How can food webs change?

Answer 1

Living things in a food web depend on one another. Suppose the population of one organism in a food web changes. A population is all the members of a single type of organism in an environment.

Kelp Forests
When one population in a food web changes, all the populations in the food web can also be affected. This is what happened in the ocean's kelp forests. Kelp is a type of seaweed. Kelp forests are home to thousands of ocean creatures. Some kelp forests have been greatly changed by just one animal. That animal is a sea otter.

Sea otters eat several animals in their ocean food web. They eat sea stars, sea urchins, mussels, crabs, and large fish. The kelp forests were almost destroyed when the sea-otter population changed about 200 years ago.

A Sea Without Sea Otters
What happened to the kelp forests? In the 1800s, too many sea otters were hunted for their fur. Without sea otters, fewer sea urchins were eaten. Soon, too many sea urchins were being born. Smaller fish could not survive, because sea urchins ate their supplies of kelp. These fish were food for sea stars and crabs. The sea stars and crabs began to die out.

Mussels also depended on kelp to stay alive. Fewer mussels meant fewer crabs and large fish that depended on mussels for food. After a while, even decomposers could not survive. Without the sea otter to help control the size of the sea-urchin population, the kelp forests almost disappeared.

In the 1900s, many countries agreed to stop hunting sea otters. The kelp-forest food web became balanced again. Now, new food-web changes are putting kelp forests in danger again.

Answer 2

Humans are constantly growing, therefore creating more organisms than can survive; quote-Charles Darwin.

Answer 3

Humans are at the very top of the food chain... everything else is under us...

Answer 4

Example: more wolves migrate into the forest and disease kills the plankton in the ocean.

Answer 5

When many food chains link together