what is pollution?
release of substances into the environment that cause harmful effects
what are the causes of air pollution?
- burning fossil fuels (CO2, SO2, NO2)
- deforestation(CO2)
- rice paddies, cattle waste (CH4)
- CFCs
what are the consequences of air pollution?
global warming
acid rain
ozone hold
smog
what is the greenhouse effect?
-high energy radiation reaches earth
-some absorbed and warms eartg, som re-emitted as longer wave radiation
-some LWR escapes into space, some absorbed by gases and reemitted back to earth tf earths surface and lower atmos heats up
-bc of increased conc of GGs, more LWR is absorbed by them and re-emmitted back to earth, incr temp further
tf sea levels rise, change in rainfall patterns, extreme weather
what is the fossil fuel combustion equation?
fossil fuel + oxygen -> CO2 + H2O
what happens in deforestation? what are its consequences?
- less PS tf less CO2 locked away tf more in atmos
- burning trees tf more CO2 released tf more CO2 and less O2 in atmos
- loss of habitats tf species endangered
- disturbances of water cycle: less trans tf reduced rainfall tf droughts
- lack of stems, leaf litter, tf increased water run off after rainfall tf flooding
- loss of soil anchor as soil washed away ∴ erosion and leaching, loss of nutrients
how does eutrophication happen?
1) excess nitrates are washed into the pond from run off fertiliser
2) as nitrate levels rise. algae and aquatic plants rapidly reproduce(algal bloom)
3) algae prevent light from penetrting through water tf submerged plants can’t PS and die
4) algae eventually die as run out of nitrates. bacteria decay them and use up more O2 in resp
5) water becomes anoxic and all life will die
what happens when sewage gets in water?
- decomposers decay organic matter using up O2
- water becomes anoxic, fish die etc.
- we can tell levels of water pollution by looking at bioindicator species which survive at different levels of O2 conecentration
What is ecology?
Set study of living things and their interactions with each other and their environment
What is a population?
All of the organisms of a particular species found in an ecosystem
What is a community?
All of the different species living in an ecosystem
What is a habitat?
Place within an ecosystem where specific organisms live
What direction are the arrows in a food chain?
They show the direction of energy transfer (thing being eaten ➯ consumer)
How is energy stored in a food chain?
- transferred as chemical energy in food
* stored as new biomass
What is a pyramid of number?
- shows the pop of each organism in a food chain
- width of bar = number of orgs
What is a pyramid of biomass?
- shows mass of each organism
- more reliable
Why is some energy lost?
- up to 90% lost
- not all eaten
- not all digested, may be excreted
- new biomass
- used in resp, e.g. Movement, body heat, reproduction
How do you stop fish coming into contact with unclean water?
- filtered to make sure fish do not eat anything unsafe to digest. This done by changing water in tank, or changing nets and location of fish outside.
- regular cleaning also means spread of disease is minimised
- also means O₂ levels high enough for resp of fish
How do you stop intraspecific predation?
Separate fish of different ages/genders. Feed fish regularly, and give them adequate room
How do you stop interspecific predation?
Fencing area fish are in, putting nets around area fish are in. Keep fish in tanks
How do you minimise spread of disease in fish farming?
Make sure small amount of fish kept together so they can’t contaminate each other
Why do you feed the fish in small amounts?
So they don’t starve but they cannot overeat
How does sampling work?
