Abstract
Seasonal variability of mercury content of Mytilus edulis (L.) was studied at monthly intervals for 18 mo (June 1978–December 1979) in a natural population from a typical estuarine environment (St. Lawrence Estuary). Body-size-induced variability was observed in the same population in spring 1980. The regression coefficients of log-log relationships between mercury content and body size of the mussels varied with time. However, the regression coefficients were never higher than 1; this indicates, therefore, no net accumulation of mercury with age of the bivalve. A normalization method, taking into account shell length and soft-tissue dry weight, is proposed to minimize the metal variations due to size differences of the mussels. The normalized mercury contents vary seasonally by a factor of two. Minimum values were observed during summer. This factor (2) is taken as the minimal difference which can be accepted as indicating a significant geographical trend in a “mussel watch”-type study in estuarine environments. In the St. Lawrence Estuary and Gulf, size-normalized concentrations range from 69 to 378 ng Hg g-1 (dry weight); highest levels were observed in areas where freshwater influence is maximum, while lower contents were encountered in regions of highest Atlantic influence. In the Gulf, mercury in mussel soft tissue is 3x104 times that of the seawater. There is some indication of a decrease in the previous measured levels near the mouth of the Saguenay fjord in the Lower St. Lawrence estuary.
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Literature cited
Berman, S. S.: ICES seventh round intercalibration for trace metals in biological tissue (ICES 7/TM/BT/Part I) — Preliminary Report. Int. Counc. Explor. Sea Comm. Meet (Mar. envirol Qual. Comm.) B44, 1–64 (1984)
Bourget, E. and D. Cossa: Mercury content of mussels from the St. Lawrence Estuary on northwestern gulf of St. Lawrence, Canada. Mar. Pollut. Bull. 7, 237–239 (1976)
Boyden, C. R.: Trace element content and body size in molluscs. Nature, Lond. 251, 311–314 (1974)
Boyden, C. R.: Effect of size upon metal content of shellfish. J. mar. biol. Ass. U.K. 57, 675–714 (1977)
Cossa, D., E. Bourget and J. Piuze: Sexual maturation as a source of variation in the relationship between cadmium concentration and body weight of Mytilus edulis L. Mar. Pollut. Bull. 10, 174–176 (1979)
Cossa, D., E. Bourget, D. Pouliot, J. Piuze and J. P. Chanut: Geographical and seasonal variations in the relationship between trace metal content and body weight in Mytilus edulis. Mar. Biol. 58, 7–14 (1980)
Cossa, D. et C. Desjardins: Evolution de la concentration en mercure dans les crevettes du fjord du Saguenay (Québec) au cours de la période 1970–1983. Rapp. tech. can. Hydrogr. Sciences océan. 32, 1–8 (1984)
Cossa, D., C. Gobeil and P. Courau: Mercury distribution in the waters of the St. Lawrence Estuary. (In preparation)
Davies, I. M. and J. M. Pirie. The mussel Mytilus edulis as a bioassay organism for mercury in seawater. Mar. Pollut. Bull. 9, 128–132 (1978)
Fagerström, T.: Body weight, metabolic rate and trace subsance turnover in animals. Oecologia 29, 99–104 (1977)
Farrington, J. H.: Bivalves as sentinels of coastal chemical pollution: the mussel (and oyster) watch. Oceanus 26, 18–29 (1983)
Fowler, S. W.: Biological transfer and transport processes. In: Pollutant transfer and transport in the sea, pp 2–65. Ed. by G. Kullenberg. Boca Raton, Fla.: CRC Press 1982
Fowler, S. W., M. Heyraud and J. La Rosa: Factors affecting methyl and inorganic mercury dynamics in mussels and shrimp. Mar. Biol. 46, 267–276 (1978)
Gault, N. F. S., E. L. C. Tolland and J. G. Parker: Spatial and temporal trends in heavy metal concentrations in mussels from Northern Ireland coastal waters. Mar. Biol. 77, 307–316 (1983)
Gobeil, C., D. Cossa et J. Piuze: Niveaux des concentrations en mercure dans les eaux du fjord du Saguenay (Québec) en octobre 1979 et septembre 1983. Rapp. tech. can. Hydrogr. Sciences océan. 36, 1–14 (1984)
Goldberg, E. D.: The mussel watch — a first step in global marine monitoring. Mar. Pollut. Bull. 6, p. 111 (1975)
Goldberg, E. D., V. T. Bowen, J. W. Farrington, G. Harvey, J. H. Martin, P. L. Parker, R. W. Risebrough, W. Robertson, E. Schneider and E. Gamble: The mussel watch. Envir. Conserv. 5, 101–125 (1978)
Lambert, J. D.: Contribution à l'étude des communautés planctoniques de la Baie-des-Chaleurs, 131 pp. Mémoire de maîtrise ès sciences (océanographie), Université du Québec à Rimouski, Québec 1983
La Touche, Y. D. and M. C. Mix: The effects of depuration, size and sex on trace metal levels in bay mussels. Mar. Pollut. Bull. 13, 27–29 (1982)
Loring, D. H.: Mercury in the sediments of the gulf of St. Lawrence. Can. J. Earth Sciences 12, 1219–1237 (1975)
Majori, L., G. Nedoclan, G. B. Modonutti and F. Daris: Study of the seasonal variations of some trace elements in the tissues of Mytilus galloprovincialis taken in the Gulf of Trieste. Revue int. Océanogr. méd. 49, 37–40 (1978)
N.A.S.: The international mussel watch. Report of a workshop sponsored by the Environmental Studies Board, Commission of Natural Resources, national Research Council MSA, 248 pp. Washington D.C.: National Academy of Sciences 1980
Phillips, D. J. H.: Quantitative aquatic biological indicators, 488 pp. London: Applied Science Publishers Ltd 1980
Smith, J. N. and D. H. Loring: Geochronology of mercury pollution in the sediments of the Saguenay Fjord, Québec. Envir. Sci. Technol. 15, 944–951 (1981)
Strong, C. R. and S. N. Luoma: Variations in the correlation of body size with concentrations of Cu and Ag in the bivalve Macoma balthica: Can. J. Fish. aquat. Sciences. 38, 1059–1064 (1981)
Williamson, P.: Variables affecting body burdens of lead, zinc and cadmium in a roadside population of the snail Cepaca hortensis Müller. Oecologia 44, 213–220 (1980)
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Cossa, D., Rondeau, J.G. Seasonal, geographical and size-induced variability in mercury content of Mytilus edulis in an estuarine environment: a re-assessment of mercury pollution level in the Estuary and Gulf of St. Lawrence. Mar. Biol. 88, 43–49 (1985). https://doi.org/10.1007/BF00393042
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DOI: https://doi.org/10.1007/BF00393042