1. Freshwater & Marine Ecosystems

2. Characteristics of Aquatic Ecosystems
Keep in mind that factors such as temperature, sunlight, oxygen, and nutrients determine which organisms live in which areas of the water.
An example: sunlight reaches only a certain distance below the surface of the water, so most photosynthetic organisms live on or near the surface.

3. Characteristics of Aquatic Ecosystems
Organisms that live in aquatic ecosystems are grouped by their locations and their adaptations.
There are three groups of aquatic organisms: plankton, nekton, and benthos.

4. Characteristics of Aquatic Ecosystems
Plankton are organisms that cannot swim against currents, so they are drifters.
Drifting plants are called phytoplankton and are the food-base for most aquatic ecosystems.
Drifting animals, which may be microscopic, or as large as jellyfish, are called zooplankton.

5. Characteristics of Aquatic Ecosystems
Nekton are free-swimming organisms such as fish, turtles, and whales.
Benthos are bottom-dwelling organisms, such as mussels, worms, and barnacles.
Many benthic organisms live attached to hard surfaces.
Decomposers, which break down dead organisms, are also present in aquatic ecosystems.

6. Lakes & Ponds
Lakes & ponds can be structured into horizontal and vertical zones.
Two main zones of standing water:
Littoral zone—near shoreline, shallow, light, nutrient rich, diverse life—plankton and neckton
Benthic zone—bottom, dark, murky—bottom dwellers and decomposers

7. Eutrophication
Build up of nutrients from decaying organisms which tends to deplete the oxygen supply to the free swimming organisms.
Artificial Eutrophication occurs when humans add fertilizers from runoff and cause rapid algae blooms and then they die, depleting the oxygen as they decompose.

8. Wetlands Have standing water part of the year. 2 types:
Marshes—non-woody plants—cattails, water lilies, grass, etc. Florida Everglades is largest marsh in US
Swamp—woody plants—trees and bushes; Okeefenokee Swamp

9. Wetlands Wetlands are a natural wonder:
Wetlands act as sponges, because they absorb and remove pollutants from water; therefore, wetlands improve the water qualities of lakes, rivers, and reservoirs
controlling water to reduce flooding;
provide spawning and nursery areas for many fish
providing a nesting site and resting site for migratory birds;
the vegetation traps carbon, which can form coal after millions of years.

10. Wetlands: Marshes
Marshes tend to occur on low flatlands that have little water movement
The salinity of marshes varies; some marshes have slightly salty (bracksih) water, while other marshes have water that is as salty as the ocean

11. Wetlands: Swamps
Swamps occur on flat, poorly drained land, often near streams.
The species of trees and shrubs in a swamp depend on the salinity of water and the climate of the area.
For example: mangroves are trees that grow in saltwater swamps in tropical climates.
Freshwater swamps are the ideal habitat for amphibians because of the continuously moist environments. Reptiles are found here as well.

12. Human Impacts on Wetlands
The wetlands have been drained:
to prevent the increase of mosquitoes and their diseases
to provide additional farmland for crops
to build roads, homes and businesses
Federal laws now prohibit the draining of wetlands.

13. Rivers Many rivers originate from snowmelt in mountains.
At its headwaters, a river is usually cold and full of oxygen, and runs swiftly through a shallow riverbed.
As a river flows down a mountain, it becomes warmer, wider, and slower-containing more vegetation and less oxygen.

14. Life in a River
Near the churning headwaters, mosses anchor themselves to rocks by using root-like structures called rhizoids.
Trout and minnows are adapted to the cold, oxygen-rich headwaters.
Trout are powerful swimmers and have streamline bodies that present little resistance to the strong current.
Downstream, plants set roots in the rivers rich sediment; fish, such as catfish, also live in the calmer waters.

15. Rivers in Danger!!!
Communities & industries affect the health of rivers by drawing water to use in homes, manufacturing and to dispose of their sewage and garbage.
These practices have polluted the rivers with toxins that have killed river organisms and made river fish unsuitable for eating.
Today, runoff from the land puts pesticide and other poisons into rivers and coats river beds with toxic sediments.

16. Marine Ecosystems
Marine ecosystems are ecosystems that contain saltwater.
Such ecosystems are found in & around the world’s oceans.
In the open water, the amount of sunlight and available nutrients varies from one part of the ocean to another.
In coastal areas, the water level and salinity usually change during the day.

17. Coastal Wetlands
Coastal wetlands are areas that are covered by saltwater for all or part of a time.
They provide habitat and nesting areas for many fish & wildlife.
They absorb excess rain, which provides areas from flooding.
They filter out pollutants & sediments.
They provide recreational areas for boating, fishing & hunting.

18. Estuaries
An area in which freshwater from a river mixes with saltwater from the ocean is known as an estuary.
As the two bodies of water meet, currents form and cause mineral rich mud and dissolve nutrients to fall to the bottom.
In many ways, they are a nutrient trap that provides available nutrients to producers.
They are very productive ecosystem because they constantly receive fresh nutrients from the river.

19. Plants & Animals of Estuaries
Estuaries support many marine organisms because they receive plenty of light for photosynthesis and plenty of nutrients for plants and animals. (rooted plants & plankton)
Light & nutrients  plants & plankton  fish dolphins, manatees, otters
Oysters, barnacles, and clams live anchored to marsh grass or rocks and feed by filtering plankton out of the water. (varying salinity)

20. Threats to Estuaries Landfill
Sewage, industrial waste, & agricultural runoff
Majority of the pollutants eventually break down over time, but estuaries cannot cope with the excessive amounts produced by dense human populations

21. Salt Marshes
In estuaries where rivers deposit their load of mineral-rich mud, salt marshes are formed.
Salt marshes support a community of clams, fish, and aquatic birds and also act as a nursery for many species of shrimp, crabs, and fish.
Salt marshes, like other wetlands, absorb pollutants and protect inland areas.

22. Mangrove Swamps
Mangroves are several species of small trees adapted for growing in shallow saltwater.
Dense growths of mangrove trees in swampy areas are called mangrove swamps and are found in tropical and subtropical zones.
They help to protect the coastline from erosion and reduce the damage from storms.

23. Rocky & Sandy Shores
Rocky shores have many more plant and animal species than sandy shores.
The rocks provide anchorage for seaweed and the many animals that live on it, such as sea anemones, mussels, and sponges.
Sandy shores less biodiversity but still abundant in life
The animals here are adapted to the effects of drying and exposure to low tide
Barrier islands often run parallel to sandy shores and help to protect the mainland and the coastal wetlands from storms and ocean waves.

24. Coral Reefs
Coral reefs are limestone ridges built by tiny coral animals called coral polyps and the algae that live inside them.
Coral polyps secrete skeletons of limestone (calcium carbonate) which slowly accumulate and form coral reefs.
Coral reefs are among the most diverse ecosystems on earth. Because reef-building corals live only in warm saltwater where there is enough light for photosynthesis, they are found in shallow, clear, tropical seas.
They are a habitat for a magnificent variety of fish, snails, clams, sponges, and many different other types of organisms.

25. Coral Reefs in Danger!!! They are fragile ecosystems.
If the surrounding waters are too hot or cold for too long or if it is too muddy, polluted or high in nutrients, the algae that live in the coral will leave or die. As a result, the corals turn white-a condition called coral bleaching.
Since the 20th century, bleaching events have been occurring more & more frequently, mainly due to human activities.
In addition=global warming, oil spills, and polluting runoff

26. Oceans
Much of the oceans life in concentrated in the shallow, coastal waters. This occurs because water absorbs light, sunlight that plants can use for photosynthesis, penetrates only about 330 feet into the ocean.
Seaweed, algae, phytoplankton  invertebrates & fish are also concentrated near the shore

27. Plants & Animals of Oceans
Phytoplankton grow only in areas where there’s enough light and nutrients. As a result, the open ocean is one of the least productive of all the ecosystems.
The seas smallest herbivores are the zooplankton (jellyfish, tiny shrimp), which live near the surface with the phytoplankton they eat.
The depths of the ocean are perpetually dark, so most food at the ocean floor consists of dead organisms. Decomposers & filter feeders and the organisms that eat them live in deep areas of the ocean.

28. Threats to the Ocean
Oceans are steadily becoming more polluted, which arises from activities on land. Example: runoff from fertilized fields = algae blooms. Waste from cities & industries, fertilizers, and sewage running off the land are the main sources of coastal pollution in the US.
Over fishing and certain fishing methods are also destroying some fish populations. (trawl nets)

29. Arctic & Antarctic Ecosystems
The arctic ecosystems at the north and south poles are marine ecosystems because nearly all the food comes from the oceans and seas.
The arctic ocean is rich in nutrients from the surrounding land masses and supports large populations of plankton  fish  birds, whales and seals  polar bears, people
The Antarctic is the only continent never colonized by humans. Plankton  fish  whales, penguins which cannot fly because their wings have evolved for swimming