Changing bryozoan fauna in Otago Harbour reflects growing urbanisation and globalisation

A comparison between historic reports dating from 1884 (78 records of 35 species) to the bryozoan fauna present today (98 colonies of 14 species) reveals considerable faunal change in Otago Harbour / Te Wai Ōtākou (45° 50'S 170° 38'E) in Dunedin, east coast of South Island, Aotearoa New Zealand. This highly-modified urban port was once a rock-edged tidal inlet surrounded by bush and grassy hills, but changes to its flora and fauna are not limited to land and the intertidal. Our modern bryozoan surveys record predominantly ‘weedy’ invasive species which colonise anthropogenic surfaces, while previously-recorded larger, slower-growing native species are now missing. This study emphasises the importance of historical data and regular monitoring in determining baselines for conservation and restoration.