1. Freshwater ecosystems
“We will never be able to feed the hungry or meet the needs of the billion people that lack access to clean water unless we can sustain the benefits and services that freshwater ecosystems are providing to society free of charge.”
Brian Richter, co-lead for the Conservancy’s Global Freshwater Team

2. Freshwater Ecosystems
3% of world’s water is fresh.
99% of this either frozen in glaciers and pack ice or is buried in aquifers.
The remainder is found in:
Lakes, ponds, rivers, and streams

3. Lakes and Ponds Three Distinct Zones:
Littoral Zone – close to shore, light reaches bottom
Producers include: plants and algae
Consumers include: tiny crustaceans, flatworms, insect larvae, snails, frogs, fish and turtles
Limnetic Zone – layer of open water, photosynthesis occurs, more prominent in lakes
Producers include: planktonic algae
Consumers include: swimming insects and fish and microscopic crustaceans

4. Lakes and Ponds Draw this in your Notes!
Profundal Zone – many lakes (but few ponds), not enough light to support productivity
Primary consumers are either attached to or crawl along the sediments (Benthos)
Sediments support bacteria and fungi
Draw this
in your Notes!

5. Freshwater ecosystem
Draw this
in your Notes!
Draw this
in your Notes!

6. Fall Overturn Change of seasons:
Warming of surface water prevents water from mixing with deeper water. (Warm water is less dense than cold.)
Surface water is oxygen rich.
Air above it
Photosynthesis
Water in profundal zone is stagnant.
In the fall,
Surface water cools, becomes denser and sinks to bottom, carrying oxygen with it

7. Fall Overturn

8. Rivers and streams Current makes the water more oxygenated
Photosynthesizers play a minor role in the food chains
Large fraction of the energy for consumers is from land (ex. Falling leaves)

9. The Role of freshwater ecosystems (Essential to Human life)
Freshwater ecosystems are a critically important source of food.
15% of the fish we consume comes from freshwater habitats
Freshwater ecosystems:
Store flood waters
Purify water supplies
Generate electricity with hydropower
Produce building materials such as timber and clay bricks
Deliver sand to replenish coastal beaches

10. Threats to freshwater ecosystems
Freshwater ecosystems have lost a greater proportion of their species and habitat than those on land or in the oceans.
Primary Threats:
Dams
Water pollution
Invasive exotic species
Direct habitat destruction
Overharvesting of plants and animals
Global climate change

11. STORMS

12. Tropical Cyclones/Hurricanes
Storm system
Characterized by:
low pressure center
thunderstorms
strong wind
flooding rain
Feed on heat released when moist air rises (water vapor releases heat as it rises, cools, condenses)

14. Storm usually doesn’t last for more than 7-10 days.
What Is a Hurricane?
Description: A hurricane can best be described as a huge tropical storm (up to 600 miles in diameter)!
Winds can be up to 200 mph!
Storm usually doesn’t last for more than 7-10 days.
It moves across the ocean at around mph…not too fast really!
Arrows indicate “feeder bands” or “rain bands”
The winds are the strongest around the eye wall. The eye of the storm is usually about 20 miles in diameter. Within the eye, winds are calm and the weather is great. Strongest winds are on the right side, heaviest rain is usually on the left side.

15. Factors necessary for tropical cyclone formation:
Water Temperature
At least 26.5 °C to depth of 50 m
Rapid Cooling with Heating
Allows release of heat of condensation
High Humidity
Continued next slide…..

16. Distance Away from Equator
Low Wind Shear
High shear is disruptive to the storm’s circulation
Distance Away from Equator
More that 500 km or 5 degrees of latitude
Allows Coriolis effect to deflect winds
Pre-existing System of Disturbed Weather

17. Storm Classification

18. Tropical Depression Organized system of clouds and thunderstorms
Maximum sustained winds <38 mph

19. Tropical Storm
Maximum sustained winds increase to between mph

20. Hurricane System with sustained winds of >74 mph
Hurricance Classification
Category 1: mph
Category 2: mph
Category 3: mph
Category 4: mph
Category 5: 157 mph or higher

21. Wind Simulator

22. Saffir-Simpson Scale of Hurricane Intensity

23. Hurricane Naming System – Why do they have names anyway?
2015 Hurricane Names
Ana Bill Claudette Danny Erika Fred Grace Henri Ida Joaquin Kate Larry Mindy Nicholas Odette Peter Rose Sam Teresa Victor Wanda
In 1953 the National Weather Service began naming storms after women.
In 1979, men’s names were added to the list of hurricane names.
In the Atlantic, there are 6 lists of names that are recycled.
In the case of storms so devastating that reusing the name is inappropriate, the name is taken off the list and another name is used to replace it. The name “Katrina” is one that has been removed from the listlist.
Next year’s list

24. Eye and Inner Core Sinking air at the center
If winds strong enough eye will form
Heaviest wind damage occurs at eye wall

25. Landfall Storm’s center crosses coastline
Coastal areas will “feel” it coming hours before landfall

26. Coastal Effects Can produce powerful winds and torrential rain
Can produce high waves and damaging storm surge

27. Inland Effects Damage to vehicles, building, bridges, etc.
Possible flying projectiles.
Heavy rains can produce significant flooding and storm surges
can produce extensive coastal flooding up to 25 miles from the coast line.
Historically resulting in 90% of cyclone deaths
In the last two centuries, tropical cyclones have been responsible for 1.9 million deaths

28. Hurricane Season
Our Season-
June 1 to November 30

29. Dissipation occurs when:
Moves over land, depriving itself of warm-water.
Remains in the same area of ocean too long mixing the upper 30 meters of water (water becomes too cool).
Moves into water < 26.5 °C

30. Long Term Trends
More intense hurricanes are expected over next century due to global climate change – the earth’s warming due to increasing levels of greenhouse gases in the atmosphere.

31. Helpful Hurricanes? Relieve drought conditions.
Help maintain equilibrium in Earth’s atmosphere and maintain relatively stable and warm temperature worldwide.

33. More cool stuff to check out…

34. Aftermath…

35. Aftermath…

36. Aftermath…

37. Aftermath…

38. The Path of Hurricane Katrina

40. Aftermath…

41. Aftermath…

42. Aftermath…

43. Aftermath…

44. Aftermath…

45. El Nino
El Niño is a long period of warming in the Pacific Ocean sea surface temperatures when compared with the average temperatures.
This is a warming of at least 0.5°C (0.9°F) averaged over the east-central tropical Pacific Ocean.
Typically, this anomaly happens at irregular intervals of two to seven years, and lasts nine months to two years.
The average period length is five years.

46. El Nino Continued The first signs of an El Niño are:
Rise in surface pressure over the Indian Ocean, Indonesia, and Australia
Fall in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean
Trade winds in the south Pacific weaken or head east
Warm air rises near Peru, causing rain in the northern Peruvian deserts
Warm water spreads from the west Pacific and the Indian Ocean to the east Pacific. It takes the rain with it, causing extensive drought in the western Pacific and rainfall in the normally dry eastern Pacific.