Ecosystem Portfolio
Freshwater Ecosystem

Freshwater Ecosystem

Abiotic and Biotic Factors

Abiotic: water, rocks, dirt

Biotic: animals, trees, algae in water

Carrying Capacity-the number or quantity of people or things that can be conveyed or held by a vehicle or container.

Resources that animals need to survive: food, water, shelter, and space.

A habitat changes all the time. There is always a race to find food, water, and shelter between all the animals in an ecosystem.

Limiting Factors

Limiting factors are the factors that limit the reaction rate in any physiological process governed by many variables.

Limiting Factors in a Freshwater Ecosystem



Dissolved Nutrients

Wave Action


Examples of predator/prey relationships:

  1. Snapping Turtle eating Crayfish
  2. Crayfish eating Pond Snail
Snapping Turtle

Energy Roles

Producer-organism that produce biomass from inorganic compounds(autotrophs).

Examples of producers in a freshwater ecosystem-algae, grass, trees

Algae underwater

Energy Roles

Herbivore- an animal that feeds on plants.

Examples of herbivores in a freshwater ecosystem- dragon fly, water spider, mayfly nymph


Energy Roles

Omnivore- an animal or person that eats food of both plant and animal origin.

Examples of omnivores in a freshwater ecosystem- crayfish

Red Crayfish

Energy Roles

Carnivore- an animal that feeds on flesh.

Examples of carnivores in a freshwater ecosystem- frogs, heron, ducks, kingfisher


Energy Roles

Decomposer- an organism that decomposes organic material.

Examples of decomposers in a freshwater ecosystem- bacteria filled water, clams, freshwater shrimp.


Energy Roles

Scavenger- an animal that feeds on carrion, dead plant material, refuse.

Examples of scavengers in a freshwater ecosystem- turtles, beetles, leeches, whirligig beetle.

Whirligig Beetle

Why are producers vital to any ecosystem?

The producers in an ecosystem get their energy from the sun, and the 1st level consumer (primary consumer) gets its energy from the producer.

Food Chains & Food Webs

What is the difference between a food chain and a food web? A food chain is a series of organisms each dependent on the next as a source of food. A food web is a system of interlocking and interdependent food chains.

Freshwater Ecosystem Food Web

Removing a Population

If  you removed a producer from a food chain or web, then the 1st level consumer wouldn't have anything to eat and possibly die out. If the 1st level consumer dies out, then the 2nd level consumer has nothing to eat possibly could die out (and so on).

Energy Pyramids and Trophic Levels

Freshwater Ecosystem Energy Pyramid

In a pyramid, if you go from the bottom to the top, it gets smaller and smaller. In an energy pyramid, since there is a large variety of producers, they are at the bottom. As you go up the energy pyramid, the trophic levels and   consumer populations get smaller and smaller.

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