Time–space matrix of potential effects associated with dredging and dredged material placement (IADC/CEDA 1998)

 

Near-field

Environmental Effects

(<1km)

Far-field

Environmental Effects

(>1km)

Short-term

Environmental Effects

(<1 week)

 

Dredging

Turbidity

Smothering/removal of organisms

Reduced water quality

Dredging

None generally expected

Disposal

Smothering of organisms

Turbidity

Reduced water quality

Acute chemical toxicity

Disposal

Offsite movements of chemicals by physical transport

Long-term

Environmental Effects

(>1 week)

Dredging

Disturbance by shipping traffic

Removal of contaminated sediment

Dredging

None generally expected

Disposal

Altered substrate type

Altered community structure

Chronic chemical toxicity

Bioaccumulation

Disposal

Offsite movements of chemicals by physical transport and/or biota migration

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