Habitat Preservation: Floating Breeding Grounds for Terns

When a waterfront breeding area for terns was being developed, the Netherlands prioritized habitat preservation using pontoons as floating breeding grounds.

“How do you deal with nature during a major dyke improvement?” Not many infrastructure projects would spend much time on that question, but it was a central concern when construction began along the waterfront of Markermeer, the Netherlands — a major breeding area for the Common Tern.

Under the direction of the ecology and landscape consultancy Bureau Waardenburg, large pontoons “designed and developed based on the requirements of breeding Common Terns” were anchored 200 meters from the shoreline.

Habitat Preservation: Floating Breeding Grounds for Terns
Habitat Preservation: Pontoons Used as Floating Breeding Grounds for Terns

“The pontoons provide alternative breeding sites during a project to strengthen the dyke around lake and form an important part of the compensation measures.”

Bureau Waardenburg

The pontoons, often referred to as “Tern Hotels,” were developed as an experiment under the “Marker Stepping Stone” project to strengthen links between the open water of Lake Marker and habitats inside the dyke. In the first year the artificial breeding islands were home to 36 pairs of Common Terns, hatching 50 chicks. In the second year, numbers increased to more than 55 breeding pairs.

An added benefit to the habitat preservation flotillas was the rare ability to monitor the Tern habitat with remote cameras. As Bureau Waardenburg writes on their website:

This remotely operated camera provides images from the pontoons day and night, giving unrivaled information from within the breeding colony without disturbance to the birds. Through the use of the zoom and high-resolution images rings can be read, nests counted and prey items seen. We also hope to be able to follow the fate of the young so that these habitats can be improved further still.

The Tern Floating Breeding Grounds Habitat Preservation project originally appeared as part of the NatureStructure exhibition and book.

tern family
A happy Tern family on the floating habitat preservation pontoons.


Images courtesy of Bureau Waardenburg. Tern Pontoons is part of the research program Natural Lake Marker/IJssel (Natuurlijk(er) Markermeer-IJmeer (NMIJ)) of Rijkswaterstaat, done in collaboration with de Vries & van de Wiel, BWZ ingenieurs and Grontmij.