IMPACTS ON BIODIVERSITYMichaelis

Overfishing and Overhunting One threat to biodiversity occurs

when humans cause ecosystems to ____________ by using too many natural resources or taking away a ______________________.

collapse

keystone species

Overfishing and Overhunting

____________________: An organism that is necessary for keeping an ecosystem in _____________.

Example: Sea Otter

Keystone speciesbalance

Overfishing and Overhunting Facts: Only marine mammal without

___________...blubber

Overfishing and Overhunting

How do they stay warm in the cold ocean? Otters have the

____________________ fur of any mammal.

Fur is so thick that their skin never gets wet when they swim: ___________ hairs per square centimeter.

densest fur

400,000

Overfishing and Overhunting During the fur trade

humans hunted otters almost to _____________ for their ____________________.

By 1911 the sea otter population had dropped to roughly 1,000 individuals.

extinctionthick warm pelts

Overfishing and Overhunting Sea Otter’s Niche: Eats _______________. Uses ___________________ to break

open sea urchins.

sea urchinsrocks and shells

Overfishing and Overhunting Sea Otter’s Niche: Predators:

_____________________________ Uses ________________________

themselves while they eat and sleep.

sharks and humansseaweed to

anchor

How Sea Otters Keep Their Ecosystem in Balance Otters keep the

___________________________. Sea urchins eat away at the _______ of

sea weed. Fish and other sea life rely on the sea

weed forests for _____________________________.

sea urchin population down base

food and shelter

Overhunting Keystone Species:How do you think the decreasing otter population affects the ocean ecosystem? Otter population is DOWN Sea Urchin Population =

______________ Sea Weed Population =

_______________ Fish Population =

____________________ Seal Population =

____________________ Orca Population =

____________________

increasesdecrea

sesdecreasesdecreasesdecreases

Overhunting Keystone Species:What are the long term implications on the food web in this situation?Urchin Barrens

Biological Magnification

When carnivores eat herbivores that have been _________________________________.

Causes concentrations of harmful substances to ___________________________________.

contaminated with pollution

accumulate in higher trophic levels

Biological Magnification

Class Demonstration In this demo assume that __________

of pollutant will cause this animal to: ___________ Make them ___________ Make them very ______________

100 ppm

diesterile

unhealthy

Biological Magnification

Class Demonstration How many parts per million does the

guppy have? How many parts per million does the

salmon have? How many parts per million does the

eagle have?

Biological Magnification

Class Demonstration1. What type of organisms are affected

the most by biological magnification?

2. How do you think biodiversity will be affected?

Invasive SpeciesSpecies that are brought to an ecosystem by humans and _________________________ because they ______________________________.

harm the ecosystemdo not have any natural

predators

Invasive Species

_______________ exotic species live in the U.S.

_____________________ spent to help undo the damage they cause

Invasive species also threaten _____________

of the species currently protected under the ________________________

50,000

$130 billion per year

nearly half

Endangered Species Act

Kudzu in Alabama

Zebra Mussels

Invasive Species – Burmese Python, Florida

Introduced Beavers - Tierra Del Fuego, South America

Cane Toad Video

Invasive Species

Example: ___________________________I’iwi Birds are ________________. They are an ________________________. I’iwi are one of many Hawaiian Birds that _______________________________________

Rats in Hawaiinative to Hawaii

endangered speciesface

extinction due to invasive species.

Hawaii Invasive Species

Hawaii Invasive Species Video

Invasive Species

Questions:How do you think rats harm the I’iwi bird population?

Why do you think the rat population does so well in Hawaii?