AQUATIC ECOSYSTEMS

SALINITY The types of organisms in an aquatic ecosystem depend upon the water’s Salinity. It's the amount of dissolved salts the water contains. Salinity determines the two main aquatic systems: Fresh water ecosystems Marine ecosystems

CHARACTERISTICS OF AQUATIC ECOSYSTEMS Plankton – Organisms that cannot swim against currents. Plankton is a Greek word which means “wanderer" or "drifter" and it is used to describe the class of marine plants and animals which have limited ability or no ability to move or "swim". They simply drift in the ocean currents and occupy most of the surface area of the earth's oceans. Marine means “of the ocean", so marine plankton are organisms which can live and grow in salt water.

TWO TYPES OF PLANKTON Phytoplankton are microscopic plant type organisms. They use photosynthesis. Zooplankton are drifting microscopic animal organisms.

ZOOPLANKTON Zooplankton have one bright red eye, travel in swarms, propel their armored bodies through ocean currents with the speed of a jaguar and originate from the time of the dinosaurs. If they weren’t smaller than 1 mm, copepods and other zooplankton might be considered fearsome aquatic predators, but instead they serve as both the low end of the food chain and a vital warning system for global climate change.

NEKTON Nekton are free-swimming organisms such as fish, turtles, whales, etc. Nekton come in all shapes and sizes. They live in shallow and deep ocean waters. Most nekton eat zooplankton, other nektons or they scavenge for wastes.  

BENTHOS Benthos are bottom dwelling organisms. The benthos live on the ocean floor. Starfish, oysters, clams, sea cucumbers, brittlestars and anemone are all benthos. Most benthos feed on food floating by or scavenge for waste on the ocean floor.

FRESHWATER ECOSYSTEMS Lakes Rivers Wetlands – water that is periodically underwater.

LAKES AND PONDS Life in a lake can be structured into zones. Littoral Zone which is nutrient-rich, near the shore. It has a high diversity of plants and animals. Benthic zone which is at the bottom of a pond or lake. It is inhabited by decomposers, insect larvae, and clams.

LITTORAL ZONE

BENTHIC ZONE

HOW NUTRIENTS AFFECT LAKES Eutrophication is an increase in the amount of nutrients in an aquatic ecosystem. Usually occurs in lakes with large amounts of algae and plant growth. Increased number of bacteria are present. The bacteria use up all the oxygen in the water and all other organisms that need oxygen must either move or die.

EUTROPHICATION Eutrophication is usually accelerated by land run-off. Fertilizers get into the water system and can cause/speed up eutrophication.

FRESHWATER WETLANDS Two types: Marshes – low, flat lands that have little water movement nutrient rich shallow water salinity of marshes vary Brackish water – slightly salty Can have as much salinity as the ocean.

ADAPTATIONS - WETLANDS Ducks have long bills adapted for fishing for fish and insects. Herons have long beaks to grasp small fish and to probe for frogs.

FRESHWATER WETLANDS Swamps – flat, poorly drained land Organisms adapt to the salinity and moistness of swamps Human impact on wetlands: Sometimes considered wastelands for insect breeding Many have been drained, filled in or cleared for _farmland, residential/commercial development. Example: Florida Everglades Once covered 8 millions acres Now 3 million acres

FRESHWATER WETLANDS Wetlands are actually purifiers of wastewaters Useful in flood prevention Freshwater game fish use it for feeding and breeding.

RIVERS Many originate from the melting waters from snow melt on mountains. As water flows farther from it start, becomes warmer and wider. Also gains nutrients from land runoff Life in a river Plant /animal species vary depending on where rivers are located Examples: trout – areas of strong currents, cold/oxygen-rich waters catfish/carp in the deeper, calmer rivers

RIVERS Rivers in danger Sewage disposal, manufacturing wastes, and pesticides are a few of the pollutants that get into out lakes and rivers. Dams alter an effect ecosystems in an around rivers.

Task: Freshwater Lake Posters Draw a cross section of a lake. Include and label the following items: Littoral Zone, Benthic Zone, Nekton, Plankton, Decomposers, and Benthos Notate the area of the highest diversity of plant and animal life.

MARINE ECOSYSTEMS All marine ecosystems contain saltwater. Coastal Wetlands Large habitats used for nesting birds Absorb excess rain-Protection from flooding. http://www.estuaries.gov/ (Videos)

ESTUARIES An estuary (pronounced es choo eree) is a coastal area where fresh water from rivers and streams mix with water from the ocean. Many bayous and lagoons along coasts are estuaries.

MARINE ECOSYSTEMS Currents cause a mineral rich mud with dissolved nutrients. Species that evolve in estuaries have adapted to the changes and extreme conditions in their environment.

PLANTS AND ANIMALS IN ESTUARIES Plants and Animals of Estuaries - The community of life found in these waters-mammals, birds, fish, reptiles, shellfish, and plants – all represented within complex food webs. Shallow areas offer a lot of light (photosynthesis). Allows for large food webs.

THREATS TO ESTUARIES Threats to Estuaries Earlier in history they were used as solid waste land-fills. Developed as building sites. Long considered to be wastelands, estuaries have had their sediments dredged, marshes and tidal flats filled, destroyed, and shorelines reconstructed to accommodate housing, transportation, commerce, industry, and agricultural needs.

ESTUARIES Pollution damages estuaries which impacts many organisms. Many species give birth in these areas. Estuaries have economic, natural, and aesthetic value. People are attracted to the water and visit estuaries to boat, fish, swim and enjoy their beauty. As our population grows and the demands imposed on our natural resources increase, so too does the importance of protecting these resources for their natural and aesthetic values.

ESTUARIES IN THE US

SALT MARSHES Estuaries where rivers deposit their mineral rich mud. Act as nurseries for many species. Absorbs pollutants http://www.knowitall.org/sclife/

MANGROVE SWAMPS Mangrove Swamps Species of small trees adapted for growing in shallow salt water with above ground root systems. Found in subtropical and tropical areas. Protect coast lines from erosion. Can provide habitats for over 2,000 animal species.

ROCKY AND SANDY SHORES Rocky Shores Rocks protect seaweed and many animals that live on it. Sea anemones, mussels, sponges.

SANDY SHORES Life on the sandy shores is more diverse than on rocky shores. Birds feed at low tide in the sand.

BARRIER ISLANDS Barrier islands – sandy/rocky islands that run parallel to sandy shore lines. Protects land from storms and ocean waves.

CORAL REEFS Coral Reefs – limestone ridges built by tiny coral animals called polyps and the algae that live inside them. http://www.mbgnet.net/salt/coral/index.htm

CORAL REEFS Thousands of plant and animal species live in these coral reefs. Most diverse habitats in the world. Found only in shallow tropical seas because of the warm salty water and enough light for photosynthesis.

CORAL REEF ANIMALS

CORAL REEFS IN DANGER Very fragile ecosystems Change in water temperature, acidity, nutrient levels can lead to death of the algae. Leads to the removal of living species– coral bleaching. 50% of the worlds coral reefs are in danger of destruction. Over Fishing upsets the balance too. Takes a long time for coral to grow  destroyed faster than it can regrow.

OCEANS Light only penetrates the ocean to about 100 m. All photosynthesis occurs above that line. Plants and Animals of Oceans Most organisms live near the coastal areas. Phytoplankton stay near the surface – the basis for most food webs in the ocean At the bottom are decomposers, filter feeders, and predators that feed on them.

THREATS TO OCEANS Threats to Oceans Fertilizer runoff  algal blooms (red tide is poisonous) Over- fishing Ocean mammals drown while caught in nets, fishing lines, plastics.

ARCTIC AND ANTARCTIC ECOSYSTEMS Diverse organisms from the plankton up to whales. Nutrient rich areas.

Brain Pop Underwater World:http://www.brainpop.com/science/earthsystem/underwaterworld/preview.weml Oceans:http://www.brainpop.com/science/earthsystem/oceans/preview.weml