T. Vehanen et J. Riihimaki, Integrating environmental characteristics and fisheries management in northern Finland river impoundments, ENVIR MANAG, 23(4), 1999, pp. 551-558
Three large rivers in northern Finland, the Kemijoki, lijoki, and Oulujoki
rivers. were dammed for hydropower generation in the 1940s-1960s. Due to di
fferences in environmental conditions, these impoundments require detailed
study to produce guidelines for fisheries management. Water quality hydrolo
gy, vegetation, and geomorphology data of 16 impoundments were gathered. Sh
oreline land-use data were derived from maps, and fish assemblage data were
collected by exploratory fishing and from the annual fishery statistics. T
he relations among environmental variables were studied, and a classificati
on of the impoundments was developed by hierarchical cluster analysis. Con
sequently, three impoundment groups with different environmental characteri
stics were formed. Significant differences among impoundment groups were al
so detected in fish yield. We conclude that the variation in environmental
conditions, together with differences in fish communities in the impoundmen
ts were important, enough to justify the claim that impoundments of differe
nt types require different management strategies.