Ch.10

Aquatic Biomes Water covers ~ 70% of Earth Aquatic habitat: organisms live in or on water Grouped by depth and salinity of water Rainfall and temp. categorize land biomes, but temp. of waters is fairly consistent and rainfall does not affect the organisms Campcrescent.com

Salinity Salinity: amount of dissolved salts in the water Saltwater: 30 parts/thousand Oceans and some lakes (Great Salt Lake in Utah) Many saltwater lakes are 40 parts/thousand…..why? Freshwater: 0.5 parts/thousand Most lakes, ponds, and rivers

Salinity Hydrometer measures density of water by testing buoyancy Buoyancy amount of mass that can float on the water Increase in salt  inc. in density  inc. in buoyancy Ex/Water_Buoyancy.htm

Depth Ecosystem depends on amount of sunlight that reaches the bottom More sunlight results in a greater number of plants Plants-basis of food web More plants leads to more animals

Depth Zones

Depth zones Plants only grow in photic and shallow parts of benthic zone Benthic animals: insect larvae, snails, catfish, turtles Alvin, the research submarine, studied cracks in the ocean floor Base of the food web down there was bacteria Bacteria use energy from chemicals that ooze through those cracks

Questions 1. H0w is salinity determined and measured? 2. Suppose a friend wants to set up an aquarium and discovers that saltwater fish are more attractive, but a freshwater tank is easier to maintain. Your friend decides to set up a freshwater aquarium but buys some saltwater fish to place in it. Predict what the result of this decision would be, and why?

2 types of freshwater biomes Standing water Ponds, lakes, marsh, swamps Flowing water

Standing Water: Abiotic FactorsBiotic Factors LakeDeepest standing water, may have aphotic zone Main producers: floating algae in the photic zone and benthic plants along shoreline PondLight reaches benthic zone; fed by rainfall Producers: plants and algae that grows on bottom MarshVery shallow; soil is saturated; often lacks oxygen….Florida Everglades is the largest marsh in US Plants roots under water, leaves above; mostly grasses; ducks, waterfowl, and benthic animals are common. SwampPoor drainage; soil saturated; along flat land; usually along coastline Dominated by large trees and shrubs; plants adapted to growth in mud & oxygen-poor soil BogInland wetland with little in or outflow; soil acidic; decay is slow; carbon stored in dead plants Sphagnum moss is dominant organism

Standing water organisms Top level Plankton Organisms that drift in water About size of a dust particle Phytoplankton: carries out photosynthesis Main producers in aquatic biomes Zooplankton: don’t carry out photosynthesis Consumers: feed on phytoplankton Benthic Zone Home to scavengers Feed on remains of other organisms

Wetlands Roots of plants are submerged under water at least part of the year Examples: marshes, swamps, bogs Soil is soaked with water and contains little dissolved oxygen Important in biosphere Filter chemicals in water Migratory fowl breed, feed, and rest there Water sweeps into and refills aquifers Protection against floods

Wetlands Common grass is papyrus Egyptians first used to make paper around 3000 bc Most common writing surface in eastern Mediterranean for over 4000 years

Wetlands-human impact More than half the wetlands in the U.S. have been destroyed Not attractive Give off unpleasant odor (methane from bacteria) Breeding ground for mosquitoes Usually on coast so can be ideal for development companies Large so are used at times as landfills Clean water act: prohibits the filling of wetlands In US only 8% wetlands are federally protected

Florida Everglades Home to a large number of organisms Adapted to cycles of growth, drought, and fire Water was drained from the everglades to create farmland 1947: Everglades National Park Created to save everglades, but needed water 1967 a canal was dug to get water to park Water came too fast in too narrow of a stream Caused flooding of the area and organisms homes 93% decrease of bird population and decline of alligators 1983: Save our Everglades campaign Designed to clean up contamination from farms and restore a natural water flow  100,000 acres of wetland has been restored

Questions 1. What is the difference between the role of phytoplankton and that of zooplankton? 2. The number of migratory birds in the tundra during the summer has been declining. How might changes that have taken place in the wetlands have contributed to this decline?

Flowing Water Rivers, streams, creeks, brooks Scientists refer to all above ground bodies of water as Streams.

Flowing Water Organisms Organisms that live in flowing water habitats are adapted to the rate of water movement. Adaptations: Hooks (grab plants) Suckers (attach/anchor to rocks) Salmon and trout are well adapted to flowing water Grow in freshwater but spend adult life in ocean Breeding season they swim upstream to same spot they hatched Find the “spot” by smelling the small amt of chemicals in H2O

Flow Most streams begin at high altitude From runoff of melting snow Gravity brings downhill Starts Inland usually then goes out to ocean Where streams slow down is where a majority of sediment accumulates Sediment provides a place for plant roots to grow Colder water contains more dissolved oxygen and therefore supports more animal life Why pop loses its fizz when room temperature

Flow Erosion along the fast-flowing outer edge and sedimentation along the slow-flowing inner edge result in the winding, or meandering, of a stream The older a stream is the more curvy it gets Human activity Streams have been dammed to make resevoirs Dams, dikes, and irrigation canals used to change stream courses Dams also used to control flooding

Questions 1. Why are there fewer organisms in the headwater of a stream than further downstream? 2. the headwaters of a stream often contain more dissolved oxygen than the water hundreds of kilometers downstream. Why is this true?