aquatic ecosystems (09-10) marine freshwater worlds aquatic ecosystems
TRANSCRIPT
Aquatic Ecosystems (09-10)
MarineFreshwater
Worlds Aquatic Ecosystems
TypesMarine (saltwater)
Coastal zoneEstuaries
• coastal wetland• bays
Rocky and sandy shores - intertidal zonesbarrier islandscoral reefs
Open Sea
Freshwater lotic lentic
Types of life
Plankton: phytoplankton - cyanobacteria to large
“seaweed” algaeno plants in ocean ecosystems
zooplankton - protozoans to jellyfishNekton: fish, turtles, whalesBenthos: bottom-dwelling
Barnacles, oysters, worms, lobstersDecomposers - mostly bacteria
Three layers -
Depends on depth What other factors?Layers
euphotic zone twilight zone aphotic zone
Physical Factors Factors determining biotic
temperature access to sunlight availability of nutrients
CO2 - reduces global warming• CO2 CaCO3 ; stored: sediments, shells, skeletons
Nutrients• sufficient in most freshwater• open ocean, short supply, except in upwellings
dissolved oxygenWhat factors affect this?
Dep
th (
met
ers)
Concentration of dissolved gas(parts per million by weight)
0
500
1,000
1,500
2,000
90 94 98 102 106 110
0
2,000
4,000
6,000
CO2
O21.5 3.0 4.5 6.0 7.5
CO2
O2
Dep
th (
feet
)
Figure 7-4Page 146
© 2004 B
roo
ks/Co
le – Th
om
son
Learn
ing
Not earth, but Ocean Planet
71% of earth’s surface99.5% of world’s habitable volumeClimate regulation - distribute heatCarbon sinksBiodiversity: unknown numbers of
speciesEconomic services:food, pharmaceuticals,
minerals and energy, recreation
Life Zones: oceans
Coastal areas Estuarine zone Intertidal zone
Open oceans
Coastal Zone
From high tide, into estuaries, to edge of continental shelves warm, nutrient rich water Includes intertidal zone 10% of oceans, 90% of all life High productivity
Coastal life zones
Estuaries: fresh mixes with salt Values waste treatment and fish production Breeding and nurseries bays, inlets, river mouths Coastal Wetlands: salt marshes, mangroves
Sandy and Rocky ShoresBarrier Islands
Figure 7-8Page 148
Figure 7-15Page 153
Barrier Islands - Can They Last
Openocean
Sound Shallowbay Creek
Tidalriver
Salt marsh (estuary)
Barrier Islands (pg 152)
How formed?
Why important?
How do humans use and alter them?
Ocean Beach
Intensive recreation,no building
Primary Dune
No direct passage
or building
Trough
Limitedrecreation
and walkways
Secondary Dune
No direct passage
or building
Bay orLagoon
Intensiverecreation
Back Dune
Most suitablefor development
Grasses or shrubs Taller shrubs
Taller shrubs and trees
Bay shoreNo filling
Why protect the dunes?
Figure 7-14Page 152
Herring gulls
Snowyegret
Peregrine falcon
Cordgrass
Short-billeddowitcher
Marshperiwinkle
Bacteria
Clamworm
Soft-shelledclam
Zooplankton andsmall crustaceans
Phytoplankton
Smelt
Producerto primaryconsumer
Primaryto secondaryconsumer
Secondary to higher-levelconsumer
All producers and consumers todecomposers
Figure 7-11Page 150
Barrier beach
Silversides
Blue crab
Low tide
Dwarfolive
Clam
Beach flea
Tiger beetle
High tide
GhostshrimpMole
shrimp
Sandpiper
Peanut worm
White sandmacoma
Sand dollar Moon snail
Figure 7-12 (2)Page 151
Figure 7-13Page 152
Black skimmerseizes small fishat water surface
Flamingofeeds on minuteorganismsin mud
Scaup and otherdiving ducks feed onmollusks, crustaceans,and aquatic vegetation
Brown pelican dives for fish,which it locates from the air
Avocet sweeps bill throughmud and surface water in search of small crustaceans,insects, and seeds
Louisiana heron wades intowater to seize small fish
Oystercatcher feeds onclams, mussels, and other shellfish into which it pries its narrow beak
Dowitcher probes deeplyinto mud in search ofsnails, marine worms,and small crustaceans
Knot (a sandpiper) picks upworms and small crustaceansleft by receding tide
Herring gull is atireless scavenger
Ruddy turnstone searchesunder shells and pebbles for small invertebrates
Piping plover feedson insects and tinycrustaceans on sandy beaches
Specialized feeding niches = resource partitioning
Coral ReefsAmong oldest, most diverse, most
productive ecosystemsHow are they produced?Threats
Suspended soil sediment from rivers Depletion ozone - UV radiation Chemicals, pesticides runoff Cyanide and commercial fishing Oil spills
Gray reef shark
Green seaturtle
Sea nettle
Fairy basslet
Bluetangs
Brittle star Banded coralshrimp
Sergeant majorParrot fish
Hard coralsAlgae
Phytoplankton
Symbioticalgae
Zooplankton
Sponges
Bacteria
Morayeel
Blackcap basslet
Coney
Producerto primaryconsumer
Primaryto secondaryconsumer
Secondary to higher-levelconsumer
All consumers and producers todecomposers
Figure 7-16Page 154
Threats to coral reefsFigure 7-17Page 155
Ocean warming
Soil erosion
Algae growth from fertilizer runoff
Mangrove destruction
Coral reef bleaching
Rising sea levels
Increased UV exposure from ozone depletion
Using cyanide and dynamite to harvest coral reef fish
Coral removal for building material, aquariums, and jewelry
Damage from anchors, ships, and tourist divers
Open SeaBegins with sharp increase in depth at edge of
continental shelvesLow net productivity, but largest contribution
to overall biomass productionThree zones
euphotic - 90% ocean’s surface, 10% of fishonly area of photosynthesis
bathyal - migration to surface abyssal - high nutrient levels
Drift down may supply most of energy-deposit feeders
some chemosynthesis98% of 250,0000 marine species
Lakes
Distinct zonesLittoral - most productive- Why?Open water
epilimnion thermocline hypolimnion benthos
Why exist: glaciers, volcanoes, crust displacement
Oligotropic vs. Eutrophic
Oligtrophic - nutrient poor deeper, colder, low primary productivity very clear water
Eutrophic shallower, water lower visibility, higher
NPP due to phytoplanktonCultural eutrophication
High productivity, followed by lowered DO
Types of Lakes: Oligotrophic
Fig. 7-21 p. 158
Types of Lakes: Eutrophic
Fig. 7-21 p. 158
Seasonal Changes
Summer- Epilimnion: less dense warm and higher
oxygen Hypolimnion: colder, denser, lower DO
Fall and spring: “overturns” as water reaches 40 C. and becomes most dense
Seasonal Changes in Lakes Epilimnion Epilimnion
Thermocline Thermocline
Hypolimnion Hypolimnion
Fall overturn Fall overturn
Springoverturn
Springoverturn Fig. 7-22 p. 159Fig. 7-22 p. 159
Streams and Rivers
Recharge - runoff and groundwaterStream orders
1st: no tributaries2nd: one tributary3rd: 2nd order streams join
Life zones of a river(contrast chacteristics - page 159) Source waters Transition zone - middle reaches Floodplain zone- leading to mouth and estuary
River Ecosystem
Fig. 7-23 p. 160
Watersheds of PA Major rivers Primary land uses Relative size Pollution concerns Invasive species concerns
WetlandsDelineation
hydric soils high water table plants adapted to wetland conditions
Types of wetlandsWetland destruction – U.S. loss of at least
50% drained and converted to farmland, filled for
housing developments and industrial facilities, or used to dispose of household and industrial waste.
Values of Wetlands
Wetlands are natural wonderlands of great value.
Wetlands help regulate water levels within watersheds;
improve water quality; reduce flood and storm damages; provide important fish and wildlife habitat; support hunting, fishing, and other
recreational activities.
Inland Wetlands
Fig. 7-25 p. 162Fig. 7-25 p. 162
Plants and Animals of a Bog EcosystemPlants and Animals of a Bog Ecosystem
Protection of Wetlands
Section 401 of Clean Water ActWater Quality Standards and Designated
Uses A use attainability analysis must be conducted
for any water body with designated uses that do not include the "fishable/swimmable" goal uses identified in the section 101(a)(2) of the Act. Such water bodies must be reexamined every three years to determine if new information has become available that would warrant a revision of the standard.