Food Webs Land Water Every organism on the

Food Webs: Land Water • Every organism on the planet, including humans, are connected through a food web.

Producers, Consumers, and Decomposers • Producers • Make their own food using photosynthesis • Plants, green algae, kelp, phytoplankton

Consumers • Eat other organisms for food • Cow, human, eagle

Decomposer • Break down the remains of other organisms • Fungi and some bacteria • Vital to ecosystems because they return important nutrients to the environment

Consumers are classified by their food source • Primary Consumers – Eat only producers • A cow eating grass is a primary consumer • Secondary Consumers – Eat primary consumers • Human eating a cow

Grassproducer Grasshopperprimary consumer Toad. Secondary consumer

Food Chain • Flow of energy from one organism to next in an ecosystem • Shows flow of energy from producer, to different consumers, and finally decomposers • Shows only one path

Food Chain

Food Web • Many food chains make up a food web • Food Web – Interconnected network of food chains within an ecosystem

Aquatic Food Web • Food web showing relationships between aquatic organisms

Terrestrial food web • Terrestrial food web – Food web showing relationships between land organisms

Terrestrial and Aquatic Food Webs • They can also be connected – Bear eating fish out of a river – Birds diving for fish in lakes and oceans – Fish eating insects that land on the water

Food Chains and Food Webs • Trophic Level – Each feeding level in an ecosystem is located within a tropic level – Organisms at each tropic level take in energy from the organisms they eat

Energy Flow Between Organisms. Pyramid • Within an ecosystem, the energy flow between trophic levels does not remain constant • At each level some animals use the energy taken in to perform life processes – Some energy is given off as heat – Some energy is stored in bones and teeth that may not be eaten by another animal

Energy Flow between trophic levels • Only 10% of the energy is passed onto the next higher trophic level Energy in an ecosystem can be measured in total number of animals or combined mass of all animals • Increase a level animals increase in size • Increase a level, animals decrease in number

Review

1. Which of these animals is a primary consumer? (eats a producer) A B C

2. If the producers in an ecosystem produce 250, 000 kilocalories of energy, how much energy is available in the third trophic level? • • A. 5, 000 kilocalories B. 2, 500 kilocalories C. 250 kilocalories D. 25 kilocalories

2. In a marine food web, which of the following would get its energy directly from the sun? • • A B C D krill fish algae killer whale

3. Which of these animals is a secondary consumer? A B C

• • 4. Which of the following situations show a terrestrial and aquatic food web connection A. A seagull eating an insect on the beach B. shark eating a tuna C. seagull eating a fish D. bear eating a deer

• • 5. Which of the following situations show a terrestrial and aquatic food web connection A. B. C. D. A furry bear eating a tasty squirrel An awesome human eating a slow deer A swift pelican eating a large tuna A frisky shark snacking on a cute dolphin

Create a terrestrial and aquatic food web poster. • Your food web must have 6 animals • There must be two connections between terrestrial and aquatic food webs. • Identify 1 primary consumer, 1 secondary consumer, and 1 producer.