Modelling bio-irrigation rates in the sediments of Port Phillip Bay

被引:14
作者
Berelson, WM [1 ]
Townsend, T
Heggie, D
Ford, P
Longmore, A
Skyring, G
Kilgore, T
Nicholson, G
机构
[1] Univ So Calif, Dept Earth Sci, Los Angeles, CA 90089 USA
[2] AGSO, Div Environm Geosci & Groundwater, Canberra, ACT 2601, Australia
[3] CSIRO, Canberra, ACT, Australia
[4] Marine & Freshwater Resource Inst, Queenscliffe, Vic 3225, Australia
[5] Skyring Environm Enterprises, Canberra, ACT 2602, Australia
关键词
D O I
10.1071/MF98076
中图分类号
S9 [水产、渔业];
学科分类号
0908 ;
摘要
The introduction of a deuterium-enriched tracer to benthic incubation chambers emplaced on the sea floor of Port Phillip Bay provides a method of modelling bio-irrigation within the sediments. Plots of deuterium v. incubation time reveal that all seven chambers, emplaced at four sites, indicate nondiffusive transport of pore-water solutes across the sediment-water interface. Modelling indicates that advection of overlying chamber water must occur to depths of 20-50 cm below the interface and at rates between 150 and 700 mL h(-1). Multiple chambers deployed in the same region within the bay are consistent with respect to bio-irrigation depth and rate. This indicates that the distribution of infauna responsible for irrigation is quite consistent within regions defined by sediment type and depth. However, various regions in the bay show distinctly different irrigation rates; thus the distribution and/or activity of infauna is not constant throughout the bay. At the lower rate of pore-water advection, the entire water column in Port Phillip Bay passes through the sediments within 200 days. Dissolved caesium, injected into the chamber, is also an effective tracer of bio-irrigation although adsorption onto sediment particles increases the uncertainty of model results.
引用
收藏
页码:573 / 579
页数:7
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