Cause for caution: response to forum contribution by van der Meer and Folmer.

Published online
05 Mar 2024
Content type
Journal article
Journal title
Journal of Applied Ecology

Piersma, T. & Koolhaas, A. & Gils, J. A. van & Dekinga, A.
Contact email(s)

Publication language


Triggered by the disappearance of the bivalve-eating red knots Calidris canutus from feeding areas in the western Dutch Wadden Sea after these intertidal flats were exposed to the harvesting of edible cockles Cerastoderma edule by shallow-draft suction dredging vessels, the admission of such dredging practices in this state nature monument, RAMSAR-site and area designated protection under the EC Habitat and Bird Directives became an issue of politicized and heated societal debate in the 1990s and early 2000s. In the absence of focussed scientific research yielding peer-reviewed papers, the few published studies on the issue were 'side-products' of a long-term study on foraging ecology and population dynamics of red knots. In their contribution, van der Meer and Folmer criticized some of the statistical analyses in, what they consider, key papers leading to the closure of these forms of shellfish-harvesting in the Dutch Wadden Sea. The material provided by van der Meer and Folmer represents useful hindsight, further analytical sophistication and a (in our view biased) literature review, and thus raises new issues of concern, while leaving intact the arguments for concern about harmful ecological effects of large-scale suction-dredging in protected intertidal areas. Policy implications. We conclude that, even in the light of the statistical concerns expressed by van der Meer and Folmer, there is still reasonable doubt on an absence of harmful ecological effects of suction-dredging. This means that the eventual precautionary ruling on suction-dredging for cockles in the protected Dutch Wadden Sea would remain perfectly valid.

Key words