Metal Chemistry in Coastal Waters and its Relationship to Bioaccumulation and Trophic Transfe

Jim Moffett

Project Duration: 6/1/96-5/31/97
Key Words: toxic metals, bioaccumulation, analytical chemistry

Proposal Abstract

The complexity of the coastal ocean is partly defined by its incredible spatial variability. RCRC research supports the development of new instruments and methods to measure variations, to manipulate experiments on site, and to provide new, accurate, and more-detailed information. For example, researchers are assessing a new substance capable of indicating an accumulation of metals in phytoplankton populations. The study aims to make new water-quality criteria more specific and quantitative.

Final Report

Contaminants of human origin are ubiquitous constituents of coastal waters. Frequently scientists and regulators ask, "How much of a given contaminant is acceptable?" "Acceptable" is often defined as a level of contaminant that does not pose a threat to the sustainability or stability of an ecosystem. However, as we learn more about coastal environments, it is clear that simple predictive measurements are in fact, complicated by a variety of factors.

My particular interest is variability in the distribution and biological availability of contaminants in dynamic coastal environments. Mixing processes that can lead to considerable spatial and temporal variability in contaminant distributions, present a real challenge for ecological assessment studies.

Normally scientists need large data sets to determine how contaminants vary at numerous locations within an estuary or harbor during storm events. Since collection of discrete samples is costly and logistically difficult, we have been working with an in situ, passive sampling probe to study the distribution and bioavailability of trace metals in harbors. I used the probes to study metal mobilization in Boston Harbor and surrounding areas during such episodic events as combined sewage overflows and dredging activities.