In:
Canadian Journal of Fisheries and Aquatic Sciences, Canadian Science Publishing, Vol. 66, No. 10 ( 2009-10), p. 1649-1657
Abstract:
We utilized laboratory microcosms to evaluate the effects of a benthic sediment bioturbator ( Heteromastus similis ; Polychaeta; conveyor-belt deposit feeder) on vertical distributions of CH 4 in sediment and net CH 4 fluxes across sediment–water–air interfaces. The effect of H. similis on sediment CH 4 concentration ([CH 4 ]) varied depending on sediment depth and was strongest at higher animal densities. In comparison with defaunated controls, microcosms with the highest density of H. similis exhibited an increase in [CH 4 ] of 3.7-fold, on average, at the sediment surface (0–2 cm), but these concentrations decreased by ~2-fold in deeper sediment layers (2–8 cm). However, irrespective of sediment depth, the density of H. similis resulted in an overall nonlinear reduction of bulk sediment [CH 4 ]. Most of the observed CH 4 losses from the sediment were due to CH 4 oxidation, but the bioturbatory activities of H. similis also promoted significant increases in [CH 4 ] in both the water column and the microcosm headspace. These results suggest that benthic invertebrates can mediate CH 4 turnover between compartments in aquatic ecosystems, with further consequences for the coupling between benthic–pelagic food chains via the methanotrophic-mediated microbial loop, as well as increase CH 4 emissions to the atmosphere.
Type of Medium:
Online Resource
ISSN:
0706-652X
,
1205-7533
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
2009
detail.hit.zdb_id:
7966-2
detail.hit.zdb_id:
1473089-3
SSG:
21,3
SSG:
12
