hypox kickoff: site introduction nw black sea – romanian...

NW Black Sea –

Romanian ShelfM.T. Gomoiu

(GeoEcoMar)

....HYPOX kickoff: Site introduction

....HYPOX kickoff: introduction to NW Black Sea –

Romanian Shelf

GeoEcoMar

area of activity


Romanian Shelf

Black Sea Catchment

Area (1)

River Basin area (103km2)

Water discharge

(km3/y)

Sediment discharge

(106t/y)

Danube 817.0 190.7 29.2

Dniestr 72.1 9.8 2.5

Dniepr 503.0 52.6 2.1

S. Bug 63.7 2.6 0.5

Don 442.5 29.5 6.4

Kuban 57.9 13.4 8.4

CaucasusRivers 41.0 29.0

AnatoliaRivers 29.7 51.0

BulgariaRivers 3.0 0.5

Total 1956.2 372.3 152.2


Romanian Shelf

Black Sea Catchment

Area (2)Length

2 860 kmDrainage basin

817 000 km2Average annual water discharge

6 550 m3/sAverage annual suspended sediment discharge:

before the building of Iron Gates I

67.50 Mt

after the building

30.32 Mt

45°

28° 32°

45°

28° 32°


Romanian Shelf

North Western Black Sea Shelf Bathymetry

47°00'

43°00'

44°00'

45°00'

46°00'

100 m

100 m

1500 m

1500 mLatit

ude

Varna

Constanta

Odessa

Sevastopol

27°00' 28°00' 29°00' 30°00' 31°00' 32°00' 33°00' 34°00'

Longitude

200 m

2000 m

0

Black SeaNorth Western

Sector

50 Nm

Scale:

2000 m

A

B

C

DF

G

HE

Abyssal fan ofUkrainian rivers

Danubeabyssal fan

Legend:Sandy sediments

Silty sediments

Clayey sediments

Mixed sediments

Depositional Zone Limit

Textural Area Limit

47°00'

43°00'

44°00'

45°00'

46°00'

47°00'

43°00'

44°00'

45°00'

46°00'

100 m

100 m

1500 m

1500 mLatit

ude

Varna

Constanta

Odessa

Sevastopol

27°00' 28°00' 29°00' 30°00' 31°00' 32°00' 33°00' 34°00'

Longitude

200 m

2000 m

0


Sector

50 Nm

Scale:


Sector

50 Nm

Scale:

2000 m

A

B

C

DF

G

HE

Abyssal fan ofUkrainian rivers

Danubeabyssal fan


Silty sediments

Clayey sediments

Mixed sediments


Textural Area Limit


Silty sediments

Clayey sediments

Mixed sediments


Textural Area Limit

High depositional variety with several well defined depositional

areas:

– A

–

Dnieper influence area–

B –

Dniester influence area–

C

– Danube Delta Front–

D

– Danube Prodelta–

E

–

Danube influence area–

F –

Sediment starving continental shelf–

G –

Shelf break and uppermost continental slope–

H –

Deep sea fan area–

I

–

Deep sea floor area–

J –

Crimea coast

High sediment diversity.All Shepard’s ten textural types

have been identified


Romanian Shelf

Depositional zones

Legend:

1973

1974

1978

1990

Source map: The development of hypoxic areas on the North WesternShelf of the Black Sea, In: Zaitsev, Yu. P. 1993 Impacts ofEutrophication on the Black Sea fauna General Fisheries Council forthe Mediterranean, Studies and reviews, FAO, 64, p. 63-86


Romanian Shelf

Hypoxia Areas on the NW Shelf 1973-1990


Romanian Shelf

Hypoxic Areas on the Romanian Shelf in the 1970s

Portita September 1979

0

10

20

30

40

50

60

0 1 2 3 4 5 6 7 8 9 10 11 12

cm3/l

Dep

th, m

E5E4E3E2E1

Sf.Ghe. September 1979

05

1015202530354045

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0

cm3/l

Dep

th, m

C4C3C2C1


Romanian Shelf

Oxygen Saturation in bottom waters September/October 2003 (GEF Cruise)

10-20 20-30 30-40 40-55 55-75 75-95 95-115 115-130BG 7.71 6.64 6.74 7.41 6.92VA 4.78 5.63 5.74 7.66 8.38 1.91 0.57 0.37CK 8.11 7.88 8.26 8.08 7.67 2.29 1.04CT 6.37 6.22 4.91 7.06 5.62 3.3 0.54 0.42SG 4.7 4.9 5.69 6.92 3.18 0.95 0.91 0.43SU 6.94 4.55 4.18 6.12 6.84 1.5ZB 5.78 6.51DN - - - - 7.09 4.66 1.39 0.96

10-20 20-30 30-40 40-55 55-75 75-95 95-115 115-130BG 91 81.6 78.6 83.8 66.8VA 55.5 70.1 69.8 91.1 84.5 20 5.8 3.8CK 94.9 92.5 98.1 95.7 76.8 23.6 10.5CT 77.4 72.6 53.7 72.6 60 34.2 5.4 4.3SG 56.5 50.4 58 68.6 33.1 9.9 9.4 4.4SU 82.5 47.3 44.1 64.2 67.9 14.6ZB 68.3 78DN - - - - 70.1 46.7 14 9.6

TransectDepth interval, m

O2 Saturation, %

O2 Concentration, mg/l

TransectDepth interval, m

Dn e p r

Da

n

ub

e

D n

es

t r

Varna

Constanta

Odessa

Sevastopol

Black SeaNorth-Western

Sector

0 50 Mm

Scale:

Legend:

0

10

30

50

70

Persistent hypoxia and local anoxia identified in 1991 in bottom waters

Normal distribution in 2003

Distance km

31 Jul 2008

13 Aug 1975CONSTANTA

Antipa

1913

Mya

arenaria

mortalityzone

Stations ECT1 –

ECT5


Romanian Shelf

OO22

1975 and 2008

Distance km


Romanian Shelf

OO22

Historic hypoxic/anoxic eventsAntipa

observed (1913, 21 July) yellow-reddish water

bordered with stripes of white foam somewhat south of the river Danube, between Zaton

and St. Georghe. He was told by

fishermen that reddish water

may be observed twice a year in a flow of cold water. Fish die

when arriving in this water, and

the fishing nets are "burnt"

by it. The cause of the reddish color has not been investigated. Antipa

supposed that water is

brought up from a depth of 180 m

where H2

S is converted into H2

SO4

. Antipa's

hypothesis was adopted by several geologists. Archangelski

states that acid water sometimes is brought to

the surface by storms.

The nature of the reddish discoloration is unknown. Provisionally fish mortality is placed under noxiousness of waterbloom.

Azoic area occurs in shallow waters only temporarily and locally


Romanian Shelf

Benthic ecological zonation

(1)

Sketch-map for the ecological zoning of the Black Sea (Eco-Regions): NW – North-West Shelf Zone; W – West Shelf Zone; B – Pre-Bosphorus Zone; CA – Central – South Zone (Anatolian Coast); E – East Zone (Batumi); KS – Kerci Shelf Zone; AZ – Sea of Azov; NE – Eastern Slope of the Shelf; WS – Western slope of the Shelf; CW – Western deep sea Zone; CE – Eastern deep sea Zone.

“Clasic” map of zonation


Romanian Shelf

Benthic ecological zonation

(2)


Romanian Shelf

Black Sea before 1970 (1)•one of the most productive seas

in the ’60s•Base line reflecting a “round -

cyclical”

function of the ecosystems at all trophic levels


Romanian Shelf

Black Sea before 1970 (2)high biodiversity;luxuriant development of both pelagic and benthic life;a vast distribution of Phyllophora red algae and good state of Zostera and Algae associations;a remarkable abundance of bottom filter-feeders (Mytilus, Modiolus and other species);an ideal feeding ground for many commercial fishes;rich and valuable developed fisheries – sturgeons, anchovies, turbot, sole fish, gray mullet, mussels etc.


Romanian Shelf

Black Sea after 1970 (1)•Degradation of the Black Sea ecosystems•Towards a simple, less diverse and

productive, unstable ecological system under the stress of anthropogenic and global changes.


Romanian Shelf

Black Sea after 1970 (2)pollution/eutrophication

by tributary rivers and effluents;coastal urban and industrial development;hydro-technical works for coastal defense or harbor facilities;development of maritime ships exchange between the Black Sea and the other seas and oceans; invasion of alien species and their naturalizations in the new Pontic

habitat; Mnemiopsis leidyi invaded the Black Sea

practice of bottom-trawl fishing;sand mining in the beach zone, etc.


Romanian Shelf

Benthic biocoenoses – Romanian shelf Supralittoral - Mediolittoral

Biocoenoses Present state Remarks

Orchestia – Enchytreus albidus – Insecta larvae – Nematoda +

*Pachygrapsus marmoratus **Xantho poressa

***Eriphia spinifrons

Impoverished after ‘80s

Recovering last years Recovering Crustacean populations

Talorchestia ? Probably extinct Littorina neritoides – Ligia italica – Tylos latreillei ? Probably extinct

Mytilaster – Mytilus – Balanus + *Enteromorpha

**Porphira ***Cladophora

Good

After a long period of loss of Cystoseira thickets,

slight recover of the Brown algae Cystoseira populations

Donacilla cornea – Ophelia bicornis + *Saccocirrus – Praegeria

**Ectinosoma melaniceps – Otoplana Extincted

Biotop site loss, covered by the new Constanta South - Agigea Harbour; re-

appearance of Donacilla cornea populations

Euxinia maeotica Very good

Black Sea after 1970 (3)


Romanian Shelf

Benthic biocoenoses – Romanian shelf Infralittoral

Donax trunculus Extincted Probably affected by pollution Re-

appearance of Donax trunculus populations

Corbula mediterranea Mya arenaria

Severe regress Good Replaced by Mya arenaria

Mytilus – Actinia – Balanus + *Cystoseira Very good Recovering after drastic reduction of

perennial algae (Cystoseira) Pholas candidus + (Corophium bonelii –

Brachynotus sexdentatus) Extincted Biotop site loss

Zostera Severe regress Spisula subtruncata – Corbula mediterranea Bad Drastic reduction of population size

Spisula – Mytilus - (Tapes) with Nephtis Bad Drastic reduction of population size Abra milashewichi Very bad Replaced partially by Melinna palmata

Spisula – Abra milashewichi – Cardium paucicostatum Very bad Replaced partially by Melinna palmata

Spisula – Mytilus / Paphia



Romanian Shelf

Benthic biocoenoses – Romanian shelf Circalittoral - Periazoic

Muddy

Mytilus galloprovincialis + *Ascidiella, Ciona

**Terebellides, Melinna ***Abra, Syndesmya, Paphia,Cardium

paucicostatum, Cardium simile, Calyptrea, Chiton

Less abundant population

Muddy Mytilus - Lithothamnion – Phyllophora ?

Muddy Mytilus galloprovincialis – Modiolus phaseolinus In extension

Muddy Modiolus phaseolinus +

*Amphiura, Leptosynapta, Sycon, Trophon, Ascidiella, Ciona, Eugyra

Reduced as extension Mytilus juv. invading and H2S arising

Muddy Terebellides – Apseudis – Cerianthus – Modiolus phaseolinus ?

Muddy Bougainvillia ramosa ?



Romanian Shelf

Black Sea after 1970 (6)The entire ecosystem began to collapse, worsening the situation:• Uncontrolled sewage pollution • Solid waste dumped directly into the sea • Oil pollution by tanker accidents and operational discharges•

Black Sea countries in economic and social transition, unable to take the necessary urgent remedial actions •

Unsustainable exploitation of the Black Sea's resources in the past few decades

The ecosystem of the Black Sea has deteriorated dramatically in terms of its biodiversity, habitats, fisheries resources, aesthetic and recreational value and water quality.

Mya

aren

aria

Mass mortality of benthic organisms – Mya arenaria case


Romanian Shelf

State of NW Black Sea benthic ecosystems in the 1990s: a new line to compare the trends in ecosystem recovery


Romanian Shelf

drastic decrease of the specific diversity;simplification of communities structures –

biocoenotic

homogenizing;decrease of the numeric abundance and biomass of benthic populations;diminution of the biofilter

strength by reduction of the filter –

feeder

populations;qualitative and quantitative worsening of benthic biological resources;thriving of opportunistic forms (worms causing sediment bioturbation) and, temporarily, some exotic species recently pervading Black Sea;great quantitative fluctuations of all benthic populations.

general or local extinction of some species;threatening populations with

disappearance;increasing vulnerability of some forms;reduction of populations size of many

species;changes of taxonomic or/and ecologic

structure populations in the communities;reduction of the ecosystem resilience.

Reduction of species diversity -

major consequence of the disturbing factors:


Romanian Shelf

Less known is the role of global changes: the improvements in the Western Black Sea ecosystem could be generated by some favorable climatic conditions over the last decade. Significant areas of the seabed had been suffering from anaerobic conditions, but nowadays

such problems have

almost completely disappeared from the Western Black Sea, where conditions are similar to those that prevailed until the 1960s. However,

fish stocks in these waters are out of balance,

–

mainly as a result of over-fishing (ICPPDR, 2006)A simple question: Where is the fish if the ecosystem is recovering?

Where is the famous fishery at the Danube

mouths?

Ecological Trend in the NW Black Sea....HYPOX kickoff: introduction to NW Black Sea –

Romanian Shelf

Crossing interfaces barriers between seas....HYPOX kickoff: introduction to NW Black Sea –

Romanian Shelf

Black Sea gates for exotic organisms –

continental inter-rivers canals, Kertch

and Bosphorous

are permanently open;new ecological conditions -

ready to absorb new populations;very weak ecosystems’ resiliencepenetration process is continuing -

attention to toxic and harmful species;impact of alien species is complex and unpredictable;monitoring is absolutely necessary-

attention to microflora

and microfauna;legal measures and regulations for limiting the invasive species

–

necessary;training specialists in biological taxonomy and systematics

-

high priority.

Variation of the benthos populations....HYPOX kickoff: introduction to NW Black Sea –

Romanian Shelf

Random distributionPatchesMeta-populations occurrence

Occurrence of recurrent species -

considered almost extinct 2-3 decades agoDecreasing abundance from shallow to deep water and from South to North

Tendency of NW Black Sea benthic ecosystem evolution in the last decade


Romanian Shelf

Abundance Macro : Meio 1995 1 : 9 1997 1 : 10 1998 1 : 4

DAVG indvs.m-2

2003 1 : 12 1995 206 : 1 1997 103 : 1 1998 10 : 1

BAVG g.m-2

2003 94 :1

Macrobenthos

abundance and distribution....HYPOX kickoff: introduction to NW Black Sea –

Romanian Shelf

Macrobenthos Density

Macrobenthos Biomass

Macrobenthos

abundance and distribution....HYPOX kickoff: introduction to NW Black Sea –

Romanian Shelf

Danube Delta

Constanta

Varna

Black Sea

Danube Delta

Constanta

Varna

Black Sea

Role of GeoEcoMar

in HYPOX (1)....HYPOX kickoff: introduction to NW Black Sea –

Romanian Shelf

Monitoring the recovery of benthic communities' structures and functions and providing data for other WPs; Monitoring and mapping the effects of water temperature and chemical stress on the pelagial

and benthic ecosystemsContributions in assessing the history of basin structure, water

level, flow and sedimentation; participation in analyzing past and recent structure of benthic communities and their resilience to oxygen depletion as potential indicator of variation in oxygen concentrationDocumenting the extent of hypoxia over Romanian continental shelf throughout the time, as a sine qua non condition in understanding hypoxia formation through an annual cycle, and for

the classification of ecosystems and their boundaries with regard to chemical stress

Role of GeoEcoMar

in HYPOX (2)....HYPOX kickoff: introduction to NW Black Sea –

Romanian Shelf

GeoEcoMar

will assist AWI in the Black Sea -

Romanian Shelf research area for design, deployment and maintenance of in-situ sensor buoys to monitor oxygen and relevant parameters in hypoxia-prone areas within the Danube River plume and the Danube ProdeltaGeoEcoMar

will organize short cruises to the Romanian inshore waters.Participation in the activities organized by the Project

Management Team.

Requirements/issues for the Black Sea benthic studies in actual post-eutrophication

period (1)


Romanian Shelf

Benthic assemblage’s identification Species composition and abundance assessment

► Number of species (including alien species)► Numerical density► Biomass► Size structure

Assemblage segregation by reflected differences in salinity and sediment-types .

Requirements/issues for the Black Sea benthic studies in actual post-eutrophication

period (2)


Romanian Shelf

Impacted and non impacted assemblages identification Species and/or higher taxa

designation as indicators

Meaningful proportion between the abundance of different taxa

as indices for the assessment of ecological state of

the ecosystem Several benthic indices

hypox kickoff: site introduction nw black sea – romanian...

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