Transboundary environmental impact assessment in marine areas
One of the clearest messages to emerge from the wealth of environmental literature that has been generated since the late 1960s is that environmental degradation does not respect jurisdictional borders. Although many intemational and intrastate borders lie along geographical 'divides' such as mountain ridges and rivers, these natural features do not break physical and biological linkages of ecosystems. These linkages are often more pronounced where human-selected borders bisect especially fluid environments, such as the ocean in which there is constant movement of water, energy and marine life. Transboundary environmental problems are generally the result of planned human activities. They may be caused by specific development projects within one State or by activities in areas beyond national jurisdiction (ABNJ), such as the high seas. Environmental impact assessment (EIA) has largely proven to be a successful tool for understanding and minimizing the environmental impacts of specific development projects or activities since it was adopted in numerous States from the early 1970s. There is extensive, worldwide, experience in conducting EIAs for large scale land-based projects. However, the application of EIA to developments and activities in the marine environment is of more recent origin and often more challenging because of the large geographical and temporal scale of potential environmental impacts, as well as the increased likelihood that environmental harm might be caused to neighbouring States. Degradation of marine environments also tends to be more difficult to monitor than terrestrial environments and ecosystems.