The use of free amino acids (FAA) as a stress indicator was assessed during a copper exposure experiment for specimens of the estuarine bivalve M. balthica from a geographical gradient extending from the Netherlands to its most southern limit of distribution in the Gironde, France. Changes in FAA were significant. A higher alanine content at the start of the experiment coincided with a lower mortality-rate during copper exposure. During copper exposure the tissue concentrations of alanine increased. It is concluded that especially the concentrations of alanine, and to a lesser degree the taurine/glycine (T/G) ratio, can be used as stress-indicators for M. balthica. Animals near the southern limit of their distribution showed the strongest deviations from average values. The age of the animals (2-7 years) had no influence on results. [KEYWORDS: free amino acids; Macoma balthica; stress; copper;bio-indicator; geographic dine Mytilus-edulis-l; pollution; proteins; cadmium]
Original languageEnglish
JournalScience of the Total Environment
Journal publication date1996

ID: 177242