Assessing the impact of beach nourishment on the intertidal food web through the development of a mechanistic-envelope model

Beach nourishment, the placement of sand onto a sediment-starved stretch of coast, is widely applied as a soft coastal protection measure because of its reduced ecological impact relative to hard coastal protection. In order to predict effects on the intertidal sandy beach ecosystem, we developed a simulation model that integrates species envelope-based projections for the dominant macrobenthos species and mechanistic food web modules for higher trophic levels. Species envelopes were estimated by using Bayesian inference of species’ biomass relationships according to the three determining abiotic variables: intertidal elevation, median grain size and total organic matter, obtained from multiple sampling campaigns along the Belgian coast. Maximum potential abundance of higher trophic levels represented by birds, shrimp and flatfish, were estimated based on their derived trophic relationship with macrobenthos. After validation, we demonstrated that unlike nourishment slope, sediment grain...