International Waters learning Exchange & Resource Network

Examples of immediate causes

Transboundary Problem

Examples of Immediate or Technical Causes



Discharge of untreated industrial effluents

Diffuse pollution from improper application of fertilizers

Point and diffuse sources of effluent from livestock farms

Pumping of polluted water from mines

Black Sea

Lake Chad

Dnipro River Basin

Orange Sengu River Basin


Excessive fisheries effort/overfishing

Destruction of benthic habitats

Damage to nursery/spawning areas

Destructive fishing methods

Mediterranean Sea

Rio de la Plata

Black Sea

Bay of Bengal LME

Changes in Biodiversity

Discharge of untreated ballast waters

Exotic species introduction (notably Mnemiopsis leidyi)

Sediments, pesticides and pollution from land-based activities

Black Sea

Black Sea

Bay of Bengal LME

Degradation of Habitats

Changes in land use

Conversion of mangroves for agriculture, aquaculture (shrimp), and salt production

Dnipro River Basin

Bay of Bengal LME

Changes in hydrological regime

Damming for abstraction

Orange-Sengu  River Basin

Introduction of exotic species

Transport of fouling organisms attached to ships’ hulls.

Rio de la Plata