Wildlife Populations. In the context of this assessment, wildlife includes populations of mammals, birds, and fishes associated with open water, subtidal, and shoreline habitats of the Port. These populations consist of both marine and terrestrial animals which use the marine environment during certain seasons or segments of their life cycle. For example, the marbled murrelet migrates through and feeds in the Port environment, but nests in inland forest stands. Wildlife populations have an aesthetic appeal to tourists, visitors, and residents of Valdez and are a valuable resource to the tourism industry. Wildlife also provides ecological functions associated with community dynamics (e.g., the influence of sea otter predation on intertidal community structure) and nutrient cycling (e.g., nutrient additions from salmon carcasses and migratory bird excrement). Assessment of risk in Port Valdez is complicated by the mobility and transitory nature of many of these populations, natural variability in population size and individual survival, and population pressures imposed by hunting and fishing. Endpoints that are relevant to populations found in the Port include: • Maintenance of the genetic integrity of individual salmon runs, particularly wild pink salmon which may be affected by fish that stray from the hatchery; • Successful spawning, egg hatch, and embryo survival for wild salmon populations, particularly in pink and chum intertidal spawning habitat; • Maintenance of shallow subtidal plant communities, which provide protective habitat and cover for many juvenile organisms; • Continued and successful nesting, egg hatch, and chick survival of seabirds, waterfowl, and shorebirds nesting near the Port; and • Maintenance of intertidal and subtidal invertebrate abundance, diversity, and age class structure used by wildlife populations in the Port as food. Measurements of these endpoints involve field and population studies that are specific to Port Valdez. Assessments can also be designed to describe certain population parameters specific to the Port, through modeling the effects of a stressor on this parameter. For instance, a study of the genetic variability of the wild and hatchery salmon populations, and the straying and cross-strain breeding rate of the hatchery salmon, could be used to model potential genetic dilution in the wild salmon.
Wildlife Populations. Research over the past 25 years has shown that a variety of persistent, bioaccumulative contaminants in the Great Lakes food chain are toxic to wildlife (Health Canada, 1997). Reproductive impairments have been described in avian, fish, and mammalian populations in the Great Lakes. For example, egg loss due to eggshell thinning has been observed in predatory birds, such as the bald eagle, within the Great Lakes (Xxxxxx and Xxxxxx, 1980). After feeding on Great Lakes’ fish for two or more years, immigrant birds (eagles) were shown to have a decline in reproductive success (Xxxxxxx et al.,, 1993). Developmental effects in the form of congenital deformities (e.g. crossed mandibles, club feet) have also been reported in the avian population within the Great Lakes basin (Stone, 1992). Effects to the endocrine system and tumor formations have been detected in fish populations. Researchers have reported enlarged thyroids in all of the 2 to 4 year-old Great Lakes salmon stocks that were examined (Leatherland, 1992). Tumors associated with exposure to high levels of PAHs have been detected in brown bullhead in the Great Lakes area (Xxxxxxx et al.,, 1982). Effects on the immune system have also been a notable finding. At a number of Great Lakes sites, a survey of xxxxxxx gulls and Caspian terns demonstrated a suppression of T- cell-mediated immunity following prenatal exposure to organochlorine pollutants particularly PCBs (Grasman et al.,, 1996). Section 4 provides a more detailed description of the effects of chemicals on wildlife, but the point here is to show that adverse effects can occur when exposure is sufficient (Health Canada, 1997). S e c t i o n 6
Wildlife Populations. (birds, mammals and wild fish) survival and integrity of wild salmon populations protection of habitat required for feeding, reproduction and survival of young maintenance of intertidal and subtidal populations of invertebrates and fishes These endpoints reflect human values and uses of the Port. Fisheries, tourism and the community’s concern for the quality of their environment influenced the emphasis of the assessment endpoints. Each endpoint is also susceptible to one or more of the stressors that may be in the Port Valdez environment. Many aspects of the assessment endpoints overlap, which creates an opportunity for understanding and protecting the dynamic and complex relationships within this ecological system. No laboratory or field measurements were taken for this risk assessment. All of the scientific data presented later in this report were collected in other studies and for other purposes. Consequently, the assessment endpoints are primarily a guide for structuring the conceptual model and the risk analysis.
