|Benthic diversity along the Delta front of the Western Scheldt estuary (a small scale multidisciplinary approach)|
Breine, N.T. (2011). Benthic diversity along the Delta front of the Western Scheldt estuary (a small scale multidisciplinary approach). MSc Thesis. Ghent University: Gent. 40 pp.
Benthos; Biodiversiteit; ANE, Nederland, Westerschelde [Marine Regions]; Marien
A small scale study on macrobenthic diversity was conducted along the delta front of the outer delta of the Scheldt estuary. North of this area, a series of flood and ebb dominated channels are present, mostly hosting large bedforms. The study area is situated at the northeastern end of such a flood channel that borders the deltafront, but also connects to a disposal ground for dredge materials at about 10km to the south-west. High resolution multibeam data was used to visualize bottom morphology and calculate depth and rugosity. Together with vertical current profiling and sediment data they were analyzed for their ability to explain observed patterns in benthic diversity. Biological samples allowed detecting the presence of the Abra alba community with very high abundances of the tube dwelling habitat engineer polychaete Owenia fusiformis. However, the study area is very heterogeneous and hosts different habitats in close proximity. Species assemblages were most influenced by O. fusiformis presence and sedimentological characteristics. The stations in the deeper waters were influenced by a flood channel, and were different from the station along the upper slope that is merely subdued to the ebb current. In between a poor area existed where a medium grained sand-layer was deposited after a storm. No direct proof for the influence of the Western Scheldt or the disposal site was found. To further investigate the habitat mosaic, more elaborated data are needed on water current patterns and velocities on a broader scale, and data on food availability and suspended particulate matter.