Biotic

Interactions8.11A DESCRIBE PRODUCER/CONSUMER,

PREDATOR/PREY AND PARASITE/HOST RELATIONSHIPS

AS THEY OCCUR IN FOOD WEBS WITHIN MARINE,

FRESHWATER AND TERRESTRIAL ECOSYSTEMS

What is happening here?

Biotic Interactions In

Ecosystems

There are three major types of interactions among organisms in ecosystems:

Competition

Predation

Symbiosis

Use this page to organize!

Competition

Competition - occurs when

organisms try to make use of

the same limited resources

Competition occurs between:

Members of the same species

Among species with similar

niches

Or competing for abiotic resources

How do these examples to the

right compete?

How does a “niche” come

about?

An organism’s particular role, or how it fits into an ecosystem, is called its niche

A niche is carved out when species compete

Many organisms are adapted to overcome competition by resource partitioning:

They feed at different times of day

Or at different levels of the same tree

Words to Know

Resource partitioning- helps competing

species share a resource and develop

a niche for themselves in an

ecosystem.

For example:

Species of birds will feed at different

times of day

Or at different levels of the same tree

Warbler example:

Predation

Predation - An interaction in which one

organism hunts and kills another for food

Hunter – predator

Gets eaten - prey

Predator Adaptations

Predators have adaptations that help them

catch and kill their prey.

Cheetahs can run very fast to catch prey

Jellyfish have poisonous tentacles to

paralyze prey

Owls have big eyes to see at night

Prey Adaptations Prey have adaptations to help

them avoid predators

Camouflage

Protective coverings

Warning coloring

Mimicry

False coloring

Effects on Predation on

Population Size

Predation can have a major effect on

population size

If predators are very effective, the

result is a decrease in the prey

population

In turn, a decrease in the prey

population will result in a decrease in

the predator population

Symbiosis

A close relationship between

two different species that

benefits at least one of the

species

Benefits of Symbiosis:

Food

Transportation

Cleaning

Protection/Shelter

Reproduction

There are three types of

symbiotic relationships:

Mutualism

Both species benefit

Giraffes and Oxpeckers

Commensalism

One species benefits and the other is unaffected

Barnacles and whales

Parasitism

One gains considerably

at the expense of the

other

Host – the organism that

the parasite lives on or

in – it will be harmed

Parasite – the organism

that benefits

Reef Symbiosis

Done with the graphic

organizer!

Let’s take a closer look at the

relationships in a specific

ecosystem

Our Oceans!

Biotic interactions within the ocean –

Biodiversity and Relationships Reading

The ocean is the last and largest unexplored place on Earth—less than 5% of it has been explored. This is the great frontier for the next generation’s explorers and researchers, where they will find great opportunities for inquiry and investigation.

Ocean exploration is truly interdisciplinary. It requires close collaboration among biologists, chemists, climatologists, computer programmers, engineers, geologists, meteorologists, and physicists, and new ways of thinking.

Ocean Food Chains

All living things need to feed in order

to get energy, which is used to grow,

move, and reproduce.

Organisms in an ecosystem are

connected to each other based on

feeding relationships called food

chains.

A food chain shows the flow of

energy through a sequence of

organisms.

In other words, a food chain shows

the order in which animals consume

plants and other animals.

It all starts with sunlight…

Ocean Food Chains Food chains always begin with the primary

producers.

Consumers are next in the food chain.

Those 3 types of consumers:

herbivores omnivores carnivores

Food Chains

At the top of the food chain is the apex predator.

This animal has no natural predators and plays a crucial role in maintaining the health of the ecosystem.

Decomposers are organisms such as bacteria and fungi that eat decaying plant and animal matter.

− Decomposers break down the decaying matter even further, releasing nutrients and minerals back into the soil and/or sediment.

Great white sharks

are apex predators!

Exploration and research -

Videos:

Studying the Great White

Census of marine organisms (4 min)

Ocearch Activity

Go to my website and find the

ocearch link

Have this handout ready – it

has information on working the

program and tracker

worksheet

Handout: