POLLUTION EFFECTS AND HISTORIES IN TWO HARBOURS, MARITIME CANADA: INDUSTRIAL (SYDNEY HARBOUR) VS. DOMESTIC (HALIFAX HARBOUR) CONTAMINATES

Although many studies have been carried out using a variety of proxies, very few studies have used microfossils (foraminifera in this case) to reconstruct an extensive history of pre-impact conditions. In this study, there was the opportunity to compare two contamination types (industrial vs. domestic) using benthonic foraminifera as proxies. This was done before in Halifax Harbour (HH) vs. New Bedford Harbour (NBH, Mass.) but the records were insufficient to extend into pre-industrial time for HH.

Analyses of foraminiferal assemblages were conducted on sediment cores from two impacted environments: HH (domestic) and Sydney Harbour (SH, industrial) in maritime Canada to reconstruct pre- and post-impact environments of both areas. Presently, and without any baseline studies HH has a treatment facility after 250 years of untreated, domestic pollution. Sydney Harbour is mainly affected by industrial pollution due to steel and coal production that began at the end of nineteenth century. The present work provides the first foraminiferal record of pollution for SH as well as a target environment for any future remediation programs.

In Halifax Harbour, the major species were agglutinated since the high organic content caused low pH in the sediments that precluded preservation of calcareous tests. However, in SH many calcareous species were found, among them Ammonia beccarii, which had not been observed sub-tidally in eastern Canada previously. The high diversity, dominant calcareous record, and presence of other fossil groups (e.g., Ostracods, Pelecypods) within the Sydney cores reflect the low pollution rate and its short duration in this area when compared to Halifax Harbour.