1988 1989 1990 1991 1992
1989
1990
1991
1992
1971 1972 1973 1974 1975 1976 1977 1978 1979 1991 1992 1993 1994
1972
1973
1974
1975
1976
1977
1978
1979
1993
1994
1988
1972 1973 1974 1975 1976 1977 1978 1979 1982
1982
1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1988 1991 1992 1993 1994
1980
1981
1988 Fresh Water 1989 Fresh Water 1989 Plant Tissue 1989 Sediment Chemistry
1989 Fresh Water
1989 Plant Tissue
1989 Sediment Chemistry
1971 1972 1973 1974 1975 1976 1977 1978 1979
1985 1986 1987
1986
1987
1985 1989 1990