Historical deposits of Alexandrium catenella resting cysts in the sediments of Queen Charlotte Sound,New Zealand |
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| Authors: | AL MacKenzie S Webber AM Watts A Tonks |
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| Institution: | 1. Cawthron Institute, Nelson, New Zealand;2. c/o School of Geography, Environment and Earth Sciences, University of Victoria, Wellington, New Zealand;3. National Institute of Water and Atmosphere, Nelson, New Zealand;4. c/o Department of Anatomy, Otago School of Medical Sciences, Dunedin, New Zealand |
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| Abstract: | In 2011, a large repository of resting cysts of the toxic dinoflagellate Alexandrium catenella was discovered in the sediments of the Onapua/Opua inlet located off Tory Channel, Queen Charlotte Sound. The inlet is a potential source of infection for other areas, such as the major mussel-growing areas of Port Underwood and Pelorus Sound. This study aimed to establish whether the dinoflagellate was a new arrival in the Sounds or had existed unnoticed in this isolated embayment for some time. Alexandrium catenella cysts were identified to a depth of 20–21?cm within the sediment cores, corresponding to a date estimated by radioisotope (210Pb and 137Cs) and Pinus radiata pollen distribution to at least the mid 1970s. Over this time span, resident populations of A. catenella have not become established beyond the confines of Queen Charlotte Sound, suggesting it does not pose an imminent threat of doing so unless increasingly intense and prolonged blooms result in more widespread cyst dispersal. |
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| Keywords: | Alexandrium catenella Marlborough Sounds New Zealand resting cysts sediment chronology |
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