Egrets at Prime Hook NWR by Bill Butcher USFWS

What are Freshwater Wetlands and Who Lives In Them?

What are freshwater wetlands and why are they important?

What unique plants and wildlife live in freshwater wetlands?

15 percent of Delaware’s landscape is unprotected wetland!
Uncover how together we can help conserve our freshwater wetlands.


What Are Freshwater Wetlands?

See that big mud puddle? It’s not puddle at all. It’s a non-tidal freshwater wetland, a unique, dynamic environment that provides valuable natural services such as improving water quality, reducing risks from flooding, and providing habitat for special plant and animal species. They are amazing places to explore.

The Land is Pretty…Wet!

In freshwater wetlands, water covers the soil or occurs at or near the surface of the soil either all year or seasonally. The amount of water determines how the soil develops, which in turn determines the species that live in and on the soil and the food webs they create.

They’re Full of Wildlife and Plant Life

Wetlands are one of the most productive habitats in the world, with a greater diversity of species and nutrient cycling than many other ecosystems, including rainforests and coral reefs. In a freshwater wetland, plant matter such as dead leaves decompose in the water, forming bits of organic material that power the food chain by feeding small aquatic insects, other invertebrates, and some small fish. These small organisms become food for larger fish and amphibians, which then become food for even larger reptiles, birds, and mammals. Meet some wildlife of Delaware Freshwater Wetlands. Each wetland community of living things is unique. Some species are so specially adapted to their native wetland, they occur nowhere else. Some are rare or declining.

Wetlands Clean Our Water

Wetlands also provide natural services that are important to people. Wetland soils filter toxic substances from the water on the surface as it trickles down into the underground water supply, helping to keep it clean and safe. Wetland plants and soils store carbon instead of releasing carbon dioxide into Earth’s atmosphere, which helps to moderate global climate conditions. That means protecting wetlands can protect our safety and welfare.

Quickly Disappearing

According to the Delaware Department of Natural Resources and Environmental Control, half of our state consisted of freshwater and saltwater wetlands in the 18th century. Today, due to development, plant and animal food production, forestry, lumber production, and sea level rise, only about one-quarter of the state’s wetlands remain.

They’re Home to Endangered Animals and Plants

About half of all our wetlands—152,000 acres­—are non-tidal freshwater wetlands. Of those, about 18,000 acres, or 5 percent, are considered ecologically unique. Known as Unique Wetland Communities, they are home to rare, threatened, or endangered animal and plant life that only lives in Delaware. They are difficult to replace, and they are an important resource for the future.

How Can I Help Delaware’s Freshwater Wetlands?

View our Freshwater Wetland Educational Materials. Learn the importance of Vernal Pools in this movie featuring DelNature’s own Jim White.

The Path to Protecting Delaware’s Freshwater Wetlands


Freshwater Wetlands Wildlife and Plant Life

Eastern Tiger Salamander

At up to 12 inches long, the Eastern tiger salamander is the largest salamander in Delaware. They spend most of their lives in burrows below the upland forests of the coastal plain, where they feed on insects, worms, and snails. This amphibian depends on seasonal vernal pools to breed but return to the forest after depositing masses of 30 to 70 eggs on submerged vegetation. Larvae stay in the pool until maturing in early- to mid-summer. Though tiger salamanders occur across North America, local populations are isolated. Due to habitat loss, pollution, and other factors, they are endangered in Delaware. Photography by Louisiana Herps.

Eastern Tiger Salamander
Bog Turtle

Bog Turtle

The bog turtle, with the distinctive orange patches on the sides of its head, is the smallest turtle in North America, reaching only to 4.5 inches in length. It prefers isolated wetlands with deep, acidic soil. They are active by day, waking early, soaking up sun until warm, then searching for aquatic plants, worms, slugs and other food. In winter, they hibernate under the mud until they emerge to breed in spring. If they breed, females produce one clutch of one to six eggs each year, which hatch in late summer. They are so sensitive to their habitats, very small changes can cause their numbers to decline. Photography by pingleo.

Barking Tree Frog

Did you hear that? That was not a small dog. That’s the call of the barking tree frog, the largest native tree frog in the United States. Found high in—you guessed it—it leaves in spring to mate in ponds and other wet areas on the ground. The single croak is the male’s mating call. Females can lay 1,500 to 4,000 eggs at a time. Its thick, leathery skin is unique among frogs and its spots may disappear and reappear over time. It feed on a variety of medium sized invertebrates and it loves crickets. Tree loss and development have reduced its population. Photography by Peggy Urban.

Barking Tree Fro
Bethany Beach Firefly

Bethany Beach Firefly

This firefly species occurs only in a limited range of shallow seasonal wetlands among the dunes of Delaware’s Atlantic coast. A buildup of organic matter in these swales provides habitat for larvae, which develop in chambers just under the soil or under logs. Look for the distinctive green double flash of the male every five seconds in the evenings of June and July. The Bethany Beach firefly is so specialized, any change to its habitat is dangerous. Diminished water quality, recreational activities, light pollution, pesticides, and sea level rise are all threats to the species. Photography by Sierra Club.

Bronze Copper Butterfly

The edges of wetland areas are perfect for this showy butterfly. Look for its brownish 2-inch wing perched on vegetation or fluttering toward for good nectar sources such as Swamp Milkweed and goldenrod. It breeds twice a summer. You can find its white or green-white, turban-shaped eggs on the undersides of leaves, on stems, and sometimes on seedheads. The velvety yellow-green caterpillar features a dark green stripe. They have a distinctive eating-pattern, chewing narrow grooves into the leaves of its host plant or creating a windowpane effect where they only scrape the surface of tough leaves. Their chrysalis is green or light tan with dark speckles. Adults die soon after reproducing. Photography by Gerald DeBoer.

Bronze Copper Butterfly by Gerald DeBoer
Tussock Sedge

Tussock Sedge

This perennial sedge usually forms a dense tussock of leafy culms about 2.5 feet to 4 feet tall. Flowers appear in late spring in reddish-brown spikes on top of its stems. Tussock Sedge grows in soil that is moist to wet, so you’ll find it in wet meadows, on the margins of creeks and stream ponds, and in other low areas that flood seasonally. It is an essential plant for many animal species. The Black Dash, a butterfly that lives in freshwater seepage wetlands on Piedmont, uses Tussock Sedge as a host species for its caterpillar, as does the butterfly Chermock’s Mulberry Wing, which lives in freshwater floodplains. The endangered bog turtle will deposit its small clutch of one to six eggs between blades of tussock sedge.

Little Brown Bat

This small, mouse-eared bat is nocturnal, searching at night for insects to eat and, by day, roosting in hollow trees. Males and females roost separately through spring in summer, then mates in fall. The bat then enters a state of torpor, or decreased physiological activity, before slipping into hibernation for the winter. Females may produce only one pup a year, in the spring. and the young mature quickly. Their average lifespan is 6.5 years, with some individuals document as living over 30. The Little Brown Bat is endangered across North America due to factors such as habitat loss and white-nose syndrome.

Little Brown Bat
Black Banded Sunfish

Black Banded Sunfish

This tiny sunfish is distinguished by the vertical black bands on its sides. They are restricted to the slow, shallow, clear waters of ponds and streams where they shelter among the aquatic plants they forage for various zooplankton, insects, and small crustaceans. The Black-banded sunfish group with others, but can become aggressive and territorial when spawning. Males determine the nest site normally among plants, let the females deposit their eggs, then chase them away and guard the eggs hatching. Populations are declining across their range due to habitat loss and pollution. Photography by John F. Bunnell.

Sedge Wren

The small, secretive Sedge Wren is perfectly camouflaged, it seems invisible. Short-billed brown birds, they live in wet fields and shallow marshes where they forage in dense habitat for insects and spiders near the ground. When courting, males may weave several hollow, ball-shaped nests for their females to line with softer materials. Males may have one mate or several. Nestlings of monogamous males have high survival rates, but males with several mates produce more offspring overall. Look for them in late morning and early evening on marsh plants and low bushes. Listen for a few dry chips followed by a trill. Photography by Michael McDowell.

Sedge Wren
Black-tipped Darner

Black-tipped Darner

These beautiful dragonflies are distinguished by the blue-green spots on their thorax and abdomen—and by the black tip of their tail, of course. They occur near ponds in bogs, and near slow streams with ample vegetation. During their flight season of spring into fall, males guard the shores, driving away intruders. Females lay their eggs in vegetation above the water, on the water, or deep in the mud. Larvae feed on aquatic insects such as mosquito larvae. Adults eat other soft-bodied flying insects such as mosquitoes and flies. Its flight season begins in late spring, but it is seen most commonly in fall. Photography by Steve Collins.

Mussels

A cousin to bivalve mollusks such as saltwater mussels, oysters, and clams, hardworking freshwater mussels are an essential component of our streams that improve water quality by filtering bacteria, algae, and other tiny organisms through their siphons. A thousand mussels can filter 24,000 gallons of water in a day – enough for 50 homes. Mussels also feed many species of fish, reptiles, birds, and mammals, and the outside of their shells gives a home to aquatic insects, algae, and plants. Empty shells even provide nesting sites for some small fish species. As valuable as these filter feeders are, in the Delaware estuary, many species are in danger of extinction. Photography by Mussels.

Mussels