New invaders in the Caspian Sea

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New invaders in the Caspian Sea (CEP-SAP,
September, 2006)
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• Invader species appear in the Caspian Sea from
  time to time during all history.
• Species invasions occurred hundreds, thousands
  and millions years ago.
• In the last century due to human activity this
  process becomes more and more rapid. Now
  phytoplankton, zooplankton and macrozoobenthos
  community are changed by invaders for more than
  90 .

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• Nereis diversicolor was deliberately introduced
  in the Caspian Sea in 1939. Now it is one of the
  abundant species with average biomass up to 3-5
  g/m2.

Distribution of Nereis diversicolor. (from
Yablonskaya, 1985 with modification according to
the later data).
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• Mollusk Abra ovata also was deliberately
  introduced in the Caspian Sea in 1939. This
  species distribute from 3 to 50 meters of depth
  with maximum abundance about 10 meters of depth.
  It biomass now range from 1 g/m2 to 4 g/m2in the
  North, up to 8-11 g/m2 in the Middle and up to
  4-6 g/m2 in the South Caspian Sea. It is one of
  the important feeding organism for many
  benthosvorous fishes.

Distribution of Abra ovata.(from Yablonskaya,
1985 with modification according to the later
data)
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• Mytilaster lineatus appeared in the Caspian Sea
  in the beginning of 20th century. In a hundred
  years it becomes one of the most abundant bivalve
  species in the Caspian Sea. It inhabit all
  possible bottoms on the depth up to 80 meters,
  but prefers depth about 10 meters. At the blow of
  abundance it biomass riches up to 1 kg/m2, but
  later on it comes to equilibrium and stabilize
  with a lower richness. In 2003 it biomass in
  average was about 6-7 g/m2 in the North Caspian
  Sea, 20-25 g/m2 in the Middle Caspian Sea, and up
  to 30 g/m2 in the Western part of the South
  Caspian Sea.

Distribution of Mytilaster lineatus(from
Yablonskaya, 1985 with modification according to
the later data).
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• Appearance of this three species (and also some
  other species) dramatically change benthic
  community. Several endemic mollusk species are
  drastically reduce their numbers and are near to
  extinct. Feeding of all benthosvorous fishes
  changes according to changes in the benthic
  community. Now these three invaders produced
  about 42 of biomass in the North, 57 of biomass
  in the Middle and up to 66 of biomass in the
  South Caspian Sea

Average biomass of some zoobenthos organisms in
2003 (g/m2)
North Caspian Middle Caspian South Caspian
Nereis diversicolor 1.71 3.97 4.38
Abra ovata 4.68 8.28 5.74
Mytilaster lineatus 6.55 24.57 31.58
Other 18.06 28.35 21.87
Total 31.00 65.17 63.57
Three invaders (per cent) 42 57 66
Data on Nereis diversicolor, Abra ovata, and
Mytilaster lineatus biomasses obtained from
Ardabieva et al., The food base of the Northern
Caspian in 2003 and L.A. Kochneva Description
of the zoobenthos of the Middle and Southern
Caspian in the Fisheries Research in the
Caspian Scientific-research works results for
2003, FSUI KaspNIRKh press, Astrakhan, 2004
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• Changes in the zooplankton community are even
  more dramatic.
• Now about 90 of all number and biomass in the
  Middle and South Caspian sea are produced by only
  one species Acartia tonsa, which appears in the
  1980th. It produces up to 20 mg/m3 (5000 sp/m3)
  in the North Caspian Sea. In the Middle and in
  the South Caspian Sea it is now the dominant
  species with abundance 1200-3000 sp/m3 and
  biomass up to 15-30 mg/m3. It forms here up to
  95-97 of the total zooplankton biomass.

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• Biomass of main zooplankton groups in 2002 - 2005
  (mg/m3)

North Caspian North Caspian North Caspian Middle Caspian Middle Caspian Middle Caspian Middle Caspian South Caspian South Caspian South Caspian South Caspian
2002 2003 2005 2002 2003 2004 2005 2002 2003 2004 2005
Acartia tonsa 3.7 19.4 19.4 15.7 31.94 33.4 7.0 5.5 14.57 33.4 7.1
Other copepods 14.6 46.8 65.1 0.2 1.76 0.6 0.01 0.1 0.76 0.6 0
Cladocera 126.6 110.7 535.3 0.3 0.012 0.1 0.2 0.1 0.1 0.1 0.03
Rotatoria 214.7 73.4 216.0 0 0.11 0 0.01 0 0 0 0.003
Other 10.4 30.6 103.3 1.00 0 0.2 0.08 0 0.25 0.2 0.01
Total 370.0 280.9 939.1 17.2 33.72 34.3 7.3 5.7 15.59 34.3 7.15
Acartia in per cents 1 7 2 91 95 97 96 96 93 97 99
Data from A. A. Polyaninova, A. G. ardabieva, T.
A. Tatarintseva, O. V. Terletskay, L. I.
Tarasova, L.V. Malinovskay, L. A. Kochneva The
present state of plankton and benthos in the
Caspian sea M. I. Karpuk et al. estimation of
the impact of Mnemiopsis Leidyi on the biota of
the Caspian Sea and development of measures to
reduce its number Materials of the international
Conference present state and ways of improvement
of scientific investigation in the Caspian
basin, May 16-18, 2006, Astrakhan, FSUI
KaspNIRKh press, Astrakhan, 2006 Ardabieva et
al., The food base of the Northern Caspian in
2003 Tinenkova D. Kh., Petrenko E. I
Description of the zooplankton of the Middle and
Southern Caspian in October 2003 in the
Fisheries Research in the Caspian
Scientific-research works results for 2003, FSUI
KaspNIRKh press, Astrakhan, 2004
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• In 2004 three new zooplankton species were
  detected in the Middle Caspian Sea.
• Oithona similis Claus,1963
• Sagitta setosa Muller,1847
• Calanus euxinus (Hulsemann)
• All three species are from the fauna of the Black
  Sea. It is difficult to predict what happened
  with these species, could they establish
  themselves in the Caspian Sea or not. But it
  shows, that the process of species invasion via
  Volga-Don canal continue

Data from T. A. Shiganova, E.I. Musaeva, L. A.
Pautova and Yu. V. Bulgakova, 2005. The problem
of invaders in the Caspian Sea in the Context of
the finding of new zoo- and phytoplankton species
from the Black Sea // Biology Bulleten, 32, 1,
65-74.
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• And few words on the phytoplankton community.
• This community experienced shock after
  introduction of diatom alga Rhizosolenia
  calcar-avis, which appear in the 1930th . It is
  one of the dominant species now. Maximum
  abundance was observed for this species in
  1960-1970th . Later on it biomass was stabilized
  on a lower level. Sometimes it abundance are as
  high as 5 mln. sp/m3 with biomass about 650
  mg/m3. Maximum was observed near the Sagandyk
  peninsula -27400 mg/m3 in 1960th.

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Graphics show evidently that Rhizosolenia
calcar-avis has not one, but two pikes. The first
was occurred in 1960th and the second one in
1990th. Now it biomass and development are on a
low level. It is substituted by other diatoms
with smaller size. But in the winter and early
Spring in biomass is still big in the Middle and
South Caspian.
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• And this is not the only invader diatoms in the
  Caspian. During last years several new species
  appears in the Sea.
• Pseudo-nitzchia seriata (Nitzchia seriate)
• appears in 1990th
• Cerataulina pelagica (Cerataulina bergonii)
• first report from 2002
• Tropidoneis lepidoptera
• first report from 2004
• Chaetoceros peruvianus (or Ch. pendulus ?)
• first report from 2004

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Biomass of main groups of algae in the Caspian
Sea in 2001-2005
North Caspian North Caspian Middle Caspian Middle Caspian Middle Caspian South Caspian South Caspian South Caspian
2003 2005 2003 2004 2005 2001 2003 2005
Green algae 213 4,74 0.2 0.9 3.8 14.4 0.6
Blue-green algae 329 ? 0.76 4.3 1.2 12.3 4.82 2.3
Pyrrophyta 13.3 ? 20.67 9.4 15.6 65.6 43.12 9.9
Diatoms 1236.8 ? 503.4 19.8 50.9 58.8 263.5 48.7
Rhizosolenia calcar-avis 593.3 ? 409.67 ? 7.1 8.7 69.4 20.1
Pseudo-nitzchia seriata ? ? 15.93 ? ? ? 95.74 ?
Cerataulina pelagica 0 ? 62.68 ? 6.3 86.98 ?
Chaetoceros pendulus 27.2 ? 18.6 5.6 19.1 20.4 4.35
Tropidoneis lepidoptera 0 ?
Other 3.4 - 0.11 - 0.1 1.8
Total 1795.5 3000 529.32 33.8 68.5 145.6 325.75 63.3
Invaders in per cent 33 95 47 77 39
These data are difficult to compare as they
obtained in different period of the year and
include different areas, but nevertheless it
shows that this invader diatoms could produce
from 40 to 95 of phytoplankton biomass.
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• I will not speak about Mnemiopsis leidyi. Not
  because it is not important.
• We are waiting for a new data from the region to
  see what is the dynamic for it population in
  terms of distribution and biomass. Only have a
  new data it will be possible to make any
  additional contribution to understanding of the
  process of the Mnemiopsis role in the Caspian
  ecosystem and it influence to Phytoplankton,
  Zooplankton, Zoobenthos, and Fish Communities
• .

Thank you for attention