Properties of water, light and oxygen Flashcards
Salinity of freshwater
Less than 0.5 PSU
Salinity of marine water
greater than 35 PSU
Zones in Aquatic environments (what is it and what are the organisms like?)
Pelagic zone
Open water
Organisms are planktonic
Zones in Aquatic environments (what is it and what are the organisms like?)
benthic zone
bottom of the water body Benthic organisms (crawlers, burrowers etc.)
Zones in Aquatic environments (what is it and what are the organisms like?)
Littoral zone
Edge of the water body that has little wave action
Planktonic and attached organisms
Zones in Aquatic environments (what is it and what are the organisms like?)
Rocky littoral zone
Edge of water body with high wave action of flowing water
Planktonic and attached
Mixing regimes
Lotic waters
running water - organisms that are not attached will flow down the river
Mixing regimes
Lentic waters
Standing water - strong currents around the perimeter
How does water density influence aquatic plants?
water density is 1g/ml
aquatic plants do not need structural tissue or xylem and phloem
Plants grow quicker because less energy used
what is the heat capacity of water and air?
what does this mean for aquatic environments?
water = 1000 cal/l Air = 0.31 cal/l
temperature in water is more stable and only fluctuates by about 20 degrees celcius
what is the relationship between temperature and density
density increases as temperature decreases
what is a Homothermal water column
temperature is the same all the way down
what is a stratified water column
water cannot mix so there are two separate circulations (the Epilimnion and Hyperlimnion, which are separated by the thermocline)
Organisms congregate at thermocline due to light and nutrient availability
Types of stratification
Holomcitic
No stratification
Types of stratification
Monomictic
stratifies once a year - if the heat from the sun is too strong the currents cannot mix the water enough - the size of epilimnion depends on temperature
Types of stratification
Amictic
permanently stratified - all oceans
what wavelengths are photosynthetically active radiation (PAR)
400-700nm
Light
what is the Euphotic zone
between 1-100% light intensity - the only place plants can grow
how is a secchi disk used to measure light penetration
it is a disk with white and black quarters - you lower it into the water until it can no longer be seen and record the depth - this is where there is less than 10% light penetration
what travels further? blue of red light?
Blue light
what is the oxygen diffusion coefficient
the speed that water diffuses - it is 800 times slower in water than in air - higher in cold water than warm water
List the order of trophic statuses from the most nutrient poor to the most nutrient rich
Ultra-oligotrophic (>90%) Oligotrophic Mesotrophic Eutrophic (0-40%) Hyper-eutrophic (0-10%)