Freshwater Flashcards
What does ‘potable’ mean?
Used for consumption
Define a lake.
Inland basin of fresh water, with a surface area of more than 1 hectare
What is a watershed?
Area of land where all water from precipitation drains to
Who is a limnologist?
Scientist that studies lakes
What are oligotrophic waters?
Lakes and ponds: low nutrient, high clarity, high oxygen conditions
What are eutrophic waters?
Lakes and ponds: high nutrient, low clarity, low oxygen conditions
What is freshwater defined as?
Less than 500mg salt per liter
What percentage of water on Earth is freshwater?
2.5%
Where is most freshwater found?
Most locked away in glaciers, groundwater; 1% on surface
What is the primary component of Earth’s water?
Ocean makes up 97.5%
What is the percentage of water usage in Canada for industry?
56%
What is the percentage of water usage in Canada for domestic purposes?
24%
What is the percentage of water usage in Canada for agriculture?
20%
What percentage of water does India use for agriculture?
87%
What is the global percentage of water usage for agriculture?
69%
What is the global percentage of water usage for industrial purposes?
23%
What is the global percentage of water usage for domestic purposes?
7%
How is water clarity measured?
Using a Secchi disk
What is thermal stratification in lakes?
Lakes divide into different layers of temperature and density
Name the three layers of lake stratification.
- Epilimnion: warmest, high O2
- Metalimnion: middle, thermocline
- Hypolimnion: cold dense water around 4C, often low to no oxygen
What is a thermocline?
Greatest temperature and density difference in a lake
What does anoxic mean?
Low to no oxygen
What is an amictic lake?
Permanent ice cover, no mixing
What is a monomictic lake?
Mixes once a year
What is a dimictic lake?
Mixes twice a year (spring and fall)
What is an oligomictic lake?
Mixes frequently
What is a polymictic lake?
Mixes multiple times a year
What is the Experimental Lakes Area (ELA)?
International Institute for Sustainable Development
When was the ELA established?
1968
What happened in 2012 regarding the ELA?
Federal government stopped funding, IISD assumed operation
What are the criteria to be an ELA?
- High lake density
- Pristine
Which lake is the most published in the world?
Lake 240
What is eutrophication?
Naturally occurring algae exposed to excessive nutrients, growing exponentially
What nutrients contribute to eutrophication?
- Nitrogen from agriculture
- Phosphorus from soaps and detergents
What are the three phases of a whole-ecosystem experiment?
- Assessment (2-4y)
- Manipulation (2-4y)
- Recovery (2+y)
What was studied during the Acid Rain Study (1976-1993)?
Lake 233 and its effects from sulphuric acid
What was the pH range in Lake 233 during the Acid Rain Study?
6.8-5.0
What was the outcome for the Mysis population in Lake 233?
Population collapsed, leading to starvation and cannibalism
What was the effect of Artificial Estrogen from 1998-2006?
Fathead minnow population crashed, remaining were feminized and intersex
What lake is used for microplastic research?
Lake L378
What percentage of microplastics is actually recycled?
9%
What is the primary size distinction between macro and microplastics?
Macro >5mm; Micro <5mm
Name some sources of microplastics.
- Tires
- Synthetic clothing
- Industry spills
- Agricultural sludge
- Poor waste management
- Wastewater effluent and stormwater run-off
- Atmospheric deposition
What are the physical effects of microplastics?
- Malnutrition from food dilution
- Block and damage digestive tracts
- Accumulate in tissues
What are the chemical effects of microplastics?
- Chemical additives leech (endocrine disruption)
- Other pollutions can absorb into microplastics (heavy metals)
What is thermal stratification?
Lakes divide into different layers and densities
How does climate change affect lakes’ oxygen levels?
More heat leads to longer stratification, resulting in less O2
What is aquaculture?
The farming of fish and bivalves due to declining wild fish populations
Where are floating net pens used in aquaculture?
In oceans and lakes
What percentage of consumed fish is farmed?
1/3 of consumed fish is fish farmed
Which region is leading in aquaculture?
Asia
List some benefits of aquaculture.
- Small scale
- Food security
- Reduce fishing pressure and bycatch
- Employment
- Less fossil fuels
- Energy efficient, produces 10x more units per area
What are some cons of aquaculture?
- Wild caught fish feed farm fish
- Dense concentrations can lead to illness
- Use of antibiotics
- Escape and interbreeding
Define a river.
A large stream of water that flows into something else
What is a tributary?
A smaller river that flows into a larger one
What is a drainage basin?
An area of land where all the water drains to
What is an oxbow lake?
A lake that forms from an extreme loop cut off from the bends of a river
Describe a braided river.
A river that moves quickly, causing sediment to shift and create multiple channels
What are flood plains?
Areas nearest to a river that are flooded ergodically
What is a riparian zone?
The riverside area that is productive and species-rich
Define wetlands.
Land that is saturated long enough to promote wetland hydrology, soil, and vegetation
What are the characteristics of a bog?
- Peat covered
- Isolated from groundwater
- Low nutrients
- Water and peat usually acidic
- Moss is common vegetation
- Trees are absent or low and stunted
What defines a fen?
- Peat covered
- Exposed to groundwater
- More nutrients
- Less acidic
- Vegetation includes grass meadows, shrubs, and trees
What is a swamp?
- Non-peat
- Waterlogged soil, often with standing water
- Dense vegetation
Describe marshes.
- Non-peat
- Waterlogged soil with fluctuating standing water
- Emergent vegetation like weeds, rushes, or sedges
What are shallow open waters?
- Non-peat
- Ponds or sloughs
- Standing water a few feet deep
- Transition zone between lakes and marshes
List some ecosystem services provided by wetlands.
- Filtration
- High net primary productivity
- Carbon reservoir
- Biodiversity preservation
- Ecosystem productivity
- Erosion prevention
- Flood prevention
- Recharging groundwater aquifers
- Maintaining surface river flows
- Improves water quality
What percentage of wetlands has been lost in prairies?
50%
What percentage of wetlands has been lost in the Okanagan?
80%
What percentage of wetlands has been lost in New Zealand?
> 90% due to urbanization and farming
Identify stressors to wetlands.
- Urbanization
- Farming
- Draining
What role do beavers play in wetlands?
- Damming
- Wetland formation
- Micro-ecosystem formation
- Carbon storage
Define groundwater.
Water that has percolated down into the subsurface
What fraction of freshwater is contained in aquifers?
1/5 of freshwater
What are aquifers?
Porous formations of rock, sand, and gravel that hold groundwater
What is channelization?
Engineered modification of river channels
What percentage of the world’s largest rivers are affected by dams, canals, and diversions?
60%
What is a canal?
A man-made river or channel of water for transport
What is a diversion?
Rerouting water from its natural river channel or drainage basin by built structures
What is the purpose of a dam?
- Prevent floods
- Provide drinking water
- Generate electricity
- Facilitate irrigation
What are the pros of hydroelectric power?
- Irrigation
- Drinking water
- Power generation
- Flood control
What are some cons of hydroelectric power?
- Captures sediment
- Affects fish populations
- Risk of failure
- Population displacement
What is a fish ladder?
Levels of water that fish can swim up to access higher lakes
List the types of pollution affecting water bodies.
- Nutrients
- Pathogens
- Toxic chemicals
- Suspended water/sediment
- Thermal pollution
What does eutrophic mean?
High nutrient, low O2
What does oligotrophic mean?
Low nutrient, high O2
What is thermal pollution?
Heated liquid introduced into waterways
Fill in the blank: The ability to hold dissolved O2 _______ as temperature increases.
decreases
List some methods to mitigate pollution.
- Legislative/regulatory
- SDGs
- Prevention vs remediation
What is a point source of pollution?
A source from which pollution can be traced back 100% to its origin, e.g., a wastewater treatment plant
