Storm surge compresses the oystercatcher breeding window

July 11, 2026

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A meteorological surge driven by low pressure and southwest winds has pushed water levels 27 centimetres above predicted tides in the Firth — an anomaly that on this six-metre tidal range coast threatens to squeeze the already narrow window when chicks can feed safely on exposed flats. The Firth's enclosed geometry amplifies these surges far beyond what open-coast tidal predictions account for.

On the morning of the peak water, levels reached 5.66 metres (MLLW), just 0.5 metres short of the range maximum — leaving the chicks less than an hour daily to forage rather than the several hours they typically have. Survival through the breeding season depends on those longer low-tide periods, and compressed windows like this raise the stakes considerably.

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