EFFECTS OF SEDIMENT RESUSPENSION ON ORGANIC-MATTER PROCESSING IN COASTAL ENVIRONMENTS - A SIMULATION-MODEL

A model, constructed using STELLA(TM), was used to simulate changes in standing stocks and flows of organic matter resulting from sediment r esuspension in shallow coastal environments. Previous studies suggeste d that resuspension may determine the sites and rates of organic matte r mineralization in shallow environments (Hopkinson, 1985, 1987). Thos e studies predicted that resuspended organic material could exert an e nhanced demand on dissolved oxygen. Our model results support this hyp othesis. Total system metabolism receives increasing contributions fro m the water column as settling rate decreases. Water column respiratio n also increases relative to benthic respiration as the frequency and intensity of resuspension events increases. This is driven by higher s pecific degradation rates in the water column than in the benthic envi ronment. Furthermore, overall respiration (benthic + pelagic) increase s in response to resuspension.