Lecture 12/13 Flashcards
Define salt water
relatively high levels of dissolved salts
Define freshwater
relatively pure, with few dissolved salts
- short supply of drinkable freshwater
- groundwater (20%) and surface freshwater (1%)
Define pollution
release of matter of energy into the environment that causes undesirable impacts on the health and well-being of humans or other organisms largely caused by human actions
point source pollution
discrete locations of pollution
-e.g factory, industry, sewer pipes, shipping
non-point source pollution
pollution from multiple cumulative inputs over a large area
- e.g cities, farms, mining, logging
define watershed
the land area surrounding a body of water over which water such as rain can flow and potentially enter that body of water
what are some examples of water pollution
- nutrient pollution
- sediment
- thermal pollution
- oil pollution
- plastic pollution
- toxic chemicals
define coral bleaching
occurs when symbiotic algae leave coral
What leads to eutrophication
fertilizers, farms, sewage, lawns, golf courses
What are some solutions to eutrophication
- phosphate-free detergents
- planting vegetation to increase nutrient uptake
- treat wastewater
- reduce fertilizer application
Define HABS
Harmful algal blooms= nutrients increase populations of algae that produce toxins
What are some examples of sediment pollution
clear-cutting, mining, poor cultivation practices
Define red tide
algal species produce reddish pigments that discolour water
- causes illness/death to wildlife/humans
- economic losses to fishing industries and beach tourism
What are some solutions to sediment pollution
- better management of farms and forests
- avoid large-scale disturbance of vegetation
what are some effects of sediment pollution
- dramatically changes aquatic habitats
- fish may not survive
What are some examples of thermal pollution
warmer water holds less oxygen
- dissolved oxygen decreases as temperature increases
- industrial cooling heats water
- removing streamside cover also raises water temperature
colder water also causes problems
- water at bottom of reservoirs is colder
- when water is released, downstream water temperatures drop suddenly and may kill aquatic organisms
What are some solutions for thermal pollution
modify industrial processes to reduce thermal shock
What are some problems caused by oil spills
- Most oil pollution from small sources: boat leakage/runoff from land
natural leaks from the seabed - Oil spills coat and poison wildlife
What are some solutions for oil spills
- Governments have implemented more stringent regulations
- Oil spills have decreased with greater oil industry compliance
What are some examples of plastic debris marine life endangerment
- Plastic is non-biodegradable
- drifts for decades
- washes up on beaches
- wildlife eat it or get entangled
- Marine debris affects people
- equipment / property damage
- negative aesthetic impacts
What are some examples of toxic chemicals
- arsenic, lead, mercury, acid rain, acid drainage from mines
- pesticides, petroleum products, pharmaceuticals, synthetic organic chemicals
What are some effects of toxic chemicals
- poisoning animals and plants
- altering aquatic ecosystems
- affecting human health
What are some solutions for toxic chemicals
- modify industrial processes
- modify our purchasing decisions
- legislating / enforcing stringent regulations of industry
What are some affects of mercury contamination
- from coal combustion and other industrial sources (mining, paper)
- Examples: Minimata Japan (1956) and Grassy Narrows First Nation Ontario (1970s)
- bioaccumulates/ biomagnifies in food web
- dangerous to young children, pregnant or nursing mothers – neurological effects
- avoid eating swordfish, shark, albacore tuna
- eat seafood low in mercury (catfish, salmon, canned light tuna)
What are some solutions for mercury (toxic chemicals)
- avoid seafood from affected areas
- monitor/regulate mercury discharges
What are some examples of toxic chemicals occur naturally
aluminum, cadmium, chromium, fluoride, lead, mercury, sulfates
What are some examples of groundwater pollution caused by humans
- wastes leach through soils
- pathogens enter through improperly designed wells and landfills
- hazardous wastes are pumped underground
- underground storage (septic tanks) leak
How can increasing water supply be a strategy for pollution prevention
- can be transported through pipes/aqueducts
- can be forcibly appropriated from weak communities
- can use new sources of water (e.g. desalinization)
Define desalinization
removal of salt from seawater or other water of marginal quality
Define distilling
hastens evaporation and condenses vapour
define reverse osmosis
forces water through membranes to filter out salts
Define lowering demand (pollution prevention)
- politically difficult in the short term
- offers better economic returns
- causes less ecological and social damage
reducing agricultural demand for water
- low-pressure spray irrigation that sprays water downward
- drip irrigation systems that target individual plants
match crops to land and climate - selective breeding and genetic modification to raise crops that require less water
reducing residential (domestic) demand for water
- Install low-flow faucets, toilets, showerheads, washing machines
- Use automatic dishwashers instead of washing dishes by hand
- Water lawns at night, when evaporation is minimal
- Eat less meat
Define xeriscaping
landscaping using plants adapted to arid conditions
Reducing industrial demand for water
- Shift to processes that use less water
- wastewater recycling
- excess surface water runoff used for recharging aquifers
- patching leaky pipes
- auditing industries
- promoting conservation/education
How does climate change affect hydrological cycle
- altered precipitation patterns
- early seasonal (spring) runoff
- more evapotranspiration
- intensified droughts
- melting glaciers
- more flooding
What are some benefits to encouraging greater water infiltration into soils
- reduce flooding
- reduce run-off
- prevent water pollution of surface waters
- capture water for lawns and reduce irrigation needs
- reduce stormwater losses
define non-consumptive use
does not remove, or only temporarily removes, water from an aquifer or surface water (e.g. electricity generation at hydroelectric dams)
define consumptive use
water is removed from aquifer or surface water body, and is not returned
engineering water projects: dam
Used to control/change water flow for human uses (e.g. agriculture, energy, urbanization)
what are some benefits of dams
- power generation
- crop irrigation
- drinking water
- flood control
- shipping
- new recreational opportunities
what are some drawbacks to dams
- habitat alteration
- fisheries declines
- population displacement
- sediment capture
- disruption of flooding patterns
- risk of failure
- lost recreational opportunities
water supplies agricultural, industrial and residential (domestic) needs (consumptive water use)
70% –> agriculture
20% –> industry
10% –> domestic
Proportions of these three types of use vary among nations
- arid countries use water for agriculture
- developed countries use water for industry
Define water mining
withdrawl of water faster than replaced
define wetlands
drained land used for agriculture, cities
Why is groundwater depleted so easily
- Groundwater easily depleted
- aquifers recharge slowly
- 1/3 of world population relies on groundwater for freshwater
what happens as aquifers become depleted
- water tables drop
- salt water intrudes in coastal areas
- sinkholes form
- wetlands dry up
define sinkholes
areas where ground gives away unexpectedly
define inland seas
large lakes that hold so much water, their biota is adapted to open water
define currents
ocean has flow patterns driven by density differences, heating, cooling, gravity, and wind
what do currents do
- transport heat, nutrients, pollution, and organisms
- affect climate
- create gyres
define gyres
vortex-like circulation patterns
what are the vertical zones the oceans are divided into
sunlight (epipelagic), twilight (meso and bathypelagic), darkness (abyssopelagic), hadal zone (deep trenches)
define how marine waters are used as transportation routes
- move people and products over vast distances
define how marine waters are used as energy resources
- crude oil/natural gas - issues of oil spills that damage fisheries
- renewable energy sources
define how marine waters are used for mineral resources
- minerals
- rich deposits of metals
- manganese nodules are scattered along the ocean’s floor
define how marine waters are used as food sources
- demand on fisheries worldwide for proteins
- demand for food and industrialization of fisheries has significantly increased pressures on fish and seafood populations worldwide
define factory fishing
highly industrialized, huge vessels use powerful technologies to capture fish in huge volumes
define drift nets
for schools of herring, sardines, mackerel, sharks
define longline
fishing for tuna swordfish
define trawling
for pelagic fish and groundfish
define by-catch
the accidental capture of non-target organisms
define marine protected areas (MPA’s)
established along coastlines of developed countries
- allowed controlled fishing
define aquaculture
farmed fisheries
- makes up for loss of capture through fisheries
- growing industry to supply seafood - replacing traditional fisheries
what are two types of aquaculture
- open-water pens
- land-based tanks
what are some benefits of aquaculture
- improves food security
- reduces pressure on wild stocks
- 10-100 times more energy-efficient
what are some drawbacks of aquaculture
- increased disease causes more antibiotic use
- high-density fishery causes more waste
