Suspended sediment contribution resulting from bioturbation in intertidal sites of a SW Atlantic mesotidal estuary: data analysis and numerical modelling

Abstract

The suspended sediment contribution arising from the bioturbation activity of Neohelice granulata at intertidal sites of the Bahía Blanca estuary was analysed using several approaches, ranging from field experiments to numerical modelling. Crabs from the mudflat remove, trap and erode more sediment from their burrows per unit area than those from saltmarshes, as a consequence of the high population density and the mobility of cohesive sediments. The results obtained through the MOHID simulations showed that the sediments that were bioavailable in the intertidal of Puerto Cuatreros were maintained in the water column much longer than sediments in Villa del Mar. This longer residence time in the area could be because of the geomorphological and hydrodynamic characteristics of the internal area of the estuary, where numerous tidal channels coexist and phenomena of “retention” occur before entry into the main channel. By contrast, in Villa del Mar, located in the middle of the estuary, the sediments are affected by a greater water depth and higher tidal current speeds. In addition, the waves caused by the winds can be a determining factor in the spatio-temporal evolution of the bioavailable sediment in the water column of the study areas.

Biological and physical drivers of bio-mediated sediment resuspension: A flume study on Cerastoderma edule

“…(Wood & Widdows, 2002;Orvain, et al, 2012)] and landscape [e.g. (Nasermoaddeli, et al, 2018;Angeletti, et al, 2019)] scale. By doing so, they open a venue to the formulation of general expectations about future scenarios of bio-mediated sediment resuspension.…”

“…(Neumeier, et al, 2006;Montserrat, et al, 2008;Joensuu, et al, 2018;Hillman, et al, 2019)] and simulation studies [e.g. (Sandford, 2008;Orvain, et al, 2012;Nasermoaddeli, et al, 2018;Angeletti, et al, 2019)] agree that the presence of bioturbators generally enhance sediment resuspension. However, bio-mediated sediment dynamics often have complex non-linear behaviour (Balke, et al, 2012;Salvador de Paiva, et al, 2018;Fang, et al, 2019;Xie, et al, 2019).…”

Validation of the 3D-MOHID Hydrodynamic Model for the Tagus Coastal Area

“…The versatility and flexibility of the MOHID Water eases its implementation in any type of system and to accomplish different modelling requirements depending on the objectives of the work to be performed. Indeed, in the last four years the MOHID Water was applied in multiple studies worldwide, namely in Canada [13], Colombia [14,15], Brazil [16], Argentina [17,18], Uruguay [19], Holland [20], France [21], Spain [22], Croatia [23], Australia [24,25], Malaysia [26] and Korea [27]. In Portugal, this model has been implemented in the entire Portuguese coast [28][29][30] and in all main estuaries [31][32][33][34][35].…”