Ponds & Lakes

A lake is a large body of fresh water. Lakes can range in size from small ponds to huge bodies of water such the Great Lakes in the U.S. 

Lakes and rivers are closely tied. Some lakes are the source for some rivers. Important rivers, most often, originate from lakes. Some rivers end in lakes.

Since both rivers and lakes are freshwater and flow in and out of each other, they share similar characteristics and many species reside in both habitats.

All About Ponds and Lakes

A pond is a body of water shallow enough to support rooted plants. Many times plants grow all the way across a shallow pond.

Water temperature is fairly even from top to bottom and changes with air temperature. There is little wave action and the bottom is usually covered with mud. Plants can, and often do, grow along the pond edge. The amount of dissolved oxygen may vary greatly during a day. In really cold places, the entire pond can freeze solid.

A lake is bigger than a pond, and is too deep to support rooted plants except near the shore. Some lakes are big enough for waves to be produced.

Water temperatures in lakes during summer months is not uniform from top to bottom. Three distinct layers develop: The top layer stays warm at around 65–75 degrees F (18.8–24.5 degrees C). The middle layer drops dramatically, usually to 45–65 degrees F (7.4–18.8 degrees C). The bottom layer is the coldest, staying at around 39–45 degrees F (4.0–7.4 degrees C). Since light does not penetrate to the bottom, photosynthesis is limited to the top layer. Because of the warmer waters and more plentiful food supply, almost all creatures spend the summer months in the upper layer.

During spring and fall the lake temperature is more uniform. Fish and other animals are found throughout the layers of the lake.

Even in cold climates, most lakes are large enough so that they don't freeze solid, unlike ponds. During the winter months some creatures hibernate in the bottom mud. Some fish continue to feed, but less actively. A layer of ice can develop on the top of lakes during winter. The ice blocks out sunlight and can prevent photosynthesis. Without photosynthesis, oxygen levels drop and some plants and animals may die. This is called "winterkill."

Pond Succession

A geological event, such as a glacier or sink hole, can create a pond. Ponds are nothing more than shallow holes where water collects. Yet, if left alone, ponds will fill in with dirt and debris until they become land.

It often takes hundreds of years for a pond to be transformed from a body of clear water into soil.

The Four Stages of Pond Succession

1) As a pond develops seeds are flown in by birds and land animals come to inhabit the pond. These are the pond pioneers.

2) As more creatures arrive the debris on the bottom increases. Pondweed, and other submergent vegetation, appears and soon grow all along the bottom.

3) Emergents then appear on the edges of the pond. Over time, sometimes hundreds of years, as ponds plants grow, die and decompose, layers of debris build up. These layers of decaying matter raise the pond floor over the years.

4) After some time, the pond floor is close enough to the bottom that emergents can grow all the way across the floor. When this happens, the ponds becomes a marsh. Many interesting creatures can reside in the shallow muddy waters of marshes. (Marshes can be created in other ways also.)

The marsh continues to fill in with dirt and debris. Eventually trees grow in the water. It is now a swamp. Over time, the swamp may dry out. Land that was once a pond, may become a forest or grassland.

Oxbow Lakes

An oxbow is a crescent-shaped lake lying alongside a winding river. The oxbow lake is created over time as erosion and deposits of soil change the river's course. You can see how an oxbow lake takes shape below:

 

NOTE:

Emergent plants are plants that have roots under water while part of their bodies resides above the water line.

(1) On the inside of the loop, the river travels more slowly leading to deposition of silt.  

 

(2) Meanwhile water on the outside edges tends to flow faster, which erodes the banks making the meander even wider.  

 

(3) Over time the loop of the meander widens until the neck vanishes altogether.

 

(4) Then the meander is removed from the river's current and the horseshoe shaped oxbow lake is formed.  

 

Without a current to move the water along, sediment builds up along the banks and fills in the lake. 

5 Largest Lakes

The Great Lakes

To the right is a view of the Great Lakes from space.  --->

      Lake Effect Snow

During the fall and winter, many areas of the eastern United States and Canada experience tremendous amounts of snowfall. This snow, known as "lake-effect snow," is generated from the temperature contrast between the cold arctic air moving over the relatively warm waters of the Great Lakes (or other large body of water). Unlike most winter storms, lake effect snows do not build their foundation upon strong areas of low pressure. Instead, they are fueled by the same dry arctic air that is responsible for clearing skies over land in other parts of the country. Specifically, cold arctic air passing over the Great Lakes picks up moisture and deposits it as snow inland from the downwind shore. So while other parts of the northeastern United States are clearing up after a recent cold frontal passage, communities near the Great Lakes wait for the lake effect snow machine to fire up!

Lake-effect snow cloud bands are remarkably persistent and have been known to cause continuous snowfall for as long as 48 hours over a sharply defined region—an amount that often exceeds that of a typical winter storm (i.e., one associated with a low pressure). Lake effect snows yielding as much as 193 cm (76 inches) of light-density snow in 24 hours and fall rates as high as 15 cm (6 inches) per hour have been reported. Furthermore, because winds accompanying arctic air masses generally originate from a southwest to northwest direction, lake effect snow typically falls on the east or southeast sides of the lakes. In general, lake effect snowfall contributes between 30 and 60 percent of the annual winter snowfall on the eastern and southern shores of the Great Lakes.

How Does it Work?

In the late fall and early winter, the waters of the Great Lakes become increasingly warmer relative to the cold dry arctic air masses that flow down from the north and northwest. When this air traverses the lake, the lower levels of the atmosphere pick up moisture and warmth. This air (along with the moisture it picked up from the lake below) is now lighter than the air above it and starts to rise as it continues its journey across the lake (a condition known as "convective instability"). As the air rises, it cools and the moisture that evaporated into it condenses (into tiny droplets or ice crystals) and forms clouds. Depending on the degree of instability of the air mass (i.e., how much warmer the lake water is than the air), bands of either stratus, stratocumulus, or heavy cumulus clouds form over the water and travel with the wind toward the downwind shore. When enough moisture condenses out of the air, it falls in the form of snow over the water and the lee side (downwind side) of the lake.

From  noaa.gov

Algae

        What are algae?

Algae are photosynthetic creatures. They are neither plant, animal or fungi. Many algae are single celled, however some species are multicellular. Many, but not all of red and brown algae are multicellular. Red and brown algae are common in marine environments. Some green algae are multicellular.

The scum found on ponds are algae. They are the green hairy growth on things found underwater objects. Algae releases oxygen into the water as it manufactures it food. Algae forms the broad base on which the food pyramids in ponds and lakes is built. In manufacturing food, algae release oxygen, increasing the amount dissolved in the water.

However, when algae becomes overabundant the decaying algae depletes oxygen levels. So during the summer, when conditions for growing algae are ripe, oxygen levels may decrease, causing "summerkill" for aquatic plants and animals.

Algae are found in all the fresh waters of the world!

Ponds & Lakes Animals

Bitterling

Class: Fishes: 4 classes

Diet: Small invertebrates

Order: Cypriniformes: Carps

Size: 6 - 9 cm (2 1/4 - 3 1/2 in)

Family: No Fish family information

Conservation Status: Non-threatened

Scientific Name: Rhodeus sericeus

Habitat: lakes, ponds, slow rivers

Range: Northern and Eastern Europe: Northern France,

Germany, east to Black and Caspian Sea basin;

introduced in North America

The attractively colored bitterling is a small, rather deep-bodied fish. It lives in densely vegetated areas and can tolerate poorly oxygenated water. It feeds on plants and small invertebrate animals.  The breeding habits of the bitterling are most unusual. The female develops a long egg-depositing tube that extends from her genital opening. Using this tube, she lays her eggs inside the gill chamber of a freshwater mussel. The male, who develops brilliant, iridescent coloration in the breeding season, sheds his sperm by the mussel's gills so that it is inhaled by the mussel and fertilizes the eggs. Safe from predators, the eggs develop inside the mussel for 2 or 3 weeks, and the young leave it about 2 days after hatching. The mussel is unharmed by this invasion.

Bullfrog

Class: Amphibia: Amphibians

Diet: Insects

Order: Anura: Frogs and Toads

Size: 9 - 20.5 cm (3 1/2 - 8 in)

Family: Ranidae: True Frogs

Conservation Status: Non-threatened

Scientific Name: Rana catesbeiana

Habitat: lakes, ponds, slow streams

Range: Eastern and central USA; introduced in western

areas and in Mexico, Cuba, and Northern Italy

The largest North American frog, the bullfrog makes a deep, vibrant call, amplified by the internal vocal sac. Although an aquatic species, it also spends time on land and is often seen at the water's edge. It is most active by night, when it preys on insects, fish, smaller frogs and, occasionally, small birds and snakes. Like all American ranid frogs, it is a good jumper and can leap nine times its own length.  In the north of their range, bullfrogs breed from May to July, but farther south, the season is longer. The female lays 10,000 to 20,000 eggs in water; they may float on the surface or attach to vegetation. The eggs hatch in 5 or 6 days, but the tadpoles take 2 to 5 years to transform into adults.

Common Carp

Class: Fishes: 4 classes

Diet: Crustaceans, insect larvae, mollusks, and some vegetation

Order: Cypriniformes: Carps

Size: 51 cm - 1 m (20 in - 3 1/4 ft)

Family: No Fish family information

Conservation Status: Data deficient 

Scientific Name: Cyprinus carpio

Habitat: lowland lakes, and rivers

Range: Originally Southern Europe and Black Sea area;

introduced in Northern Europe, North and South America,

Australia, New Zealand, parts of Asia and Africa

Now an extremely widely distributed fish, the common carp belongs to the large, freshwater family Cyprinidae. Carp are robust, fairly deep-bodied fishes; some are fully scaled, but there are other varieties, such as leather carp, which are scaleless, and mirror carp (illustrated here), which have some exceptionally large scales on the sides and at the base of the dorsal fin.  Inhabitants of slow-moving waters with much vegetation, carp tolerate low oxygen levels which would be fatal for many other fishes. They feed mostly on crustaceans, insect larvae, mollusks and some vegetation. Breeding occurs in spring and summer. The eggs are laid in shallow water, where they adhere to aquatic plants until they hatch.

Great Crested Grebe

Class: Aves: Birds

Diet: Fish

Order: Podicipediformes: Grebes

Size: 51 cm (20 in)

Family: Podicipedidae: Grebes

Conservation Status: Non-threatened

Scientific Name: Podiceps cristatus

Habitat: lakes, ponds, rivers, coastal waters

Range: Europe, Asia, Africa, south of the Sahara;

Australia, New Zealand

Easily recognized on water by its long slender neck and daggerlike bill, the great crested grebe is rarely seen on land, where it moves awkwardly, or in flight. It feeds mainly on fish, which it catches by diving from the surface of the water. The great crested is one of the largest grebes; adults are particularly striking in their breeding plumage, when they sport a double-horned crest on the head and frills on the neck. In winter this crest is much reduced, the frills lost and the head largely white. The sexes look alike, but males generally have longer bills and larger crests and frills. Before mating, these grebes perform an elegant mutual courtship dance to establish the pair bond. Both partners perform head-wagging and reed-holding displays and other ritualized movements. They mate on a reed platform near the nest, which is among the reeds. The female lays 2 to 7 eggs, which are incubated by both parents for 27 to 29 days.

Great White Pelican

Class: Aves: Birds

Diet: Fish

Order: Pelecaniformes: Seabirds

Size: 140 - 175 cm (55 - 69 in)

Family: Pelecanidae: Pelicans

Conservation Status: Non-threatened

Scientific Name: Pelecanus onocrotalus

Habitat: inland lakes, marshes

Range: Southeastern Europe, Asia, Africa

A large white bird with the characteristic pouched bill, the great white pelican is well adapted for aquatic life. The short strong legs and webbed feet propel it in water and aid the rather awkward takeoff from the water surface. Once aloft, the long-winged pelicans are powerful fliers, however, and often travel in spectacular V-formation groups. The pelican's pouch is simply a scoop. As the pelican pushes its bill underwater, the lower bill bows out, creating a large pouch which fills with water and fish. As the bird lifts its head, the pouch contracts, forcing out the water but retaining the fish. A group of 6 to 8 great white pelicans will gather in a horseshoe formation in the water to feed together. They dip their bills in unison, creating a circle of open pouches, ready to trap every fish in the area.  Large numbers of these pelicans breed together in colonies. The female lays 2 to 4 eggs in a nest of sticks in a tree or on the grass. The young are cared for by both parents.

Green & Gold Bell Frog

Class: Amphibia: Amphibians

Diet: Insects

Order: Anura: Frogs and Toads

Size: up to 8 cm (3 1/4 in)

Family: Hylidae: Treefrogs

Conservation Status: Non-threatened

Scientific Name: Litoria cyclorhynchus

Habitat: large ponds

Range: Western Australia: south coast

A distinctively marked species, this bell frog climbs only rarely and lives mostly in water or on reeds. It moves on land only in heavy rainfall. Active during the day, it is a voracious predator, feeding on any small animals, including its own tadpoles.  In the breeding season, males call from the water to attract mates, making a sound rather like wood being sawn. The female lays her eggs among the vegetation in the pond.

Lake Trout

Class: Fishes: 4 classes

Diet: Fish, insects, crustaceans, plankton

Order: Salmoniformes: Salmon

Size: 1.2 m (4 ft)

Family: No Fish family information

Conservation Status: Non-threatened

Scientific Name: Salvelinus namaycush

Habitat: lakes, rivers

Range: Canada, Northern USA

One of the most important commercial freshwater fishes and a popular sport-fishing species in North America, the lake trout is actually a char, not a true trout. It has now been successfully introduced into lakes out of its natural range. A beautiful fish, it has characteristic pale spots on head, back and sides. Lake trout feed on fish, insects, crustaceans and plankton.  From late summer to December, lake trout spawn in shallow, gravel-bottomed water. There is no nest, but males clear the spawning ground of debris. The eggs are laid on the gravel and settle among the stones; they remain there for the winter and hatch in early spring.

Largemouth Bass

Class: Fishes: 4 classes

Diet: Crustaceans, fish, frogs, aquatic invertebrates

Order: Perciformes: Perch-like fishes

Size: 25.5 - 46 cm (10 - 18 in)

Family: No Fish family information

Conservation Status: Non-threatened

Scientific Name: Micropterus salmoides

Habitat: shallow lakes, ponds, rivers

Range: Southeastern Canada; USA: Great Lakes area,

south to Gulf of Mexico; introduced in other areas of USA and in Europe and Africa

A member of the sunfish family, the largemouth bass is usually greenish and silvery in coloration, with a dark band along each side; its dorsal fin is divided almost in two by a notch. A predatory fish, it feeds on crustaceans and other invertebrates when young, gradually progressing to fish, frogs and larger invertebrates when mature.  Spawning takes place in spring or early summer, depending on temperature and latitude. The male excavates a nest in sand or gravel in shallow water and attracts a female to his nest to lay her eggs, usually a few hundred. The male fertilizes the eggs and may then attract more females to his nest. The sticky-surfaced eggs attach themselves to the bottom of the nest and are guarded by the male until they hatch, 7 to 10 days after laying.

Platypus

Class: Mammalia: Mammals

Diet: Crustaceans

Order: Monotremata: Monotremes

Size: 140 - 175 cm (55 - 69 in)

Family: Ornithorhynchidae: Platypus

Conservation Status: Non-threatened

Scientific Name: Ornithorhynchus anatinus

Habitat: lakes, rivers

Range: Eastern Australia, Tasmania

The platypus is a semiaquatic animal, and many of its physical characteristics are adaptations for its life as a fresh-water predator. Its legs are short but powerful, and the feet are webbed, though the digits retain large claws, useful for burrowing. On the forefeet the webs extend beyond the claws and make efficient paddles; on land, the webs can be folded back to free the claws for digging. On each ankle the male platypus has a spur connected to poison glands in the thighs; these spurs are used against an attacker or against a competing platypus but never against prey. The poison is not fatal to man but causes intense pain.  The platypus's eye and ear openings lie in furrows which are closed off by folds of skin when the animal is submerged. Thus, when hunting underwater, the platypus relies on the sensitivity of its tactile, leathery bill to find prey. The nostrils are toward the end of the upper bill but can only function when the head is in air. Young platypuses have teeth, but adults have horny, ridged plates on both sides of the jaws for crushing prey.

The platypus feeds mainly at the bottom of the water, making dives lasting a minute or more to probe the mud with its bill for crustaceans, aquatic insects and larvae. It also feeds on frogs and other small animals and on some plants. Platypuses have huge appetites, consuming up to 1 kg (2 1/4 lb) of food each night.  Short burrows dug in the riverbank above the water level are used by the platypus for refuge or during periods of cool weather. In the breeding season, however, the female digs a burrow 12 m (40 ft) or more in length, at the end of which she lays her 2 or 3 eggs on a nest of dry grass and leaves; the rubbery eggs are cemented together in a raft. She plugs the entrance to the burrow with moist plant matter, and this prevents the eggs from drying out during the 7-to 14-day incubation period. When the young hatch, they are only about 1.25 cm (1/2 in) long and helpless. Until they are about 5 months old, they feed on milk, which issues from slits in the mother's abdominal wall. Unlike spiny anteaters, they do not draw up tucks of skin into pseudonipples but lap and suck the milk off their mother's abdominal fur.

Rough-Skinned Newt

Class: Amphibia: Amphibians

Diet: Insects

Order: Urodela: Newts and Salamanders

Size: 6.5 - 12.5 cm (2 1/2 - 5 in)

Family: Salamandridae: Newts and Salamanders

Conservation Status: Non-threatened

Scientific Name: Taricha granulosa

Habitat: ponds, lakes, slow streams and surrounding grassland or woodland

Range: Western North America: Alaska to California

The most aquatic of Pacific newts, the rough-skinned newt is identified by its warty skin and its small eyes, with dark lower lids. It searches for its invertebrate prey both on land and in the water, and its toxic skin secretions repel most of its enemies.  In the breeding season, the male's skin temporarily becomes smooth and his vent swells. Unlike other western newts, the female rough-skinned lays her eggs one at a time, rather than in masses, on submerged plants or debris. The eggs hatch into aquatic larvae.

Spectacled Caiman

Class: Reptilia: Reptiles

Diet: Small mammals

Order: Crocodilia: Crocodiles, Alligators, Gavial

Size: 1.5 - 2 m (5 - 6 1/2 ft)

Family: Alligatorianae: Alligators and Caimans

Conservation Status: Lower risk 

Scientific Name: Caiman crocodilus

Habitat: slow still waters, lakes, swamps

Range: Venezuela to Southern Amazon Basin

There are several species and subspecies of this caiman, and its name has been the subject of much dispute; it is often known as C. sclerops. Its common name derives from the ridge on the head between the eyes, which resembles the bridge of a pair of glasses. The population of wild caimans has declined drastically in some areas since they are not only hunted for skins but the young are also collected and sold as pets or stuffed as curios. The female caiman makes a nest of plant debris scraped together into a pile and lays an average of 30 eggs.

Zambesi Softshell

Class: Reptilia: Reptiles

Diet: Snails

Order: Chelonia: Turtles and Tortoises

Size: 51 cm (20 in)

Family: Trionychidae: Softshell Turtle

Conservation Status: Non-threatened 

Scientific Name: Cycloderma frenatum

Habitat: ponds, lakes, rivers

Range: Africa: Tanzania, Mozambique, Zambia, Malawi

A carnivorous turtle, the Zambesi softshell feeds mainly on mollusks. It lays its 15 to 20 eggs from December to March and is most active in rainy weather. Hatchlings have pale green carapaces and dark lines on their heads. In adults these lines are outlined with white dots and become fainter with age. The only other species in this genus is Aubry's softshell, C. aubryi, found in West Africa.

Information & Pictures from www.mbgnet.net

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