Aquatic Life Zones Types of organisms in an aquatic ecosystem are mainly determined by salinity(amount of salt): Saltwater/ Marine life zones Freshwater life zones
Limiting Factors All zones that we discuss have limiting factors. So what is a limiting factor? Limiting factor: a resource or environmental condition that limits the growth, abundance, or distribution of an organism or a population of organisms in an ecosystem.
Limiting factors that affect aquatic organisms: Temperature Availability of light for photosynthesis Confined to Euphotic (photic) zone Dissolved oxygen content Decreases with depth Availability of nutrients (CO2, NO3-, PO43-) CO2 increases with depth Turbidity: degree of cloudiness in water Inhibits photosynthesis
Why are our oceans important? List at least 3 reasons our oceans are important. http://www.ted.com/talks/sylvia_earle_s_ted_prize_w ish_to_protect_our_oceans
What We Get From The Ocean: Climate control Nutrient cycling Habitats Food Oil Etc.
Marine Zones
Note Break!! Looking at the words phytoplankton and zooplanktion, what is the difference between the two organisms? Remember what you know about the prefix zoo and the definition of phyto is something pertaining to or derived from plants.
Types of Aquatic Organisms: Plankton: free floating organisms; 3 types: Phytoplankton = Primary producers Ex: Diatoms, cyanobacteria Zooplankton = Primary and secondary consumers Single-celled to large invertebrates like jellyfish Ultraplankton Tiny photosynthetic bacteria
Plankton!!!
Beautiful plankton http://www.planktonchronicles.org/en/episode/plankton
Types of Aquatic Organisms cont.: Nekton Strong swimmers: fish, turtles, whales https://www.youtube.com/watch?v=B6M_XgiONoo&index=4&list=PL8B8EDD0D0 2DA14B7 Benthos Bottom dwellers: oysters, sea stars, clams, lobsters, crabs, worms Decomposers: mostly bacteria
Major Life Zones
3 Major Zones Horizontal Zones (Extending from land out to sea) EX: Intertidal zone
Limiting Factors in the Horizontal Zone Temperature Salinity Nutrient availability
3 Major zones Vertical life zones
Limiting Factors of Vertical Zones Temperature Nutrient availability Available sunlight DO As you move down through the zones all of these factors decrease. Colder, darker, less dissolved oxygen, etc.
3 Major Zones Benthic Zones: Everything on the bottom. Includes all zones.
Limiting Factors in the Benthic Zone Organisms that are benthic must adapt to the limiting factors listed in the zone where they live. For example, a barnacle in a tidal pool will have different limiting factors than organisms on a deep sea vent.
Major Marine Ecosystems Coastal Ecosystems From shore to edge of continental shelf Warm, nutrient rich, shallow High in nutrients because of increased photosynthesis Contains 90% of all marine species & most fisheries
Coastal Ecosystems: ecological and economic services Maintain water quality by filtering: Toxic pollutants Excess plant nutrients Sediments Provide food, timber, fuelwood, habitats Reduce storm damage and erosion
Types of Coastal Ecosystems Estuaries: where rivers meet the sea Questions with video https://www.youtube.com/watch?v=XLumSN4G5P4 (5 min) B. Coastal Wetlands: land covered with water all or part of year: Inlets, bays, sounds, mangrove forests, salt marshes https://www.youtube.com/watch?v=jmebAjdMr Ls (3 min) Video question on estuaries: How are estuaries distinct from every other ecosystem? How much of the US population visit estuaries? Why are estuaries important? What are estuaries known as? How are estuaries part of the economy? What are some other benefits estuary give us? How much of our population live in coastal areas? Is this a good or a bad thing?
Coastal Ecosystems: c. Coral Reefs Formation Tiny animals (polyps) secret calcium carbonate shells, which become coral reefs Polyps and zooxanthellae algae have mutualistic relationship: Algae provide oxygen from photosynthesis & chemical energy Coral polyps provide home https://www.youtube.com/wat ch?v=nWyw5H88PBw (3 min)
Coastal Zone: Coral Reefs Ecosystem Services: Marine equivalent of tropical rain forests Provides habitat for one- fourth of all marine species Moderates climate b/c takes up CO2 Economic/ Social Services: Food Potential medicine Employment & Recreation https://www.youtube.com/watch?v=cbN161yBBGA (4 min)
Coastal Zone: Coral Reefs Causes of Degradation: (Human-caused) Warmer ocean temperatures leading to coral bleaching: kills algae and thus the polyps https://www.youtube.com/watch?v=iW8nCAL x5iA
How do we contribute to coral bleaching? https://www.youtube.com/watch?v=aEdoizgeNJk
Open Ocean: Three vertical zones: Euphotic zone: lit upper zone Phytoplankton perform photosynthesis Nutrient levels low & d-Oxygen levels high Have fast swimming, predatory fish Bathyal zone Dimly lit, few producers Have zooplankton and smaller fishes
Open Ocean: Three vertical zones: Euphotic zone Bathyal zone Abyssal zone Dark & cold No photosynthesis, little d- oxygen High nutrients Have deposit & filter feeders (eat marine snow), slow fish https://www.youtube.com/watch?v=BXGF3XS-yAI (2 min)
Deep Sea Adaptations https://www.youtube.com/watch?v=UXl8F-eIoiM
Major threats to marine systems: Coastal development Habitat destruction Overfishing Use of fishing trawlers Pollution Introduction of invasive species Climate change
Ocean Acidification https://www.youtube.com/watch?feature=player_embedded&v=cAwZ7VCYn44 https://www.youtube.com/watch?v=5cqCvcX7buo (20 min)
Aquatic Life Zones Freshwater Zones: services: Climate moderation Nutrient cycling Flood control Habitat Food Recreation & employment Etc.
Freshwater Life Zones: includes: Lentic (standing) bodies of freshwater: Lakes Ponds Inland wetlands Lotic (flowing) systems of freshwater: Streams Rivers
Lakes: bodies of standing fresh water formed when precipitation, runoff, or groundwater seepage fill depressions in earth’s surface
Aquatic Life Zones 4 Lake Zones: Littoral zone Near shore with rooted plants High biodiversity: turtles, frogs, crayfish, some fish Limnetic zone Open, sunlight area away from shore Main photosynthetic zone Some larger fish
Lake Zones: Profundal zone Deep water too dark for photosynthesis Some fish Benthic zone Decomposers & detritus feeders Nourished primarily by dead matter
Aquatic Life Zones Lake Types Based on Nutrient Levels: Oligotrophic lakes Low nutrients and low NPP Very clear water Eutrophic lakes High nutrients and high NPP Murky water with high turbidity Cultural (artifical) eutrophication: input of excess nutrients (fertilizers) causing excess algal growth
Oligotrophic lake
Eutrophic lake
The Effect of Nutrient Enrichment on a Lake Figure 8.17: These photos show the effect of nutrient enrichment on a lake. Crater Lake in the U.S. state of Oregon (left) is an example of an oligotrophic lake, which is low in nutrients. Because of the low density of plankton, its water is quite clear. The lake on the right, found in western New York State, is a eutrophic lake. Because of an excess of plant nutrients, its surface is covered with mats of algae.
Aquatic Life Zones Freshwater Degradation: Dams destroy habitat Flood control levees and dikes along rivers alter flow & destroy habitat Pollutants from cities and farms on streams, rivers, and lakes Draining wetlands for agriculture & development