BSEP116B Biodiversity in the Baltic Sea - Helcom

can be considered as having been a beneficial
process to fisheries owing to increased fish production.
However, it has affected fish stocks selectively;
for example, increased turbidity of water
has favoured percids and cyprinids and negatively
affected salmonids, which prefer clear water.
Eutrophication has affected fish communities in
other ways also, such as through lost shelter or
spawning ground function caused by reduced
macro-vegetation coverage.
6.5.4 Conclusions
Eutrophication is a Baltic-wide problem of serious
concern which has a negative effect on most components
of biodiversity in the Baltic Sea. It reduces
water quality and extends to nearly all areas of
the Baltic Sea, including the marine protected
areas. This implies that spatial protection measures
cannot result in a favourable conservation status of
biodiversity unless eutrophication is reduced to a
level causing no disturbance.
For further conclusions and recommendations, see
the integrated thematic assessment of eutrophication
in the Baltic Sea (HELCOM 2009a).
Table 6.6.1. Substances or substance groups of
specific concern to the Baltic Sea and included in
the HELCOM BSAP.
1. Dioxins (PCDD), furans (PCDF) & dioxin-like
polychlorinated biphenyls
2. a. Tributyltin compounds (TBT)
b. Triphenyltin compounds (TPhT)
3. a. Pentabromodiphenyl ether (pentaBDE)
b. Octabromodiphenyl ether (octaBDE)
c. Decabromodiphenyl ether (decaBDE)
4. a. Perfluorooctane sulfonate (PFOS)
b. Perfluorooctanoic acid (PFOA)
5. Hexabromocyclododecane (HBCDD)
6. a. Nonylphenols (NP)
b. Nonylphenol ethoxylates (NPE)
7. a. Octylphenols (OP)
b. Octylphenol ethoxylates (OPE)
8. a. Short-chain chlorinated paraffins (SCCP or
chloroalkanes, C 10−13
)
b. Medium-chain chlorinated paraffins (MCCP
or chloroalkanes, C 14−17
)
9. Endosulfan
10. Mercury
11. Cadmium
6.6 Hazardous substances
The Baltic Sea is particularly sensitive to persistent,
toxic and bioaccumulating substances because of
its special abiotic characteristics and the fact that
many of the resident species are not originally
adapted to a brackish water environment.
Once released into the Baltic Sea, hazardous substances
can remain in the marine environment
for very long periods and can accumulate in the
marine food web to levels which are toxic to marine
organisms. Adverse effects on biodiversity caused
by hazardous substances include impaired general
health status of animals, impaired reproduction,
and increased pollutant levels in fish consumed by
humans. Effects on plants and invertebrates may be
less pronounced because hazardous substances tend
to accumulate over time and magnify through the
food chain to species at higher trophic levels.
The loads of some hazardous substances to the
Baltic Sea have decreased considerably over the
past 20–30 years but problems still persist. With
the increased use of chemicals and the development
of new synthetic chemical compounds,
concentrations of certain new substances have
increased in the marine environment.
One of the four segments of the Baltic Sea Action
Plan (BSAP) is devoted to hazardous substances
(HELCOM 2007a). With the hazardous substances
segment, the HELCOM Contracting Parties have
committed themselves to numerous actions to
diminish pollution. HELCOM has agreed to focus its
work on two heavy metals, cadmium and mercury,
and nine organic substances or substance groups
(Table 6.6.1), which are specifically addressed in
the BSAP.
6.6.1 Sources and inputs
to the Baltic Sea
The main pathways of hazardous substances to the
marine environment are atmospheric deposition
and industrial and municipal wastewaters which
are discharged directly to the Baltic or transported
via rivers. In industrial processes, hazardous substances
are emitted during all stages of the production
chain.
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PCDD = polychlorinated dibenzo-p-dioxin; PCDF = polychlorinated
dibenzofuran