Nutrients in the Black Sea, LAZAR talk

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Integrated Regional monitoring Implementation Strategy in the South European Seas

Pilot Project - New Knowledge for an integrated management of human activities in the sea Activity Nr.2 NUTRIENTS IN THE NORTH WESTERN BLACK SEA

Luminita LAZAR llazar@alpha.rmri.ro

National Institute for Marine Research and Development “Grigore Antipa”, NIMRD, Constanta, Romania, www.rmri.ro www.iris-ses.eu


Black Sea in figures*: Hydrographic basin Total length of the coastline :

4 338 km

Bulgaria

300 km

Georgia

310 km

Romania

225 km

Russia

475 km

Turkey

1 400 km

Ukraine

1 628 km

Surface

432 000 km2

Freshwater flow average input Water volume Black Sea hydrographic basin (UNEP, 2011)

2 000 000 km2

Maximum depth Salinity

350 km3 547 000 km3 2 212 m 18 – 22 ‰

*http://www.blacksea-commission.org/_geography.asp



Drivers -Population growth - Industry - Agriculture - Urbanization – insufficient treated waters - Atmospheric emissions - Climate change

Response - Nutrient reduction measures - Monitoring - UE and national legislation -Research

Pressures -Danube’s nutrients enrichment -Hydrological changes

Impact Eutrophication enhancement

State - Higher nutrients input - Chemical state change

DPSIR analysis – Eutrophication in the Romanian Black Sea waters

-Increasing planctonic primary productivity - transparency decreasing - Hipoxic events - Biological state change


DIP (Phosphate) • Constanta station - 19592011 (daily) • Surface coastal water - not under the direct influence of the Danube

Mean = 0.6452-0.0118*x 2.0 Mean

Mean±0.95 Conf. Interval

1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 -0.2

1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2006 2007 2008 2009 2010 2011

DIP [µM]

• East Constanta transect, 1964-2011, N=6964, • 0.01 - 8.61 µM (surface) • 0.01 – 15.87 µM (water column) • Water column 15-50m depth

1.8

Year

• Decreasing values close to pristine period


• Water column has two layers delimited , all seasons, by the approx. level of 0.2 µM . • Winter – max. values – phosphate stock regeneration • Spring – min. values due to the biological specific consumption. End of spring – higher values at interface water-sediment. • Autumn – the increasing gradient with depth is maintained but in lower values DIP - Monthly mean concentrations – 1964-2011

• Generally, the distribution is characterized by two maximum values: in the photic layer 020m and at the interface water-sediment.


19641970

19711980 19811990

19912000

20012011

February

May

August

November

Seasonal (decadal) vertical distributions of the Phosphate – 1964-2011


Dissolved inorganic nitrogen - DIN • • • •

No significant differences Decreasing trend N/P increasing Eutrophication N/P less than 10.

Mean = 15.5016-0.2267*x

60.00

20

Mean

Mean±0.95 Conf. Interval

18

50.00

16

40.00

DIN [µM]

14

30.00 20.00 10.00

12 10 8 6 4

19 8 19 0 8 19 1 8 19 2 8 19 3 8 19 4 8 19 5 8 19 6 8 19 7 8 19 8 89 19 1990 9 19 1 9 19 2 9 19 3 9 19 4 9 19 5 9 19 6 9 19 7 9 19 8 9 20 9 2000 0 20 1 0 20 2 0 20 3 04 20 0 20 5 0 20 6 0 20 7 0 20 8 0 20 9 1 20 0 11

0.00

2 0

N/P

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

An

1996

1997

1998

1999

2000

2001

2002

2003

2004

2006

2007

2008

2009

2010

2011


Water column has two layer limited , all seasons, by the concentration 2 µM at approx. 25m depth •

Max. values –upper layer - spring due to increase of river and coastal inputs and to the thermocline shaping

Summer – after the specific consumption of spring blooms – removing the maximum from surface in the layer 10-20m (below DCM) highlighting the nitrogen regeneration and .

End of summer – the stock nutrient regeneration is interrupted by the second bloom – minimum concentrations.

Autumn -together with the thermocline breaking and increase of the surface input (land, atmospheric?) the nitrogen stock starts to regenerate and continues in winter.

DIN - Monthly mean concentrations – 1980-2011


Seasonal (decadal) vertical distributions of the Inorganic Nitrogen 19811990

19912000

20012011

February May August November


We are here


Further considerations/Conclusions • The recovery of the ecosystem is not done on the same pathway like its deterioration •Are the 60’s levels available/reliable or enough nowadays to be used as reference values ? •Studies on nutrient availability and transformations in order to estimate the distinction between the natural productive state and the eutrophic state. •Assessments for diffuses sources – e.g. atmospheric deposition. •Studies/data on climate change impact on nutrient availability and transformations in the NW Black Sea marine ecosystem. •An aggregate indicator in order to assess eutrophication


Thank you for your attention!

llazar@alpha.rmri.ro www.rmri.ro


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