Aquatic Sciences Meeting, Albuquerque 2001

SS35 Biological and Ecological Responses to Low Oxygen in Constant and Fluctuating Environments (Spatial and Temporal Connections)

Date: Thursday, February 15, 2001, Time: 2:00:00 PM

Location: La Cienega

Marinelli, R, L, University of Maryland, Chesapeake Biological Laboratory, Solomons, USA, marinelli@cbl.umces.edu

Woodin, S, A, University of South Carolina, Columbia, USA, woodin@biol.sc.edu

Edwards, D, , University of South Carolina, Columbia, USA, deirdre@biol.sc.edu

POREWATER AND RECRUITMENT: PART I. MODEL PREDICTIONS AND ENVIRONMENTAL RELEVANCE

Recent studies show that new recruits respond negatively to sediment surfaces which are disturbed and positively to sediments which are either undisturbed or allowed to recover. These data, and a numerical model of transport-reaction processes in sediments, suggest (1) the disturbance signal is related to changes in surface solute chemistry associated with sediment disruption and (2) organic matter diagenetic processes govern recovery dynamics. The model also suggests that the significance of the disturbance signal varies with the diagenetic environment, i.e. sediments with steep gradients (i.e. muds) convey significant disturbance signals whereas sediments with shallow gradients do not. Experiments with Capitella and Mercenaria suggest that the utility of surface solute chemistry as a disturbance cue differs according to the diagenetic environment. Disturbed sands have surficial oxygen and ammonium concentrations similar to undisturbed sediments, and are not rejected by new recruits. Disturbed muds have significantly altered surficial ammonium and oxygen concentrations relative to undisturbed muds, and are rejected by new recruits. Subsequent experiments (see talk by Woodin, Marinelli and Edwards) confirm that dissolved substances drive the observed behavioral differences.

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Aquatic Sciences Meeting, Albuquerque 2001

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