(Mustela vision) it could be shown that PCB's, not DDT in the diet are responsible
for an increase of the percentage of non-pregnant females and for a reduction ofthe
whelp number (Jensen et al. 1977).
Recently it could be demonstrated that DDT and PCB concentrations in flounder
(Platichthys flesus) caught in the Western Baltic vary largely from fish to fish (0.0050.73 mg/kg in liver, 0.005-0.317 mg/kgin ovaries,on wet weight basis). 100% streight
and healthy appearing larvae could only be obtained from females which had PCB
concentrations less then 0.12 mgfkg. When eggs from females with higher concentrations of PCB's were incubated, there was a significantly reduced survival of hatched
larvae (Westernhagen et al. 1981). These results mean that the presently existing PCB
concentrations in the water of the Baltic are such that females which by some circumstance of their life history or by their physiological conditions have accumulated
higher PCB concentrations in their tissues than other females, exhibit toxic effects of
PCB in their offspring. Unfortunately there is evidence that this toxic effect may not
be restricted to the Baltic. For example cod from the North Atlantic and the North
Sea have PCB concentrations in tissues which are only slightly less than in Baltic cod
(Ernst 1981).
It is also not possible to exclude that plankton life in the oceans is adversely affected
through chlorinated hydrocarbons. In experiments, concentrations of 1 Jlgfl of DDT
have a toxic effect on the Cyclotella diatom from the Sargossa Sea (Menzel et al. 1970),
and just 0.1 Jlgfl of PCB's apparently has a toxic effect on the Thalassiosira diatom
(Fisher et a1. 1974). Existing data shows that 1-10 Jlg/l of PCB's have a negative
effect on the biomass and cell size of phytoplankton cultures of coastal areas
(O'Connors et a1. 1978), and that the frequency of cell division, as well as photosynthesis efficiency, are therefore impaired (Harding and Phillips 1978). Such concentrations are only 100 times higher than in the ocean (Fig. 90).
Fortunately there are indications that the concentrations of DDT and other pesticides
in marine organisms have been decreasing in the last few years. This could be demonstrated with sea fish (see Chap. 9.2), with oysters on the coasts ofthe U.S.A. (Butler
1973), with the shag of British bird colonies (Fig. 91), and with the double-crested
cormorant (Phalacrocorax auritus) in the Bay of Fundy ,Canada (decrease from 10 mgt
kg to 2 mg/kg DDT concentration in eggs, on dry weight basis; Zitko 1976). Examples
from other cormorants and pelicans have been given in this chapter.
Unfortunately however, in general ,PCB concentrations in fish from the North Atlantic,
the North Sea and the Baltic up to now did not show Significantly decreasing trends.
World wide a reduction of PCB production from some 80,000 t in 1970 to some
20,000 t in 1977 has been achieved, but factories in France, in the Federal Republic
of Germany, in Italy and Spain are still producing. The development of trends of PCB
concentration should be carefully watched, and stricter measures should be taken.
One should, too, carefully watch trends of pesticide concentrations in organisms and
sea water from shores in tropical areas where persistent chlorinated hydrocarbons are
all the time used in large quantities. In air collected at Enewetak Atoll far away from
any pollution source in the Pacific, concentrations of organic pollutants were, in 1979:
DEHP 1.4 ngfm 3 , DBP 0.87 ng/m 3 , PCB 0.54 ng/m 3 , HCH 0.25 ngfm 3 , HCB
0.10 ng/m 3 , chlordan 0.013 ng/m 3 , dieldrin 0.010 ng/m 3 , DDE 0.003 ngfm 3 (Atlas
and Giam 1981).
183
for an increase of the percentage of non-pregnant females and for a reduction ofthe
whelp number (Jensen et al. 1977).
Recently it could be demonstrated that DDT and PCB concentrations in flounder
(Platichthys flesus) caught in the Western Baltic vary largely from fish to fish (0.0050.73 mg/kg in liver, 0.005-0.317 mg/kgin ovaries,on wet weight basis). 100% streight
and healthy appearing larvae could only be obtained from females which had PCB
concentrations less then 0.12 mgfkg. When eggs from females with higher concentrations of PCB's were incubated, there was a significantly reduced survival of hatched
larvae (Westernhagen et al. 1981). These results mean that the presently existing PCB
concentrations in the water of the Baltic are such that females which by some circumstance of their life history or by their physiological conditions have accumulated
higher PCB concentrations in their tissues than other females, exhibit toxic effects of
PCB in their offspring. Unfortunately there is evidence that this toxic effect may not
be restricted to the Baltic. For example cod from the North Atlantic and the North
Sea have PCB concentrations in tissues which are only slightly less than in Baltic cod
(Ernst 1981).
It is also not possible to exclude that plankton life in the oceans is adversely affected
through chlorinated hydrocarbons. In experiments, concentrations of 1 Jlgfl of DDT
have a toxic effect on the Cyclotella diatom from the Sargossa Sea (Menzel et al. 1970),
and just 0.1 Jlgfl of PCB's apparently has a toxic effect on the Thalassiosira diatom
(Fisher et a1. 1974). Existing data shows that 1-10 Jlg/l of PCB's have a negative
effect on the biomass and cell size of phytoplankton cultures of coastal areas
(O'Connors et a1. 1978), and that the frequency of cell division, as well as photosynthesis efficiency, are therefore impaired (Harding and Phillips 1978). Such concentrations are only 100 times higher than in the ocean (Fig. 90).
Fortunately there are indications that the concentrations of DDT and other pesticides
in marine organisms have been decreasing in the last few years. This could be demonstrated with sea fish (see Chap. 9.2), with oysters on the coasts ofthe U.S.A. (Butler
1973), with the shag of British bird colonies (Fig. 91), and with the double-crested
cormorant (Phalacrocorax auritus) in the Bay of Fundy ,Canada (decrease from 10 mgt
kg to 2 mg/kg DDT concentration in eggs, on dry weight basis; Zitko 1976). Examples
from other cormorants and pelicans have been given in this chapter.
Unfortunately however, in general ,PCB concentrations in fish from the North Atlantic,
the North Sea and the Baltic up to now did not show Significantly decreasing trends.
World wide a reduction of PCB production from some 80,000 t in 1970 to some
20,000 t in 1977 has been achieved, but factories in France, in the Federal Republic
of Germany, in Italy and Spain are still producing. The development of trends of PCB
concentration should be carefully watched, and stricter measures should be taken.
One should, too, carefully watch trends of pesticide concentrations in organisms and
sea water from shores in tropical areas where persistent chlorinated hydrocarbons are
all the time used in large quantities. In air collected at Enewetak Atoll far away from
any pollution source in the Pacific, concentrations of organic pollutants were, in 1979:
DEHP 1.4 ngfm 3 , DBP 0.87 ng/m 3 , PCB 0.54 ng/m 3 , HCH 0.25 ngfm 3 , HCB
0.10 ng/m 3 , chlordan 0.013 ng/m 3 , dieldrin 0.010 ng/m 3 , DDE 0.003 ngfm 3 (Atlas
and Giam 1981).
183