Unit 6: Essential Question

How do the organisms in an ecosystem interact with each other?

 

Predation- occurs when an organism catches another and feeds on it for energy. For example, a lion catching deer to eat.

Mutualism- occurs when both species in the interaction benefits- such as flowers depending on bees to pollinate it and the bees using the flowers' nectar.

Commensalism- occurs when one member of the interaction benefits while the other is unaffected or unharmed (barnacles catching a "ride" with whales for protection and food)

Parasitism- occurs when an organism lives inside or on another organism and harms the host organism. (mosquitoes biting humans for their blood)

Citation: Prentice Hall Biology Book- Chapter Three 4-2

Down at the Bay Question #8

What will be the long-term effect of natural and man-made changes on the ecosystem of the Chesapeake Bay?

Postive:

Positive effects of the Bay such as conservation and the ecosystem thriving can be achieved from educating citizens about ongoing conservation projects on the Chesapeake Bay. This can be achieved by programs that instruct people on ways to help keep the Bay clean and safe.

Negative:

Negative long term effects of natural and man-made changes on the ecosystem of the bay will be the ecosystem's population declining from hazardous human activity and expansion. 

Citation: 
http://www.chesapeakebay.net/issues
http://www.chesapeakebay.net/issues/issue/population_growth

Module D: Impacts on the Bay

What natural and man-made changes in environmental conditions affect organisms of the Bay?

Man made changes such as pollution from vehicles, factories, gas powered lawn tools, and farm operations has cause a negative impact on the Chesapeake Bay.

Air pollution becomes water pollution when wind and weather carry air pollution over long distances to the Chesapeake Bay. Atmospheric deposition occurs when pollution that is released into the air eventually falls back to the earth's surface, harming the area around the Bay and the Bay itself.

This pollution harms organisms in the water, causing the population to decline.

Other Changes:

~Population Growth

~Deforestation

~Invasive Species

~Stormwater Runoff

~Weather & Climate

~Chemical Contaminants

~Agriculture




Citation: http://www.chesapeakebay.net/issues/issue/air_pollution

Down at the Bay Question #6

How do biotic and abiotic factors influence the growth of populations?

Biotic and abiotic factors determine an organism's chance for survival- they can extend or reduce the life of an individual and over time can lead to the overall population's increase or decrease.

Biotic factors such as the availability of food and the presence of predators both determine a population's increase or decrease. For example, if clams were taken out of the Chesapeake Bay, then the smaller fish that normally consume the clams would gradually perish over time if they can not find another food source.

Abiotic factors such as climate, shelter, light, and soil conditions are factors that also determine whether or not a population increases. For example, if a chemical or harmful substance is released into the Bay, then the organisms would be affected and over time the Bay would be lifeless. 

"Each consumer depends on the trophic level below it for energy."

Citation: http://schoolworkhelper.net/biotic-and-abiotic-factors-influence-on-ecosystems/

Module C: Interactions of the Chesapeake Bay

How does energy flow through a system, and how does it impact organisms?

 

Energy flows through an ecosystem in one direction beginning from the sun or inorganic compounds, to producers, to a diverse group of heterotrophs. Energy is passed along an ecosystem through a food chain.

Sunlight is the main energy source of life on Earth- it is captured by plants which are producers or autotrophs during photosynthesis. Some autotrophs use chemical energy to produce food that they can use.

Those organisms that can not produce their own food are called consumers or heterotrophs. They depend on the producers for energy and they can either be carnivores, omnivores, herbivores, decomposers, or detritivores.

The flow of energy through an ecosystem is a very important factor that determines the ecosystem's capacity to sustain life. 

 

Citation: 
Prentice Hall Biology Book Unit Two Chapter Three
http://www.sheppardsoftware.com/content/animals/kidscorner/foodchain/producersconsumers.htm

Down at the Bay Question #4

How does the energy of the sun get to the top carnivore in the Chesapeake Bay? 

 

A specific example of a food chain in the Chesapeake Bay is one that starts with algae. The algae harvests energy from the sun to food that it can use during photosynthesis. 

The algae is then consumed by a filter feeder such as clams, which in turn is consumed by a secondary consumer such as smaller fish. 

It is then consumed by a large bass which makes up the third trophic level.



Source: Prentice Hall Biology Book Unit Two Chapter Three

Module B: Energy Flow of the Ecosystem

Compare and contrast biotic and abiotic factors and explain how biotic factors affect life on the Bay.

Biotic Factors (the ecological community)

~organic matter
~phytoplankton
~zoo plankton,
~small fish
~blue crabs
~oysters
~bass
~bald eagle

Abiotic Factors (nonliving factors)

~the climate
~temperature
~precipitation
~humidity
~wind
~nutrient availability
~soil type
~sunlight

How it affects the Bay

Biotic factors, along with abiotic factors determine whether an organism serves and grows and also it determines the general productivity of the ecosystem. 


Citation: http://wiki.answers.com/Q/What_are_some_biotic_factors_of_the_Chesapeake_Bay

Down at the Bay Question #2

How can the removal of biotic elements drastically affect the ecosystem's abiotic conditions? (Choose 1 specific factor)

The abiotic condition of water would be affected if benthos (organisms that live on the bottom of the Chesapeake Bay) such as filter feeders like oysters and clams that feed on organic matter and plankton were to be removed from the ecosystem. Since there's no one to link the autotrophs to the higher levels of the food web, the water quality would change. The plankton would thrive and something like an algal bloom might occur. The organisms living in the Bay's water, especially the carnivores, would decline and so would the whole community. The whole balance of the ecosystem would change. 



 Citation: http://www.chesapeakebay.net/discover/bayecosystem/bottom

Module A: Introduction to Ecology

What are the characteristics of this unique ecosystem and how have humans impacted the bay?

*Physical Characteristics

~Salinity- The upper Chesapeake Bay is described as fresh while the lower Bay is salty- salinity increases as you go south while it decreases as you go up north. The highest salinity level of the Bay is at its mouth, (because of the Atlantic Ocean's waters) averaging 25-30 ppt. (parts per thousand) 

The middle portion of the Bay is brackish, which is a mixture of both the fresh and salt water.

~Temperature- Due to the shallowness of the bay, heat is not stored over time. Temperatures can range from a cold 32 degrees Fahrenheit in the winter to a hot 84 degrees Fahrenheit in the summer. The temperature of the bay, which is an abiotic factor of the ecosystem, determines the organisms' niche.

Because of the bay's surface being warmer during the spring and summer, two recognizable temperature layers are physically separated.

~Circulation- The bay's movement of fresh water is from the north while circulation of salt water is from the south. The area where the fresh and salt water meet has many nutrients and is called the zone of maximum turbidity. This zone has an abundance of wildlife since it is used as a nursery area by many organisms in the Chesapeake ecosystem.

*Human Impact

Land development by humans now and in the past have affected the Bay negatively. The clearing of land itself cause many animals to be extinct due to loss of habitat.

Even though people live far from the Bay, pollutants such as garbage, chemicals, soap, and debris, are washed off into the bay ruining areas where fish keep their eggs and polluting the water that the organisms live on. 

Citation

www.mascd.net/envirothon/wildlife/.../Ches%20Bay%20Ecosystem

http://www.chesapeakebay.net/discover/bayecosystem/physical