Non-indigenous species in the Romanian BlackSea littoral zone: Mya arenaria, Rapana venosa

and others

Marian-Traian Gomoiu

GeoEcoMar, Constantza, Romania

curriculum in natural environmental science, 2005

0

10

20

30

40

+10 +20 +30 +40 +50 +60 +70 +80 +90

Size classes - mm

Freq

uenc

y - %

1970

1971

Length classes frequency of Mya arenaria shells from beach deposits

curriculum in natural environmental science, 2005

Comparative quantitative distribution of Mya arenaria populations at the Romanian Black Sea littoral in 1982 vs. 1974

curriculum in natural environmental science, 2005

10

100

1000

10000

100000

1955 1960 1965 1970 1975 1980 1985

Den

sity

- s

ps.

m-2

Corbula Mya

100

1000

10000

100000

1000000

10000000

1955 1960 1965 1970 1975 1980 1985

Y e a r sB

iom

ass

- m

g.m-2

Variation of Mya arenaria stocks

0

500000

1000000

1500000

1973 1974 1975 1976 1977 1978 1979 1980 1981

Y e a r s

T o

n s

Quantitative variation of Corbula mediterranea and Mya arenaria populations from the Black Sea sedimentary bottoms between Danube mouth and Constanta

curriculum in natural environmental science, 2005

Constancy (% ) of populations

0

50

100

4m 9m 15m 22m 30m 35m

Bathimetric zones

Con

stan

cy -

%

Mean density and biomass

1

10

100

1000

Bathimetric zones

Bio

mas

s -

g.m

-

2

110100100010000

Den

sity

-

sps.

m-2

B-81D-81

Minimum and maximum densities and biomasses

1

10

100

1000

10000

100000

4m 9m 15m 22m 30m 35m

Bathimetric zones

Den

sity

- sp

s.m

-2

1

10

100

1000

10000

Bio

mas

s - g

.m-2

Dmin Dmax Bmin Bmax

Elements for synoptic analysis of Mya arenaria population in 1981

curriculum in natural environmental science, 2005

Frequency (%) of main molluscs species at different depths in 1981 at the Romanian littoral of the Black Sea, including nuclei delimitation of communities formation

(Ce-Cardium edule lamarckiMy - Mya arenaria Cb - Corbula mediterranea Mg - Mytilus galloprovincialisSs - Spisula subtruncata Pr - Paphia rugata Cp - Plagiocardium papillosum)

curriculum in natural environmental science, 2005

Average biomass of molluscs

1 10 100 1000 10000 100000 1000000

Hy - Hydrobia ventrosa

Tt - Tellina tenuis

Cp - Acanthocardia paucicostata

Nr - Nassarius reticulatus

Pr - Paphia rugata

Ce - Cardium edule

My - Mya arenaria

Biomass - mg.m-2

Structure of molluscs biomass - 322 g.m-2

My73%

Ss0%

Pr0%

Sy0%

Cb1%

Ce3%

Mg23%

Ch0%

Tt0%

Cp0%

Hy0% Cy

0%Nr0%

Average structure of molluscs biomass on the sedimentary bottomsat the Romanian Black Sea littoral in the beginning of 1980s

curriculum in natural environmental science, 2005

0 50 100 150 200 250 300

I

III

V

VII

IX

XITra

nsec

ts fr

om S

ulin

a - D

anub

e D

elta

(I) t

o M

amai

a - C

onst

anta

(X

I)Tons*10

3

Spatial distribution of Mya arenaria losses by mass mortalityat the Romanian Black Sea coast.

curriculum in natural environmental science, 2005

0

10

20

30

40

50

60

70

80

Mya arenaria

Hydrobia ventrosaMytilus galloprovincialis

Corbula mediterranea

Cardium edule lamarcki

Scapharca inaequivalvis

Rissoa splendida

Chrysallida interstincta

Retusa truncatula

Chione gallinaAbra albaTellina tenuis

Eulimella nitidissima

Cyclonassa neritea

Syndesmia fragilis

Spisula subtruncata

Nassarius reticulatus

Cerithiolum sp.

Cardium simile

Cardium paucicostatumBarnea candida

1960-1961 1986-1990

Comparative situation of molluscs associations ante- (1960-1961)and post- (1986-1990) Mya arenaria introduction into the Black Sea

curriculum in natural environmental science, 2005

The expansion ways into the Black Sea of some immigrant species:Rapana venosa, Rithropanopaeus harrisii and Menmiopsis leidyi

curriculum in natural environmental science, 2005

0

20

40

<50 +50 +60 +70 +80 +90 >100

Size classes - mm

Perc

enta

ge -

%

Sandy bottoms Rocky bottoms

Average size class structure of Rapana venosa populationsliving on sandy and rocky bottoms

curriculum in natural environmental science, 2005