Chen, Z. Darling Marine Center, University of Maine, zchen41@maine.edu
Mayer, L. Darling Marine Center, University of Maine, lmayer@maine.edu
Sampson, S. Darling Marine Center, University of Maine,
Quetel, C. Laboratorie de Photochemie et Photophysique Moléculaire, Université de Bordeaux 1,
Donard, O. Laboratoire de Chimie Bio-Inorganique et Environnement, Universite de Pau , olivier.donard@univ-pau.fr
Jumars, P. A. School of Oceanography, University of Washington, jumars@ocean.washington.edu

 
ENHANCED SOLUBILIZATION OF TRACE METALS IN DEPOSIT FEEDERS' GUTS
 
Sediment particles are subjected to intensive biochemical attacks in the guts of deposit feeders which contain extraordinarily high concentrations of metal-binding, dissolved amino acids (AA). To examine the impact of gut passage on metal biogeochemical behavior in situ, we measured Class A and borderline metal concentrations in gut fluids of a deposit feeder, Arenicola marina, and Cu concentrations in gut fluids of 50 other invertebrate species. Class A metals in gut fluid are at levels similar to seawater, while concentrations of borderline metals are orders of magnitude greater than in seawater, which cannot be explained by gut pH values. Linear correlations between Cu and AA concentrations were found among species, within a population of A. marina, and along gut sections. Enrichment factors of the first-row transition metals relative to average crustal rock show the Irving-Williams sequence, consistent with soft gut ligand complexation. Solutions of a relatively metal-depleted protein (BSA) were incubated ten times with uncontaminated sediments from the worm's habitat to mimic the process of metal solubilization during deposit feeding. Metal concentrations in BSA solutions also developed the Irving-Williams sequence over time.
 
Day: Friday, Feb. 5
Time: 02:30 - 02:45pm
Location: Sweeney Center
 
Code: SS28FR0230S