Topic 4 Flashcards
Water statistics
97% in oceans, 2.6% freshwater
Human impacts on the water cycle
Withdrawals (domestic, irrigation, agriculture, industry)
Discharges (adding pollution)
Changing the speed/direction of the water flow
Oceans and energy distribution
Important in distribution of global energy
Water scarcity
How much we use, how it’s used, little to no access
Things that impact water
Climate changes impacts rainfall Aquifers are being exhausted Freshwater can become contaminated Irrigation leads to salinization Pollution Warm water released w less DO
Solutions
Increase freshwater supplies Reduce domestic usage Use carwashes Grey water systems Reduce pesticides and fertilizer use Replace chemicals with organics
Marine ecosystem and food webs are
High biodiversity
Higher productivity
Phytoplankton
Can do photosynthesis, 99% of productivity in oceans
Zooplankton
Animals, eat phyto and their waste
Benthic
Lives on sea bed
Pelagic
Lives suspended in the water
Fisheries
Shellfish and vertebrates
Important food source for humans
70% are exploited
Demand is rising w better technology but fish aren’t there
Aquaculture impacts
Loss of habitat Pollution Spread of disease Escape of GM species Escape may outcompete native species
Why is the wild fishing industry unsustainable?
Advanced technology Large fleets (can keep taking more and more)
Maximum sustainable yield
Highest amount that can be taken without permanently depleting the stock
SY=total energy or biomass at time plus one - total energy and biomass at time two
SY= annual growth and recruitment-annual death and emigration
Cons to using MSY
Populations predicted, not counted Impossible to be precise about pop size Estimates are made on past years Model doesn't allow for sex or age dynamics Disease may strike a population
Freshwater pollutant sources
Agriculture, sewage, industrial discharge, solid domestic waste
Marine pollutant sources
Rivers, pipelines, atmosphere, human activities at sea
Biochemical oxygen demand(BOD)
Measurement of DO required to break down organic material
Biotic index
Indirectly measures pollution by looking at the species in the community and their tolerances, diversity, and abundance
Direct measurements of water pollution
Salt water: salinity pH temp
Freshwater: pH temp DO
Altering human activity
Ban or limit detergents
Buffer zones
Detergents w/o phosphates
Regulating and reducing
Treat wastewater before release (remove phosphates and nitrates)
Divert or treat sewage waste effectively
Minimize fertilizer usage on agricultural lands
Restoration
Pump air thru lakes
Remove excess weeds
Restock water w appropriate organisms
