1. Day 3
Topic 2 –
Ecosystems

2. Bell Ringer: Ride the Waves
The marine ecosystem that is exposed to regular and extreme changes in its surroundings is the intertidal zone. During high tide, the intertidal zone is covered by seawater. During low tide, this area is exposed to air, sunlight, and heat.
1. What types of organisms would you expect to find living in the intertidal zone?
2. What characteristics do you think these organisms have that enable them to live in this zone?

4. What are we learning today?
Benchmark
Objectives
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.
Explain that different types of organisms exist within aquatic systems due to chemistry, geography, light, depth, salinity, and/or temperature.

5. What is the essential question?
What are the characteristics of aquatic ecosystems?

6. What factors affect life in aquatic ecosystems?
Aquatic organisms are affected primarily by the water’s depth, temperature, flow, pH, salinity, and amount of dissolved nutrients.
What factors affect life in aquatic ecosystems?
(left) Hawaii’s water temps
(right)This figure denotes the temperature and salinity distributions from the edge of the continental shelf out to about the center of the Gulf Stream. The intersection of the colored and white region denotes the bottom. The outer continental shelf is on the left, where the water depth is about 70 m. The maximum water depth occurs at about 55 km offshore.

7. Water Depth
Water depth strongly influences aquatic life because sunlight penetrates only a relatively short distance through water.
The sunlit region near the surface in which photosynthesis can occur is known as the photic zone.
The photic zone may be as deep as 200 meters in tropical seas, but just a few meters deep or less in rivers and swamps.
“The physical and chemical structure of the ocean provides habitats that marine organisms depend on. Variations in such factors as temperature, light, and nutrient concentration create distinct conditions to which organisms have adapted. For example, the planktonic seaweed in the Sargasso Sea grows slowly and lives a long time, an adaptation to low nutrient concentrations. Fish that live at deeper levels of the ocean have developed bioluminescence and photic organs that help them to cope with low-light conditions.”
Figure 1. Divisions of the marine environment. The two large divisions are the benthic realm (organisms that live on the seafloor) and the pelagic realm (organisms that live in the water). The benthic and pelagic environments are subdivided into zones based on depth. From deepest to shallowest, the zones are hadal, abyssal and bathyal zones. In the pelagic environment, the shallowest zone is called the photic or surface zone. In the benthic environment, the shallowest zones are called the intertidal and subtidal zones.
NOTE: this diagram has a large amount of vertical exaggeration (slopes look MUCH steeper than they really are).

8. Water Depth
Photosynthetic algae, called phytoplankton, live in the photic zone (Producers/autotrophs they do photosynthesis).
Zooplankton—tiny free-floating animals—eat phytoplankton. (heterotrophs)
Below the photic zone is the dark aphotic zone (no light), where photosynthesis cannot occur.
Phytoplankton
Levels
Low
Medium
High

9. Plankton  drifter
Zoo  animal
zooplankton
Phyto  Plant
phytoplankton

10. Water Depth
Many aquatic organisms live on, or in, rocks and sediments on the bottoms of lakes, streams, and oceans.
These organisms are called the benthos, and their habitat is the benthic zone.

11. Temperature and Currents
Aquatic habitats are warmer near the equator and colder near the poles.
Temperature in aquatic habitats also often varies with depth. The deepest parts of lakes and oceans are often colder than surface waters.
(both) Trinity River, CA.

12. Nutrient Availability
Organisms need certain substances to live, such as oxygen, nitrogen, potassium, and phosphorus.
Upwelling allows nutrients to move from the bottom of the ocean to the surface which supports marine productivity, by stimulating the growth and reproduction of primary producers such as phytoplankton and they attract hundreds of species throughout the trophic levels
Nutrients move upward from the bottom of the ocean
(top) The strip of a green alga (Enteromorpha) along this shore indicates that there is a nearby source of nutrients (probably nitrates or ammonia from a small estuary).

13. Currents and their importance
Currents move nutrients around the world.
Where cold currents flowing from the polar seas and the warm currents from the low latitudes converge there are major fishing grounds.
There the chemical nutrients on the floor of the sea can be mixed upward so that they are readily available to fish in surface waters where there is sufficient light and adequate quantity of oxygen

14. Freshwater Ecosystems
What are the major categories of freshwater ecosystems?
Freshwater ecosystems contain very small amounts of salt. Not enough to affect organisms.
Freshwater ecosystems include streams, rivers, lakes, ponds, and freshwater wetlands (bogs, swamps, and marshes).

15. Rivers and Streams (fresh water)
Characterized by moving water.
Animals in many rivers and streams depend on terrestrial plants and animals that live along their banks for food.

16. Lakes and Ponds (fresh water)
The food webs in lakes and ponds often are based on a combination of plankton and attached algae and plants.
Plankton is a general term that includes both phytoplankton and zooplankton.
Water flows in and out of lakes and ponds circulating between the surface and the benthos, distributing heat, oxygen, and nutrients. Otherwise, very little movement.
Gizmo
Pond Ecosystem

17. Freshwater Wetlands
A wetland is an ecosystem in which water either covers the soil or is present at the surface for at least part of the year.
Wetlands are often nutrient-rich, highly productive, and serve as breeding grounds for many organisms.
Freshwater wetlands purify water by filtering pollutants

18. Freshwater Wetlands
Three main types of freshwater wetlands are freshwater bogs, freshwater marshes, and freshwater swamps.
What lives here? Mammals, amphibians, insects and many more
Freshwater Bog
(Peat-accumulating–> decaying plant matter)
Freshwater Marsh in Canada
(herbaceous rather woody plants)
Swamp in Florida
(more woody plants)

19. Estuaries
Saltwater wetlands are called estuaries and are where a river meets the sea.
Estuaries serve as spawning and nursery grounds for many ecologically and commercially important fish and shellfish species including bluefish, striped bass, shrimp, and crabs. Migratory birds also live in these habitats.
Why are estuaries so important?
Healthy estuaries are critical for the continued survival of many species of fish and other aquatic life, birds, mammals, and reptiles
Atlantic coast salt marsh

20. Estuaries
Many are shallow, which means that enough sunlight reaches the benthos to power photosynthesis.
They house many habitats including coral reefs, rocky shores, submerged aquatic vegetation, and mangroves.
Mangrove swamps are tropical estuaries that have several species of salt-tolerant trees, collectively called mangroves.
The largest mangrove area in America is in Florida’s Everglades National Park.
Columbia River Estuary, Cathlamet Bay,
Mangrove Estuary in the Everglades

21. Marine Ecosystems Contains large amounts of salt.
How do ecologists usually classify marine ecosystems?
Ecologists typically divide the ocean into zones based on depth and distance from shore.
Starting with the shallowest and closest to land, marine ecosystems include the intertidal zone, the coastal ocean, and the open ocean.
Ecologists typically divide the ocean into zones based on depth and distance from shore.
Starting with the shallowest and closest to land, marine ecosystems include the intertidal zone, the coastal ocean, and the open ocean.

22. Marine Ecosystems
This diagram shows the different zones in an ocean.

23. Intertidal Zone
Organisms in the intertidal zone are submerged in seawater at high tide and exposed to air and sunlight at low tide.
These organisms are subjected to regular and extreme changes in temperature and are often battered by waves and currents.
Such as, barnacles and seaweed permanently attach themselves to the rocks, sea urchins, sea stars, and crabs

24. Coastal Ocean
The coastal ocean extends from the low-tide mark to the outer edge of the continental shelf—the relatively shallow border that surrounds the continents.
Water in the coastal ocean is brightly lit, and is often supplied with nutrients by freshwater runoff from land. As a result, coastal oceans tend to be highly productive.
Kelp forests and coral reefs are two important coastal communities.

25. Coastal Ocean Kelp Forest Coral Reefs
They occupy less than 0.1% of the world's ocean surface
coral reefs form some of the most diverse ecosystems on Earth
they provide a home for 25% of all marine species, including fish, clams, worms, crustaceans, starfish, sponges, tunicates and sea anomies
Kelp Forest
They are recognized as one of the most productive and dynamic ecosystems on Earth

26. Open Ocean
More than 90 percent of the world’s ocean area is considered open ocean.
Depth ranges from 500 m along continental slopes to more than 10,000m in ocean trenches.
The open ocean is divided into two zones based on light penetration—the photic and aphotic.

27. The Open Ocean Photic Zone
The open ocean typically has low nutrient levels and supports only the smallest species of phytoplankton.
Still, because of its enormous area, most photosynthesis on Earth occurs in the sunlit top 100 meters of the open ocean.
Whales, tuna, herring and sharks live here

28. The Open Ocean Aphotic Zone
The permanently dark aphotic zone includes the deepest parts of the ocean.
photosynthesis cannot occur, so the usual foundation of food webs, plants and cyanobacteria, are absent
Some animals that live in the aphotic zone include the gulper eel, giant squid, smaller squids, anglerfish, vampire squid, and numerous jellyfish, and fish that make their own light.

29. Unusual Watery Place
The Dead Sea is so salty that the only thing that lives there is a type of bacteria called a halophile (salt lover)
It is so salty that you can float in it

30. Unusual Watery Place
At Deep sea vents, organisms get their food directly from the vents themselves . This process is known as chemosynthesis (no light needed). Bacteria in the water actually feed on what would otherwise be a lethal soup of noxious chemicals. Smaller animals feed on these bacteria, and these smaller animals provide food for the larger animals. It is an entire ecosystem totally separate from the world of light

31. As depth increases: water becomes colder and darker; pressure increases; oxygen content decreases; and diversity of organisms decreases.
Bodies of water near the equator are warmer than those farther away.
Some water ecosystems are fast-moving, others not.
pH differs in bodies of water around the world.
Some aquatic ecosystems have more salt than others. Those with very little salt is known as freshwater.
The amount of dissolved nutrients is different around the world. Nutrients are moved around in each aquatic ecosystem.

32. Acid Rain (changes the chemistry of an aquatic ecosystem)
Acid rain causes a cascade of effects that harm or kill individual fish, reduce fish population numbers, completely eliminate fish species from a body of water, and decrease biodiversity.
the young of most species are more sensitive to environmental conditions than adults. At pH 5, most fish eggs cannot hatch
Who is more sensitive to pH? Who is more tolerant of pH change?

33. Ocean Acidification decrease in the pH of the Earth's oceans
caused by the uptake of carbon dioxide (CO2) from the atmosphere
30–40% of the carbon dioxide released by humans into the atmosphere dissolves into the oceans, rivers and lakes
It causes corals and some plankton to have a hard time creating their hard deposits
Thus, ongoing acidification of the oceans also poses a threat to the food chains connected with the oceans

34. Can a fresh water fish live in salt water or vice versa?
Aquatic Cartoon

35. What is the essential question?
What are the characteristics of aquatic ecosystems?