Large-scale temporal and spatial patterns of marine phytoplankton in the north-east Atlantic

• Main Author: Edwards, Martin
• Other Authors: School of Biological and Marine Sciences
• Format: Thesis
• Language: English
• Published: University of Plymouth 2000
• Subjects: North Atlantic; North Atlantic oscillation; North East Atlantic
• Online Access: http://hdl.handle.net/10026.1/2552; https://doi.org/10.24382/3862

Phytoplankton constitute the main algal biomass in pelagic ecosystems and, therefore, play a fundamental role in the functioning of the marine trophic web. Information on long-term trends in marine phytoplankton may help to distinguish between biological responses to natural oscillations in climate and global warming, and to evaluate possible regional effects of eutrophication. The aim of this work was to contribute to the general understanding of how phytoplankton are spatio-temporally structured at the large-scale. To achieve this aim, the Continuous Plankton Recorder (CPR) survey data were used to identify the dominant large-scale spatial patterns of phytoplankton in north-western European continental shelf waters. Spatial patterns have been described in relation to their variability in time (seasonal and decadal). Finally, fluctuations of phytoplankton in space and time are described in relation to changes in the environment of the North Atlantic. The analysis included approximately 70,000 samples taken between 1960-1995. The large-scale, spatio-temporal patterns ranged from the meso to the macro-scale (50-10,000 km) and from months to decades. The structure of the thesis follows a progression from the seasonal to the inter-annual scale and from phytoplankton biomass to the phytoplankton community. Particular emphasis is placed on a broad overview of the long-term changes in marine phytoplankton and interpreting anomalous phytoplankton values. Overall, the results suggest that the environment plays a fundamental role in structuring the phytoplankton from the seasonal scale to the decadal scale. The seasonal spatial evolution of phytoplankton shows close associations to the hydrography of the north-east Atlantic, from the overall biomass to the timing and ending of the seasonal growth period. At larger-scales, atmospheric forcing (principally governed by the North Atlantic Oscillation index) has a dominant effect on decadal variability of phytoplankton populations in the north-east Atlantic. Although there is ...