Scope of the Port Xxxxxx Assessment. The scope of an EcoRA depends on the stressors involved, the understanding of the local ecology, and the policy goals of the system managers (Xxxxx, 1993). In Port Xxxxxx a variety of anthropogenic stressors, as well as a variety of natural stressors, is possible. Natural environments are inherently variable. For example, fish stocks fluctuate in size and precipitation differs from year to year. This variability is compounded in Port Xxxxxx by the extreme seasonal patterns of light and temperature found at high latitudes, and by frequent natural disturbances such as earthquakes and winter storms. In a system with high variability, detection of effects due to human disturbances is more difficult against the background of natural disturbance. Ecological knowledge of an area determines the degree to which environmental impacts can be defined, understood, and differentiated from natural events within the system. In Port Xxxxxx, much of the scientific work reflects baseline data collection and environmental monitoring performed in the late 1960s and the 1970s prior to and during the construction of the trans-Alaska Pipeline and the Valdez Marine Terminal. Available data include physical and chemical characteristics of the Port waters and sediment, as well as information about the pelagic, intertidal, and benthic subtidal organisms of the Port. Ongoing monitoring studies since that time have focused on the intertidal and subtidal organisms, and the hydrocarbon levels in the sediments of the Port. Other studies were conducted to assess the potential for environmental impacts of proposed petroleum refineries in the 1970s, to study hatchery fish released by the Solomon Gulch fish hatchery built in the late 1980s, and to evaluate the Duck Flats (Mineral Island Flats) as an important ecological area in the 1990s. The research focused on wild salmon, hatchery salmon, migratory and nonmigratory waterfowl, and sea otters. Bears and eagles were also addressed in studies of the terrestrial components of the Port Xxxxxx ecology. The following items are reports or papers that we used for background information concerning risks in the Port.
