Trichlorethylene
Perchlorethylene
Dibutyl phthalate
PCB [Araelar 1254]
Pentachlorophenol
! - HCH
Dield ri n
DDT
0.01
0.1
10
•
- -
-
-
I
-
I
I
i
I
I
I
10010310410510610710Bngll
Fig. 90. Range of concentration of organic pollutants in seawater (hatched areas) in comparison
to range of concentration which exhibits acute toxicity effects in experiments with fish and
shrimps (black bars) (Ernst 1980)
mg/kg
4.0
3.0
0.5
1 .
I
mg/kg
2.0
0.5
0.1
0.1
I
I
I
1964 1965 1966 1967 1968 1969 1970 1971
1964 1965 196619671966 19691970 1971
Fig. 91. From 1964 to 1971 the amount of pesticides in the eggs of the shag (Phalacrocorax
aristotelis) was being regularly examined in two British bird colonies: Fame Island (Northumberland, points) and Isle of May (Scotland, triangles). Apparently the reduced application of pesticides had already led to a reduction of pesticide concentrations in sea birds living on fish: shown
here are, on the left. DDT and on the right dieldrin. The analyses of 1968 are irrelevant, since
after wide-spread deaths of adult shags, only a few eggs could be collected in that year. (After
Coulson et al. 1972)
182