BALTIC SEAENVIRONMENT PROCEEDINGS No. 59 - Helcom

to the Baltic proper, with a similar doubling of phytoplankton
biomass and its subsequent sedimentation.
- Environmental influences on the stocks of demersal fish and
shellfish, primarily due to low oxygen conditions, was clearly
seen in certain areas.
- Concentrations of organochloride residues in fish from the
Baltic proper were still 3 - 10 times higher than in fish from
the Shetland Islands. DDT and PCB concentrations in biota have
decreased since the 1970s and are now on a low and steady level.
After the ban on HCH, the decrease of a-HCH concentrations in
water is still continuing. There has been an increasing number
of organic substances identified which are potentially harmful
to the environment.
- Fish and shellfish from sampling locations in the Kattegat and
the Belt Sea showed tendencies for decreasing lead
concentrations. This might be due to the increased use of
unleaded gasoline.
FURTHER DEVELOPMENT OF BMP
Monitoring stratesv
Future improvements of BMP were discussed at the HELCOM
Environmental Committee Meeting in Gdynia in September 1991.
The general philosophy in having a mandatory part for the
traditional parameters was supported, while the tentative part
dealing with e g micropollutants needed a mechanism to provide
quicker results. The BMP should therefore consist of a mandatory
part performed by all CP's (as today), and a baseline part where
only a few laboratories would be involved on behalf of the other.
In this context, l'base-line'l should be understood in a wider sense
and should also include various types of monitoring of
contaminants for which already some information exist. The term
could also include biological effects studies or any other study
not performed regularly on a larger geographical scale. The
results of the baseline studies could be assessed either
separately or together with periodic assessments if the timing is
appropriate.
It was also suggested to abandon the present five-year periodicity
of the up-dating procedure and instead introduce a new rolling
procedure for the BMP.
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