Kārewa / Gannet Island (Māori: Kārewa) is a small island some 19 kilometres (12 miles) offshore from Kawhia on the west coast of New Zealand's North Island.
Description
The island consists of the eroded remnant of a tuff ring, erupted about half a million years ago. It is considerably younger than, and compositionally distinct from, the nearby onshore Alexandra Volcanics (Mount Karioi and Mount Pirongia) and Okete Volcanics. It is located on the eastern edge of the North Taranaki Graben, rising 15 metres (49 ft) above sea level from a base about 65 metres (213 ft) deep.[1] In heavy swells the island can be washed over, so that only about 3 square metres (32 sq ft) has vegetation and that limited to Prasiola (algae), Tortula (moss) and Xanthoria, and Xanthoparmelia lichens.[2]
^Wodzicki, K .; Robertson, C. J. R.; Thompson, H. R.; and Alderton, C. J. T. (1984). The distribution and numbers of gannets (Sula serrator) in New Zealand. Notornis 31, 232–261.