Tamara Shiganova

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Gelatinous plankton surveys in the Ponto-Caspian
Seas
Tamara Shiganova P.P.Shirshov Institute of
Oceanology Russian Academy of Sciences
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There are four indigenous gelatinous species in
the Black Sea
The smallest gelatinous species dinoflagellate
Noctiluca scintillans Kofoid Swezy 1921 , which
bloomed in 1960-1970s, particularly in
northwestern Black Sea
Sciphomedusae Aurelia aurita (L) , which bloomed
in late 1970s
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Not blooming but harmful species
Sciphomedusae Rhyzostoma pulmo(Macri)
Ctenophore Pleurobrachia pileus O. Muller
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Invasive gelatinous species
Ctenophore Mnemiopsis leidyi (A.Agassiz)
Ctenophore Beroe ovata Mayer,1912
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Sampling design
Sampling of small gelatinous animals with usual
plankton net (WP-2, Juday) net opening 0.1 m2,
mesh size 200 ?m) with usage closing devise.
Hensen net, WP-3 or Russian Bogorov-Rass net (a
square net with opening of 1 m2, and mesh size
500?m), taking vertical hauls from the anoxic
layer (120-150 m) to the surface, and from the
thermocline (15-25 m) to the surface
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Long term Mnemiopsis leidyi abundance (
1-inshore 2-offshore) and surface water
temperature in winter, spring and summer before
and after B.ovata development
Beroe ovata appearance
Beroe ovata appearance
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Interannual variation M.leidyi and zooplankton
biomass (WW) in spring and summer
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Interaction between M.leidyi (1)and B.ovata(2) in
the Black Sea
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Mnemiopsis leidyi biomass, g.m-2 (1) and grazing
pressure of Beroe ovata, (2). A- in 1999-2000
B- in 2001 C-in 2002
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Interannual variation of fish eggs(A) and
larvae(B) in the Black Sea 1-anchovy, 2-scad,
3-others
Beroe appearance
Mnemiopsis appearance
Beroe appearance
Mnemiopsis appearance
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Catch of the Azov and Black Sea planktivorous
fish 1-anchovy 2 kilka 3-sprat 4-total catch
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Seasonal spatial distribution M.leidyi in the
Caspian Sea A-in January B-in May C-in July
D- in August (data CaspNIRHK and SIO RAS)
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Pattern of M.leidyi spatial distribution in the
Northern Caspiana- in 2002, b-in 2001
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Map of sampling sites
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M.leidyi abundance (ind.m3) in August
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Zooplankton biomass(1) and grazing rate of
M.leidyi(2) in the Caspian
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Distribution of biomass of kilka for Caspian
countries (after data of kilka surveys, data of
lab kilka stocks assessment , KaspNIRKH)
anchovy kilka B- common kilka C-big-eye kilka.
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From Khuraskin et al.,2001
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Pelagic Fish Eggs larvae
Merozooplankton
Demersal Plankton
Holozooplankton
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Small Pelagic Fishes
Demersal Fishes
Small Benthic Fishes
Pelagic Fish Eggs larvae
Pelagic Fish Eggs larvae
Indigenous gelatinous
Merozooplankton
Demersal Plankton
Holozooplankton
Merozooplankton
Demersal Plankton
Holozooplankton
Benthos
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Dolphins
Large Pelagic Predator Fishes
Small Pelagic Fishes
Demersal Fishes
Small Benthic Fishes
Small Pelagic Fishes
Demersal Fishes
Small Benthic Fishes
Pelagic Fish Eggs larvae
Pelagic Fish Eggs larvae
Indigenous gelatinous
Merozooplankton
Demersal Plankton
Holozooplankton
Merozooplankton
Demersal Plankton
Holozooplankton
Benthos
Benthos
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Dolphins
Large Pelagic Predator Fishes
Small Pelagic Fishes
Demersal Fishes
Small Benthic Fishes
Small Pelagic Fishes
Demersal Fishes
Small Benthic Fishes
Pelagic Fish Eggs larvae
Pelagic Fish Eggs larvae
Holozooplankton
Indigenous gelatinous
Merozooplankton
Demersal Plankton
Holozooplankton
Merozooplankton
Demersal Plankton
Holozooplankton
Phytoplankton
Phytobenthos
Zooflagellates
Infusoria
Bacteria
Detritus
Mucus production
Larvae
Nutrients
Benthos
Benthos
Benthos
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Dolphins
Large Pelagic Predator Fishes
Small Pelagic Fishes
Demersal Fishes
Small Benthic Fishes
Pelagic Fish Eggs larvae
Pelagic Fish Eggs larvae
Small Pelagic Fishes
Demersal Fishes
Small Benthic Fishes
Pelagic Fish Eggs larvae
Small Pelagic Fishes
Demersal Fishes
Small Benthic Fishes
Small Pelagic Fishes
Demersal Fishes
Small Benthic Fishes
Pelagic Fish Eggs larvae
Pelagic Fish Eggs larvae
Indigenous gelatinous
Merozooplankton
Demersal Plankton
Holozooplankton
Merozooplankton
Demersal Plankton
Holozooplankton
Indigenous gelatinous
Merozooplankton
Demersal Plankton
Holozooplankton
Holozooplankton
Indigenous gelatinous
Merozooplankton
Demersal Plankton
Holozooplankton
Merozooplankton
Demersal Plankton
Holozooplankton
Phytoplankton
Phytobenthos
Zooflagellates
Infusoria
Bacteria
Detritus
Detritus
Mucus production
Larvae
Nutrients
Benthos
Benthos
Benthos
Nutrients
Benthos
Benthos
Benthos
Mucus production
Larvae
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Seal
Great Sturgeon
Small Pelagic Fishes
Sturgeons
Small Benthic Fishes
Pelagic Fish Eggs larvae
Pelagic Fish Eggs larvae
Small Pelagic Fishes
Sturgeons
Small Benthic Fishes
Pelagic Fish Eggs larvae
Small Pelagic Fishes
Sturgeons
Small Benthic Fishes
Small Pelagic Fishes
Sturgeons
Small Benthic Fishes
Pelagic Fish Eggs larvae
Pelagic Fish Eggs larvae

Merozooplankton
Demersal Plankton
Holozooplankton
Merozooplankton
Demersal Plankton
Holozooplankton
Hydromedusae
Merozooplankton
Demersal Plankton
Holozooplankton
Holozooplankton
Hydromedusae
Merozooplankton
Demersal Plankton
Holozooplankton
Merozooplankton
Demersal Plankton
Holozooplankton
Phytoplankton
Phytobenthos
Zooflagellates
Infusoria
Bacteria
Detritus
M. leidyi
Detritus
M. leidyi
Mucus production
Larvae
Nutrients
Benthos
Benthos
Benthos
Nutrients
Benthos
Benthos
Benthos
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Conclusions

• Thus in a decade M.leidyi became the most
  distributed comb-jelly in the World Ocean and
  economical damage to native and nonnative
  habitats may be estimated in millions US dollars

• High level of euthrophication and overfishing
  were the reasons of huge outbreak of M.leidyi in
  the Black and Azov Seas.

• M.leidyi development declined abundance, biomass
  and species diversity of all group of pelagic
  ecosystem of the Black, Azov and Caspian Seas,
  greatly simplify it.

• The functioning of the ecosystem changed in the
  Caspian the same way as that of the Black Sea.
  Cascading effect occurred at the higher trophic
  levels, from a decreasing zooplankton stock to
  collapsing planktivorous fish to vanishing
  predatory fish and seal. Similar effects occurred
  at lower trophic levels from a decrease in
  zooplankton stock to an increase in
  phytoplankton, released from zooplankton grazing
  pressure. The majority of these effects were
  top-down, but few were also bottom-up.

• Absence of predators until recently was another
  important reason of such a high bloom and a great
  effect at all trophic levels of the ecosystem in
  the Black Sea and now situation is even much was
  in the Caspian Sea

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• With Beroe ovata introduction new trophic web
  appeared in the Black Sea and ecosystem began to
  recover but during seasonal absence of B.ovata,
  M.leidyi can reach high density and have
  considerable effect on ecosystem. The
  introduction of B.ovata was a positive accident,
  and this experience should be used to save rich
  fish stocks of the Caspian Sea

• The M.leidyi and B.ovata outbreaks in nonnative
  areas have significantly advanced our
  understanding of the complex nature of coastal
  marine ecosystems and the role of invasive
  species therin. This is an example of how low
  organized gelatinous animals can affect whole
  ecosystems one of them completely suppressed
  productive ecosystems,while the other recovered
  them in a short period of time. This events
  should be taken advantage of to improve mans
  understanding and control.

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Thank you