Evaluation of a tidal flat sediment nourishment as estuarine management measure
The tidal flats in the Eastern Scheldt tidal basin (The Netherlands) are eroding as a result of the construction of the storm surge barrier. These intertidal areas are important foraging grounds for birds and therefore it is important to mitigate the negative effects of erosion. As a pilot, a small part (20 ha) of the Galgeplaat tidal flat in the middle of the Eastern Scheldt was nourished with 130,000 m3 of sediment in 2008. This paper investigates this tidal flat nourishment using a large set of morphological and ecological monitoring data from 2008 to 2012. The nourishment proved effective in mitigating the negative effects of tidal flat erosion. The elevated tidal flat provides a foraging area for birds that is available for a longer period. The nourished area was relatively stable, giving time for the recovery of benthic macrofauna such that birds can benefit from the longer exposure time. Therefore, we conclude that sediment nourishments are an effective management measure to counteract the negative consequences of tidal flat erosion in the Eastern Scheldt, and have potential for other estuaries worldwide.
Review of the geomorphological, benthic ecological and biogeomorphological effects of nourishments on the shoreface and surf zone of the Dutch coast
Most knowledge on the morphodynamic behaviour of shoreface and beach nourishments originates from data analysis studies. Numerical modeling tools have been used successfully in hindcasting behaviour of nourishments, but do not yet have the predictive power for reliably forecasting.
Nonmarine Cretaceous bivalve assemblages in China
Abstract Bivalve fossils are very abundant in nonmarine Cretaceous rocks in China. Six assemblages are documented: Nakamuranaia-Margaritifera ( Mengyinaia )- Neomiodonoides and Peregrinoconcha-Koreanaia-Pseudohyrioides (Berriasian-Barremian); Trigonioides (T.)-Plicatounio (P.)-Nippononaia (N.) (Aptian-Albian); Plicatounio (P.?)-Maninsonella-Kwanmonia (?) and Trigonioides (Hoffetrigonia)-Trigonioides (Kumamotio?)-Plicatounio (P.) (Cenomanian Santonian); and Pseudohyria-Sainshandia Limnocyrena (Campanian -Maastrichtian). During the Early Cretaceous there appears to have been provincialism of these assemblages, notably the second-named assemblage which is limited to the extreme southwest of China.