Human Impact on Environment Flashcards
overfishing
there is a maximum sustainable yield (quantity that can be caught + replaced in a year) but almost impossible to predict
what to know for msy
population numbers - mark + recapture birth rate death rate age at maturity age structure growth rates
prevent overfishing
quotas or catching days
exclusion days
fishing seasons
mesh sizes (make holes bigger)
fish farming
profitable
however density dependent factors like disease mean food must have antibiotics which can lead to antibiotic resistance and wasted food to eutrophication
if net breaks, genetically different to wild population and can weaken line
coppicing
cut down above ground - trees like willow can still grow so used as a biomass (fuel source)
CITES
can’t trade animals/animal parts of endangered species
SSSIs
Sites of Special Scientific Interest
Seed banks
if plant foes extinct, samples stored can be used
rare breeds
farms
zoos
captive breeding programmes
move males zoo to zoo to prevent interbreeding and maintain biodiversity
breeding disease resistance
e.g. potatoes naturally resistant, cross breed, prevent another potato famine
medicine
chemicals in plants/animals used to treat disease
how to stop soil going anaerobic
ploughing
drainage ditch
9 planetary boundaries
climate change biosphere integrity land system change biogeochemical flows stratospheric ozone ocean acidification fresh water use aerosols introduction of novel entities
climate change boundary
greenhouse gases control earths temp high atmospheric CO2 = high average global temp (affects winds, ocean currents) positive feedback (polar ice melts, sea levels rise)
biosphere integrity boundary
need or lose possible cures to diseases
land system change boundary
limit ice free land for crop growth + human habitation
grow efficient crops
eat less meat
biogeochemical flows
disrupted e.g. Haber process
consequences e.g. eutrophication, acidification
stratospheric ozone boundary
ozone absorbs ultraviolet light
CFCs destroy ozone
avoid by deliberate action, ozone repairs itself (becomes thicker)
ocean acidification boundary
CO2 dissolves in water decreasing pH, affects fish, corals, enzymes
fresh water use boundary
only 2.5% of worlds water is fresh
not always available and not uniformly distributed around world
agriculture wastes water
climate change affects rainfall
increased pop with long life span
consequences - desertification, fisheries destroyed, Rivera may fail to reach seas
atmospheric aerosol loading boundary
some natural (volcano ash)
soot absorbs heat adding to global warming
particles from diesel engines inhaled
consequences - ‘Asian Brown Cloud’ pollution blocks sunlight
introduction of novel entities boundary
synthetic organic pollutants radioactive material GM organism nano materials micro plastics
ecotourism
money from tourists by setting up accommodation in rainforests, locals dont need to cut down then
