MEPS 363:131-145 (2008)  -  DOI: https://doi.org/10.3354/meps07373

Increased seawater viscosity, Phaeocystis globosa spring bloom and Temora longicornis feeding and swimming behaviours

Laurent Seuront1,2,*, Dorothée Vincent3

1School of Biological Sciences, Flinders University, GPO Box 2100, Adelaide, South Australia 5001, Australia
2South Australian Research and Development Institute, Aquatic Sciences, West Beach, South Australia 5022, Australia
3Laboratoire d’Océanologie et de Géosciences, Centre National de la Recherche Scientifique (CNRS) UMR 8187, Maison de la Recherche en Environnement Naturel, Université du Littoral-Côte d’Opale, 32 avenue Foch, 62930 Wimereux, France

ABSTRACT: The suggested influence of increased seawater viscosity on the feeding and swimming behaviours of adult females of the calanoid copepod Temora longicornis was investigated during a Phaeocystis globosa spring bloom in the coastal waters of the eastern English Channel. Adult female gut contents did not exhibit any significant correlation with chlorophyll concentration or seawater excess viscosity over the course of the bloom. Instead, the highest gut contents were observed when the seawater viscosity was maximum (up to 4.6 centipoise [cP]), after a 5-fold decrease in chlorophyll concentration related to the formation of foam. This demonstrates that even high viscosity did not mechanically hamper zooplankton grazing. Gut contents were controlled by the taxonomic availability rather than the quantitative availability of phytoplankton-based food. This is consistent with the observed sustained egg production rates despite drastic changes in the composition of protist resource over the course of the bloom. Before and after the bloom (in the absence of P. globosa), T. longicornis exhibited similar swimming paths characterized by their large spatial extent and low curviness. In contrast, during the bloom their movements were spatially more localised, significantly slower and more convoluted. This behaviour is suggested as an adaptive strategy to optimise foraging activity during P. globosa blooms, which have been recently shown to generate high level of phytoplankton patchiness.


KEY WORDS: Zooplankton · Motility · Behaviour · Viscosity · Phaeocystis · Temora longicornis · Fractal


Full text in pdf format 
Cite this article as: Seuront L, Vincent D (2008) Increased seawater viscosity, Phaeocystis globosa spring bloom and Temora longicornis feeding and swimming behaviours. Mar Ecol Prog Ser 363:131-145. https://doi.org/10.3354/meps07373

Export citation
Mail this link - Contents Mailing Lists - RSS
- -