- Email: [email protected]
A comparison of stress indicators at the biological, organismal and community level of organization
Marine Environmental Research 14(1984) 503 504
A Comparison of Stress Indicators at the Biological, Organismal and Community Level of Organization Edward S. Gilfillan, David S. Page, J. C. Foster, D. Vallas, L. Gonzalez, A. Luckerman, J. R. H o t h a m , E. Pendergast & S. Hebert Bowdoin College Marine Research Laboratory and Hydrocarbon Research Center. Bowdoin College, Brunswick, Maine 04011, USA
In August 1981 a portion of the shoreline of Long Cove, Searsport, Maine, was exposed to a test spill of 250gal of Murban crude oil. Following the spill, replicate samples were taken for infaunal community analysis. Samples of Mya arenaria and Mytilus edulis were taken for physiological analysis. Scope for growth measurements was made for both species. At the same time the specific activity of the physiologically important enzymes, glucose 6-phosphate dehydrogenase and aspartate aminotransferase, was determined. Samples of sediments and animals were also taken for hydrocarbon analysis. Samples were taken at 1-week intervals up to 9 weeks after the spill. The post-spill data were compared with data from an unoiled reference area and with data from the oiled area collected during the 12-month period prior to the test spill. The results of the chemical analysis of tissues and sediments showed oil uptake by sediments and tissues. Low levels of oil persisted in the sediments after 9 weeks and in the tissues through 2 weeks after the spill. In the infaunal community in the spill zone, a number of opportunistic polychaete species bloomed. Maximum population densities were found 3 weeks after the spill. The dominance of opportunistic species decreased thereafter as the sediment hydrocarbon levels declined. Scope for growth measurements showed that perturbations in scope for growth in M. arenaria and M. edulis occurred only during the 2 weeks immediately following the spill when the animals had elevated tissue hydrocarbon levels. Oil-exposed animals showed elevated activities of 503 Marine Environ. Res. 0141-1136/84/$03.00 c;i Elsevier Applied Science Publishers Ltd,
England, 1984. Printed in Great Britain.
504
Edward S. Gil[dlan et al.
glucose 6-phosphate dehydrogenase. These elevated activities persisted throughout the 9-week post-spill sampling period. By the summer of 1982 (10 months after the spill) enzyme activities in the oil-exposed animals were normal. In comparing stress responses at the biochemical, organismal and community levels, it is clear that both changes in enzyme activity and changes in community structure are very sensitive to oil. Scope for growth is much less sensitive as a stress indicator for short-term changes. The major advantages of using changes in enzyme activity in bivalves as an ecosystem indicator include: 1. 2. 3.
Very sensitive to oil in tissues. Bivalves are integrators of waterborne pollutants. Enzyme assays are relatively inexpensive and easy to perform.
A Comparison of Stress Indicators at the Biological, Organismal and Community Level of Organization Edward S. Gilfillan, David S. Page, J. C. Foster, D. Vallas, L. Gonzalez, A. Luckerman, J. R. H o t h a m , E. Pendergast & S. Hebert Bowdoin College Marine Research Laboratory and Hydrocarbon Research Center. Bowdoin College, Brunswick, Maine 04011, USA
In August 1981 a portion of the shoreline of Long Cove, Searsport, Maine, was exposed to a test spill of 250gal of Murban crude oil. Following the spill, replicate samples were taken for infaunal community analysis. Samples of Mya arenaria and Mytilus edulis were taken for physiological analysis. Scope for growth measurements was made for both species. At the same time the specific activity of the physiologically important enzymes, glucose 6-phosphate dehydrogenase and aspartate aminotransferase, was determined. Samples of sediments and animals were also taken for hydrocarbon analysis. Samples were taken at 1-week intervals up to 9 weeks after the spill. The post-spill data were compared with data from an unoiled reference area and with data from the oiled area collected during the 12-month period prior to the test spill. The results of the chemical analysis of tissues and sediments showed oil uptake by sediments and tissues. Low levels of oil persisted in the sediments after 9 weeks and in the tissues through 2 weeks after the spill. In the infaunal community in the spill zone, a number of opportunistic polychaete species bloomed. Maximum population densities were found 3 weeks after the spill. The dominance of opportunistic species decreased thereafter as the sediment hydrocarbon levels declined. Scope for growth measurements showed that perturbations in scope for growth in M. arenaria and M. edulis occurred only during the 2 weeks immediately following the spill when the animals had elevated tissue hydrocarbon levels. Oil-exposed animals showed elevated activities of 503 Marine Environ. Res. 0141-1136/84/$03.00 c;i Elsevier Applied Science Publishers Ltd,
England, 1984. Printed in Great Britain.
504
Edward S. Gil[dlan et al.
glucose 6-phosphate dehydrogenase. These elevated activities persisted throughout the 9-week post-spill sampling period. By the summer of 1982 (10 months after the spill) enzyme activities in the oil-exposed animals were normal. In comparing stress responses at the biochemical, organismal and community levels, it is clear that both changes in enzyme activity and changes in community structure are very sensitive to oil. Scope for growth is much less sensitive as a stress indicator for short-term changes. The major advantages of using changes in enzyme activity in bivalves as an ecosystem indicator include: 1. 2. 3.
Very sensitive to oil in tissues. Bivalves are integrators of waterborne pollutants. Enzyme assays are relatively inexpensive and easy to perform.