Rivers, Streams and Lakes

The Situk River is among the most productive resource in Alaska, with nine native fish species and 10 times the density of juvenile coho salmon than any other Southeast Alaskan watershed. The associated fisheries in the Situk River and its adjoining estuary drive a $2 million economy for the community of Yakutat (population 600), with 89 percent of the households harvesting salmon for subsistence

Water temperature plays a large role in freshwater ecosystems in the Arctic and sub-Arctic. It affects the physical and biological features of rivers, like how the water interacts with the landscape and the life cycles of organisms that live in the river. For example, unseasonably warm water temperatures in Alaska’s large rivers in 2019 caused large numbers of salmon to die before they could reach

Surface-water availability has been identified as one of the biggest issues facing society in the 21st century. Where and when water is on the landscape can have profound impacts on the economy, wildlife behavior, recreational use, industrial practices, energy development, and many other aspects of life, society, and the environment. Projections indicate that surface-water availability will be gen

Ensuring the long-term sustainability of water resources requires careful stewardship of water for societal uses (i.e. municipal, agricultural, and industrial sectors) and also for the many other benefits that aquatic ecosystems provide to humans. In particular, reservoir fisheries and river ecosystems provide a range of economic, cultural, and recreational benefits. Maximizing the benefits that w

Water temperatures affect the distribution, growth potential, and productivity of stream fishes that are targeted in subsistence, sport, and commercial fisheries across Alaska, making stream and lake temperature data critical for managing freshwater resources. Evaluating the variation in temperatures across Alaska will improve understanding of impacts of both climate change and development on fres

Freshwater is a critical driver for island ecosystems and essential part of the water cycle in tropical islands, which is threaten by climate change. Changes in streamflow patterns may impact streams, estuarine, and coastal habitats. In Hawai‘i, these habitats support five native stream fish species. To examine how changes in streamflow have impacted habitat quality for these native aquatic speci

There are significant investments by states and resource agencies in the northeast U.S. for invasive aquatic species monitoring and management. These investments in jurisdictional waters help maintain their use for drinking, industry, and recreation. It is essential to understand the risks from invasive species, because once established, species can be costly to society and difficult or impossible

The greater Mississippi River Basin (MRB) is the largest river basin in North America and the fourth largest basin in the world. The MRB encompasses 24 terrestrial ecosystems, providing habitat for 100 species of mammals, reptiles, and amphibians Its floodplain supports 40% of the waterfowl and wading birds in North America, and the MRB’s rivers transport 40% of the nation’s total exports. Dozens

As climate change is impacting water resources and aquatic ecosystems, there is a great need for natural resource managers to assess adaptation measures in a holistic manner. This can be done by integrating model predictions of climate, hydrology, and ecosystems with observational data to better refine estimates of conditions on-the-ground; however, it can be challenging to combine these different

Stream flow is directly tied to climate, and numerous studies provide substantial evidence that climate change is a threat to future aquatic water flow processes. In the southwestern United States, mountain snow is a primary water source for streams and rivers. However, climate change is threatening the region's mountain snow, leading to reduced snowpack, earlier snowmelt, and more precipitation f

Rain-on-snow events occur when warm rain falls on an existing snowpack, causing rapid snowmelt that can lead to damaging floods, reduced spring and summer streamflow, and altered stream temperatures, with ecological, social, and economic consequences. Rain-on-snow events can result in a loss of riverine biodiversity, decreases in fisheries production, and degradation of stream habitat; water short

High latitude northern ecosystems are currently warming twice as fast as the global average. Over the last several decades, this has caused dramatic losses of frozen area in the Arctic and sub-Arctic. However, it is unclear how melting coastal mountain glaciers, thawing permafrost, and declines in snowpack will affect the quality of freshwater habitat for culturally and economically important salm