MEPS 492:41-56 (2013)  -  DOI: https://doi.org/10.3354/meps10503

ABSTRACT: Dynamic processes (physical, chemical and biological) challenge our ability to quantify and manage the ecological risk of chemical contaminants in estuarine environments. Selenium (Se) bioavailability (defined by bioaccumulation), stable isotopes and molar carbon-to-nitrogen ratios in the benthic clam Potamocorbula amurensis, an important food source for predators, were determined monthly for 17 yr in northern San Francisco Bay. Se concentrations in the clams ranged from a low of 2 to a high of 22 µg g^-1 over space and time. Little of that variability was stochastic, however. Statistical analyses and preliminary hydrodynamic modeling showed that a constant mid-estuarine input of Se, which was dispersed up- and down-estuary by tidal currents, explained the general spatial patterns in accumulated Se among stations. Regression of Se bioavailability against river inflows suggested that processes driven by inflows were the primary driver of seasonal variability. River inflow also appeared to explain interannual variability but within the range of Se enrichment established at each station by source inputs. Evaluation of risks from Se contamination in estuaries requires the consideration of spatial and temporal variability on multiple scales and of the processes that drive that variability.

KEY WORDS: Selenium · Bioaccumulation · Exposure · Estuaries · Biomonitoring · Hydrology

Full text in pdf format Supplementary material

Cite this article as: Stewart AR, Luoma SN, Elrick KA, Carter JL, van der Wegen M (2013) Influence of estuarine processes on spatiotemporal variation in bioavailable selenium. Mar Ecol Prog Ser 492:41-56. https://doi.org/10.3354/meps10503 Export citation Share:    Facebook - - linkedIn