Towards a methodological framework for the prediction and mitigation of the ecological impact of beach nourishment: a case study on intertidal benthic macrofauna
Speybroeck, J.; Vincx, M.; Degraer, S. (2007). Towards a methodological framework for the prediction and mitigation of the ecological impact of beach nourishment: a case study on intertidal benthic macrofauna, in: Speybroeck, J. Ecologie van macrobenthos als een basis voor een ecologische bijsturing van strandsuppleties = Ecology of macrobenthos as a baseline for an ecological adjustment of beach nourishment. pp. 141-153 In: Speybroeck, J. (2007). Ecologie van macrobenthos als een basis voor een ecologische bijsturing van strandsuppleties = Ecology of macrobenthos as a baseline for an ecological adjustment of beach nourishment. PhD Thesis. Universiteit Gent. Vakgroep Biologie, sectie Mariene Biologie: Gent. 189 pp., more |
| Keywords | Accretion > Beach accretion > Beach nourishment
Ecology
Environmental assessment
Impacts
Macrobenthos
Methodology
Sandy beaches
Bathyporeia pilosa Lindström, 1855 [WoRMS]; Bathyporeia sarsi Watkin, 1938 [WoRMS]; Scolelepis squamata (Müller, 1806) [WoRMS]
ANE, Belgium [Marine Regions]
Marine/Coastal |
| Abstract | Beach nourishment is a widely applied means for coastal protection in Europe and North America. Nowadays, beach nourishment is widely considered as a better alternative than the construction of hard structures to protect a coast against detrimental erosive effects, both from an ecological as from an engineering perspective. Even though beach nourishment is considered as the more ecologically sound option, this form of beach restoration also brings about sizable changes in the sandy beach ecosystem. Most studies conducted on the ecological impact of beach nourishment are short-term, post hoc monitoring investigations of the benthic macrofauna. Little is known of long-term effects, recovery after nourishment, effects of repeated replenishment at the same site (cumulative effects) or what processes are of ecological importance during and after nourishment, to understand recovery. Therefore, little or no effort has been made to facilitate recovery by investigating the ecosystem prior to nourishment and drawing guidelines for impact mitigation. A methodological scheme is developed for pre-impact assessment of the ecological impact of beach nourishment. First, data needs on the physical and biological environment are specified. Secondly, methodological aspects of data collection are presented and a distinction is made between indispensable and less essential types of data. Cost-benefit considerations are made and options to cut costs are raised. Thirdly and finally, we applied the scheme to a case study on the intertidal macrobenthic fauna of Belgian beaches. We selected three key species (Scolelepis squamata, Bathyporeia pilosa and B. sarsi) and conducted field research on their population on Belgian beaches, as well as experiments on their habitat charactertistics. The results from this research allowed drawing guidelines for ecological impact reduction of beach nourishment. For the focal species, nourishment would preferably be executed by foreshore nourishment in winter (December-January). Desirable characteristics of the fill sediment are a good match with the natural sediment and especially low levels of fines. The applied methodology is proposed for use on other species, other ecosystem components and even other impact studies. |
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