Co-occurrence of copepods and dissolved free amino acids in shelf sea waters

Autor: R. Williams, Serge A. Poulet, D. V. P. Conway, C. Videau
Rok vydání: 1991
Předmět:
Zdroj: Marine Biology. 108:373-385
ISSN: 1432-1793
0025-3162
DOI: 10.1007/bf01313646
Popis: The vertical distribution of chlorophylla, copepods, dissolved free amino acid concentration and the fixation of14C by phytoplankton were monitored in the springs of 1983, 1987 and 1988 in the Ushant front region, shelf edge of the Celtic Sea and central Irish Sea, respectively. In each area, two stations characterized by mixed and stratified water conditions were compared. Vertical distributions of amino acids coincided with the distribution of copepods. A positive and significant correlation was found between the abudance of copepods and the concentration of amino acids dissolved in seawater. A negative and significant correlation was found between chlorophylla and the concentration of amino acids. Enrichment of amino acids (≥ 20 to 500 nM l−1 at specific depths) due to aspartic and glutamic acids, glutamine and ornithine, was assumed to reflect copepod feeding activity and faecal production. At these depths, the natural concentration and diversity of amino acids, including aspartic acid, glutamic acid, asparagine, serine, histidine, glutamine, arginine, threonine, glycine, alanine, tyrosine, valine, phenylalanine, ornithine and lysine, were high enough and in the correct proportions for triggering feeding and swimming and swarming behavior of copepods, as well as their remote detection of food at the micro- and meso-scales (1 to 10 m). This accumulation of amino acids also constitutes a potential additional source of organic nitrogen for bacteria and phytoplankton.
Databáze: OpenAIRE
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