Freshwater Environment L2 Flashcards
What percentage of the world’s water does freshwater make up?
0.01%
What percentage of the Earth’s surface does freshwater make up?
0.8%
How many species does freshwater support? What percentage of all species is this?
Freshwater supports 100,000 species out of approx. 1.8 million, so that is almost 6% of all described species.
Why is freshwater important?
Despite only making up a small fraction of water on the planet, freshwater is disproportionately important in terms of ecosystem services (e.g. drinking water), global carbon flow and biodiversity
List eleven freshwater environments.
1) Streams
2) Rivers
3) Canals
4) Ditch
5) Reservoir
6) Pond
7) Lake
8) Swamp
9) Ephemeral pool
10) Marsh
11) Groundwater
What are some important abiotic factors in the freshwater environment?
1) Temperature
2) Nutrient concentrations
3) Light availability
4) Water depth
5) pH
6) Water flow
How many grams of solutes are there per kg in freshwater?
Freshwater: 0.06-0.3 grams of solutes per kg of water
Freshwater organisms have _________ concentrations of salts than the surrounding environment.
The organisms’ cells have a higher concentrations of salts than the surrounding environment.
What are some adaptations to living in an environment with such low salinity?
1) Large quantities of urine with reabsorption of salts
2) Water-impermeable membranes
3) Salt in food
4) Contractile vacuoles in unicellular organisms.
What kinds of nutrients are found in freshwater?
Nutrients
Enzymes
Proteins
What is the limnetic zone?
The limnetic zone is the open and well-lit area of a freestanding body of fresh water
What is the aphotic/profundal zone?
The proportion of a body of water where there is little or no sunlight
What is the littoral zone?
The littoral zone or nearshore is the part of a sea, lake or river which is close to the shore.
What is the epilimnion zone?
The epilimnion or surface layer is the top-most layer in a thermally stratified lake, occurring above the deeper hypolimnion. It is warmer and typically has a higher pH and higher dissolved oxygen concentration than the hypolimnion.
What is the hypolimnion zone?
The hypolimnion or under lake is the dense, bottom layer of water in a thermally-stratified lake. It is the layer that lies below the thermocline. … In deep, temperate lakes, the bottom-most waters of the hypolimnion are typically close to 4 °C throughout the year.
Gleick, 1996
Freshwater makes up 0.01% of the world’s water and approx. 0.08% of the Earth’s surface
What percentage of freshwater is stored in glaciers?
68.6%
What percentage of all water do oceans hold?
97%
What is the residence time of water in glaciers?
12,000 years
But now they are melting!
List three ecosystem services that freshwater provides.
Drinking water
Irrigation
Sanitation
List three ecosystem services that freshwater biota provide.
Water purification
Food
Nutrient cycling and sequestration
How many gigatons per year of carbon do human emissions contribute?
9 gigatons of carbon per year
How much carbon is stored in fossils?
10,000
How much carbon is stored in the deep ocean?
37,000
