Ecologische monitoring natuurinrichtingsproject Lombardsijde t1 situatie - 2009 Eindrapport 30/04/2010

The beach of Lombardsijde, situated at the eastern side of the eastern palisade of Nieuwpoort, was nourished from March until September 2009. Approximately 650 000 m³ of sand was deposited on top of the beach over a distance of around 1200 m. The sand (grain size between 200 and 250 µm) originated from the new fair way to Oostende, more specifically from the zone situated seaward from the waiting zone border (1500 m seaward of the old western jetty). The nourishment was in full progress during this study so a clear overview of the ecological situation after completion of the works (t1 situation) remains to be obtained. Biotic (macrofauna) and abiotic data were sampled on the impact site (Lombardsijde) and its control site (Nieuwpoort-Bad) during the nourishment. Every anthropogenic influence has an impact on the ecosystem. The scientific evaluation of ecological effects of such an influence, like beach nourishment, can only be done by comparing the status of the environment before (t0 situation) and after the influence has taken place. Four studies concerning the t0 situation have taken place during previous years (Speybroeck et al., 2003; Welvaert, 2005; Van Ginderdeuren et al., 2007; Vanden Eede et al., 2008). Each phase comprises a thorough study of the macrobenthos (organisms larger than 1 mm inhabiting the seafloor) and the physical-chemical environment. Only phase 3 (2006) and 4 (2008) contained enough relevant information to define the initial state of the current sites of interest. The impact of beach nourishments on the intertidal and subtidal coastal ecosystems has been researched in the past (Speybroeck et al., 2004). On the short term, a negative influence is to be expected such as mortality of benthos due to the sand deposition. However, most macrobenthic organisms have planktonic or pelagic larvae and the adult populations are always situated nearby. An estimated period of 1 to 2 years is enough to renew most of the macrobenthic communities. Complete renewal takes around 4 to 5 years because long living organisms like Bivalvia and Echinodermata can’t reproduce successfully every year. If the environmental circumstances changed too drastic, renewal can even fail to occur. Especially changes in the median grain size and the beach profile have profound consequences. The current study showed no notable changes on the beach of Lombardsijde between 2006 and 2009. We did find a rougher median grain size during autumn 2009 compared to the previous years. The beach profile of Lombardsijde was altered in such a way that it now resembles the beach profile of Nieuwpoort-Bad almost perfectly. No other distinct negative trends for the macrobenthos were found but we did show (again) that Nieuwpoort-bad is a better reference site for Lombardsijde than Koksijde-Oostduinkerke. The real effects of the beach nourishment on the macrofauna are yet to be discovered. Hopefully we manage this in future t1 studies

Natuurbescherming in het Belgische deel van de Noordzee 2017

Wist je dat het Belgische deel van de Noordzee het grootste natuurgebied is van België? Al beslaat het slechts 0,5% van de totale Noordzee, deze ”elfde provincie” (3.454 km²) heeft meer te bieden op het vlak van natuur dan je denkt. Duik mee in deze onderwaternatuur en ontdek wat er in het Belgische deel van de Noordzee zoal te beleven en te beschermen valt

Impact of beach nourishment on coastal ecosystems, with recommendations for coastal policy in Belgium = Impact van zandsuppleties op kustecosystemen met aanbevelingen voor het Belgische kustbeleid

Sandy shores or beaches line 70 % of the world’s oceans, including the entire Belgian coastline. They have a multitude of ecosystem functions, constitute an important habitat for a variety of fauna and flora and hold important economic, social and cultural value as prime recreational assets. Predictions on sea level rise, intensified storms, accelerated erosion and flood risk for the North Sea have led to the drafting of the Belgian Integrated Coastal Safety Plan. In order to protect the Belgian coastline against erosion and coastal flooding on a short and long term basis (up to 2050), the Belgian sandy beaches face a multitude of beach nourishment activities over the next years. This soft coastal defence measure safeguards the natural dynamics of the coast and has little impact on the beach ecology and tourism compared to other options. However, together with the multitude of human beach functions such as tourism and economic development, beach nourishment potentially threatens the natural balance of the beach and coastal ecosystem. As management of the coastal zone is clearly a multi-faceted and complex endeavour, where the interests of several stakeholders need to be combined, coastal management desperately needs ecological dimensions. Hence, solid and meaningful biological and ecological information is needed. Clear and user-friendly management tools are essential to guide integrative and ecosystem-based strategies to sustainably manage ongoing space-use activities at the Belgian beaches and coast

Assessment of the ecological characteristics of the Belgian beaches prior to the implementation of the Belgian Master Plan for Coastal Safety

Sandy shores or beaches line 70 % of the world’s oceans, including the entire Belgian coastline (67 km). They have a multitude of ecosystem functions, constitute an important habitat for a variety of fauna and flora and hold important economic, social and cultural value as prime recreational assets. In order to protect the Belgian coastline against erosion and coastal flooding on a short and long term basis (up to 2050), the Belgian sandy beaches face a multitude of beach nourishment activities over the next years, as stipulated in the Belgian Master Plan for Coastal Safety. Monitoring the ecological characteristics of the Belgian beaches will aid in the detection of possible impact effects of past, current and future beach nourishment activities.To this end, 686 intertidal and 582 shallow subtidal samples from the period 1997 – 2011 were analysed to describe the macrobenthic communities and corresponding abiotic patterns on 16 Belgian beaches. The 15 intertidal and 9 shallow subtidal locations were treated separately. The partitioning of macrobenthic community structure within the Belgian beach ecosystem showed a large within beach variability, linked to elevation on the beach (intertidal: 44 % and shallow subtidal: 50 %) and median grain size of the sediment (intertidal: 35 % and shallow subtidal: 23 %), in both the intertidal and shallow subtidal zone. Large scale along-shore spatial (intertidal: 14 % and shallow subtidal: 13 %) and long-term temporal (intertidal: 5% and shallow subtidal: 12 %) variability clearly explained less variation. Several spatial and temporal trends in abiotic factors (overall median grain size between 150 and 300 µm) and in macrobenthic species richness (intertidal: 0 – 19 species; shallow subtidal: 0 – 28 species), abundance (intertidal: 0 – 3988.75 individuals.m-²; shallow subtidal: 0 – 1949.32 individuals.m-²) and biomass (intertidal: 0 – 6.95 g AFDW.m-²; shallow subtidal: 0 – 246.14 g AFDW.m-²) were measured. The mean macrobenthic abundance in the intertidal and shallow subtidal zone fluctuates between 0 and 350 individuals.m-² over the years. Furthermore, the realized niches of the dominant macrobenthic species of the Belgian beaches were defined as the area where these species really live during low tide, characterized by elevation on the beach and median grain size of the sediment.Since all sampling locations were considered to be outside the influence of major impacting activities, these findings improve our knowledge of the natural abiotic and macrobenthic variability of the Belgian beaches. As such, this study can be used as a preconceived basis (t0 situation) of ‘natural’ macrobenthic variability on the Belgian beaches