Freshwater Ecology - EXAM 1 Comprehensive

limnology

the study of inland waters

what is the study of inland waters called?

limnology

when did the UN declare access to clean water was a human right?

2010

what does water scarcity lead to politically?

political instability and conflict

how long has water restriction been used as a tool of war?

since 2500 BC

where is Ruston’s water sourced from?

the Sparta aquifer

approximately how many gallons a day do USA households use?

300 gal/day

how does the approximate use of water in USA households compare to the rest of the world?

it is much higher, however Luxembourg uses more

what is the world average of gallons used per day per household?

~100 gal/day

what is water consumption in US households mostly from?

toilets (24%)

consumptive use of water

uses the water up; water cannot be reattained

what is an example of consumptive use of water?

irrigation, water lost to soil or evaporation

nonconsumptive use of water

once the water is done being used, it can be recollected and used for something else

sustainable water use

water is used at the same rate or slower than the rate that it is replenished

water mining

depleting water faster than its replenished, often used in reference to aquifers

residence time

the average length of time a molecule of water is in a body of water

what is the value of global wetlands economically?

~ $3.2 trillion/year

what is the value of rivers and lakes economically?

~ $1.7 trillion/year

what is the value of freshwater fisheries economically?

~ $45 billion/year

what impacts does climate change have on freshwater sources?

• expected to make water supplies more unpredictable

• more flooding, more droughts

• cause less Oxygen to be in the water, impacting fish and other organisms

• cause more problems with nutrients and algal blooms

why does climate change cause less Oxygen to be available in water?

Oxygen is less soluble in water at higher temperatures

what are 5 properties of water important to living organisms?

density, surface tension, viscosity, solvent, heat capacity

why is density of water important?

it influences the flow and physical behavior of water

less dense water floats or sinks in the presence of denser water?

floats

stratification

stable layers of water that don’t mix

what causes stratification?

water that contains different densities

at what temperature is water most dense?

4 C

solid water is more or less dense than liquid?

less

what 2 properties influence water density?

ions and temperatures

geologic weathering

breakdown of rocks

what is notable about water as a solvent?

it is one of the best solvents known and can dissolve water and gases

what is the source of nutrients that don’t have a gas phase in water?

geologic weathering

what are some examples of nutrients that don’t have a gas phase?

phosphorus, iron, calcium, sulfur

karst

landscape underlain by limestone which has been eroded by dissolution, producing ridges, towers, fissures, sinkholes, and other characteristic landmarks

what percentage of continental land is kartic?

20%

solubility

how readily a solute dissolves in solvent

a higher temperature has what impact on the solubility of ions and gases?

ions become more soluble, gases become less soluble

heat capacity

the amount of heat/energy needed to raise a substance’s temperature by 1 C

is water’s heat capacity high or low?

high

what does it mean when we say water has a high heat capacity?

it means that water takes more energy to heat up

what does water having a high heat capacity cause ecologically?

aquatic environments don’t experience as much of a temperature swing as terrestrial environments, due to how long it takes the water to warm up

surface tension

makes it difficult to break the air/water boundary; caused by adhesion and cohesion

what is a respiratory siphon?

a device that some organisms use to breathe oxygen without gills by essentially using a snorkel

what is an example of an organism that uses a respiratory siphon?

mosquito larvae

viscosity

the amount of internal friction holstered within a liquid, reducing the flow rate

denser water has a higher or lower viscosity?

higher

TRUE OR FALSE: viscosity is directly related to density

true

what does water viscosity affect?

ability to swim and filter particles

is it harder or easier for organisms to swim and filter particles in colder water? why?

harder; cold water is denser and therefore more viscous

laminar flow

all water flow paths are parallel

turbulent flow

water flow paths include mixing and eddies

does turbulent flow increase or decrease at smaller scales?

decrease

what happens to water flow near solid surfaces?

it becomes more laminar

what is the outer edge between laminar and turbulent flow called?

flow boundary layer

flow boundary layer

the outer edge between laminar and turbulent flow

what causes the flow boundary layer to become thicker?

slower moving water, increased roughness of surface, larger objects

a streamlined body is more useful for what types of organisms?

larger organisms above 1 mm in size

what processes are the diffusion of chemicals important to?

predator/prey detection, algae acquiring nutrients, fish and insects getting O2, movements of contaminants

what affects diffusion rates? (6)

concentration gradient, molecule size, advective transport, temperature, presence and structure of sediment, movement of organisms

molecular diffusion

involves only the diffusion based on the concentration gradient

diffusion increases or decreases with temperature rising?

increases

what causes diffusion to increase with rising temperatures?

advective diffusion

advective diffusion

a process that causes water to be constantly in motion, cycling up and down. warm water moves up towards the cooled evaporation surface then sinks back down

what can be used to release hydrophobic molecules from sediment to therefore remove them from water?

detergents

where does water velocity reach 0?

near a solid surface

diffusion boundary layer

a thin layer in which molecular diffusion predominates

how do small organisms overcome slow diffusion?

they change their shape to allow for more surface area, creating a greater surface area to overall volume ratio

what is an example of an organism increasing its surface area?

plankton adding spines to itself

what use do plankton spines have for the organism other than increasing its surface area?

can deter predators and slow how fast they sink

how do large organisms overcome slow diffusion?

with gills that increase the diffusion of O2 in and CO2 out

do the gills of organisms tend to be larger or smaller in high velocity streams? why?

smaller, the diffusion boundary later is thin

bioturbation

the event in which an organism disturbs sediment and therefore alters water flow through them

what can migration of animals do for nutrient distribution?

increase it grealy

watershed

land draining into one channel

true or false: the total length of low order streams make up more total stream miles than the total length of high order streams

true

what are some problems with the Strahler Classification System of streams?

1 - finding the smallest streams is difficult (they aren’t always on a map)

2 - stream order doesn’t always correlate with discharge

stream velocity

the speed of water at a point in the channel

discharge

the volume of water passing through a point in the channel per unit time

what is the equation for finding discharge?

Q = VA

weir

constructed channel that can correlate depth with discharge

what is a hydrograph a plot of?

discharge through time

what are some examples of things that can cause greater discharge variability?

steep watersheds and intense storms

perineal stream

flows all the time

intermittent stream

flows some of the time

ephemeral

flowing rarely and not receiving any groundwater input

if two different Secchi disk depths are at 1.55 and 1.44 what would you estimate the attenuation coefficient as using one of these?

1.14

how do you find the light attenuation coefficient using Secchi disk depth?

1.7/SD

what color disappears first when going underwater?

red

what light does chlorophyll absorb?

red and blue

what do phycobilins do? where can they be found?

they can be found in cyanobacteria; they use green light when the green algae have absorbed most of the red and blue light

what can changes in heating cause?

currents

how does water gain heat energy?

1 - solar radiation

2 - diffusion of heat from atmosphere

3 - warmer water flowing from somewhere else

how does water lose heat energy?

1 - reflection

2 - evaporation

3 - back radiation

4 - cooler water flowing from somewhere else

how can stratification last a long time?

molecular diffusion of heat is really slow

heat budget

the total amount of energy required to heat the lake from its winter minimum temperature to its summer maximum temperature

heat budgets of tropical or temperate lakes are larger?

temperate lakes

thalweg

water velocity is at its maximum in the center of the water

water on the top moves faster or slower than the water on the bottom?

faster