1. Why is DDT harmful? What effect of DDT (DDE) is linked to the slow decline of birds of prey in the United States during the late 1960s and early 1970s?

2. Does DDE accumulate in all species equally? Why not? What type of species is most likely to accumulate large amounts of DDE due to biomagnification?

3. When was DDT banned?

Opening Questions

Was the DDT ban effective in reducing

the DDE concentrations in

wildlife?

• Contains data concerning contaminants in mammals, birds, amphibians and reptiles that live near coastline or estuaries in the United States.

• Created by scientists working for the Biological Resources Division of the U.S. Geological Survey, a part of the Department of the Interior of the United States Government.

• Data in CEETV is mostly from articles published in peer-reviewed journals. Some data are from government reports and government websites.

There is a lot of data in CEETV, over 11,000 records on more than 400 species.

What data do we need to examine if the DDT ban was effective?

What type of species should we investigate?

Tertiary Consumer

What factors should we consider before selecting a tertiary consumer to investigate?

1. Do all tertiary consumers have the same likelihood of accumulating high concentrations of DDE?

2. Can we combine species or do we need to pick one?

3. How much data is available?

CEETV Data for DDE in OspreysWe have data on DDE concentrations in osprey eggs

collected from various locations in the U.S. between 1968 and 1991. What question do we want to ask?

What is our hypothesis?

Hypothesis: In the two decades following the 1972 banning of DDT, DDE concentrations in osprey eggs did not consistently decrease in the United States below a harmful concentration(< 3ug/g ww). 

Our investigation is clearly defined:Species: OspreyMatrix (body part): Egg contentsLocation: United StatesHarmful concentration of DDE: > 3 ug/g wwTime frame: DDE concentrations < 3 ug/g ww by 1992

We are going to investigate our hypothesis by graphing DDE concentrations in osprey eggs collected in the U.S.

by year.

What do we expect the graph to look like if the hypothesis is supported?

DD

E

Year

DD

E

YearD

DE

Year

What do we expect the graph to look like if the hypothesis is rejected?

DD

E

Year

RECORD_ID COMMON_NAME YEAR_FROM YEAR_TO LOCATION STATE MATRIX N DDE UNITS10004 Osprey 1969 1969 Franklin ME egg content 2 11.9 ug/g ww10005 Osprey 1969 1969 Dyer Neck ME egg content 1 20.5 ug/g ww10006 Osprey 1969 1969 Boyden Pond* ME egg content 1 12.4 ug/g ww200287 Osprey 1969 1969 Kodiak Island AK egg content 6 1.8 ug/g 200587 Osprey 1969 1969 Bird Island, Kodiak AK egg content 1 4.9 ug/g 200595 Osprey 1969 1969 Admiralty Island AK egg content 1 10.8 ug/g ww200357 Osprey 1972 1972 Amchitka Island AK egg content 1 1.9 ug/g 200358 Osprey 1972 1972 Amchitka Island AK egg content 1 4.3 ug/g ww231529 Osprey 1972 1972 * CA egg content 5 44.8 ug/g ww90092 Osprey 1973 1973 Bryans Church* MD egg content 1 6.3 ug/g ww10032 Osprey 1974 1974 Swan Island ME egg content 1 20.0 ug/g ww10033 Osprey 1974 1974 Hog Bay ME egg content 1 35.0 ug/g ww10034 Osprey 1974 1974 Nehumpkeag Island ME egg content 1 42.0 ug/g ww10035 Osprey 1975 1975 Machias ME egg content 1 20.0 ug/g ww10037 Osprey 1975 1975 Nequasset Lake ME egg content 1 23.0 ug/g ww10038 Osprey 1975 1975 Little Round Pond* ME egg content 1 19.0 ug/g ww200289 Osprey 1975 1975 Barlow Point AK egg content 1 3.9 ug/g ww200290 Osprey 1975 1975 Northeast Juneau AK egg content 1 2.1 ug/g ww200292 Osprey 1975 1975 Clear Point AK egg content 1 0.9 ug/g ww10040 Osprey 1976 1976 Mark Island* ME egg content 1 19.0 ug/g ww10042 Osprey 1976 1976 Nequasset Lake ME egg content 1 21.0 ug/g ww200295 Osprey 1976 1976 Ugaiushak Island AK egg content 1 2.6 ug/g ww10043 Osprey 1977 1977 Northeast Creek ME egg content 1 14.0 ug/g ww10046 Osprey 1977 1977 Round Lake ME egg content 1 4.8 ug/g ww80016 Osprey 1977 1977 Bombay Hook DE egg content 1 51.0 ug/g ww90093 Osprey 1977 1977 Welcome MD egg content 1 14.0 ug/g ww90094 Osprey 1977 1977 Tolchester Beach MD egg content 1 26.0 ug/g ww90095 Osprey 1977 1977 Tolchester Beach MD egg content 1 12.0 ug/g ww90096 Osprey 1977 1977 Tolchester Beach MD egg content 1 8.8 ug/g ww10047 Osprey 1978 1978 Salt Pond ME egg content 1 15.0 ug/g ww80017 Osprey 1978 1978 Bombay Hook (1) DE egg content 1 25.0 ug/g ww80018 Osprey 1978 1978 Bombay Hook (2) DE egg content 1 30.0 ug/g ww90097 Osprey 1978 1978 Ferry Landing MD egg content 1 9.8 ug/g ww

Individual data records

Groups based on year

Average DDE concentration for each group

Sum of DDE concentrations of all individuals in the group

Total number of individuals in the group

Average DDE concentration for = each group

DDE (ug/g ww average concentration) in Osprey eggs by Year

YEAR DDE (ug/g ww)1968-1969 8.31970-1972 8.41973-1975 4.31976-1979 3.21981-1991 2.2

DDE concentrations in Osprey eggs collected in the U.S. from 1968 to 1991

8.3 8.4

4.3

3.2

2.2

0

1

2

3

4

5

6

7

8

9

1968-1969 1970-1972 1973-1975 1976-1979 1981-1991

Year

DD

E in

ug

/g w

w

The bald eagle, our National Bird and a symbol of freedom is also very sensitive to DDE! Adverse

reproductive effects begin to occur when concentrations in bald eagle eggs reach about

3ug/g.