Rivers, Streams and Lakes

In recent decades, average temperatures across the U.S. Southwest have increased substantially and precipitation patterns have increased in variability. The warmer temperatures directly impact water availability within Southwest ecosystems, including earlier snowmelts; reduced snowpacks, soil moisture, and streamflow; and lower humidity. Collectively, this has led to an increase in...

Brook trout are the only native fish from the salmon family in the southeastern United States. Despite their recreational and cultural significance, human activities, such as habitat degradation and introduction of non-native species, have led to serious declines of brook trout populations in the region. Stream temperature and flow alterations from climate change are projected to impact...

Several times during the severe drought of 2010-2015, communities within the jurisdictional territories of the Chickasaw Nation and the Choctaw Nation of Oklahoma were precariously close to running out of water. According to previous studies, temperatures are expected to continue to rise throughout the southern states, and droughts are predicted to be longer and more severe. Even small...

Alaska is an ecologically, commercially, and recreationally diverse state, providing value to people and terrestrial and aquatic species alike. Presently, Alaska is experiencing climatic change faster than any other area of the United States, but across the state, comprehensive environmental monitoring is logistically difficult and expensive. For instance, only about 1% of U.S Geological...

Cyanobacteria blooms are one of the most significant management challenges in the Great Lakes today. Recurring blooms of varying toxicity are commonly observed in four of the Great Lakes, and the fifth, Lake Superior, has experienced intermittent nearshore blooms since 2012. The recent advent of cyanobacterial blooms in Lake Superior is disconcerting, given the highly valued, pristine...

The climate of the Southeast is changing rapidly. As streams warm and streamflow dynamics change due to climate and land-cover changes, previously unsuitable habitats may become hospitable for invasive species. Warmwater and large-river adapted invasive species such as Asian carps may move upstream as habitats that were previously too cold or had too little flow become welcoming...

Freshwater is a critical driver for island ecosystems. In Hawaiʻi, though rainfall intensity has increased, total rainfall has been on the decline for the last two decades and, as a result, streamflow has also been reduced. The changes in dynamic patterns of streamflow could result in impacts to river, estuarine, and coastal habitats. In turn, these changes also affect the nine native...

As freshwater streams and native fish are threatened by changing environmental conditions, efforts to coalesce existing data and integrate modeling and projection tools are increasingly necessary for informing effective land, water, and species management. For example, identifying and integrating disparate datasets of streamflow, stream water temperature and species distribution is...

Residents living along the coast of Lake Ontario and the St. Lawrence River have experienced two record-setting floods, one in 2017 and another in 2019. These floods caused tremendous property damage and disruptions to the regional economy. The water levels on Lake Ontario are influenced by the operations of the Moses Saunders Dam on the St. Lawrence River. These operations are...

Freshwater ecosystems support the health and well-being of human life and society through a myriad of services. Intact freshwater biodiversity maintains the health of freshwater ecosystems and the benefits they provide. However, staggering rates of freshwater biodiversity loss and declining ecological function of freshwater ecosystems threaten these natural benefits and human life. This...

Nearshore marine ecosystems in Alaska and Hawai‘i rely heavily on organic materials and nutrients delivered by rivers and streams. It is hypothesized that the magnitude and timing of stream flows influences this delivery of materials to coastal ecosystems. However, despite previous research on the topic, there is still considerable uncertainty about how stream flow may influence these...

Freshwater is a critical driver for island ecosystems. Climate change has fundamentally altered the water cycle in tropical islands. The changes in dynamic patterns of streamflow could result in the temporal and spatial difference in the riverine, estuarine, and coastal habitats that support native species. In particular, these habitats support the nine native aquatic species in Hawaiʻi...