SC.912.L.17.2 ESSENTIAL QUESTION

Explain the general

distribution of life in

aquatic systems as a

function of chemistry,

geography, light, depth,

salinity, and temperature.

How is life distributed in

aquatic ecosystems?

1. Jill made the table below during her research on aquatic zones and

living organisms. Based on Jill’s observations, which conclusion

could you draw?

A. Organisms in the intertidal zone must be able to withstand very

cold water.

B. There are no producers in the benthic zone that rely on

photosynthesis.

C. Organisms in the benthic zone must be able to tolerate large

amounts of oxygen.

D. The warm water and abundant sunlight in the nertic zone limits the

plankton population.

Explain the general distribution of life in

aquatic systems as a function of

chemistry, geography, light, depth,

salinity, and temperature.

These factors are limited to water depth,

latitude, temperature, underwater

topography, and proximity to land.

The study of physical features of the

Earth and its atmosphere, and of human

activity as it affects and is affected by

these, including the distribution of

populations and resources, land use, and

industries.

Pressure increases as

depth increases.

What would happen if we traveled 1,000

meters below the ocean’s surface? Why?

• Most organisms with gas-filled spaces

(like us) would be crushed by the

pressures that other deep-sea life

experience.

Many creatures have no problem living in

the deep ocean. Why?

• Most organisms living in the deep ocean

are largely water and water is incom-

pressible. Without gas-filled spaces,

organisms in the great deep are less

affected by pressure.

If you were going diving, what would happen to the amount of light as you deeper?• There is less light; it gets darker.

What chemical process is light important to as a reactant?• Photosynthesis

Why is this process important?• It is used by plants, algae and certain bacteria to harness

energy from sunlight into chemical energy. One way aquatic ecosystems can be divided is into two

zones called the PHOTIC zone and APHOTIC zone.

Check for Understanding –What is going to be found in the photic zone that is not found in the aphotic zone?

LIGHT!

#TBT – Between winter and summer,

why does the average temperature on

land change much more than the

average temperature of water?

If you were to get into a submarine and dive deep into the ocean, what would happen to the temperature of the water and why? • It would get colder because of the absence of

sunlight.

What else can influence the temperature of water besides depth and why?• Latitude - distance from the equator.

Due to the curvature of the Earth, temperatures will drop in areas farther away from the equator. Also, in areas closer to the poles, sunlight has a larger area of atmosphere to pass through and the sun is at a lower angle in the sky.

Checks for Understanding –

What is the relationship between light

and depth of the ocean?

How does latitude and ocean depth

affect temperature?

How do these differences affect living

organisms?

Explain the general distribution of life in

aquatic systems as a function of

chemistry, geography, light, depth,

salinity, and temperature.

These factors are limited to pH, oxygen,

carbon dioxide, nitrogen, phosphorus,

and salinity.

The branch of science that deals with the

identification of the substances of which

matter is composed; the investigation of

their properties and the ways in which

they interact, combine, and change; and

the use of these processes to form new

substances.

If the pH of water is too high or too low,

the aquatic organisms living within it will

die.

The majority of aquatic creatures prefer a

pH range of 6.5-9.0, though some can live

in water with pH levels outside of this

range.

Oxygen• Oxygen is necessary for the process of respiration in marine

organisms.

• Aquatic environments are low oxygen distribution environments.

• Where in aquatic ecosystems would you expect to find more oxygen? Why?

Carbon dioxide• If CO2 levels increase, it can react with water molecules to

decrease the water’s pH.

• What process is carbon dioxide important to as a reactant?

Cellular respiration

Other materials such as nitrogen and phosphorusare important nutrients.

Salinity is the measure of all the salts dissolved in water.

Aquatic ecosystems include bodies of water varying in salinity – fresh water, salt water and estuaries.

Global warming – decreasing salinity• It causes the icebergs to melt, adding freshwater

back to the oceans. • The additional freshwater will decrease the amount

of salt in the surrounding water. In areas with high evaporation, the water

will have a higher salinity because the salt is not evaporated with the water.

Organisms have specific salinity

ranges in which they can survive.

Give an example of the three

types of aquatic environments in

Jacksonville.

Checks for Understanding

• What can change the distribution of oxygen,

carbon dioxide and pH?

• What portions of the globe would have a

higher than normal salinity?

1. Jill made the table below during her research on aquatic zones and

living organisms. Based on Jill’s observations, which conclusion

could you draw?

A. Organisms in the intertidal zone must be able to withstand very

cold water.

B. There are no producers in the benthic zone that rely on

photosynthesis.

C. Organisms in the benthic zone must be able to tolerate large

amounts of oxygen.

D. The warm water and abundant sunlight in the nertic zone limits the

plankton population.

Clear your desk of everything

except something to write with

The pH of the water in several lakes in Norway and Sweden had decreased to below 5.0 due to an increase in acid rain. Which of the following is most likely to happen in these lakes?

A. the decline of several fish populationsB. an increase in numbers of fishC. an increase in the amount of primary producersD. increased predator-prey relationships

Coral reefs cover less than 1 percent of the ocean floor — all of them combined would equal an area of about 110,000 square miles (285,000 square kilometers), which is roughly the size of the state of Nevada. These reefs are generally found in warm, clear, and shallow waters where plenty of sunlight is available to nurture the algae that the coral rely on for food. Why are coral reefs among the most productive and diverse ecosystems on Earth?

A. Since coral reefs are found in environments with a higher salinity, they are able to support a larger variety of organisms.

B. Since coral reefs are structures that have existed for many years, more organisms have had time to interact with the coral.

C. Coral reefs are small structures, and the smaller an aquatic ecosystem the more life it can support.

D. Coral reefs are found in warm areas with favorable characteristics, and more life can be supported in warmer temperatures.

The highest concentrations of life exist in the top 200 meters of ocean water. As you dive deeper into the ocean, the environmental conditions change and biodiversity decreases. Which of the following statements is true in relation to environmental changes in a body of water?

A. As depth increases, both temperature and light increase.

B. As depth increases, both temperature and light decrease.

C. As latitude decreases, both temperature and depth are increasing.

D. As latitude decreases, both temperature and depth are decreasing.