Assessment of the main drivers of the Black Sea ecosystem
functioning Mnemiopsis leidyi and Beroe ovata impact on
the Black Sea ecosystem. Modeling approach.
Tamara Shiganova
P.P.Shirshov Institute of oceanology RAS,
Moscow, RUSSIIA
Paul Nival
Laboratoire d'Oceanographie de Villefranche
Villefranche-sur-Mer, FRANCE
Distribution of M. leidyi in the native and invaded areas
Native area
Invaded area
Costello J. H., J. E. Purcell, K. M. Bahya, H. W. Mianzan & T. A. Shiganova, 2011
In the Black Sea, native gelatinous species belong to moderately
cold-water species: the ctenophore Pleurobrachia pileus,
scyphomedusa Aurelia aurita, and the pyrophyte alga Noctiluca
scintillans. Two warm water invasive ctenophores arrived and
established in the heated upper layer
Cold water species
Warm water species
Subdivision of the gelatinous species in their relation to mean
seasonal, annual and minimal winter SST: analyses of field data
according to main component method )
Dispersal of Mnemiopsis leidyi in the Eurasian seas
Mnemiopsis leidyi
2006
2007
2005
2006
2006
2007
2005
1988
2005
2009
1982
2009
1999
1990
1992
1993
2009
Population genetic analyses supported its invasion from the Gulf of
Mexico (e.g., Tampa Bay) into the Black Sea, then secondary into the
Dispersal of Beroe ovata in the Eurasian seas
2000
2005
1997
1997
2004
1999
2011
Beroe ovata
Environmental data and
Black Sea
M.leidyi invasion in the seas
of Eurasia
Sea of Azov
The dark area
Corresponds to the
period of Mnemiopsis leidyi Aegean Sea
occurance
(observations)
Caspian Sea
Baltic Sea
After Shiganova et al., in press
Interannual variation of M.leidyi and B.ovata in the Black Sea
Abundance, ind.m-2
2500
M.leidyi,ind.m2
2000
2500
1200
1000
M.leidyi,ind.m2
2000
1500
800
B.ovata,ind.m2
1500
600
1000
1000
400
500
500
0
0
0
2008
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
1989
1988
1984
Years
200
Zooplankton are the main food of M.leidyi
Change of interannual variability of edible zooplankton after
appearance of invasive ctenophores in the inshore and offshore
waters in August in the northeastern Black Sea
Zooplankton in the offshore waters,ind.m2
2
450000
450000
400000
400000
350000
zooplankton,ind.m2
Zooplankton, ind.m -2
Zooplankton in the inshore waters,ind.m
500000
350000
300000
300000
250000
250000
200000
200000
150000
150000
100000
100000
50000
50000
0
0
VIII.2008
VIII.2007
Paracalanus parvus
Acarthia clausi
Pontella mediterrania
Oikopleura dioica
Larvae_Bivalvia
Larvae_Decapoda
Cirripedia Larvae
Penilia avirostris
Isopoda
VIII.2006
IX.2005
VIII.2004
VIII.2003
IX.2002
IX.2000
VIII.1999
Calanus euxinus
Pseudocalanus elongatus
Oithona similis
Oithona nana
Parasagitta setosa
Larvae_Polychaeta
Larvae Gastropoda
Cladocera without Penilia
Centropages ponticus
VIII.1998
VII.1996
VIII.1995
VIII.1994
VIII.1993
VIII.1989
VIII.2008
VIII.2007
Paracalanus parvus
Acarthia clausi
Pontella mediterranea
Larvae_Polychaeta
Larvae Gastropoda
Parasagitta setosa
Penilia avirostris
Oikopleura dioica
Years
VIII.2006
VIII.2005
VIII.2004
VIII.2003
VIII.2002
VIII.2001
IX.2000
VIII.1999
VIII.1998
VII.1996
VIII.1995
VIII.1994
VIII.1993
VIII.1989
Calanus euxinus
Pseudocalanus elongatus
Oithona similis
Larvae_Bivalvia
Larvae_Decapoda
Cirripedia Larvae
Cladocera without Penilia
Centropages ponticus
Harpacticoida
Mnemiopsis leidyi seasonal cycle in cold (1993) and
warm (1994) year before B.ovata arrival
Field data in the coastal area
Warm year
r=0,6-08, p<0,001
Cold year
8
9
9
8
8
8
7
7
6
6
5
5
4
4
3
3
2
2
9
1994
7
6
6
5
5
4
4
3
3
2
2
1
1
1
1
0
0
0
0
I
II
III IV V VI VII VIII IX X XI XII
Mnemiopsis
Zooplankton
mnemiopsis,г.м-3
7
I
II
III IV V VI VII VIII IX X XI XII
Mnemiopsis
Zooplankton
Before the arrival of B.ovata, M.leidyi abundance was controlled by
temperature and zooplankton prey
Zooplankton,g.m-3
1992
Zooplankton,mg.m-3
Mnemiopsis,g.m-3
9
30
2001
25
25
Temperature,
Temperature,
15
10
C
0
20
15
10
5
5
0
0
20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360
500
Zooplankton
300
200
300
200
Mn.adult 1
Mn.Juv
Mn.eggs
Mn.larvae
220
200
180
160
140
A
120
100
E
M.leidyi
80
60
Mnemiopsis, ind.m3
240
J
L
40
20
40
60
40
60
80
300
250
200
150
0
80 100 120 148 160 180 200 220 240 250 260 266 270 280 300 320 340 350
260
240
240
220
220
200
200
180
160
140
120
100
80
100 120 140 160 180 200 220 240 260 280 300 320 340 360
80
60
40
20
20
0
20
40
60
80 100 120 140 160 180 200 220 240 260 280 300 320 340 360
0
L
Ber.larva
60
J
50
40
30
E
B.ovata
20
10
60
50
40
0
20
40
60
80
100
120
140
160
180
Days
200
220
240
260
280
300
320
340
360
80 100 120 140 160 180 200 220 240 260 280 300 320 340 360
70
60
50
40
30
20
20
10
10
0
0
60
80
30
A
40
90
70
Beroe, ind. m -3
Ber.eggs
70
20
100
80
Ber.Juv
100 115 139 162 168 169 200 220 234 252 280 300 320 340 360
100
Beroe, ind.m3
80
80
120
90
Ber.adult 1
60
140
100
90
40
160
40
0
100
20
180
60
0
20
350
260
0
0
400
0
20
96 101 120 140 166 210 235 236 237 249 254 264 276 300 320 340 360
Mnemiopsis, ind.m-3
80
500
450
100
50
0
60
260
Mnemiopsis, ind. m-3
Time (days)
550
400
0
40
20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360
600
100
100
Beroe,ind.m -3
0
Zooplankton, mg.m-3
500
Zooplankton,mg.m-3
Zooplankton, mg.m-3
600
20
10
Time (days)
600
0
15
0
0
20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360
20
5
Time (days
400
2008
25
C
0
0
C
Temperature
20
0
30
2003
Temperature,
30
0
0
20 40
60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360
Days
0
20
40
60
80 100 120 140 160 180 200 220 240 260 280 300 320 340 360
Time (days)
Interannual variability of phenology of ctenophores
M. leidyi and B.ovata in the coastal area of the NE Black Sea
360
340
320
--- M.leidyi
--- B.ovata
300
Time (days)
280
260
240
Time of appearance of B.ovata
220
Time of beginning reproduction
of B.ovata
200
Time of appearance of M.leidyi
Time of pick of reproduction of
M.leidyi
180
160
140
120
1999
2000
2001
2002
appearance B.ovata
Reproduction start of B.ovata
Peak of B.ovata reproduction
Disappearance B.ovata larvae
2003
2004
Year
2005
2006
2007
2008
Reproduction start of M.leidyi
Peak of M.leidyi reproduction
Disappearance M.leidyi larvae
L
Life stages and forcing factors
J
for M.leidyi and B.ovata
A
E
Individual based modeling
approach was used to take
into account life cycle and
physiological features
E – eggs
L-larva
J-juvenale
A-adult

Temperature
 -mortality
food
25
Forcing functions
Zooplankton
biomass
biomasse zoopk (mmolN.m-3)
20
15
10
5
0
0
50
100
150
200
250
time (days)
300
350
400
200
250
temps days
300
350
400
30
Temperature
Temperature (°C)
25
20
15
10
5
0
50
100
150
mortality
1,2
Mortality rate
mortality rate
1
0,8
0,6
0,4
0,2
0
0
0,1
0,3
0,4
food concentration (m m ol N.m -3)
3
2.5
mmA1
2
2,5
1.5
1
0.5
0
40
30
0.4
0.3
20
0.2
10
0.1
0
0
Adult mortality (day-1) mmA1
Mortality rate
0,2
2
1,5
1
0,5
0
0
Model
5
10
15
20
Temperature (°C)
25
30
35
Prey – predator individual based model structure
food
M.leidyi
Z
E
L
A
B.ovata
J
J
L
A
Temperature
E
Age classes
1

2
no
L
1
2
nL
J
1
2
nJ
2
nA
A
process
ageing
1
0%
1

50%
2
Age classes
100%
no
L
1
2
nL
J
1
2
nJ
2
nA
A
process
ageing
1
Change in stage duration depending on physiology (food, temperature)
25
fast
length (units)
20
slow
15
10
5
0
0
10
20
30
40
50
age (days)
egg
larva
juvenile
Adult
fast growing
egg
slow growing
larva
juvenile
Adult
n individus per unit
unit of volume
pervolume
Number individuals
Ontogenetic cycle of M.leidyi and B.ovata development
150
100
eggs
larvae
juveniles
50
adults
old adults
0
0
5
10
15
temps days
20
25
30
Time (days)
first adult
first juvenile
Model
first larva
first egg
Reproduction rate
Experiments
Model
700
0.9
500
400
300
200
100
0
20
21
22
23
24
25
26
27
28
Temperature, 0C
180
160
egg.gWW -1,day
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
B.ovata
140
spawning rate coef. (d-1)
WW,g,egg- 2.day-1
1
M.leidyi
600
0
120
5
10
15
20
temperature (°C)
100
80
60
40
20
0
20
21
22
23
24
Temperature, C
25
26
27
28
25
30
Ingestion rate
Ingestion rate coefficient (0 – 1)
experiment
Model
1
0.9
3,5
ingestion rate coef. (d-1)
Ration,DW.day -1
4
3
2,5
2
1,5
1
0,5
0
0
2000
4000
6000
8000
10000 12000
zooplankton,ind.m-3
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0
minFood
0.05
0.1
0.15
0.2
available food concentration
Food
C2= (Food- minFood)/ (Kf+ (Food-minFood))
C2 = 0
when Food < minFood
0.25
0.3
Stage duration
age to 50% transfer
Stage duration (days
20
15
10
5
0
0
0.05
0.1
0.15
0.2
5
10
15
20
25
30
35
optimum conditions
First stage: M.leidyi present
B.ovata absent
400
L
numbers (n m-3)
350
A
300
250
J
200
150
100
E
50
0
0
50
100
150
200
250
temps (days)
300
350
400
Second stage
numbers (n m-3)
350
M.leidyi
Model
300
250
L
200
150
A
100
E
50
0
0
50
100
150
J
200
250
300
350
400
temps (days)
Simulation of input of
B.ovata in surface
water at time 200th day.
M.leidyi develops a
bloom, which is grazed
by B.ovata
Predation on larvae,
juveniles and adult on
M.leidyi makes them
disappear
250
B.ovata
200
numbers (n m-3)
B.ovata
appears in
surface water at
time 200th day
400
L
150
J
100
E
A
50
0
0
50
100
150
200
250
time (days)
300
350
400
Model
Field observations
400
260
Mnemiopsis, ind. m -3
numbers (n m-3)
240
M.leidyi
350
300
L
250
200
150
A
100
180
160
A
140
120
100
E
80
60
40
J
0
0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360
Mn.adult 1
0
50
100
150
200
250
300
350
Time days Mn.ova
Mn.Juv
Mn.larvae
400
temps (days)
250
100
90
B.ovata
200
B.ovata
80
L
70
Beroe,ind.m -3
numbers (n m-3)
L
20
50
0
M.leidyi
220
200
150
A
100
L
60
50
E
40
J
A
30
20
10
50
0
0
0
0
50
100
150
200
250
time (days)
300
350
400
20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360
Time days
Ber.adult 1
Ber.Juv
Ber.ova
Ber.larva
Conclusions
In present Black Sea ecosystem there is a bottom up control
from zooplankton to its consumer Mnemiopsis leidyi and
finally to its predator Beroe ovata.
Annual changes in temperature and food availability are
considered as the main factors that control these predators’
dynamics and their impact on pelagic ecosystem of the Black
Sea.
Both field data analyses and individual based modeling
confirmed that, with appearance B. ovata that controlled M.
leidyi population, a recovering shift of the ecosystem appeared
but was controlled by climate forcing.
Now in any case it is another ecosystem with two
ctenophores that affected ecosystem but the time of high effect
of M.leidyi is much shorter.
Acknowledgement
The research was performed in framework
of project GK-0422
Thank you for attention