Aim: What would happen if an ecosystem becomes unbalanced?

DO NOW: List 2 ways an ecosystem can be unbalanced.

Notepack # 53

Students that need to finish lab after school Wednesday.

• Noah Concepcion

• Brandon Lajara

• Octavia Napier

• Juan Ramirez

• Rasheim Daisley

• Jonathan Rosorio

• .Dante Garia

• Angel Jimerez

• Andrew Smart

• Andre Brown

• Infranique Kinloch

• Kaela Jones

• Dennis Matias

• Helena Alvino

• Chelsea Ponder

• Malique Kelly

• Eliza Diaz

• Deandre Peerman

• Datzenco Hernandez

• Shanice Knox

• Camille Bedward

• Elese Hernandez

• Rebecca Webb

• Attalia McLean

• Chastidy Cepeda

• Abigail Osoorio

• Devin Graham

• Michael Germosen

What does over hunting do to an ecosystem? • Food chains and food webs are very delicate and

balanced. If something happens to one of the populations in the chain, it affect the entire chain.

• In normal predator/prey relationships, a balance exist because of the interdependency of both the prey population and the predator population

• When a predator population kills more prey than it needs it is called overhunting.

• Overhunting can occur to any organism in the food chain (including plants).

•Overhunting the top predators in a food chain can upset the balance of a food chain.

•One of the niches (job) of predator is to manage the prey population.

•If the top predator is gone, the population of prey that it used to eat will increase.

•The increased prey will put a strain on the resources that the prey uses.

What would happen to the food chain if the shark is overfished?

1. The seal population will increase because it will have no predators. 2. The fish population will decrease because it now has more predators. 3. The plankton population will increase because if has less predators.

What would happen to the food chain if the fish is overfished?

1. The seal population will decrease because it will have less food. 2. The shark population will decrease because it will have less food. 3. The plankton population will increase because if has less predators.

Example of over hunting: Whale Hunting

• http://www.youtube.com/watch?v=8GGHgYbDmtM

Overfishing

Hunting for Sport

http://www.youtube.com/watch?v=WMYtuMgwNCY

What does overhunting do with the do to an ecosystem?

• Another problem with over hunting is that a species is hunted to extinction.

• Extinction refers to the elimination of an entire population of a species.

Mekong Giant Catfish

Cross River Gorilla

Javan Rhinoceros

The Dodo

The passenger Pigeon

What’s the problem with extinction? • When an organism becomes extinct, the

species is gone forever.

• As ecosystem losses species to extinction, that ecosystem has less biodiversity.

• The less biodiversity an ecosystem is, the less stable it becomes.

What is biodiversity?

• Biodiversity refers to the amount of different species that live is a given area.

• When an ecosystem has a lot of different species, if something happens to one population, another populations can take over the niche (job) of the lost population (TO A POINT).

What would happen if a new organism is introduced into an ecosystem?

• Sometimes when a new organism is introduced into an existing ecosystem, they can disrupt the food chain.

• If the new organism is better adapted for a niche, the original may be out competed. This new species is known an intrusive species.

• Also a new species can become a predator to a population that never have a predator before.

The Zebra Mussel

• The zebra mussel is a shell fish that was introduced to the ecosystem of the Great Lakes.

• Zebra mussels originally came from Russia, but later reached England, than the United States.

• They got here by clinging to the bottom of cargo ships.

• The problem with the Zebra Mussel is that it can quickly colonizes (spread) and outcompete the native (original) shell fish. Killing most of them.

Guam’s Brown Tree Snake • Guam is an island in the Pacific

Ocean.

• Until the mid 1900’s, the birds of Guam had no natural predators.

• Brown Tree snakes from Indonesia are thought to have been introduced to the island by hiding in the landing gears of military airplanes.

• The Brown Tree snake is responsible for killing more than half of the native bird population of the island.

One of Guam’s

Food Chains

Northern Snakehead Fish • Originally from China, the

Northern Snakehead fish was imported for use in aquariums.

• For some reason, they were let go in nature.

• These fish will eat everything in the water.

• They can also slither over land and invade

neighboring stream or lakes. • Introduce in Delaware, now

all the way to Louisiana

Pythons in Florida •Pythons are sold at local pet stores for pets.

•Pythons can get very big (16 ft) very quickly.

•Many Python owners let these snake loose into Florida swamps because the owners cannot take care of them any more.

•Pythons are native to southeastern Asia where their population is balanced do to the presence of natural predators.

•With no natural predators in the US, the snakes’ population explodes.

•With the large number of python in the swamp, other animals are in danger.

http://video.google.com/videosearch?q=sn

akehead+fish&www_google_domain=www.

google.com&hl=en&emb=0&aq=0&oq=sna

kehe#

http://deathby1000papercuts.com/2010/01/

african-rock-pythons-anaconda-green-

mambas-added-to-list-of-snakes-on-the-

loose-in-florida/

http://www.youtube.com/watch?v=nmU7et

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