In situ variations of the xanthophylls diatoxanthin and diadinoxanthin: photoadaptation and relationships with a hydrodynamical system in the eastern English Channel

1993 ◽  
Vol 95 ◽  
pp. 69-77
Author(s):  
C Brunet ◽  
JM Brylinski ◽  
Y Lemoine
Keyword(s):  
English Channel ◽  
Hydrodynamical System

scholarly journals Twenty years of satellite and in situ observations of surface chlorophyll-a from the northern Bay of Biscay to the eastern English Channel. Is the water quality improving?

2019 ◽  
Vol 233 ◽  
pp. 111343 ◽  
Author(s):  
Francis Gohin ◽  
Dimitry Van der Zande ◽  
Gavin Tilstone ◽  
Marieke A. Eleveld ◽  
Alain Lefebvre ◽  
...  
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Bay Of Biscay ◽  
English Channel ◽  
In Situ Observations

Seasonal phytoplankton production in the western English Channel 1964–1974

1978 ◽  
Vol 58 (4) ◽  
pp. 943-953 ◽  
Author(s):  
G. T. Boalch ◽  
D. S. Harbour ◽  
E. I. Butler
Keyword(s):  
Primary Production ◽  
Carbon Fixation ◽  
Statistical Analyses ◽  
Annual Production ◽  
Phytoplankton Production ◽  
English Channel ◽  
Cell Counts

Over a period of 10 years, 1964–74, primary production has been measured at three stations across the western English Channel using the 14C method. Results for carbon fixation, cell counts and mean seasonal production are illustrated. Statistical analyses show that, at two of the three stations, carbon fixation in 1966 was significantly greater than expected and that annual production differs significantly at each of the stations. The variations observed are discussed in relation to other changes recorded in the area during the same period. A deck incubator used for simulated in situ14C experiments is illustrated.

scholarly journals A Single Species, Micromonas pusilla (Prasinophyceae), Dominates the Eukaryotic Picoplankton in the Western English Channel

2004 ◽  
Vol 70 (7) ◽  
pp. 4064-4072 ◽  
Author(s):  
Fabrice Not ◽  
Mikel Latasa ◽  
Dominique Marie ◽  
Thierry Cariou ◽  
Daniel Vaulot ◽  
...  
Keyword(s):  
Aquatic Ecosystems ◽  
Fluorescent In Situ Hybridization ◽  
Algal Species ◽  
Sampling Period ◽  
Single Species ◽  
English Channel ◽  
Green Algal ◽  
Micromonas Pusilla ◽  
Green Algal Species

ABSTRACT The class Prasinophyceae (Chlorophyta) contains several photosynthetic picoeukaryotic species described from cultured isolates. The ecology of these organisms and their contributions to the picoeukaryotic community in aquatic ecosystems have received little consideration. We have designed and tested eight new 18S ribosomal DNA oligonucleotide probes specific for different Prasinophyceae clades, genera, and species. Using fluorescent in situ hybridization associated with tyramide signal amplification, these probes, along with more general probes, have been applied to samples from a marine coastal site off Roscoff (France) collected every 2 weeks between July 2000 and September 2001. The abundance of eukaryotic picoplankton remained high (>103 cells ml−1) during the sampling period, with maxima in summer (up to 2 × 104 cells ml−1), and a single green algal species, Micromonas pusilla (Prasinophyceae), dominated the community all year round. Members of the order Prasinococcales and the species Bathycoccus prasinos (Mamiellales) displayed sporadic occurrences, while the abundances of all other Prasinophyceae groups targeted remained negligible.

A temporal study of mycosporine-like amino acids in surface water phytoplankton from the English Channel and correlation with solar irradiation

2003 ◽  
Vol 83 (1) ◽  
pp. 1-9 ◽  
Author(s):  
C.A. Llewellyn ◽  
D.S. Harbour
Keyword(s):  
Amino Acids ◽  
Surface Water ◽  
Algal Blooms ◽  
Mixed Layer Depth ◽  
Ground Level ◽  
Fold Increase ◽  
Ultraviolet B ◽  
Solar Irradiation ◽  
English Channel

A seasonal survey was undertaken, over a year, of phytoplankton from surface water in the western English Channel (Station L4) measuring mycosporine-like amino acids (MAAs), photosynthetic pigments and microscopic counts. Ground level solar radiation (ultraviolet-B, ultraviolet-A and photosynthetically active radiation; UV-B, UV-A and PAR) was measured at a nearby site. From this we estimated in situ solar irradiance received by phytoplankton using measurements of the mixed layer depth and calculations of the 50% light level cut-off. The MAAs occurred year round, with concentrations increasing rapidly during spring and summer (maximum 8·5 μg l−1) to levels exceeding those of chlorophyll-a (chl-a maximum 3·6 μg l−1). On two occasions, increases in specific MAAs coincide with algal blooms. In spring, increases in mycosporine-glycine (λmax 310 nm in the UV-B) coincide with a bloom of the prymnesiophyte Phaeocystis pouchetii and in July and August increases in an unidentified MAA (λmax 328 nm) match a bloom of the diatom, Guinardia striata (=Rhizosolenia stolterfothii). Concentration of MAAs, but not chlorophyll, correlate with in situ irradiance. The ratio of MAA to chl-a increases linearily with in situ irradiance received by phytoplankton reaching 13·9 nmol MAA (nmol chl-a)−1 at 101 W m−2. Evidence of photoinduction is observed during the P. pouchetii bloom with a four fold increase in the concentration of mycosporine-glycine (maximum 2 pg cell−1) as UV-B:PAR ratio increases from 0·0011 to 0·0014. Dinoflagellates, although contributing to <10% of biomass, are found through the correlation of MAAs to the biomarker peridinin, to contribute to baseline levels of MAAs throughout the year. Our MAA:chl-a values for the English Channel are similar to those measured in coastal areas of southern USA. Similarities with studies on Antarctic phytoplankton are also found with the dominance of porphra-334 and the presence of mycosporine-glycine in P. pouchetti.

Eocene Limestones to the West of Jersey

1960 ◽  
Vol 97 (4) ◽  
pp. 289-298 ◽  
Author(s):  
Dennis Curry
Keyword(s):  
English Channel ◽  
The West ◽  
Structural History ◽  
History Of ◽  
East West

AbstractThis note records the presence of Eocene limestones in situ on the bed of the English Channel along an east-west line to the west of the island of Jersey. The microfauna of samples of these limestones is compared with those of some other beds of similar age. There are comments on the relevance of the above discoveries to the structural history of the area.

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