The laboratory's research focuses on the interactions of metals and metalloids with marine organisms. This work is aimed at evaluating the bioavailability and fate of metals, including important long-lived radionuclides associated with nuclear wastes, in marine organisms. Our research examines various processes regulating the uptake and trophic transfer of these contaminants in marine food webs. Thus, some of our work has explored the nature of binding of metals to diverse types of particles and the influence these have on the extent to which the metals are in a biologically available form. As a consequence, the effects of chemical and phase (particulate, dissolved, colloidal) partitioning of metals on their bioaccumulation in marine food webs is assessed. Particle types considered include abiotic particles such as suspended sediments (e.g., iron oxides with and without organic coatings, clay particles, calcite crystals) and living particles (e.g., phytoplankton cells, bacterioplankton). As well, research has focused on the adsorption/desorption of metals to biogenic detrital matter and the influence this material can have on the vertical flux and geochemical cycling of metals in diverse oceanic regimes, including open ocean and continental shelf waters.

Studies have assessed rate constants for metal uptake and release from living and abiotic particles under different environmental conditions, and the results are applied to understanding processes in specific environmental regions. For example, studies are underway to assess the partitioning and bioavailability of metal components of long-lived radioactive waste products discharged into the Ob River in Siberia and into coastal regions of the Kara Sea north of Siberia. We have also been engaged in risk assessment evaluations of radioactive waste disposal in these regions. Other ongoing studies consider the fractionation of metals between dissolved, particulate and colloidal phases and their influence on trophic transfer in the plankton and from plankton to marine bivalve molluscs of Long Island and Mediterranean waters. Additionally, physiological, field, and modeling studies are ongoing in Long Island Sound and in San Francisco Bay to assess the bioaccumulation of metals in marine bivalve molluscs from dissolved and particulate phases. We have also been active in developing a bioenergetic-based kinetic model to quantify the bioaccumulation, including specific uptake pathways, of metals in marine bioindicator organisms. This work, started with bivalves, is being extended to include other marine herbivores, particularly zooplankton.

Additionally, research is underway to relate bioaccumulation and toxicity of select metals to marine herbivores and to marine and freshwater phytoplankton. These studies emphasize physiological and biochemical responses to sublethal concentrations of metals. Two new programs just underway will also consider the bioavailability of sediment-bound mercury to benthic invertebrates and the biogeochemical consequences of metal partitioning patterns in phytoplankton.

Research opportunities exist for motivated students at all levels. Students should contact Nicholas S. Fisher by mail, phone, fax, or email.

Nicholas S. Fisher
Marine Sciences Research Center
Stony Brook University
Stony Brook, NY 11794-5000

tel: 631-632-8649
fax: 631-632-8820

Email: nfisher@notes.cc.sunysb.edu