Small but Mighty: Streams and Wetlands that Matter

Marshes, wetlands, intermittent streams, and even some lakes fill from rainwater or snowmelt then empty through evaporation—coming and going throughout the year. These small but mighty habitats filter out pollution, ease the effects of flooding, and provide water for wildlife in dry climates.

These habitats, called ephemeral bodies of water, are critical for many species, but small streams and wetlands are at risk and need our help.

Here are a few examples of wildlife that need these on-again, off-again waters!

River Otters

river otters
Three river otters. Photo by James “Newt” Perdue, USFWS
River otters are playful semi-aquatic mammals who spend a lot of time in the water – they can even hold their breath for up to 8 minutes! They make their homes near many types of water, including marshes and wetlands. However, they are extremely sensitive to water pollution, which in tandem with unregulated trapping and hunting, had diminished their numbers in the past. Their numbers are coming back strong, but clean water is key to their survival.


Pronghorn running
Pronghorn running. Photo by National Wildlife Photo Contest entrant Kathy Gervais.
Pronghorn are the fastest land animal in North America, and can reach a peak speed of 60 miles an hour. So while they won’t beat a cheetah in the sprint, they can maintain their speed for much longer. In Wyoming, around 400 pronghorn migrate from the Grand Teton National Park to the Upper Green Basin for the winter. During the 150 mile journey, they rely on bodies of water like terminal basins, which are closed, standing bodies of water. These are important for both the water they provide and the food from the ecosystem of terminal basins.

Bighorn Sheep

Bighorn sheep, Theodore Roosevelt National Park
Bighorn sheep in Theodore Roosevelt National Park, courtesy of the National Park Service.
Bighorn sheep are known for- you guessed it- their big horns! The male horns can weigh up to 30 pounds, and some can grow to over 3 feet long. In California, federally-listed bighorn sheep rely on pools of standing water called tenajas as a key source of water in an otherwise arid and hot climate. Desert bighorn sheep tend to live within 2-3 miles of water, so the disappearance of any of these tenajas would threaten the species’ survival.


Spotted Salamander, Great Smoky Mountains National Park
Spotted salamander in Great Smoky Mountains National Park, courtesy of the National Park Service
A few species of salamanders have adapted to the changing life of living in a vernal pool, a temporary pool that usually fills in the spring and evaporates depending upon the weather, but often contains water well into the summer. While adult salamanders live on dry land, during the spring they will go to a vernal pool to lay their eggs, which will develop and hatch during the summer. If the pool lasts long enough, the young salamanders will grow and emerge to become terrestrial animals. One cool thing about these salamander eggs is that they contain green algae, so that when the embryonic salamander produces carbon dioxide it turns it into oxygen that the embryo can use.

American Avocets

American Avocet and chick
American avocet and chicks. Photo by National Wildlife Photo Contest entrant Andrew Lee.
American avocets are migratory birds that use ephemeral waters as their pit stops along their migratory path. Prairie pothole wetlands are often frequented by avocets. These “potholes” provide a shallow habitat for avocets to search for food, as well as to nest in the spring. Their chicks are quick learners – within 24 hours after hatching, they can already walk, swim, and dive to avoid predators!

In its 2008 Ephemeral Streams report , the U.S. EPA estimates that these types of waters make up about 59% of all streams in the United States (except Alaska). For more than a decade, Clean Water Act protections for these waters have been uncertain, putting them at increased risk of pollution and destruction.

But you have a chance to change that. A bill that would allow polluters free rein in these bodies of water is coming to a vote this week. You can do your part to protect these and hundreds more species by urging members of Congress to oppose this attack on the Clean Water Act.

Take ActionBe a voice for the wildlife that depend on water—urge your members of Congress to oppose attacks to the Clean Water Act.