundity) of Mnemiopsis were obtained. These data will be evaluated with respect to ongoing monitoring studies to evaluate the impact of Mnemiopsis on the pelagic ecosystem of the Caspian Sea in near future.

Dr. V.P. Ivanov was not able to attend the workshop and on behalf of Russian institutions Dr. T. Shiganova presented the results of Mnemiopsis and Beroe studies performed in the Russian labs by the institutions of the Russian State Fisheries Committee (Appendix 9). Experiments were done as in Dagestan with Beroe delivered from the Black Sea and from the Sea of Azov region, where both natural Caspian Sea water and the diluted Black Sea water were used. The results were similar to those obtained in the Iranian labs. Even in the conditions of a sustained starvation Beroe did not feed on plankton (Caspian organisms and Artemia salina) and upon abundance of plankton tightly squeezed its oral cavity assuming an oval form. Beroe did not feed on small coelelminths.

It was mentioned by the participants during the final discussion that the results of experiments are very positive from the point of view of possible introduction of Beroe into the Caspian Sea. However, there is further need of in-vitro experiments including the interactions of Beroe with fish eggs and larvae and Beroe reproduction before any proposal.

IV. Development of the Action Plan

Dr. H. Dumont presented then the summary of presentations and discussions on the field and laboratory studies. His findings are incorporated into the meeting conclusions and recommendations.

Dr. V. Panov made a presentation on the methodological implications of international legal instruments on alien species for the Caspian Sea region. He discussed the Legal Instruments on Conservation of Biological Diversity (CBD) and Sustainable Use of Biological Resources, regarding alien invasive species and applicable to the Caspian Region. He described in detail CBD COP5 Decision V/8, 2000 (Appendix 10). "Alien Species that Threaten Ecosystems, Habitats and Species" and the CBD "Interim Guiding Principles for the Prevention, Introduction and Mitigation of Impacts of Alien Species." He stressed the attention of the participants to the necessity of free and fast data and information exchange relevant to the invasive species according to the best international practice. He presented information on the Regional Biological Invasions Center and a large variety of the Internet sources on the invasive species. He mentioned the urgent need for the development and implementation of the regional alien invasive species strategy and action plan, which should consider prevention of AIS introductions as a priority issue.

Dr. V.Panov proposed also to extend the Term of References of the Regional Mnemiopsis Advisory Group and rename it to the Regional Invasive Species Advisory Group, considering susceptibility of the Caspian Sea ecosystem to biological invasions, high risk of new invasions of harmful organisms and urgent need of preventive actions, along with significance of the Caspian as a region-donor of invasive species worldwide.

Creation of the Joint Caspian Sea Mnemiopsis database was discussed then by the workshop participants on the basis of presentation done by V. Vladymyrov and draft document on "The Principles for Creation and Procedures for Future Utilization of the Caspian Sea Mnemiopsis Data Base" prepared by the PCU (Attachment 6). In general, participants agreed to join their data on the basis of this document, however, some additional consultations are needed, especially with KaspNIRKH.

Resent situation in the Black Sea was discussed by Drs. G. Finenko (Appendix 11), A. Kideys, and T. Shiganoiova. They stressed the positive role of the Beroe in addressing the Mnemiopsis problem in the Black Sea region. All of them recommended to consider the Beroe introduction to the Caspian Sea urgently.

Two papers prepared by the scientists from the AzNIRKH (Russia) were also presented to the workshop participants, a paper of Z.A. Mirzoyan, S.P. Volovik, M.L. Martinyuk "Features of Development of the Population Beroe ovata in the Azov-Black Seas Basin and Consequences of its Intrusion" (Appendix 12) and a paper of S.P.Volovik, I.G. Korpakova "To the Biological Substantiation of the Intrusion of Beroe ovata in the Caspian Sea as the Factor of Biocontrol the Population of Mnemiopsis leidyi" (Appendix 13). It was noted that the results of the AzNIRKH work are similar to the results presented at the meeting by other researches and they support strongly the possibility and necessity for introduction of Beroe into the Caspian Sea.

The concluding discussion (Appendix 14) on the current situation in the Caspian Sea and necessity for urgent action was long and at times nested. As a result, the Advisory Group reached the consensus that a proposal be formulated under the banner of the CEP for the release of the Beroe into the Caspian Sea. The conclusions and recommendations of the workshop are given below.

V. Conclusions and Recommendations

1. A truly remarkable body of data has been gathered, both from the field and from the laboratory.

2. The landmark determined by the April meeting of 1 kg m^-2 (+/- 10%) for Mnemiopsis biomass (wet weight, uncorrected for net effects), corresponding to the Black Sea level of 1988, was repeatedly reached and overshot.

3. A process of the Mnemiopsis development in the Caspian Sea is running faster than in the Black Sea.

4. The situation in the Caspian Sea is dangerous and control actions should be provided on the urgent basis.

5. It can be considered that preliminary Environmental Impact Assessment for the Beroe introduction is done.

6. The preliminary laboratory study of Beroe is completed.

7. The introduction of Beroe, should be considered at present as the only measure to control Mnemiopsis.

8. The Advisory Group has reached the consensus that a proposal to be formulated under the banner of the CEP for the release of the Beroe into the Caspian Sea. Details of procedures for obtaining approval from the five littoral states are yet be finalized.

9. More laboratory studies of Beroe are desirable, in particular:

• Interaction with the fish egg and larvae,
• Interaction with zooplankton,
• Parasitological research,
• Biotechnology of Beroe growing
• Estimation of number of organisms for successful introduction
• Modelling the effect of possible introduction on Mnemiopsis and other plankton species.

Some recommendations are done in more details in the updated version of the Action plan (Attachment 7).

VI. Workshop’s Closure

The workshop’s participants noted the high productivity of the meeting. The Chairman expressed his gratitude to workshop participants for active, result-oriented work, pointed out the importance of the decisions made, and wished participants further successes.