Spatial and temporal covariation in the recruitment and abundance of Atlantic salmon populations in the Baltic Sea

Abstract

Synchronous trends in the abundance of hatchery and wild Baltic salmon populations are examined using correlation analysis. The river catch of wild adult salmon, the recruitment of age 0+ wild salmon parr, and the recapture rate of tagged hatchery smolts are positively correlated among rivers in the Baltic Sea. The spatial correlation among populations is greater than reported for other anadromous salmonids. Baltic salmon populations have undergone low frequency, high amplitude changes in abundance during the past 200 years. Recent production levels have been supported largely by hatcheries. Efforts to conserve the remaining wild populations through fisheries regulation appear to be having a positive effect on spawner abundance.