A daily study of the diatom spring bloom at Roscoff (France) in 1985. I. The spring bloom within the annual cycle

• Published in: Estuarine, coastal and shelf science Vol. 25; no. 3; pp. 355 - 367
• Main Authors: Sournia, A., Birrien, J.-L., Douvillé, J.-L., Klein, B., Viollier, M.
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 1987; Elsevier
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Brackish; Demecology; diatoms; English Channel; Fundamental and applied biological sciences. Psychology; light attenuation; Marine; nutrient cycles; particulate matter; plankton blooms; Plants and fungi; Rhizosolenia delicatula; tidal variations; France; particulate matter; plankton blooms; nutrient cycles; diatoms; tidal variations; English Channel; light attenuation; Algae; Atlantic Ocean; Europe; Brittany; Chrysophycophyta; Finistere; Marine environment; Seasonal variation; Bloom; North Atlantic; Population dynamics; France; Thallophyta
• ISSN: 0272-7714; 1096-0015
• DOI: 10.1016/0272-7714(87)90078-3

The repeated occurrence of a monospecific bloom of the plankton diatom Rhizosolenia delicatula at Roscoff (western English Channel) was made the subject of an interdisciplinary research programme. Samples were taken at daily intervals from April to July and at longer intervals during the remaining part of the year 1985. Routine physical parameters, light transmission, nutrients, dissolved oxygen, particle load, particulate N and P, chlorophyll content, phytoplankton counting, and zooplankton biomass were measured as a basis for more specific studies (to follow as subsequent papers in this series). The area is characterized by: high tidal range, permanent mixing throughout the year, low attenuation coefficients, moderate nutrient supply, and the dominance of benthic algae over phytoplankton. The spring bloom is significantly delayed with respect to the usual model for the temperate seas. Tidal cycles are expected to exert the main influence on bloom dynamics at the time scale of phytoplankton growth.