The purpose of these guidelines is to: - Highlight the issues of concern in the WIO region, especially how transboundary impacts on coastal and marine ecosystems could foreclose future livelihood and development options. - Provide guidance on how transboundary impacts should be assessed, using Strategic Environmental Assessment (SEA) and Environmental Impact Assessment (EIA) tools. - Advise on how best to develop and/or strengthen legal and administrative instruments in the WIO Region. This document is primarily intended for people who have to make decisions on environmental issues through the impact assessment process, namely: national, provincial/state and local authorities who comment on impact assessment reports and make decisions about the environment and development. These authorities include, but are not limited to: local authorities, departments or ministries of environment, planning and land use, mines, energy, water, fisheries, agriculture, forestry, housing, roads, tourism, heritage and health.