BREDERODE N VAN (2008) The Hondsbossche and Pettemer Seawall an artificial rocky coast of (inter)national importance for Turnstones Arenaria interpres. LIMOSA 81 (2): 62-67.

The Hondsbossche and Pettemer seawall (HBZ) forms a 5 km long artefact in the chain of natural dunes forming the Dutch coastal defence against flooding. Year-round this small site harbours a substantial population of Turnstones. Overwintering birds belong to the Nearctic breeding population. In autumn and spring their numbers are supplemented by birds from the Northerm European breeding population, which use the area to replenish their fat reserves on their way to and from wintering areas inWestern Africa. Turnstones are completely dependent on the artificial tidal area along the seaward side of the dam,where large numbers ofmussels and sea pocks that grow on the basaltmake up their diet. Several small inland wetlands are used as high tide refuges and the inland grasslands may temporarily form an alternative feeding area in winter if high tides prevent Turnstones from feeding along the seashore. Although the available feeding area is only 10 ha, numbers of Turnstones that use the area as an overwintering site (200-900 birds) or during migration (700-1400) can be as high as 76% of the numbers staging in the Dutch Wadden Sea (with120 000 ha potential feeding area at low tide). In all years between 1995 and 2002 numbers along the HBZ exceeded the 1% criterium for wetlands of international importance adopted under the Ramsar Convention. However, the feeding habitat of Turnstones along this site is threatened. One of the options considered in plans to enforce the coastal defence in response to sea level rise is to supply large quantities of sand on the rocky shore. Such a change will render the area unsuitable as a feeding site for Turnstones.

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