Monday, October 1, 2012

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