1. Aquatic Ecosystems
Unit 4 (Ch 4)

2. Watersheds
A region drained by or contributes to a stream, lake, or other body of water
Also called a drainage basin
Large watersheds are broken into smaller sub-watersheds
Anything that happens on the land in a watershed can affect the quality of the water that it empties into
As well as the organisms that live there

3. PA Watersheds
All the freshwater in PA eventually drains into the Atlantic Ocean
There are 5 major watersheds in PA which are broken down into 104 sub-watersheds

4. Great Lakes Basin Only 1% of this lies in PA
The Conneaut, Elk and Walnut Creeks (in PA) all empty into Lake Erie
PA areas

5. Ohio River Basin 2nd largest watershed in PA
Covers ~16,000 square miles of the state
Contains the Ohio and Allegheny Rivers along with some others in the western part of PA

6. Susquehanna/Chesapeake Basin
Largest watershed in PA
Contains the Susquehanna River (which starts in NY)
Empties into the Chesapeake Bay which flows into the Atlantic Ocean

8. Potomac Basin
Only about 1% of the state is in this watershed even though the Potomac River is not
The Shenandoah River is a tributary (feeder) into the Potomac

9. Delaware Basin Covers 6,500 square miles in PA
3rd largest watershed in PA
Much of the water from the Delaware River and its tributaries empty into the Hudson basin which provides most of the drinking water for New York City

10. Freshwater Ecosystems
Divided into two groups
Lotic: relatively fast moving water
Rivers, streams, brooks, creeks and human-made channels
Lentic: relatively slow moving water
Lakes, ponds, and wetlands
What is the difference between a lake and a pond?
Lakes larger, too deep for plants to root
Pond smaller, shallow enough for rooted plants to grow across the bottom

11. Streams Streams are classified by their size
Sometimes called creeks or brooks
First order stream- smallest
Second order – form when two first order streams meet
This area of meeting is called a confluence
Third order – a confluence of two second order streams
This process continues until the stream empties into a larger body of water

12. Arrows show areas of confluence- where streams meet to make larger streams before emptying into larger bodies of water

13. Floodplains
Areas of flat land along a stream or river that is periodically flooded
These areas contain organisms that are adapted to living in wetter ecosystems
Amphibians, algae, insects thrive in these ecosystems

14. Aquatic Habitats Surface Film  place where water meets the air
Organisms found here are mostly insects
Open Water  area where rooted plants do not reach the surface of the water
Organisms include large fish, turtles, and birds
Bottom  are of rocks, sand or mud that is the habitat for small organisms
Bacteria, snails, worms, sponges, crayfish and larvae or insects
Water’s Edge  where water meets the land
Greatest number of plants and animals found here

15. Surface Film
Bottom
Open Water
Water’s Edge

16. Checkpoint
What characteristic is used to classify a body of water as a lake or a pond?
Which aquatic habitat would contain the largest variety of organisms?
How does a watershed form?

17. Answers Depth and the ability of plants to take root
The water’s edge. It would have plants and animals from the land and aquatic ecosystem
A watershed forms where ever the majority of water in an area drains into.

18. Marine Ecosystems Water with high salt content
Life depends on temperature and amount of sunlight

19. Zones of the Oceans

20. Estuaries Salt water wetland
Place where fresh water from rivers meets salt water from oceans
Delaware Bay, Chesapeake Bay
Most bay areas and harbors

21. Adaptations Estuaries are very productive (lots of organic matter)
Lots of sunlight and nutrients available
Large populations of plants that are rooted into the mud
Lots of phytoplankton (microscopic plants) and zooplankton (microscopic animals)
Organisms are able to tolerate variations in salinity (salt content) and depth
Some animals- dolphin, manatees, oysters, clams, variety of fish

23. Threats Pollution- sewage, industrial waste, agricultural runoff
Ship waste, oil
Development- adds to pollution and overfishing

24. Coral Reefs

25. Coral Reefs
Corals- small marine animals that live on a limestone skeleton they create
Small polyps anchor to an area, release limestone (calcium carbonate) and form amazing reefs
Found only in warm, tropical salt water
Have a mutualistic relationship with some algae that helps maintain reefs
They need light for photosynthesis

26. Adaptations
There are very few plants in coral reefs- they need shallow water and warm temperatures
Corals are predators- they have stinging tentacles that catch plankton or fish that swim too close
Other animals are adapted to specific habitats with in the reef
There are many mutualistic relationships in reefs

27. Bulldozer shrimp and goby fish – mutualistic relationship
Sea anemone and clownfish

28. Threats Pollution Change in water temperature (global warming)
Sedimentation
Too much sediment from rivers, block sunlight so algae die and smother corals

29. Dead coral reef in Indonesia

30. The Ocean Ocean cover about 75% of the earth’s surface
Most ocean life is in shallow waters near coasts
There, sunlight is plentiful and lots of nutrients from land and river runoff

31. Plant Adaptations
Plants are only found around shores and where sunlight reaches
Phytoplankton is main source of food for herbivores in open ocean

32. Animal Adaptations Smallest herbivores- zooplankton
Include jelly fish, tiny shrimp, fish larvae
Dozens of fish feed on zooplankton
Fish bodies are shaped for movement through the water
Camouflage
Deep ocean- mutualistic relationship with bacteria for bioluminescence to occur

34. Threats to the Oceans
Pollution
Overfishing
Global warming

35. Polar Regions Ice covered polar caps of the North and South Poles
Nearly all food is provided by phytoplankton
No plants

36. The Arctic (N)
No land
The arctic is made up of massive frozen part of the Arctic Ocean surrounded by floating icebergs
Food web relies on phytoplankton which provides food for many fish
Whales, seals, penguins and polar bears are some organisms that make their homes here

37. Antarctic (S) Only continent never settled by humans
Is governed by an international commission and is only used for research
Plankton is base of food web
Fish, whales, penguins and other birds are some organisms found here

38. Threats
Mineral and Oil extraction