Wetlands

Fresh water wetlands are found all over the world in lowland areas or along rivers, lakes, and streams. 

Some wetlands are temporary and seasonal.They occur for a few weeks at a time and then disappear until they are refilled with water. Other wetlands are always under water.

What Are Freshwater Wetlands?

The term "wetlands" encompasses a wide variety of aquatic habitats including swamps, marshes, bogs, prairie potholes, flood plains, and fen. 

Natural wetlands are lands which, due to geological or ecological factors, have a natural supply of water—either from tidal flows, flooding rivers, connections with groundwater, or because they are perched above aquifers or potholes. Wetlands are covered or soaked for at least a part, and often all, of the year. This makes wetlands intermediaries between terrestrial and aquatic ecosystems. They are neither one or the other, and yet they are both. 

What is a marsh?

A freshwater marsh is an inland area inundated with 1–6 feet (33–200 cm) of water, containing a variety of perennials (mostly grasses), forbs (flowers), and bushes, rather than trees, as in swamps. 

Marshes have an interesting mix of plant and animal life, one that effectively demonstrates the interconnectedness of living things. They are home to yellow-headed and red-winged blackbirds, herons, egrets, rails, bitterns, moorhens, ducks and geese. Most migratory species, in fact, rely on a network of wetlands to get from their southern habitats to nest sites further north. 

Muskrats are central to many marshes, keeping aggressive plants in check and crafting bird protection by carving out habitat. Minks and otters frequent wetlands. Raccoons, opossums, even moose can be found foraging around marshes, particularly when water levels drop. Marshes also host frogs, turtles, and snakes, salamanders, and an immense variety of insects, including aquatic, flying, and grazing insects. 

What is a swamp?

Swamps are slow moving streams, rivers or isolated depressions that host trees and some shrubs. 

What is a bog?

A bog is a peat-accumulating wetland. Some shrubs and evergreens grow in bogs, as do mosses. Most water comes from precipitation. There is usually no direct inflow or outflow of water.

What is a prairie pothole?

A prairie pothole is a wetland area found in the northern Great Plains. These shallow or bowl-like depressions have variable wetness. They are often used for breeding by birds. Prairie potholes are not wet year-round.

What is a riparian marsh?

Marshes that occur along rivers are called riparian marshes. These marshes serve two ecological roles: to absorb excess water when river levels are high and to release water when river levels are low. These balancing forces help prevent floods and droughts. 

However, for the past 100 years mankind has straightened and deepened rivers in order to make them more accessible for commerce. The unfortunate side effect is the loss of riparian marshes. Today, very few riparian marshes are left. Some scientists believe that the great Mississippi River flood of 1993 was worsened, in part, by the loss of these wetlands.

The Importance of Marshes 

Wetlands are important for so many reasons:

The Role of Wetlands in an Ecosystem

Wetlands prevent flooding by holding water much like a sponge. By doing so, wetlands help keep river levels normal and filter and purify the surface water. 

Wetlands accept water during storms and whenever water levels are high. When water levels are low, wetlands slowly release water.

 

A Marsh in Scotland

Wetlands also release vegetative matter into rivers, which helps feed fish in the rivers. Wetlands help to counter balance the human effect on rivers by rejuvenating them and surrounding ecosystems. 

Many animals that live in other habitats use wetlands for migration or reproduction. For example, herons nest in large old trees, but need shallow areas in order to wade for fish and aquatic life. Amphibians often forage in upland areas but return to the water to mate and reproduce.

While wetlands are truly unique, they must not be thought of as isolated and independent habitat. To the contrary, wetlands are vital to the health of all other biomes and to wildlife and humans everywhere. 

Unlike most other habitats, wetlands directly improve other ecosystems. Because of its many cleansing benefits, wetlands have been compared to kidneys. The analogy is good one. Wetlands and kidneys both help control water flow and cleanse the system.

Erosion Control

Looking at pictures of deltas, one can tell that rivers deposit a lot of sediment into the ocean. The sediment is from top soil that has been eroded and washed away. 

Emergents (plants firmly rooted in the muddy bottom but with stalks that rise high above the water surface) are able to radically slow the flow of water. As a result, they counter the erosive forces of moving water along lakes and rivers, and in rolling agricultural landscapes. Erosion control efforts in aquatic areas often include the planting of wetlands plants.

Wetlands and Water Purification

Wetlands also clean the water by filtering out sedimentation, decomposing vegetative matter and converting chemicals into useable form. 

The ability of wetlands to recycle nutrients makes them critical in the overall functioning of earth. No other ecosystem is as productive, nor as unique in this conversion process. In some places artificial wetlands were developed solely for the purpose of water purification. 

Wetlands in Danger

Historically wetlands have been thought of as useless wastelands -- muck-filled breeding grounds for pests and dangerous disease. In movies and on TV, swamps are dirty, murky places full of hidden danger. Through years of "progress" we have turned over half our wetlands into land. All along we thought we were doing good. Could we have been wrong? 

As it turns out, wetlands are far more important than we would have believed. We now realize that they are a very important ecosystem. We know why wetlands are important, but what are we doing to protect them?

Wetlands are disappearing rapidly, at about the rate of 300,000 acres (120,000 hectares) annually in the U.S. alone. Some legislators have tried to introduce a "no-net-loss" plan for wetlands. This states that for every acre of natural wetlands lost, a new acre of "wetlands" should be created. Creating artificial bodies of water that act, in some ways, like wetlands is becoming a popular way to deal with loss of original wetlands. However, man-made wetlands are usually not successful and lack the functionality of natural wetlands. 

Ralph Tiner, a U.S. Fish & Wildlife service scientist, said, "Trying to create a wetland is like taking a vein in your arm and moving it where there is no vein. It may look like a vein, but it does not function like one." 

Adding to this confusion is the difficulty of defining a wetland. Wetlands, like few other ecosystems, are dynamic areas that are always in a state of transition. Sometimes, they are land, sometimes they are water, sometimes they are both.

There are some laws, such as Section 404 of the Clean Water Act, which control wetland development. However, these laws are weak and have many loopholes. There is no true national wetland protection law. Additionally, few states have wetlands programs of their own. 

Restoration programs offer a degree of success in restoring wetlands. Right now there is an attempt to rejuvenate Florida's Everglades. These programs improve the situation, but do not restore the ecosystem to their original state and level of function. 

Wetlands destruction, like many environmental problems, is one of sustainability. We have to learn to balance today's needs with future environmental needs.

Crooked Tree Wildlife Sanctuary

This sanctuary is operated by the Belize Audubon Society. The 3,000 acre (1,200 hectare) reserve is mostly marshes and swamp.

Belize is a small country in Central America, near Mexico and Guatemala.

The largest bird in the Western Hemisphere, the jabiru, nests here. Other common birds found in the reserve include: herons, ducks, kingfishers, vultures, ospreys, grebes, egrets and hawks. 

Corkscrew Swamp

Click the frog to take a virtual tour of the Corkscrew Swamp.

Wetlands Animals

American Alligator

Class: Reptilia: Reptiles 

Diet: Small mammals

Order: Crocodilia: Crocodiles, Alligators, Gavial 

Size: up to 5.5 m (18 ft) 

Family: Alligatorianae: Alligators and Caimans 

Conservation Status: Non-threatened 

Scientific Name: Alligator mississipiensis 

Habitat: marshes, rivers, swamps 

Range: Southeastern USA 

The American alligator, once struggling for survival against hunters and habitat destruction, has been so effectively protected by conservation laws that the population is now on the increase. These alligators usually mate in shallow water in April, and courtship is slow and quiet. The male stays with the female for several days before mating, occasionally stroking her body with his forelimbs. As she nears acquiescence, he rubs her throat with his head and blows bubbles past her cheeks. The female finds a nest site near water and scrapes up whatever plant debris is available with sweeping movements of her body and tail. She packs the vegetation together to form a mound, with a cavity for the eggs. She lays 28 to 52 eggs and crawls over the mound to close the cavity with more vegetation. She guards the nest while the eggs incubate for about 65 days. The hatching young call out to their mother, prompting her to open the nest and free them. They remain with her for up to 3 years.

American Bittern

Class: Aves: Birds

Diet: Fish, crabs, snakes, frogs, insects,small mammals

Order: Ciconiiformes: Wading birds

Size: 66 cm (26 in)

Family: Ardeidae: Herons, Bitterns

Conservation Status: Non-threatened

Scientific Name: Botaurus lentiginosus

Habitat: marshland

Range: North America; winters in South America

The American bittern has a distinctive cry, rather different from the characteristic boom of other bitterns. This strange, three-syllable cry has inspired one of the bird's common names: "thunder pumper." This bittern feeds alone, moving slowly and deliberately with bill always at the ready to jab quickly at fish, crabs, snakes, frogs, insects or small mammals. It is a migratory species; although birds in milder areas do not actually migrate, they do disperse after breeding. The clutch of 4 to 6 eggs is laid in a nest platform on land or in water, and the female bird seems to perform most of the parental duties.

Boat-Billed Heron

Class: Aves: Birds

Diet: Fish, shrimp

Order: Ciconiiformes: Wading birds

Size: 45 - 50 cm (17 3/4 - 19 3/4 in)

Family: Ardeidae: Herons, Bitterns

Conservation Status: Non-threatened

Scientific Name: Cochlearius cochlearius

Habitat: swamps and wetlands

Range: Mexico to Peru and Brazil

The classification of this species has been the subject of some dispute,and it is sometimes placed in a family on its own. Its only important distinction from other herons is the broad, scoop-like bill. Boat-billed herons generally feed at night on fish and shrimps. The bill seems to be extremely sensitive and opens at the merest touch, drawing in water and prey; it is also used with a scooping action. These birds perform bill-clattering and preening displays, accompanied by vocal signals,at mating time. They nest alone or in groups in trees and bushes. The female lays 2 to 4 eggs which both parents incubate.

Black-Winged Stilt

Class: Aves: Birds

Diet: Insects, aquatic animals

Order: Charadriiformes: Auks, Waders, Laris

Size: 38 cm (15 in)

Family: Recurvirostridae: Avocets

Conservation Status: Non-threatened

Scientific Name: Himantopus himantopus

Habitat: mainly freshwater swamps, marshes, lagoons

Range:  Southern and southeastern Europe, Near East to about 50 degrees N

This distinctive stilt has long pink legs, longer in proportion to its body size than those of any bird except the flamingo; in flight, its legs project far beyond the tail. Stilts walk quickly, taking long strides, and wade into water to pick insects and small aquatic animals off vegetation and off the water surface. The long slender bill is ideally adapted for this purpose.  Colonies of stilts nest together near water. Some nests are substantial structures, built up in shallow water from sticks and mud; other are small flimsy ground nests. Between April and June the female lays 3 to 5 eggs, which both parents incubate for 26 days. The young leave the nest soon after hatching.

Cape Lopez Lyretail

Class: Fishes: 4 classes

Diet: Small invertebrates

Order: Atheriniformes: Toothcarps, Sandsmelts

Size: 6 cm (2 1/4 in)

Family: No Fish family information

Conservation Status: Non-threatened

Scientific Name: Aphyosemion australe

Habitat: swamps, ditches

Range: Africa: Gabon, Cape Lopez area

The male Cape Lopez lyretail is an attractive, brightly colored fish, with large, pointed dorsal and anal fins and a tail with extended lobes. The female is plainer, and her fins lack the decorative points and extensions.  The lyretail deposits its eggs among the mud and detritus at the bottom of its habitat. If there is then a prolonged dry season, the embryos cease their development and lie dormant in the mud, protected by their drought-resistant egg membrane. Although the parent fishes die in the drought, the eggs resume development with the arrival of rain and hatch shortly afterward.

Common Snipe

Class: Aves: Birds

Diet: Principally larvae, also insects, crustaceans

Order: Charadriiformes: Auks, Waders, Laris

Size: 25.5 cm (10 in)

Family: Scolopacidae: Sandpipers

Conservation Status: Non-threatened

Scientific Name: Gallinago gallinago

Habitat: marshes, wet meadows, moors

Range: Breeds in Canada, Northern USA, Europe to Northeast Asia;

winters in Central and South America, Africa, India, Indonesia

A shy, secretive bird, the common snipe has rather pointed wings, a long bill and striped and barred plumage, which provides effective camouflage among vegetation. Insects, particularly fly and beetle larvae, are the snipe's most important food items, but it also eats earthworms, small crustaceans, snails and small quantities of plant material.  Males arrive at breeding grounds before females and establish territories for display. In the most common display, the male dives through the air at great speed, causing a drumming sound as air rushes through his outer tail feathers. The nest is made on dry ground when possible and near clumps of grass, which the birds pull down over it. The 3 or 4 eggs are incubated for 17 to 19 days, usually by the female alone.

Dwarf Siren

Class: Amphibia: Amphibians

Diet: Small aquatic invertibrates

Order: Urodela: Newts and Salamanders

Size: 10 - 25 cm (4 - 9 3/4 in)

Family: Sirenidae: Sirens

Conservation Status: Non-threatened

Scientific Name: Pseudobranchus striatus

Habitat: ponds, swamps, ditches

Range: USA: coastal plain of South Carolina, Georgia, Florida

The smallest of its family, the dwarf siren is a slender, eel-like creature which lives among dense, submerged vegetation. It has no hind limbs and only tiny forelimbs, with three toes on each foot. The external gills are retained throughout life. A nocturnal creature, the siren feeds on the tiny invertebrate animals it finds among the plant debris near the bottom of the water. If its habitat is in danger of drying up, as in a drought, the siren can burrow into the mud and remain there, dormant, for up to 2 months. Mucus produced by skin glands prevents the body drying out during such a period.  The female lays her eggs, one at a time, on aquatic plants, and the larvae hatch out about 4 weeks later. There are about 5 races of dwarf siren over the range, which vary in coloration and in the shade and distribution of the stripes along the sides of the body.

Gold Spiny Reed Frog

Class: Amphibia: Amphibians

Diet: Insects

Order: Anura: Frogs and Toads

Size: 2 cm (3/4 in)

Family: Hyperoliidae: Hyperoliid Frogs

Conservation Status: Non-threatened

Scientific Name: Afrixales brachycnemis

Habitat: pools, swamps

Range: South Africa: East and Southeast and Southern coastal regions

Also known as the golden leaf-folding frog, this very tiny, slim amphibian, equipped with adhesive disks on each digit, is a good climber. Its back may be covered with tiny dark spines, hence one of its common names; this feature is common in frogs in the south of the range but rare in the north.  Breeding males take up a position among reeds or on water-lily leaves in pools or vleis (temporary, rain-filled hollows) and call to females. The female frog lays a small batch of eggs on a leaf above or below water level. Once the eggs are fertilized, the leaf is folded over and the edges are glued together with sticky secretions from the female's oviduct. When the eggs hatch, the tadpoles emerge from the leaf nest into the water, where they complete their development.

Siamese Fighting Fish

Class: Fishes: 4 classes 

Diet: Small invertebrates

Order: Perciformes: Perch-like fishes

Size: 6 cm (2 1/4 in)

Family: No Fish family information 

Conservation Status: Non-threatened

Scientific Name: Betta splendens

Habitat: ponds, ditches, slow rivers

Range: Thailand 

The Siamese fightingfish has long been bred in captivity, and many forms with extremely long fins, particularly in the male, have been developed. Male fishes may be green, blue or red, but females are usually yellowish-brown. In the  wild, males are brown or green. Well known for their aggressive nature, male fightingfish are kept in captivity to take part in staged fights; keen observers bet on the outcome. In natural conditions, however, the fishes fight for dominance or to maintain territory, but much of the contest takes the form of ritualized threat displays, rather than actual combat. The fishes adopt postures, extending their fins and raising their gill covers, one of them usually submitting before an actual fight becomes necessary.  Like many members of the Belontiidae family, to which it belongs, the Siamese fightingfish often lives in stagnant, oxygen-poor water. It is able to take in air at the surface, however, using auxilliary breathing organs within its gill chambers. Mosquito larvae, as well as other aquatic insects, are the main diet  of the Siamese fightingfishes, which are consequently extremely important as controllers of these insect pests.  In the breeding season, the male fish selects a suitable nest site and blows a bubble nest from air and mucus, which both protects the eggs and keeps them at the well-oxygenated water surface. As  the eggs are shed, they are fertilized by the male, who spits them into the nest. The male guards the nest and replaces the bubbles if necessary.

South American Lungfish

Class: Fishes: 4 classes 

Diet: Fish

Order: Lepidosireniformes: African, South American Lungfish

Size: 1.2 m (4 ft)

Family: No Fish family information 

Conservation Status: Non-threatened

Scientific Name: Lepidosiren paradoxa 

Habitat: swamps, weeded river margins 

Range: Central South America 

The South American lungfish has a pair of lunglike organs connected with its esophagus. This fish usually lives in oxygen-poor, swampy areas, but because of its lungs it is able to supplement the oxygen obtained from the water by breathing air at the surface.  The swamps this lungfish inhabits are periodically flooded and then undergo a dry season. The fish survives the dry period by digging itself a burrow in which it lives, breathing air, while the swamp dries out. Once the surroundings become really arid, the fish closes the burrow entrance with mud, curls up and covers itself with a protective covering of mucus secretion to conserve moisture. Its body slows down to a state of dormancy, but it continues to breathe air. When the rains return, the lungfish emerges from its burrow. This form of inactivity in a hot climate is known as estivation.  During the rainy season, lungfish pairs spawn in burrows made by the male. He guards the eggs and then the young. The newly hatched young have adhesive glands by which they hang from vegetation and which are lost after 6 to 8 weeks.

Two-Toed Amphiuma

Class: Amphibia: Amphibians

Diet: Crustaceans

Order: Urodela: Newts and Salamanders

Size: 45 cm - 1.2 m (17 3/4 - 4 ft)

Family: Amphiumidae: Amphiumas

Conservation Status: Non-threatened

Scientific Name: Amphiuma means

Habitat: swamps, bayous, drainage ditches

Range: USA: Southeastern Virginia to Florida, Eastern Louisiana

This aquatic salamander has tiny, virtually useless limbs, each with two toes. Mainly active at night, it hunts in water for crayfish, frogs, small snakes and fish and may come onto land in extremely wet weather. It takes refuge during the day in a burrow it digs in the mud or takes over the burrow of another creature.  Two-toed amphiumas mate in water, and the female lays about 200 eggs in a beadlike string. The female coils around the eggs as they lie on the bottom and protects them until they hatch about 5 months after being laid. When the larvae hatch, they are about 5 cm (2 in) long; their tiny limbs are of more use to them at this stage than when they metamorphose to adult form, at about 7.5 cm (3 in) long. The three-toed amphiuma, Amphiuma tridactylum, also found in the southern USA, is similar in appearance and habits but has three toes on each of its tiny limbs.

Walking Catfish

Class: Fishes: 4 classes 

Diet: Fish, aquatic invertebrates

Order: Siluriformes: Catfishes

Size: 30.5 cm (12 in)

Family: No Fish family information 

Conservation Status: Non-threatened

Scientific Name: Clarias batrachus

Habitat: slow-moving, often stagnant waters

Range: India, Sri Lanka, Southeast Asia; introduced in USA: Florida

The walking catfish is, indeed, capable of moving on land and, when it does so, is able to breathe air. It belongs to the family Clariidae, whose members have additional, specialized breathing organs opening off the gill arches. These are saclike structures containing many-branched extensions, well supplied with blood vessels for respiration.  An elongate fish, this catfish has long-based dorsal and anal fins and several pairs of sensory barbels; its skin is scaleless but liberally supplied with mucus, which protects the fish when it is out of water. These catfishes live in ponds or temporary pools, some of which may disappear in prolonged dry spells. When this happens, the catfish can move overland to another body of water, making snakelike movements and using its pectoral fins as "legs." If necessary, the walking catfish can bury itself in mud at the bottom of a pond and remain dormant throughout a dry season until the rains return. It feeds on aquatic invertebrates and fish.

Information & Pictures from www.mbgnet.net

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