M2-2 Flashcards
saturation
the maximum amount of oxygen that an aquatic environ can host, based on the current abiotic conditions
supersat
DO conc is above sat. meaning that O2 will bubble out of solution
sub-sat
DO lvl are below sat
an/oxic vs an/areobic
they both address the absence or presence of O2 respectively.
temp and O2
less O2 w/ high temp
pressure and O2
more O2 w/ inc pressure
salinity and O2
Less O2 w/ inc salts
sources of O2 in lakes
atmos and PHOSYN
sink of O2 in lakes
diffusion, RESP AND OXIDATION
importance of O2
the DO in a system will influence the biological activity that can occur.
expressed as mg/L or mol/L or % sat
4 DO profiles (how much O2 found in a system)
orthograde
clinograde
heterograde
anamalous
DO profiles and how it changes seasonally (oligo)
fall and spring mixing will have lower temps and high O2 throughout then water colunm (often spring has more O2 than fall)
summer will follow an orthograde profile)
winter- similar to fall and winter as no O2 consumption is taking place
DO profile and diurnal pattern of streams
a delayed cycling event, aligning with sun rise and fall.
eutrophic systems have large amplitude and oligo (much more stable. minor shifts in O2- likely due to temp)
lowest (5mg/l) @ 4AM and highest (12mg/l) O2 at 4pm
anomalous profile
often inc in O2 lvl due to inflows into lakes
heterograde profile
less O2 in epi, as most primary prod are at the top of the meta. many O2 consumers are the bottom (non mobile). as tem dec in the hypo, o2 solubility ges back up w. less consumption too)
clinograde profile
O2 follows temp and is infleunced by productivity, surface has more O2 due to inc Phosyn and light
orthograde profile
: temp driven, often in oligo trophic lakes. less temp is more O2
DO profiles and how it changes seasonally (eutrophic)
fall and spring mixing will have lower temps and high O2 throughout then water colunm (often spring has more O2 than fall)
summer: clinograde profile (high phosyn at the top, dec with depth)
winter: cold temps, but O2 dec w/ depth. some phosyn may continue with light, but O2 also consumed through the winter in the water. Hypolimnin has almost nothing.
any ice cover also limits mixing
fishkills
seasons/ periods of anoxia. often amplified through oxidation and decomp of organic matter (consumed O2)
O2 lvl in main vs tributary streams
main rivers will have less fluctuation due to fast movement and less macrophyte anchorage
tributary rivers often flow slower and can facilitate more O2 via phosyn, but also have a greater fluctuation throughout the day
DIC
dissolved inorganic carbon: Co2, and carbonate derivatives
TOC
total organic carbon in a system
DOC
small
(humic or non humic compounds)
- lend a brown colour to the water
-can form complexes with metal ions
non= carbs, pro, lipid, sugar pigments…
POC
larger
living orgs or dead OM (fine or coarse)
role of fresh water in carbon cycling
it was once throught that inand water had no impact on the carbon cycle, but it has now been found that in land water retains alot of carbon, reducing the amount that makes it to the ocean.
- through CO2 evasion and sediment storage
importance of carbon
essential to life as it is a main form of energy and chemical backbone of org moles
it can act as a buffer
aids in climate regulation (or not lol)
what is the abundance of the carbon types in lakes
DIC>DOC>POC
what are the primary carbon forms in acidic water vs basic
acidic: CO2 and H2CO3
neutral: HCO3-
basci: Co3 2-
autochthonous
to be sourced inside the lake (phosyn or resp)
allochthonous
to come from outside the lake or streasm
