Dolly Varden are temperature sensitive trout, preferring temperatures lower than 55oF and avoiding waters reaching 60oF or higher

Global trends in climate will have widespread and varied impacts on our fisheries resources.  Science anticipates drastic shifts in both abundance and distribution of species.  As global temperature gradually increases, there will be changes in the patterns of precipitation, distribution of drought, and amount of snowfall and runoff. 

These alterations to both water quality and quantity will affect fisheries and their ecosystems.  Distribution of fishes will expand in some cases and contract in others as conditions become more favorable for aquatic invasives to outcompete native species.  The health and production of wild and hatchery fishes will be compromised by increased susceptibility to disease and changes in bioenergetics and growth.  Rising water temperatures in lakes and stream may lead to an altered nutrient balance, decreased dissolved oxygen content, and ultimately, fish kills.  

Ice formation in Wichita Mountains NWR

The Role of the Fisheries Program

Climate change requires dramatic new approaches to natural resource management.  The U.S. Fish and Wildlife Service’s Fisheries Program is taking steps now to monitor and maintain at risk fish populations, protect and restore critical habitat, and adapt its management program to mitigate the effects of climate change.  As a Federal partner, the Fisheries Program provides key leadership and technical assistance to guide and coordinate conservation activities that address climate change issues at local, regional, and national scales.  The Fisheries Program:

• Conducts conservation planning, monitoring, and management of at risk fish populations and habitats through the Fish and Wildlife Conservation Offices.  It is particularly important to understand the baseline to accurately manage for current and future conditions.
• Removes barriers to fish passage and restores critical habitat through the National Fish Passage Program and the National Fish Habitat Action Plan. Habitat loss associated with climate change will be a key threat to many fish species.
• Detects and tracks emerging fish health issues with the National Wild  Fish Health Survey.  Climate change will increase disease and parasite  issues related to temperature stress, particularly in cold water fish.
• Applies DNA technology at Fish Health Centers and Fish Technology
  Centers to determine disease origin and transmission patterns associated
  with climate change.
• Focuses recovery efforts on refugia by using the National Fish Hatchery System’s unique water supply to develop captive propagation techniques for aquatic species impacted by climate change.