Potential impact of an exceptional bloom of Karenia mikimotoi on dissolved oxygen levels in waters off western Ireland |
| |
| Institution: | 1. Environmental Protection Agency, Office of Evidence and Assessment, Richview, Clonskeagh Road, Dublin 14, Ireland;2. Environmental Protection Agency, Office of Evidence and Assessment, John Moore Road, Castlebar, Co. Mayo, Ireland;3. Marine Institute, Rinville, Oranmore, Co. Galway, Ireland;1. Metagenomics Research Group, National Research Institute of Fisheries Science, Fisheries Research Agency, 2-12-4 Fukuura, Kanazawa-ku, Yokohama, Kanagawa 236-8684, Japan;2. K Mikimoto & Co. Ltd., Osaki Hazako, Hamajima-Cho, Shima, Mie 517-0403, Japan;3. Research Center for Biochemistry and Food Technology, National Research Institute of Fisheries Science, Fisheries Research Agency, 2-12-4 Fukuura, Kanazawa-ku, Yokohama, Kanagawa 236-8684, Japan;4. Laboratory of Planktology, Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Minato, Tokyo 108-8477, Japan;1. Geosciences Department, University of Oslo, P.B. 1047 Blindern, NO-0316 Oslo, Norway;2. Sherkin Island Marine Station, Sherkin Island, Co. Cork, Ireland;1. Plymouth Marine Laboratory, Prospect Place, West Hoe, Plymouth PL1 3DH, UK;2. Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK;3. Functional Plant Biology & Climate Change Cluster, University of Technology Sydney, PO Box 123, Broadway, NSW 2007, Australia;1. Environmental Protection Agency, Office of Environmental Assessment, Richview, Clonskeagh Road, Dublin 14, Ireland;2. Environmental Protection Agency, Office of Environmental Assessment, John Moore Road, Castlebar, Co. Mayo, Ireland;3. Department of Botany and Plant Science, School of Natural Sciences, National University of Ireland, Galway, Ireland |
| |
| Abstract: | In the summer of 2005 an exceptional bloom of the dinoflagellate Karenia mikimotoi occurred along Ireland's Atlantic seaboard and was associated with the mass mortality of both benthic and pelagic marine life. Oxygen depletion, cellular toxicity and physical smothering, are considered to be the main factors involved in mortality. In this paper we use a theoretical approach based on stoichiometry (the Anderson ratio) and an average K. mikimotoi cellular carbon content of 329 pg C cell−1 (n = 20) to calculate the carbonaceous and nitrogenous oxygen demand following bloom collapse. The method was validated against measurements of biochemical oxygen demand and K. mikimotoi cell concentration. The estimated potential oxygen utilisation (POU) was in good agreement with field observations across a range of cell concentrations. The magnitude of POU following bloom collapse, with the exception of three coastal areas, was considered insufficient to cause harm to most marine organisms. This indicates that the widespread occurrence of mortality was primarily due to other factors such as cellular toxicity and/or mucilage production, and not oxygen depletion or related phenomena. In Donegal Bay, Kilkieran Bay and inner Dingle Bay, where cell densities were in the order of 106 cells L−1, estimated POU was sufficient to cause hypoxia. Of the three areas, Donegal Bay is considered to be the most vulnerable due to its hydrographic characteristics (seasonally stratified, weak residual flow) and hypoxic conditions (2.2 mg L−1 O2) were directly observed in the Bay post bloom collapse. Here, depending on the time of bloom collapse, depressed DO levels could persist for weeks and continue to have a potentially chronic impact on the Bay. |
| |
| Keywords: | Oxygen depletion Cell biovolume Exceptional bloom Hypoxia |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
