Seminars

Seminar Abstract

Climate change and harmful algal blooms: a case study in the north-east Atlantic

Globally, eutrophication is considered a major threat to the functioning of nearshore ecosystems, as it has been associated with the occurrence and perceived increase of harmful algal blooms (HABs).

HABs have important ecological and economic consequences via their effects on coastal marine resources and can endanger human health through shellfish poisoning and respiratory illness. Some authors have suggested HABs are increasing globally due to anthropogenic influences, while others have stressed that climate variability and increased monitoring are equally important. Distinguishing the effects of anthropogenic eutrophication embedded within a climate signal is therefore extremely difficult.

While there have been many studies focusing on the role of HABs and eutrophication in the northeast Atlantic, there has been limited work on the role of climate oscillations and very few on climate-change impacts. In the current study, we use one of the few long-term datasets and the only one with extensive spatial records, the Continuous Plankton Recorder data to address (1) whether there are any clear signs of HAB hotspots in the northeast Atlantic, (2) whether the frequency of bloom formation is increasing in the North Sea, and (3) the role of climate in bloom formation.

We show that HABs have increased over the last 40 years in some hotspots, notably off Norway, and that these blooms have been a consequence of warming coupled with increased nutrients through wind mixing and inflow of nutrients from outside the North Sea.

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CSIRO = Marine Laboratories Auditorium, Castray Esplanade, Hobart

For further information, or to schedule a seminar, contact:
To schedule a seminar, contact:
Karen Wild-Allen, (Oceanographic seminars) CSIRO Marine and Atmospheric Research (03) 6232 5010
Piers Dunstan, (Biological seminars) CSIRO Marine and Atmospheric Research (03) 6232 5382
Annabel Ozimec (seminar administrator) CSIRO Marine and Atmospheric Research (03) 6232 5462
Sandra Zicus, Antarctic Climate and Ecosystems CRC (03) 6226 7888 & Institute of Antarctic and Southern Ocean Studies (IASOS) University of Tasmania (03) 6226 2509