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
....HYPOX kickoff: introduction to NW Black Sea –
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
....HYPOX kickoff: introduction to NW Black Sea –
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°
....HYPOX kickoff: introduction to NW Black Sea –
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
Black SeaNorth Western
Sector
50 Nm
Scale:
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
Legend:Sandy sediments
Silty sediments
Clayey sediments
Mixed sediments
Depositional Zone Limit
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
....HYPOX kickoff: introduction to NW Black Sea –
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
....HYPOX kickoff: introduction to NW Black Sea –
Romanian Shelf
Hypoxia Areas on the NW Shelf 1973-1990
....HYPOX kickoff: introduction to NW Black Sea –
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
....HYPOX kickoff: introduction to NW Black Sea –
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
....HYPOX kickoff: introduction to NW Black Sea –
Romanian Shelf
OO22
1975 and 2008
Distance km
....HYPOX kickoff: introduction to NW Black Sea –
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
....HYPOX kickoff: introduction to NW Black Sea –
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
....HYPOX kickoff: introduction to NW Black Sea –
Romanian Shelf
Benthic ecological zonation
(2)
....HYPOX kickoff: introduction to NW Black Sea –
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
....HYPOX kickoff: introduction to NW Black Sea –
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.
....HYPOX kickoff: introduction to NW Black Sea –
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.
....HYPOX kickoff: introduction to NW Black Sea –
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.
....HYPOX kickoff: introduction to NW Black Sea –
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)
....HYPOX kickoff: introduction to NW Black Sea –
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
Black Sea after 1970 (4)
....HYPOX kickoff: introduction to NW Black Sea –
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 ?
Black Sea after 1970 (5)
....HYPOX kickoff: introduction to NW Black Sea –
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
....HYPOX kickoff: introduction to NW Black Sea –
Romanian Shelf
State of NW Black Sea benthic ecosystems in the 1990s: a new line to compare the trends in ecosystem recovery
....HYPOX kickoff: introduction to NW Black Sea –
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:
....HYPOX kickoff: introduction to NW Black Sea –
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
....HYPOX kickoff: introduction to NW Black Sea –
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)
....HYPOX kickoff: introduction to NW Black Sea –
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)
....HYPOX kickoff: introduction to NW Black Sea –
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