Technical notes: Marine-based pollution

Our indicator is based on distance to ports stratified by size (NIMA, 1998), location of major shipping lanes (NCASM, 1998; Morgan and Valencia, 1983), and location of oil infrastructure (ESRI, 1993). The components in Table A2 were combined into an aggregate estimate of threat from marine-based sources (TH_MP_RAW), and adjusted for the natural vulnerability of the area (resulting in TH_MP_ADJ).

Table A2. Marine-based pollution component summary
Subject /
Stressor 		Qualifier High Medium Low
Ports Large 0-20 km 20-50 km  
  Medium 0-10 km 10-30 km  
  Small 0-3 km 3-10 km  
  Small   0-5 km  
Oil Tanks and Wells All types 0-4 km 4-10 km  
Shipping Lanes Several sources   0-2 km 2-5 km

Note: Areas not classified as high, medium, or low were classified as very low.