1. Factors Affecting Aquatic Ecosystems
BENCHMARK
SC.912.L.17.2 Explain the general distribution of life in aquatic systems as a function of chemistry, geography, light, depth, salinity, and temperature.

2. ABIOTIC vs. BIOTIC FACTORS
Study the pictures below. Can you name the abiotic factors as well as the biotic factors?

3. Copy table and list 5 abiotic & biotic factors

4. Are non-living materials essential to the continuation of life?
Essential Question
Are non-living materials essential to the continuation of life?

5. Factors Needed for Survival
All living organisms require some non-living (abiotic) factors to survive.

6. Essential Question
What kind of environmental changes might alter the availability of these resources?

7. Effect of Temperature on the Rate of Photosynthesis
Enzymes are an important factor in photosynthesis. But they are sensitive to temperature. The enzymes will not function if temperatures are extreme. Enzymes will reduce or even halt their processes in extremes. Study the graph below and answer the questions following.

8. Data Analysis
What happens to the rate of photosynthesis (y axis) as the temperature climbs to 25 degrees Celsius?
Once the temperature exceeds 25 degrees Celsius, what happens to the photosynthesis production?
Compare the ineffectiveness of photosynthesis on either side of the graph. Make a statement about the “curve” as you compare both sides.
Considering that photosynthesis is food production (glucose) for the plant, what can you generalize about temperature and the health of plants?

9. Effect Sunlight on the Rate of Photosynthesis

10. Producers (Terrestrial & Aquatic)
So often we think of trees as the oxygen producers for living organisms, when in reality, it is the oceans’ algae that produces at least half, if not more of our atmospheric oxygen. The green areas below indicate the highest degree of high biological productivity.

11. Types of Aquatic Systems?
Can you give some locale examples from each type?

12. Essential Question
How can we define a pond environment as it differs from the aquatic environment of a deep ocean trench?

13. Factors Affecting Aquatic Ecosystems

14. Table: Factors Affecting Aquatic Ecosystems
Description
Light
Depth
Temperature
Salinity
Dissolved Oxygen

15. FACTOR: Light sunlight is essential for photosynthesis to occur
as light strikes the surface of the water, much is reflected back
more movement made by the water, the more light is reflected off of the surface and back into the atmosphere
most visible light waves are absorbed within 33 ft. (10 meters)
blue and violet waves of light travel deepest, giving most water its color

16. Euphotic vs. Aphotic

17. FACTOR: Depth where sunlight reach more organisms live
So what about the depths of aquatic environments?
where sunlight reach more organisms live
aquatic plants use sunlight to make food
as sunlight decreases amount of plants and animals decrease
deep ocean water is too dark for photosynthesis
Is it lifeless and useless?

18. If the recycled nutrients are on the bottom, how do they bring nourishment to plant life near the surface?
Upwelling
Temperature and currents will cause the recycled nutrients on the bottom of the ocean to move up and come to the surface
provides nutrients for the phytoplankton, and thus for the entire ecosystem

19. FACTOR: Temperature visible light translates into heat
three temperature zones in ocean water.

21. Where would you expect to see more constant temperatures?
Surface waters due to changes in light intensity and wind convection/currents
At great depth and nearest the poles (north and south).
Where would you expect to see temperature fluctuate , or change, the most?
Where would you expect to see more constant temperatures?

22. FACTOR: Salinity
salt water becomes more concentrated in areas where the sun’s intense heat causes water to evaporate
denser surface water forms currents as it falls to the lower levels of the ocean and rises again
called thermohaline current ( “Thermo” = heat, “haline” = salt)

24. salinity: measure of dissolved solids
organisms have specific salinity ranges in which they can survive in

25. Estuaries: Tolerant to Changes in Salinity
animals that have the ability to adapt are blue crabs and oysters
mangroves are short trees with roots that not only tolerate change in salinity, but they also provide protection for nesting animals among their many exposed roots
mud worms (bristleworms), stalk-eyed mud crabs and cockles, a small burrowing shellfish
scallops, a popular seafood live in this constant flux of salinity

26. FACTOR: Dissolved Oxygen
oxygen is an essential element required for aerobic respiration
the concentration of dissolved oxygen (DO) varies in water.
Where do you think most of the oxygen is located in the ocean waters?
Hint #1- Wind currents and waves stir up the surface water.
Using prior knowledge of light, temperature and depth, hypothesize about the concentration of DO in various levels of the ocean: Hint #2-Decomposers are doing a lot of work at depth (cellular respiration) and there are typically no plants (no photosynthesis)

28. A marine biome characterized by no sunlight and deep water depths is
the photic zone
a bog
a lake
an aphotic zone D

29. Based on the data, at what time of the day is the dissolved oxygen level in the tide pool greater that in the ocean?
6 am
4 pm
midnight
2 am B

30. A body of water in which both fresh and salt water mix is called a(n)___________________.
lake
estuary
stream
tidal zone B

31. insects water light rock
Which of the following resources is a biotic factor?
insects
water
light
rock A

32. Which of the following statements about a body of water is true?
As depth increases, both temperature and light increase.
Where light decreases, both temperature and depth are increasing.
As depth increases, both temperature and light decrease.
Where depth decreases, both light and temperature decreases as well.

33. Food production in this particular plant is affected by temperature
Food production in this particular plant is affected by temperature. Which statement is true?
Food production slows dramatically at temperatures between 10 and 20 degrees Celsius.
Food production remains the same following the rise to 20 degrees Celsius.
Food production drops as temperatures continue to increase beyond 30 degrees Celsius.
Food production is greatest at lower temperatures. C