Biological and biogeochemical methods for estimating bio-irrigation: a case study in the Oosterschelde estuary [post]

Emil De Borger, Justin Tiano, Ulrike Braeckman, Tom Ysebaert, Karline Soetaert
2019 unpublished
<p><strong>Abstract.</strong> Bio-irrigation, the exchange of solutes between overlying water and sediment by benthic organisms, plays an important role in sediment biogeochemistry. Quantification of bio-irrigation is done either through measurements with tracers, or more recently, using biological traits to derive the community (bio-) irrigation potential (IPc). Both these techniques were applied in a seasonal study of bio-irrigation in species communities of subtidal and
more » ... of subtidal and intertidal habitats in a temperate estuary. A tracer time series with high-temporal resolution allowed to simultaneously estimate the pumping rate, and the sediment attenuation, a parameter that determines irrigation depth. We show that although the total pumping rate is similar in both intertidal and subtidal areas, there is deeper bio-irrigation in intertidal areas. This is explained by higher densities of bio-irrigators such as <i>Corophium sp.</i>, <i>Heteromastus filiformis</i> and <i>Arenicola marina</i> in the intertidal, as opposed to the subtidal. The IPc correlated more strongly with the attenuation coefficient than the pumping rate, which highlights that this index reflects more the bio-irrigation depth rather than the rate.</p>
doi:10.5194/bg-2019-413 fatcat:ywos7hjofvgqpdfexnc3q23fqm