Saving Biological Diversity: An Overview

Abstract

The Atlantic salmon is an anadromous salmonid native to New England. Populations were decimated mostly due to barrier dams from the late 1700s to the mid-1900s. Government sponsored restoration programs began in the 1960s and continue to the present day, with the challenges and methods evolving considerably during the past 40 years. Although improving fish passage and hatchery production remain important, greater emphasis is now placed on population genetics and natural selection. Restoration programs resulted in increasing population sizes until the early 1990s, when populations uniformly declined. Oceanic conditions are considered to be a primary factor in this downturn, along with other contributing factors such as salmon aquaculture, habitat degradation, increased water temperatures, and endrocrine disruptors. One segment of the species’ U.S. population is now listed as Endangered under the U.S. Endangered Species Act. The programs began as single-species management but are slowly changing to multispecies diadromous fish restoration programs.