The study of inland waters such as ponds, lakes, and streams is called limnology.

What is a pond? A pond is a quiet body of water so shallow that rooted plants grow completely across it. The temperature is fairly uniform from top to bottom and may change with the air temperature. Plants usually grow around the shore, and there is usually little wave action.

What is a lake? A lake differs from a pond in that it is larger. The water is too deep for rooted plants to grow to the surface except for around the shore. The water temperature is usually stable from top to bottom. Since a lot of water is exposed to the wind, waves are common in a lake.

What is succession? The kinds and number of plants and animals living in and around the pond change constantly. These progressive changes are called succession. Some of the changes are slow and others happen quickly. Usually hundreds of years go by before the succession of life in a pond is completed. There are four main stages in the succession of a pond.

1. Young Stage: A pond in this stage has open water with a clear bottom. Small plants begin to grow on the bottom and line the shore. Small layers of organic debris accumulate on the bottom from plants and animals.

2. Stage Two: Small animals such as fish, snails, mayflies, and dragonflies now can find enough food to live in the pond. Eventually plants become abundant on the bottom and emergent shore plants grow out further into the pond. Emergent plants have their roots growing in water and the tops grow out of the water. The pond continues to fill in with organic debris as plants and animals die and sink to the bottom. As the plant species change, the vertebrate and invertebrate species change.

3. Stage Three: A pond reaches stage three when the emergent vegetation grows all the way across the pond’s surface. It becomes a marsh at this point. Salamanders, frogs, turtles, and bullheads are the major animals. Worms live in the thick mud bottom and many aquatic insects live in the shallow water. Land plants grow close to the shore in the rich soil that fills in the pond.

4. Stage Four: Dead and decaying material completely fills in the pond so that it now becomes either a grassy prairie or a forest. At this stage the pond has completed its cycle of succession.

This shows the succession of a typical pond from 1840 through to 1990.

Where is the life in a pond? There is four major habitats found in ponds: surface film, open water, bottom, and shore. Animals that live on the surface film either float or are able to walk on the surface without breaking through it. Certain insects such as water striders and whirligig beetles live on the upper side of the film. Others such as mosquito larvae hang on the underside of the film to get air. These surface dwellers eat floating plants, each other, or other animals that drown and float on the surface.

Open water dwellers consist of free-swimming animals such as fish and microscopic plants and animals that drift in the water. The microscopic drifting plants are called phytoplankton, which are mainly algae, and are the basic food in ponds and lakes. Turtles, birds, and large fish like the open water area, and the small fish live among the plants near the shore. The open water area ends where plants become rooted. Ponds that have rooted plants growing from shore to shore have no open water area.

Bottom dwellers have a choice of living conditions from the shore out to the deepest regions. A sandy bottom near the shore provides a place for insects, snails, and earthworms. Also emergent plants can grow in this area of shallow water. They are called emergent plants because their roots are in the water and the stems and leaves grow above the surface of the water. If the water is quiet, the bottom is usually covered with mud and much organic debris. Crayfish and nymphs of dragonflies and damselflies are some of the many kinds of animals that burrow into the bottom mud.

Shore habitats include those animals that come to the pond for food and water such as deer and birds. Plants grow along the shoreline providing habitats for insects and other animals.

What is a producer? Green plants are termed producers since they are capable of making their own food. Animals cannot make their own food.

What is a consumer? Animals are called consumers since they cannot make their own food. They must find or catch things to eat. Animals can either eat plants or animals or both plants and animals.

What are the food webs in a pond? A pond produces everything that is necessary for survival of its inhabitants. The only thing missing is sunlight, which is needed by green plants for photosynthesis. Photosynthesis is how plants make their food and is also why plants are green.

All green plants from microscopic phytoplankton to pond lilies are food for such things as mayfly nymphs, small crustaceans, and some types of beetles. Other animals such as fish and dragonfly nymphs eat these animals. Larger fish eat smaller fish, crustaceans, and insects. If a plant or animal is not eaten, it eventually dies and decomposes into basic materials that green plants need to grow. The food cycle is continuous.

What specific organisms live in a pond?

Plants:

Duckweed is a tiny floating plant that water birds like to eat. It is a small circular plant about 1/8 inch across. It has one or two rootlets that hang underneath it but do not touch the bottom. The plants grow in groups on the surface of the pond.

Cattails are very common to the shoreline of ponds and shallow water areas. They are often rooted in water with their long slender leaves growing upward. The brown hot dog-shaped head is the flower stalk. Cattails can grow to be 3 to 9 feet tall.

Water lilies or lily pads are platter-shaped plants that float on the surface of ponds. The flowers are white or pinkish with many petals and may or may not be fragrant. The flowers can grow to be 3 to 5 inches across. These plants grow in quiet water areas. They are rooted in the mud bottom with the leaves floating on the surface. The leaves are 5 to 9 inches across.

Cottonwood is a type of tree that often lives near ponds because the species does well in very moist soil. The tree will not die if the roots are submerged in water for a long time, unlike most other trees, which would drown. The leaves are triangle-shaped, have toothed edges, and feel thick and waxy. These trees grow to be 75 to 100 feet tall and 3 to 4 feet in diameter. The seeds are released from pods and each one is attached to cottony fluff so the wind will carry them.

Animals:

Dragonflies are very common to pond areas. They can be brown, green, or blue in color. They have four wings, enabling them to fly very quickly. They feed upon flying insects such as mosquitoes and flies. Eggs are laid in the water where the nymph hatches and lives. Nymphs are carnivorous, feeding on insects and even small tadpoles and fish.

Damselflies are related to dragonflies but have a slightly different appearance. They are more slender than dragonflies and have smaller wings. They hold their wings folded over the body where a dragonfly holds its wings out straight from the body. The damselfly nymphs live in the water and feed on mosquito larvae, water fleas, or young fish.

Water striders are dark brown to black with a body that is short for its long legs. It many or may not have wings. Water striders live on the surface water film of ponds or slow moving streams. They like to eat aquatic insects including mosquito larvae that rise to the surface or insects that fall into the water and drown. The female lays parallel rows of cylinder-shaped eggs on an object near the water’s edge. They “skate” on the water surface like ice skaters.

Salamanders are a type of animal in the amphibian family. Amphibians have a thin skin that needs to be kept moist. Amphibians can sometimes live away from water, but they always return when it is time to reproduce since the young (tadpoles) have no lungs or legs for life on land.

Tiger salamanders are rusty black with yellow spots on the body and a yellow chin. It lays its eggs in the deep areas in ponds. This salamander is the largest land dwelling one in the world. It only comes to water when laying eggs and spends the rest of its time burrowing in the ground. It gets to be 6 to 13 inches long.

Mud puppies are another type of salamander. Unlike the tiger salamander, the mud puppy stays in water all the time since they retain the gills throughout their life. These gills are basically like the ones fish have. Mud puppies gray to rusty brown above with fuzzy-edged dark blue spots. The belly is gray with dark spots. They like to live in lakes, ponds, and streams and are active at night feeding on worms, crayfish, insects, and small fish.

Frogs also belong to the amphibian family. One of the most common frogs near ponds is the bullfrog. It is the largest frog in North America and is green to yellow with random mottling of dark gray. Its hind feet are fully webbed. The belly is cream-colored to white. Bullfrogs like to eat insects, crayfish, other frogs, and minnows. These frogs are used for frogs’ legs that people eat. Bullfrogs live in ponds and lakes where they can hide in abundant vegetation. These frogs have a deep pitched jug o’ rum call that can be heard for more than a quarter mile on quiet mornings.

Fish are common in our ponds, streams, and lakes. Largemouth bass are found in ponds. These fish average 2 pounds and 15 inches in length. They are black to olive to dark green with greenish sides and a greenish gold head. Its mouth is very large. These bass like to live in quiet, clear water in streams, ponds, and lakes. It feeds on other fish and worms. It is one of the most highly sought after sport fishes and lives 8 to 10 years.

Bluegill is another type of fish that lives in ponds and lakes. These fish average about 1 or 2 pounds and 6 inches in length. Its body is dark olive green, the sides are lighter olive green, and the belly is orange. The mouth is small. Bluegill tends to live in clear warm pools, usually in shallow areas. Bluegill feed on insects, small fish, plants, and worms.

Turtles are another type of animal that lives in pond areas. Turtles are a member of the reptile family. Reptiles are different from amphibians and fish in that they do not need to be in water. Reptiles have a leathery skin and sometimes scales to prevent drying out. Reptiles also lay eggs that do not need to be wet because their eggs have a tough leathery shell to keep them from drying out. The turtles listed here live near water because their food lives in our near water in the pond.

Snapping turtles range from 8 to 19 inches long. This turtle has a massive head and powerful jaws. They are tan to dark brown in color and are often covered with algae or mud. There are three rows of pointed bumps on top of the shell pointing toward the back. The tail is as long as the shell. The average weight for a snapping turtle is 45 pounds and can get as large as 75 pounds. Snappers like to live in fresh water with soft mud bottoms and abundant vegetation. They eat plants, fish, birds, small mammals, and dead animals.

Painted turtles also live in ponds. They have an olive green or black shell which is oval, smooth, and flattened. The edge of the shell is bordered with olive green, yellow, or red. The neck has yellow and red stripes. The legs and tail also have red and yellow stripes. These turtles are found in slow-moving shallow streams, ponds, and lakes. They eat plants, minnows, and insects. They are the most widespread turtle in North America and are often found lying in the sun on a stump or rock.

Muskrats build their homes in pond areas. Their bodies are 10 – 14 inches long and the tail is 8 to 11 inches long. They weigh 2 – 4 pounds. The fur of a muskrat is dense and dark brown. The tail has no fur on it and is black. Muskrats build cone-shaped houses that are 2 – 3 feet above the water. These houses are built of plants with the entrance usually under water. They also make burrows into the sides of banks. Muskrats like to live in marshes, edges of ponds and lakes. They eat aquatic plants, clams, frogs and fish.

Muskrat

Raccoons also like to frequent ponds and streams as they search for food. Raccoons have a black mask and a tail ringed with black. They are mostly active at night near edges of ponds and lakes. They eat frogs, crayfish and other small animals. They have a habit of washing their good before eating it. The body is 18 to 28 inches long and the tail is 8 to 12 inches long. Raccoons weigh from 12 – 15 pounds.