MEPS 656:1-18 (2020)  -  DOI: https://doi.org/10.3354/meps13555

ABSTRACT: Macrobenthic animals living in a tidal-flat area in the westernmost part of the Wadden Sea were monitored for 50 yr (1970-2019) using consistent methods. About 100 papers were published on this project. We review a number of results and conclusions on observed changes and their possible underlying causal processes. The most significant changes in population sizes and growth rates of several species could be attributed to climate warming (by about 2°C), along with increasing trends in species richness and total late-winter zoobenthic biomass. In the initial years, eutrophication (doubling of nutrients and chlorophyll concentrations) resulted in a doubling of zoobenthic biomass. The subsequent de-eutrophication after the mid-1980s was reflected only in the biomass values observed in late summer. A long-term trend in food supply for birds was not observed. Disturbances from fisheries were intermittent and modest. In several bivalve species, magnitudes of production and biomass were determined primarily by recruitment variation, which was mainly caused by spring abundance of epibenthic predators (shore crabs and shrimps). Their abundance increased with temperatures in the preceding winter. In contrast to this top-down regulation, bottom-up processes apparently played only a minor role in the determination of bivalve biomass. Rarely occurring extremely high bivalve numbers resulted in reduced rates of growth and production. We conclude that the uniquely long monitoring of the tidal-flat macrozoobenthos yielded data series which not only indicated several long-term trends, but also contributed to our insight in processes underlying the observed trends. Most of the observed trends were related to climate change and eutrophication followed by de-eutrophication.

KEY WORDS: Monitoring · Zoobenthos · Wadden Sea · Tidal flats · Dynamics of benthic animals · Growth rates · Climate change · Eutrophication

Full text in pdf format Information about this Feature Article

Cite this article as: Beukema JJ, Dekker R (2020) Half a century of monitoring macrobenthic animals on tidal flats in the Dutch Wadden Sea. Mar Ecol Prog Ser 656:1-18. https://doi.org/10.3354/meps13555 Export citation Share:    Facebook - - linkedIn