Effect of activities associated with coastal reclamation on the macrobenthos community in coastal wetlands of the Yellow River Delta, China: A literature review and systematic assessment

• The dominant species changed remarkably from Mollusca in the 1980s to Polychaeta, Crustacea, and Insecta after 2000.
• The species number and biomass decreased significantly under the comprehensive influence, but not under individuals.
• Reclamation intensity has an initially negative impact on the species number, biomass, abundance, and biodiversity indices.
• A suggested list of criteria has been prepared for future researchers to increase the quantity and quality of the data.

Human activities such as seashore reclamation can have profound negative impacts on the macrobenthos of coastal wetlands. Using the Yellow River Delta as a case study, we conducted a thorough search of the literature to create a synthesis about the effects of reclamation processes. We found 31 publications that met our selection criteria, and we summarized their data to systematically quantify the impacts of reclamation on the dominant species, biomass, abundance, and biodiversity indices. We found that the dominant species changed remarkably, from Mollusca in the 1980s to Polychaeta, Crustacea, and Insecta (indicating a transition from a marine to a terrestrial environment) after 2000. The number of macrobenthos species in the community decreased by more than half from the 1980s to the 2010s and the effect sizes in the 2000s and 2010s both differed significantly from 0 (p < 0.01; t-test). Both the biomass and the abundance of the macrobenthos decreased significantly in the 2000s (p < 0.05 and p < 0.01, respectively; t-test), but not in the 2010s. The Margalef, Shannon-Wiener, and Pielou biodiversity indices did not differ significantly among four periods (from 1985 to 2015) or among the various reclamation activities. The number of species and biomass have decreased significantly under the comprehensive influence of seashore reclamation activities. Under individual reclamation activities, the number of species and their biomass decreased slightly but not significantly. The results of this research improve our understanding of the relationships among reclamation activities and the resulting changes in the macrobenthos community, thereby improving our ability to sustainably use these wetlands. We have prepared a suggested list of criteria to help future seashore reclamation researchers increase the quantity and quality of the data available to support future meta-analyses.