Introduction to Limnology Flashcards
study of structural and functional interrelationships of organisms of inland waters as they are affected by dynamic physical, chemical, and biotic environments
Limnology
water bodies included in the study of Limnology
- Lakes
- Ponds
- Rivers
- Watershed
- Reservoirs
Lakes
- in land waters and is a freshwater ecosystem
- hold standing fresh or saline water
- larger than ponds
- enclosed by land and created naturally/man-initiated
- chemically and physically stable but undergo considerable changes within a year
Types of Lakes & Their Characteristics
Seepage Lakes
- natural lake
- has no stream/inlet/outlet
- limited fishery
- land-locked
- low nutrient level
- susceptible to acidification
- source: groundwater, runoff, precipitation
Types of Lakes & Their Characteristics
Groundwater Drainage
- natural lake
- has no inlet but has outlet (overflow)
- source coming from groundwater flowing at the bottom, runoff, and precipitation
Types of Lakes & Their Characteristics
Drainage/ Drained Lakes
- natural lake
- has stream/inlet/outlet
- has higher nutrient level
- water level fluctuates depending on supply
- support different species of fishes
- has access to other water bodies, but different to stream
Types of Lakes & Their Characteristics
Drainage/ Drained Lakes
- natural lake
- has stream/inlet/outlet
- has higher nutrient level
- water level fluctuates depending on supply
- support different species of fishes
- has access to other water bodies, but different to stream
Types of Lakes & Their Characteristics
Coastal Lagoons
- natural lakes
- separated from sea by sandbars (gravel, fine sediments)
- associated with estuaries
- large seasonal variation in salinity bc it comes from both the sea and river
Types of Lakes & Their Characteristics
Impoundments or Reservoirs
- man-made lakes
- result from dug minig operations (quarry lakes)
- support fish populations
- has inlet and outlets
- for agri, power generation, flood control, drinking water supply
Classification: Origin
Glacial lakes
- from scouring large shallow basins from rocks due to ice activities
- v-shaped valleys transform to u-shaped valleys bc of glacial erosions
- cirque lakes: depressions filled with water
Classification: Origin
Glacial lakes
- from scouring large shallow basins from rocks due to ice activities
- v-shaped valleys transform to u-shaped valleys bc of glacial erosions
- cirque lakes: depressions filled with water
Classification: Origin
Rift Valley or Tectonic Lakes
- found in fault lines
- deep lakes
- Landslide lakes: formed from catastrophic events, collapsing of debris
Classification: Origin
Depression Lakes
- formed from process: up-warping, down-warping, and drainage reversal during Pleistocene era
- small & shallow, cover great lakes
- origin: remnants of large bodies of water partly filled with siltation or uplifting of earth’s crust
- endorheic - very saline over time
Classification: Origin
Volcanic Lakes
- volcanic origin, formed in calderas by subsidence of magma chambers
- inactive (caldera lakes)
- craters of extinct volcanoes (crater lakes)
- relatively small and isolated
Classification: Origin
River Lakes
- result from erosive forces of rivers
- sediments are resuspended and deposited downstream
- oxbow lake: crescent-shaped, small lakes in river valleys
Classification: Origin
Salt lakes or Saline lakes
- no natural outlets
- water evaporate rapidly
- higher-than-normal salt content
Coastal lakes
- formed along irregularities of the sea
- process promoted by currents and produce fresh to brackish (salty but not as salty) water
Coastal lakes
- formed along irregularities of the sea
- process promoted by currents and produce fresh to brackish (salty but not as salty) water
Classification: Origin
Karstic lakes
- result of collapsed cave
- form in calcareous regions
- karstification: running over water dissolve carbonate constituting rocks
- water solluble rocks: gypsum, limestones, dolomite
Classification: Richness
Oligotrophic lakes
- less DO, nutrient poor lakes or glacial origins
- deep, transparent water with few organisms
- made up of mainly granite
Classification: Richness
Mesotrophic lakes
- meso: some, balanced nutrient status
- allow thermal stratification causing diff abundance of nutrients, phytoplankton & zooplankton
Classification: Richness
Eutrophic Lakes
- nutrient-enriched
- algal blooms
- intensive agricultural activities around
- shallow, soft, mocky bottom
- water not clear, tea color
Classification: Richness
Eutrophic Lakes
- nutrient-enriched
- algal blooms
- intensive agricultural activities around
- shallow, soft, mocky bottom
- water not clear, tea color
Classification: Richness
Dystrophic Lakes
- aka humic lakes, poor in nutrients
- bogs and marshes
- low food value
- brown water, full of soil particles
- high concentrations of tannic acids (decay vegetation)
Classification: Richness
Hypertrophic lakes
-nutrient-enriched lakes
- low transparency
contain devastating algal blooms
- poor ecosystems, low DO
- cyanobacteria
Classification: Mixing and Stratification
Holomictic lakes
- completely mixed, reach uniform T & density from top to bottom once a year
Classification: Mixing and Stratification
Holomictic lakes
- completely mixed, reach uniform T & density from top to bottom once a year
Classification: Mixing and Stratification
Monomictic
- mix from top to bottom during 1 mixing period a year
2 types: (1) warm monomictic - thermally stratified, never freeze (2) cold monomictic) - inversely stratified
Classification: Mixing and Stratification
Dimictic Lakes
- mix from top to bottom in 2 mixing periods a year (autumn and spring)
Classification: Mixing and Stratification
Polymictic Lakes
- holomictic lakes mixing several times a year
- shallow to develop thermal stratification
- types: (1) cold polymictic - 4 degrees top to bottom, (2) warm polmictic - beks down often
Classification: Mixing and Stratification
Polymictic Lakes
- holomictic lakes mixing several times a year
- shallow to develop thermal stratification
- types: (1) cold polymictic - 4 degrees top to bottom, (2) warm polmictic - beks down often
Classification: Mixing and Stratification
Oligomictic lakes
- irregular mixing, do not occur every year
infrequent mixing
Classification: Mixing and Stratification
Amictic lakes
- never mix / circulate
- usually ice covered throughout the year
4 degrees below ice water (highest density)
Classification: Mixing and Stratification
Meromictic lakes
- bottom (dangerous) never mixes with surface water
- dissolved substance found at bottom
*mixolimnion - superficial layers, possible mixing (epilimnion, thermocline, hyplimnion)
*chemocline / pycnocline - deep layer, never mix, intermediate and sudden change
[ectogenic - transport saltwater to freshwater]
[cryogenic- saline spring at bottom of lake]
[biogenic - salts from organic matter]
Lake Zonation
Littoral Zone
- horizontlly extending from shore to point, submerged macrophytes and benthic algae can live
- emergent plants, submergent, floating-leaved
- reached by solar radiations including photic zone
Lake Zonation
Pelagic Zone
- open sea / ocean
- comprising the water column
Lake Zonation
Photic zone
-vertically extending, from surface to depth, reached by solar radiation
Lake Zonation
Aphotic zone
- water column not reached by solar radiation
Epilimnion / Hypolimnion
- overlaying or underlaying layers
Thermocline / Metalimnion
- layer where T change by 1 Centigrade
Benthic zone
- located at water sediment interface
- soil part
- include aphotic zone - profound benthic zone
Benthic zone
- located at water sediment interface
- soil part
- include aphotic zone - profound benthic zone
