Fucus-epifauna as a marine biological monitoring technique in environmental impact and rehabilitation assessments : a case study with preliminary examination and discussion of its applicability to other coastal regions
Date
1982
Authors
Cross, S. F.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Analysis of the macroinvertebrates associated with the common 'rockweed' Fucus has been shown to provide an effective community-based biological technique for monitoring displacements in shoreline ecosystem structure and function as a result of surface imposed societal stresses.
Initially employed as one of 3 biomonitoring techniques in an environmental rehabilitation assessment (E.R.A.) at the Port Alice sulfite-based pulpmill, the method was restricted to an analysis of the amphipod associates of Fucus. Field distribution data and supportive effluent toxicity estimates clearly demonstrated environmental recovery within the inlet. Comparable physiological requirements between taxonomic ally similar organisms, however, was considered a possible limitation to this approach and supported a recommendation to avoid restriction of the Fucus-epi fauna technique to a single group such as the amphipods. Use of the entire macroinvertebrate community was considered an appropriate alternate approach in that it incorporates organisms with differential pollutant sensitivities, and it documents structural changes due to indirect pollutant effects such as disruption of functional group dependencies.
A multivariate ordination of the epifaunal community associated with Fucus samples taken at 107 shoreline sites around Vancouver Island, and a long the British Columbia mainland coast, revealed the natural variation within the 25 invertebrate species comprising this algal habitat. Variation within the 'normal' community appears to be related to the degree to which the sampling site is exposed to wave or current action. In all cases, similarity of Fucus community structure between 'normal' sites and those sampled in the vicinity of industrial waste discharges, was directly proportional to distance from the waste source. Community responses due to changes in natural environmental parameters (e.g. salinity) were differentiated from pollutant effects by correlating species richness with a measure of numerical dominance. In regions influenced by industrial effluents, dominance increased significantly with decreased species richness, in response to the imposed waste. Natural environmental variation supported the converse relationship.
This technique was successfully tested in the Port Alice E.R.A.. Fucus-epifauna samples taken both prior to and after implementation of pollution controls illustrated a significant biological recovery within the Fucus communities at sites previously affected by the discharged pulping waste. This recovery was correlated with water quality improvements observed over this period.