Bottom‐up as well as top‐down processes govern zoobenthic secondary production in a tidal‐flat ecosystem

For decades, we monitored numbers and weights of the macrozoobenthos in a vast tidal-flat area Dutch Wadden Sea. We used data collected since 1992 to estimate annual secondary production. Data on chlorophyll concentrations primary production were available for nearby tidal inlet, showing rapid increases late 1970s gradual declines 1980s. The benthos responded with doubling biomass around 1980 summer biomass, as well seasonal gain 1992–2019 de-eutrophication period. In nearly all years, bivalves (on average 25.5 gAFDM m−2 yr−1) accounted more than half total zoobenthic (averaging 42.7 yr−1). Production values individual years not correlated or that year, but did show significantly positive relationship bivalve recruitment success preceding year. As was governed by predation pressure early bottom stages, it is top-down process. Bottom-up processes expressed gradually declining long-term trend growth rates during period also few when so high reduced food competition. far most animals too low fully exploit carrying capacity system increased linearly recruitment.