Biology and Conservation of Moxostoma spp. Occurring in Canada with Emphasis on the Copper Redhorse (M. hubbsi, Legendre 1952), an Endemic Species on an Extinction Trajectory

Abstract

Freshwater fishes are one of the most threatened animal taxa in North America. In Canada, roughly 30% of the occurring species are currently listed and under protection, including redhorses. This review covers Moxostoma spp. ecology, biology, conservation efforts, and highlights challenges to galvanize actions and outcomes through research. The threats to their survival are strongly associated to increasing anthropogenic pressures, superimposed by climate change effects. In Canada, recovery plans for the copper and the black redhorse, and a management plan for the river redhorse, are operational. The recovery strategy for the copper redhorse relies on stocking campaigns of 0+ juveniles, which was exclusively based on artificial breeding of captured wild broodstock. A conservation aquaculture program that includes genetic diversity and adaptation considerations was recently initiated, and the areas of refinement identified are the following: broodstock and early-life rearing protocols and environmental and physical enrichment protocols to improve juveniles’ post-release fitness. Research through the prism of conservation physiology is proposed in the identification welfare and health bioindicators and adaptability/response to climatic change. Concurrently, aquatic ecosystem protection/restoration, control of invasive species, eDNA detection/telemetry tracking, and post-release monitoring efforts should also be reinforced.