Sediment pH in Profundal Core Samples from the Turkey Lakes (Algoma, Ontario)

Abstract

Vertical pH profiles were recorded in sediment cores from four of the Turkey Lakes in the Algoma region of northern Ontario. In the three upper lakes of the chain, median down-core pH, which should be correlated with historic lake water pH, was below the median down-core pH for other lakes in northeastern Ontario. The Turkey lakes had probably been relatively acidic, therefore, since pre-industrial times. Down-core pH tended to be lower in upstream lakes. While a pH minimum was typically observed at the sediment–water interface, the surficial sediments were not acidified relative to down-core sediments.