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Streams and Wetlands (and intro to Aquaculture?). August 28 th , 2007. LAKES: Nutrient cycling and algal blooms. Is this lake eutrophic or oligotrophic?. Streams and Rivers. Streams and Rivers. 1 st order (headwaters). 2 nd order. 3 rd order. 4 th order. 5 th order. - PowerPoint PPT Presentation
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Streams and Wetlands (and intro to Aquaculture?)
August 28th, 2007
LAKES: Nutrient cycling and algal blooms
Is this lake eutrophic or oligotrophic?
Streams and Rivers
Streams and Rivers
5th order
4th order
3rd order
2nd order
1st order (headwaters
)
How do large and small streams differ?
• Low stream order (i.e., 1st or 2nd order)• Small, narrow, shallow• Steep, fast-flowing rocky bottom• Detritivore community breaks down litter
• High stream order (i.e., 4th or 5th order)• Big, wide, deep• Shallow slope, slow flowing• Processed litter comes from upstream
Stream/River Characteristics
• Streamflow is determined by:– Relief– Volume of Input– Temperature
• Important abiotic factors:– Sediment/Turbidity– Nutrients– Temperature– Substrate
Adaptations to Stream and River Ecosystems:
How have humans impacted Salmon?
Alterations to Stream Habitat
ChannelizationChannelization Fish barriers (roads/bridges)Fish barriers (roads/bridges)
Change in riparian vegetationChange in riparian vegetation
Changes in temperature, flow rate,turbidity, dissolved oxygen, p.p.,substrate, …..
Local Watersheds
http://www.sbck.org/pdf/GSTReport-Background.pdf
Atascadero Creek http://www.sbck.org/pdf/GSTReport-Background.pdf
What’s a Wetland?
Ecotones- contain characteristics of two habitats (in this case, aquatic and terrestrial)
Wetland- a broad term for all the different kinds of wet habitats where the land is wet for some period of time each year but not necessarily permanently wet.
Wetlands of the World
Wetlands: where water meets land
Types of Wetlands:
• Intertidal zone marine wetland
• Estuarine: river mouth + tides= brackish
• Freshwater: swamps, fens, bogs, and vernal pools
Which US state has lost the largest % of its wetlands (1780-1980)?
CA- 91% decline (source: USGS)
U.S. total = 53% decline
• When land is flooded, O2 gets used up by decomposers and the soil becomes anaerobic
• Demand for O2 is still high• Other minerals containing oxygen get reduced
• Reduction is when a compound gains an electron- in this case by giving up an O2 atom
• Some molecules release O2 more easily than others
Wetland Biogeochemistry: Depends on HYDROPERIOD!
O2 NO3- Fe(OH)3 MnO2 SO4
2- CO2
•If the water level drops, O2 enters the soil again, and
the reduced substances can get oxidized
Salt Marsh Biogeochemistry
Wetland Adaptations
Why Should we Care about Wetlands?
Wetland Ecosystem Services
• Food/Jobs
• Important Habitat for Species
• Clean water/Nutrient storage
• Flood control
• Erosion control
• Carbon storage (sink?)
• Tourism
• “No net loss” protection for wetlands?
•How could you calculate the value of a wetland?
What is the value of a wetland?
• “Value” is a human judgement call– Depends on if you are a:
• Developer• Farmer• Engineer• Hunter• Ecologist• Chemical plant owner
Why are Wetlands Diminishing?• Drained or Filled
• Agriculture/residential development/industrial development/oil and gas exploitation
• Lowering of water table
• Polluted• wetlands are in low-lying areas
• Natural causes
Local Watersheds
http://www.sbck.org/pdf/GSTReport-Background.pdf
Goleta Slough
Goleta Slough: Endangered Species + Globally Important Bird Area
Tidewater Goby
CA least tern Red-legged Frog
American peregrine
falcon
Diminishing Wetlands
Salt MarshLake: Santa Barbara Bird Refuge
Penfield & Smith Engineers, Inc.. 1985. Limnological investigation of euthrophication at the Andree Clark Bird Refuge and recommendation for mitigating actions.~135 pp.
“Mother Nature at work,” ? http://www.virtualtourist.com
Other Local Wetland Projects:
• Vernal Pools
• Carpinteria Salt Marsh
• Ormond Wetland
Changing Perceptions of Wetlands
http://www.countyofsb.org/project_cleanwater/Web_Images/South_Turnpike_BMP_Xsection.jpg
Bioswales: mimic wetland processes
Wetland Value and Natural Disaster
Cypress trees mitigate impactsof Hurricane Katrina
Mangroves lessen tsunamiimpacts
Wetlands and Aquaculture: Conversion of Mangroves to Shrimp Farms
Mangrove forests once covered 3/4 of the coastlines of tropical and subtropical countries. Today, less than 50% remain. Many factors contribute to mangrove forest loss, including the charcoal and timber industries, urban growth pressures, and mounting pollution problems. However, one of the most significant causes of mangrove forest destruction in the past decade has been the consumer demand for luxury shrimp
The Rise and Fall of the Blue Revolution: Article by Alfredo Quarto published in the East Africa Wildlife Society's magazine SWARA
AQUACULTURE: The AQUACULTURE: The BlueBlue Revolution? Revolution?
Aquaculture• Status: fastest growing food production industry in the
world (1/3 of all fishery landings)
Aquaculture: Fish Farms
• Energy flow perspective– Fish vs. Cows – Salmon vs. carp vs. filter feeders– Farmed salmon vs. wild salmon
Sustainable Aquaculture?
Sustainable Aquaculture?
Aquaculture: Risks
– Impact on wild fish populations• Feed for farmed fish
• ‘Seed’ for farmed fish
• Fish escapes- invasive species
– Algal blooms
– Oxygen depletion
– Downstream impacts
– Disease
– (Wet)land conversion
Aquaculture: Integrated Systems Approach
Aquaculture: Integrated Systems Approach
BENEFITS:
• Waste = food
• Whole is greater than sum of parts
COSTS/RISKS:
• Pesticide use
• Labor intensive
• Limit to fish density
What Can You Do?
• Vote with your dollars!
• Get involved!
• Educate others!
Summary• Wetland: definition
– Types– Biogeochemistry (just know the basics!)– Ecosystem Services (filtration, C storage, flood control, habitat,
food, tourism, etc)– Human causes of wetland loss– Ecosystem Value… depends on perspective.– Local Wetlands
• Aquaculture– Types– Potential impacts: wetland loss, impact on marine fisheries– Energy flow perspective– Risks– Integrated systems approach