HELSINKI COMMISSION (HELCOM)
Ziel der HELCOM "Indicator Fact Sheets"
ist es, Kurzinformationen zu einzelnen Aspekten und zu Trends des Umweltzustand der Ostsee zu geben. Wissenschaftler aus
verschiedenen Instituten der Ostseeanrainerstaaten stellen diese Informationen zusammen auf der Grundlage der Daten aus
den Monitoring Programmen für die Ostsee:
- Pollution Load Compilation (PLC-Air und PLC-Water)
- Cooperative Monitoring in the Baltic Marine environment - COMBINE
- Monitoring of Radioactive Substances (MORS)
Die Indikatoren, die nach Zustimmung der
HELCOM Arbeitsgruppe "Monitoring and Assessment"
(MONAS) veröffentlicht werden, stellen bestimmte Umweltaspekte in vereinfachter
Form dar, erklären aber nicht die komplexen Zusammenhänge des Systems Ostsee als Ganzes. Zu diesem Zweck werden alle paar Jahre
sogenannte thematische Assessments herausgegeben.
Liste der "Indicator Fact Sheets" für 2006 mit der
jeweiligen "key message" in englischer Sprache und
Total and regional Runoff to the Baltic Sea
(Pia Andersson, SMHI)
During the last 8 years the total inflow has decreased from a top flow rate of over
17500 m³/s in 1998 to less than 11000 in 2003. Since
2003, the runoff has slightly increased and in 2005 the runoff was just below the mean values reaching
All sub basins but the Gulf of Finland, had lower runoff values in the year 2005 compared to the mean values.
In the Gulf of Bothnia, the Gulf of Finland and the Gulf of Riga, the difference to the mean value was less
than 1 %. In the Baltic Proper, the difference to the mean value was more than 9 %. When looking
at the entire Baltic Sea, the difference to the mean value was 2 % hence the general runoff for the
entire area was slightly lower compared to the yearly mean runoff value.
During the period 1950 - 2005, the total runoff to the Baltic Sea area shows no long-term trends.
On the other hand this time period is characterised by dry and wet periods lasting for a couple of years to
a decade generally following the NAO index.
Water exchange between the Baltic Sea and the North Sea, and conditions in the
(Rainer Feistel, Günther Nausch and Eberhard Hagen,
The inflow activity of recent years from the Kattegat into the Baltic Sea was coined by a
quite unusual sequence of events: a warm summer inflow 2002 was followed by a cold gale-forced one in
January 2003, and again by a warm summer inflow 2003, all together they terminated the stagnation period
in the Baltic deep water which lasted since 1995. The period afterwards was characterized by only low
inflow activities. Thus a new stagnation period has started in the deep basins in 2004 which continues
Hydrography and oxygen in the deep basins
(Philip Axe, SMHI)
The saline inflows of November 2002 - March 2003 caused major changes to the
hydrographic conditions in the deep basins between Arkona and the East Gotland Basin. Deep water salinity
in the south eastern Baltic Proper remains higher than in 2002. In the Bornholm and East Gotland Basins,
salinity is again close to the 2002 level.
Deep-water oxygen levels, from Arkona to the East Gotland Basin, were significantly better in autumn 2003
than in 2002. Since then, hydrogen sulphide levels have steadily increased again in the East Gotland Basin,
though do not yet appear to extend as far as in 2002.
Water transparency in the Baltic Sea between 1903 and 2005
(Vivi Fleming-Lehtinen, Maria Laamanen and Riitta Olsonen,
Decrease in summer time water transparency was observed in all Baltic Sea sub-regions
over the last one hundred years. The decrease was most pronounced in the Northern Baltic Proper (from
almost 9 m to 4 m) and the Gulf of
Finland (from 8 m to 4 m).
In the Kattegat, southern and eastern Baltic Proper, the Bothnian Sea and the Bothnian Bay the decreasing
trend ceased during the past 10 to 15 years and since then the water transparency remained in about
the same level.
Wave climate in the Baltic Sea 2005
(Heidi Pettersson, FIMR; Thomas Hammarklint,
The wave climate in the northern Baltic Sea in 2005 was characterised by a stormy January and by a
December that was calmer than usually. In spring, summer and autumn the wave climate was typical for each season.
The highest measured significant wave height in the Northern Baltic Proper was 7.2 metres (January) and in the
Gulf of Finland 4.2 metres (November). In the northern parts of the Danish Sounds the significant wave height
reached 6.2 metres in November and in Kattegat 4.0 m (January).
Development of Sea Surface Temperature in the Baltic Sea in 2005
(Herbert Siegel, Monika Gerth, IOW)
The year 2005 was characterized in the water surface temperature by comparatively warm months January,
July as well as October, November and December and was in the annual average the warmest year of the investigation
period 1990 - 2005. January belonged almost in the entire Baltic Sea after 2001 to the warmest since 1990.
The July was the warmest month of the year which was observed since 1990 only in the year 2001 otherwise August
was always the warmest month of the year. The high temperatures of July initiated an intensive cyanobacteria bloom,
which had its maximum expansion and intensity on the warmest day (13 July). The warm autumn contributed to
the high annual average.
The ice season 2005 - 2006
(Simo Kalliosaari, FIMR;
Natalija Schmelzer, BSH;
Torbjörn Grafström, SMHI;
Inga Dailidiene, Center of Marine Research, Lithuania; Evgeni Komissarov, P. Soloshchuk,
Hydrometeorological Center of St.-Petersburg, Russia)
The ice season 2005/2006 was late and normal in terms of ice extent.
The ice season started during December and the ice conditions developed like for a warm winter.
Ice conditions gradually became more difficult in the beginning of March due to cold north-easterly winds. The
largest ice cover - 210,000 km² - was reached on March 16th.
After this the ice situation began to decrease gradually.
The ice winter was, by the extent of the ice cover, classified as average. The ice breaking up was in most
waters about week later than normal and the 29th May the Baltic Sea was ice free.
From point of view of the navigation, the ice conditions on the Gulf of Finland for winter 2005/2006 were
unfavourable, especially on second half of season – stormy winds often led to appearance the compressed ice
on the fairway and rapid changes of ice conditions complicated the choice of the optimal ways of assistance
Nitrogen emissions to the air in the Baltic Sea region
(Jerzy Bartnicki, EMEP MSC-W)
Annual emissions of nitrogen oxides and annual emissions of ammonia from the
HELCOM Contracting Parties were lower in 2004 than in
Atmospheric nitrogen depositions to the Baltic Sea
(Jerzy Bartnicki, EMEP
The total deposition of nitrogen to the Baltic Sea in 2004 was 214
ktonnes. The annual load varies across different parts of the Baltic Sea:
from 300 mg/m² N in
the northern Gulf of Bothnia up to 1000 mg/m²
N in the Belt Sea.
Mainly because of interannual changes in meteorology, no significant temporal pattern in nitrogen depositions
to the Baltic Sea and its sub-basins can be detected in the considered period. Annual depositions of nitrogen
to the Baltic Sea are oscillating around the 1995 value within 20 % range, however depositon of oxidized,
reduced and total nitrogen in 2004 was respectively 15 %, 9 % and 13 % lower than in 1995.
Atmospheric emissions of heavy metals in the Baltic Sea region
(Alexey Gusev, EMEP
Annual emissions of heavy metals from HELCOM
countries have decreased during the period from 1990 to 2004 by 44 % for cadmium, 42 % for mercury,
and 86 % for lead.
Atmospheric depositions of heavy metals on the Baltic Sea
(Alexey Gusev, EMEP
Total annual atmospheric depositions of heavy metals to the Baltic Sea have decreased in
period from 1990 to 2004 by 51 % for cadmium, 44 % for mercury, and 69 % for lead.
Atmospheric emissions of
PCDD/Fs in the Baltic Sea
(Alexey Gusev, EMEP
Annual emissions of dioxins and furans have decreased during the period from 1990 to 2004
in most of the HELCOM countries. The most significant drop of
PCDD/Fs emissions can be noted for
Sweden (39 %), Estonia (34%) and Russia (34 %). Some decrease of emission can also be noted for
Denmark (16 %) and Poland (9 %). For Finland, Latvia, Lithuania, and Germany the level of
PCDD/Fs emissions in 2004 is
higher than emissions of 1990.
Atmospheric depositions of
PCDD/Fs on the Baltic Sea
(Alexey Gusev, EMEP MSC-E)
Total annual atmospheric depositions of
PCDD/Fs to the Baltic Sea have
decreased in period from 1990 to 2004 by 33 %.
Heavy metals in Baltic Sea water, 1993 - 2005
(Christa Pohl, Ursula Hennings , IOW)
In general the 2005 (February) results of lead (Pb), mercury
(Hg), and cadmium (Cd) concentrations in Baltic
Sea surface and deep waters revealed no pronounced changes compared to previous years. Regional and temporal
limited variations of trace metal concentrations, which have been observed periodically in the western Baltic,
have been attributed to the wind induced mixing of the water column coupled to a more or less enrichment of
suspended matter and associated trace metals in the water column.
Spatial distribution of the winter nutrient pool
(Philip Axe, Pia Andersson, SMHI)
The excess ortho-phosphate (dissolved inorganic phosphorus) available in surface waters at the end of
2004, coupled to the extremely calm summer of 2005, led to an intense and widespread cyanobacteria bloom in the
central Baltic Proper. Sedimentation of these cyanobacteria, as well as transport by currents, has reduced the
concentration of dissolved inorganic phosphorus in the central Baltic Proper. Levels remain extremely high in the
Arkona Basin, and are high even in the Gulfs of Finland and Bothnia. This remaining excess phosphorus was the
cause of the even-more widespread cyanobacteria blooms of summer 2006.
Temporal and spatial variation of dissolved nutrients in the Baltic Sea in 2005
(Anniina Kiiltomäki, Tapani Stipa, Seppo Kaitala, FIMR)
2005 the chlorophyll a values were lower than the Alg@line-reference (the average of the
years 1993 - 2004) in Arkona and Bornholm Basins.
In the Gulf of Finland the chlorophyll a concentration spring peak lasted longer in 2005 than in the
Alg@line-reference. In the Eastern Gotland Basin the second chlorophyll a concentration peak was
higher than in the Alg@line-reference.
The winter surface water concentrations of dissolved inorganic phosphate were higher than the Alg@line-reference
and the EUTRO-target
values in all regions. In Arkona, Bornholm and Gotland Basins the phosphate values were higher than
Alg@line-reference throughout the year 2005.
According to the EUTRO-target levels all examined open sea regions - Arkona Basin, Bornholm Basin,
Eastern Gotland Basin, Northern Gotland Basin, Gulf of Finland and Bothnian Sea - are again classified as
an eutrophication problem areas in the year 2005.
Chlorophyll a concentrations, temporal variations and regional differences from satellite
(Wolfram Schrimpf and Samuel Djavidnia, European Commission - Joint Research Centre, Institute
for Environment and Sustainability, Ispra, Italy)
Chlorophyll a concentrations derived from satellite remote sensing show a high spatial variability
reaching relative high values in the Eastern and South Eastern part of the Baltic Sea. The chlorophyll a
concentrations show also significant inter-annual variability that might be related to the variability of the
meteorological conditions in the basin and its catchment (e.g. high/low
precipitation in spring -> high/low river discharges -> high/low nutrient input and stratification ->
higher/lower biological productivity).
Summer chlorophyll a concentrations in the sub-basins can deviate significantly from an overall average in
the Baltic. The satellite-derived chlorophyll-like pigments in the Baltic Sea are clearly higher than in the
Skagerrak and North Sea.
Phytoplankton spring bloom biomass in the Gulf of Finland, Northern Baltic Proper and Arkona
Basin in 2006
(Vivi Fleming and Seppo Kaitala, FIMR)
The spring bloom in the Gulf of Finland was less than half the size of last years bloom.
The spring bloom was negligable in the Arkona Basin.
No rising trend can be detected from 1992 to 2006 in the Gulf of Finland, the northern Baltic Proper or the
Unusual phytoplankton events in 2005
(Susanna Hajdu, Stockholm University; Irina Olenina Centre of Marine Research, Lithuania;
Norbert Wasmund, IOW; Lars Edler,
SMHI; Barbara Witek,
University of Gdansk)
Strong bioluminescence were observed in several coastal areas in late summer 2005.
Marine species (Cerataulina pelagica, Chaetoceros brevis, Dactyliosolen fragilissimus)
penetrated far into the Baltic Proper up to the Lithuanian coast in late autumn. They may indicate warm water
inflows that cannot be identified on the basis of salinity measurements.
Cyanobacterial bloom in the Baltic Sea
(Martin Hansson, SMHI)
Cyanobacterial blooms in the Baltic Sea during the summer 2006 had the third greatest extent during
the period 1997 - 2006. The duration of the bloom was equal to the bloom 2005 but the intensity of the
bloom was the greatest during the period 1997 - 2006.
Nutrient conditions in the southern Baltic Proper during 2006 show increased phosphate level in the surface layer,
while phosphate concentrations were back to normal in the northern and central Baltic Proper.
Sunny, warm and calm weather during early July 2006, with water surface temperatures well over
20 degree C., in combination with available phosphate, resulted in a widespread bloom.
Affected areas stretched from the Bothnian Sea, the Gulf of Finland, the Gulf of Riga, the Baltic Proper, the Gulf of
Gdansk, the Belt Sea and Kattegat.
Cyanobacteria bloom index
(Seppo Kaitala, Seija Hällfors, FIMR)
During the assessment period cyanobacteria were most abundant in 1999 and 2000. In the consecutive
years the abundance showed large variation. In the year 2005 the index was slightly under the average.
In 2005, the index shows, that the toxic Nodularia spumigena rank based abundance was almost at the same
level as in the previous four years, while Aphanizomenon flos-aquae showed a minor decrease during the
Bacterioplankton growth rate
(Johan Wikner, Umeå University)
Bacterioplankton growth rate is a powerful indicator of the decomposition of organic matter and thereby trophic status
of the Sea. The decomposition is closely connected to the oxygen consumption in the water column.
The bacterioplankton growth rate represented at least good condition in the off-shore Bothnian Bay and Bothnian Sea.
The bacterial growth has been stable for the past decade, suggesting a balanced nutrient supply to and organic
production in the two basins.
Temporal trends in contaminants in Herring in the Baltic Sea in the period 1980-2004
The temporal trend analyses of heavy metals showed 16 significant trends (8 upwards and 8 downwards)
out of 50 tests. The remarkable upward trends were cadmium (2), zinc (5), and copper (1). The downward trends were
lead (5), and mercury (5).
The temporal trend analyses of PCB's (Poly Chlorinated
Biphenyls) and Lindane showed 39 significant trends (all downwards) out of 78 tests.
Cadmium concentrations in fish liver
(Anders Bignert, Elisabeth Nyberg, Swedish Museum of Natural History)
Cadmium concentrations in herring are showing significant increasing trends followed by decreasing
trends in several of the investigated biotic matrices of sufficient length. In general the recent levels are not
significantly lower compared to the concentrations measured at the beginning of the 1980s, despite measures taken
to reduce discharges of cadmium to the environment.
Lead concentrations in fish liver
(Anders Bignert, Elisabeth Nyberg, Swedish Museum of Natural History)
Lead is showing significant declining trends in almost all investigated biotic matrices of sufficient length,
obviously as a result of measures taken to reduce discharges of lead to the environment.
PCB concentrations in fish muscle
(Anders Bignert, Elisabeth Nyberg, Swedish Museum of Natural History)
sPCB concentrations show
significant declining trends in the investigated biotic matrices as a result of measures taken to reduce discharges of
PCB to the environment. The concentrations are
still significantly higher in the Baltic Proper and in the southern Bothnian Sea compared to the Kattegatt and the
Skagerakk (based on data from the Swedish Monitoring Programme).
Concentrations of the artificial radionuclide caesium-137 in Baltic Sea fish and
(HELCOM MORS Project Group)
Overall the levels of radioactivity in the Baltic Sea water, sediments and biota have shown declining
trends since the Chernobyl accident in 1986, which caused significant fallout over the area. Radioactivity is now
slowly transported from the Baltic Sea to the North Sea via Kattegat. The concentrations of
Cs-137 in water as well as in herring and flounder muscle are still above the pre-Chernobyl
levels in major part of the Baltic Sea.
Minor amounts of radioactivity from Sellafield are transported in the opposite direction. Routine discharges of
radioactivity from nuclear power plants into the Baltic Sea area are small and only detectable locally.
Total amounts of the artificial radionuclide caesium -137 in Baltic Sea sediments
(Erkki Ilus, STUK - Radiation and
Nuclear Safety Authority, Finland)
The most significant source of artificial radioactivity in the Baltic Sea is the fallout from the
Chernobyl accident. The distribution pattern of Chernobyl derived Cs-137 in the Baltic
Sea sediments is very scattered, with the highest values occurring in the Bothnian Sea and the eastern Gulf of Finland.
The total inventory of Cs-137 in the Baltic Sea sediments was estimated at
2 100 - 2 400 TBq in the beginning of the 2000s.
However, in 2000 - 2005 the concentrations of man-made radionuclides in the sediments were generally
at or below the concentrations of naturally occurring radionuclides, and were not expected to cause harmful
effects to the Baltic Sea wildlife.
Temporal development of Baltic coastal fish communities and key species
(HELCOM Coastal Fish Monitoring Experts)
Coastal fish community indicators show few significant temporal changes during the period
1996 - 2005. As no consistent trends were observed within any of the sub-basins, the observed temporal changes
in some areas would mainly to be related to local impact. Despite the lack of consistency, high water temperatures
during growth seasons recent years possibly have affected the fish communities in Bothnian Sea. This is reflected as
an increased recruitment success and/or increased individual growth rate of dominating, warm water dwelling, species,
e.g. perch (Perca fluviatilis) and roach (Rutilus rutilus). A
significant impact of temperature on the coastal fish is supported by the consistent trends in some key species
indicators within sub-basins that were observed in both Bothnian Sea and western Baltic Proper. Effects of changes
in exploitation rate were observed in Gulf of Riga and in southern Baltic Proper. In the former area a high
exploitation rate of piscivorous fish during mid 1990's was clearly recognised. In the latter area, flounder
(Platichthys flesus), the key species for the southern Baltic proper, has increased during the period
possibly due to population recovery after a previous high exploitation rate.
Ecosystem regime state in the Baltic Proper and the Gulf of Riga
(Christian Möllmann, Rabea Diekmann, Hamburg University; Bärbel Müller-Karulis, Latvian
Institute of Aquatic Ecology; Juha Flinkman, FIMR)
Three distinct regimes in Baltic ecosystem structure were detected from 1974 - 2004.
Regime shifts - major changes in pelagic ecosystem structure - occurred at the end of the 1980s and during the early 1990s.
Pelagic food web changes were climate driven and further accelerated by fishing pressure and internal processes.
Abkürzungen der Institute, Programme, Projekte
||Swedish Meteorological and Hydrological Institute
||Baltic Sea Research Institute / Institut für Ostseeforschung Warnemünde
||Finnish Institute of Marine Research
||Federal Maritime and Hydrographic Agency / Bundesamt für Seeschiffahrt und Hydrographie
||Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission for Air Pollutants in Europe
||Meteorological Synthesizing Centre-West
||Meteorological Synthesizing Centre - East
||International Council for the Exploration of the Sea
||Helsinki Commission, Monitoring of Radioactive Substances
||HELCOM Pilot-Projekt:"Development of tools for an eutrophication assessment" (HELCOM EUTRO 2005-2006)
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