No abstract

A simple sperm/fertilization bioassay, primarily using sea urchin gametes, has been developed and used by a variety of laboratories. This assay was recently refined into a standard test and is now being used by the U.S. Environmental Protection Agency and others for toxicity testing in marine waters. One factor that has lagged behind the development of this assay is the comparison of its sensitivity to various common toxicants as compared to other bioassay systems and life stages of other marine organisms. The objective of this study was to compare the sensitivity of a standardized sea urchin sperm/fertilization assay to the responses of embryo, larval, and adult marine organisms to metals (Ag, Cd, Cu, Pb, Zn) and pesticides (DDT, Dieldrin, Endrin, Endosulfan) added to natural seawater. The results, although highly variable, generally showed that sperm/fertilization and embryo assays were quite sensitive to the metals tested, but that the larval and adult assays were more sensitive to the pesticides. These comparative data, together with other studies of complex effluents, show that the standardized sperm/fertilization bioassay is an especially quick and useful tool for biomonitoring of marine waters.

A 30‐month study of the comparative dynamics of the fish populations inhabiting Kelsey Creek, located in the City of Bellevue, Washington, and a nearby pristine control stream suggest that urban development has resulted in a restructuring of the fish community. Environmental perturbations, including habitat alteration, increased nutrient loading, and degradation of the intragravel environment appeared to have a greater impact on coho salmon Oncorhynchus kisutch and nonsalmonid fish species than on cutthroat trout Salmo clarki. Although the total biomass (g/m2) of fish in each stream was similar, its composition differed markedly. Ages 0 and I cutthroat trout were the majority of the fish community inhabiting Kelsey Creek, whereas the control stream supported a diverse assemblage of salmonids of various ages and numerous nonsalmonids. The rapid growth and greater biomass of salmonids in Kelsey Creek (a 2‐year mean of 3.51 g/m2 versus 2.03 g/m2 in the control stream) resulted in a total annual net production of these species of 1.6 to 3.3 times that of the control stream (a 2‐year mean of 7.6 g/m2 versus 3.5 g/m2 in the control stream). Marking and outmigrant studies indicated that environmental disruptions in the urban stream do not result in the displacement of the salmonid inhabitants.

Differences among states in the procedures used to formulate fish consumption advisories and increased use of cancer‐risk‐based advisories are sources of confusion for fishery professionals and anglers. One of the most controversial aspects of fish consumption advisories is the accuracy of their estimates of risk. Unfortunately, our ability to detect trace concentrations of contaminants in the environment far surpasses our ability to accurately predict the effects of these contaminants on human health. Mathematical models are most frequently used to estimate the cancer risk of low levels of contaminants to humans. At best these models give a crude estimate of the health effects. Consequently, as fishery professionals, we must do a better job of informing anglers about these advisories. We can put the health risks involved in eating contaminated fish in perspective by comparing them with other types of risks. We can also inform anglers of various alternative behaviors that will decrease the health risks associated with eating contaminated fish, such as changing their fishing habits and the proper techniques for cleaning and cooking fish. A proper understanding of fish consumption advisories will increase anglers' concern for water quality, protect their health, and still encourage their enjoyment of the fishery.