The Bioeffects program is a nationwide program of environmental assessment and related research designed to describe the current status of environmental quality in our nation's estuarine and coastal areas. Over thirty multidisciplinary project studies have been carried out since 1991 in close cooperation or in partnership with coastal states or regional organizations. Field studies examine the distribution and concentration of over 100 chemical contaminants in sediments, measure sediment toxicity.
Why We Care
The goal of this project is to assess habitat conditions that influence biodiversity and distribution of soft bottom benthic infaunal communities in Kachemak Bay, a relatively poorly studied habitat in the Bay. This project will characterize physicochemical sediment properties, benthic infaunal community distributions and condition, sediment contaminant concentrations, and toxicity.
Therefore, the value of this project stems not only from the importance of the locale, but also from the fact that it will begin to include Alaska in an expanding national database that is readily accessible to Alaskan coastal managers, scientists and local communities.
Bioeffects projects are designed to assess the spatial distribution and magnitude of effect of chemical contamination, and develop indicators of environmental contaminant exposure in water bodies, ranging from small estuaries to large bays and coastal areas. Data are applicable to environmental risk assessments, damage assessments, and for planning future resource management and restoration activities. Using consistent methods over the life of the program allows for comparison of the magnitude and extent of contaminant effects relative to other locations throughout the U.S., and over time. All data are generated following strict performance-based quality control and quality assurance protocols. Data are available to regional, federal, state, and local resource managers and the public via publications, presentations, and a website data portal.
What We Did
Kachemak Bay will be sub-divided into strata based on geophysical, chemical, and hydrodynamic properties. Strata will be synoptically sampled in a stratified random statistical design. Sediment subsamples will be collected for physical characterization, comprehensive chemical analyses, benthic macroinvertebrate analysis, and toxicity bioassays; in addition, basic water quality parameters will be measured. Data will be analyzed in the sediment quality triad framework for ecosystem assessment. Results will contribute to a broader understanding of the marine ecosystems off Alaska that will enable effective management and sustainable use of marine resources. This project will also provide important benthic community and sediment toxicity data that can be integrated into the AOOS and the National Status and Trends (NS&T) database.
Bioeffects studies are generally a one-time, intensive sampling effort. All sites within the study area are sampled for chemical analyses, and sea floor community assessment in as short a time as possible, so the data reflect a snapshot of the condition of the entire system at a point in time. In brief, field procedures include sampling sediment and the overlying water column. Two sediment samples are taken at each site using what is known as a “Young-modified Van Veen grab sampler.” Only the upper 2–3 cm of the sediment is retained in order to assure collection of recently deposited materials. The sediment samples are thoroughly homogenized in the field and are then subdivided for distribution to various testing laboratories. A third sample is taken for sea floor community analysis. A profile of water quality in the water column is measured to include standard variables such as temperature, depth, salinity, dissolved oxygen, etc. Detailed descriptions of the sampling techniques and procedures are available by contacting the project manager.