ecology section B

Pollution

pollution- any harmful addition to the environment
pollutant- any substance that causes damage to the environment

Area= industry
named pollutant= sulphur dioxide
effect= acid rain which leads to fish kills and prevents plants from forming chlorophyll

Control of Pollutant
sulphur dioxide control- burn natural gas

indicator species

some organisms are easily killed by pollutants such as sulphur dioxide, and so are used as pollution indicators
lichens are an indicator species
-lichens consist of symbiotic relationship between fungus and blue-green alga
-the presence of lichen indicate clean air but their absence indicates air pollution

Global warming is very topical at present

Waste management

Importance:
- needed to prevent pollution and to conserve the environment
-waste disposal methods include:
-landfill
-incineration
-recycling

Problems associated with waste disposal
-landfill sites are unsightly and are in short supply
-incineration may release toxic gases
-increased risk of pollution ~ toxins can pollute drinking water
-disease resulting from microorganisms in waste

Example of waste management

activity	waste product	waste management
agriculture	slurry	-spread slurry in summer on dry land -store slurry in leak-proof pits
fisheries	fish heads, tails fins & intestines	-waste parts from fish processing are: -treated with chemicals -dried and pulped -producer produced is recycled as fertiliser or pig feed
forestry	branches tree tops tree stumps	-smaller branches from the forest are allowed to rot and return to minerals to the soil so more trees grow -wastes from tree processing in sawmills are recycled and made into mulch for paths/playgrounds/flowerbeds

suggest why caution is advised when spreading slurry
- as slurry can pollute waterways and cause eutrophication or nutrient enrichment of water which can leads algal bloom and kills fish as O₂ is used up when algae are decomposed by bacteria

Suggest for waste minimisation

reduce consumption of unnecessary goods
reduce packaging ~ avoid pre wrapped fruit, veg and bread
reuse ~ reusable shopping bag reusable drinking bottles
recycle ~ recycle plastic bottles as containers for snacks

Role of microorganisms in waste management and pollution control

Role in waste management:

bacteria and fungi decompose kitchen and garden waste forming compost heaps ~ compost is a natural fertiliser
in sewage treatment plants microorganisms are used to decompose organic matter, resulting in the release of methane gas.
methane may be used as fuel to generate electricity
landfill sites, bacteria and fungi decompose organic materials

role in pollution control:

microorganisms are used to treat oil spills and break them down to less harmful substances

Conservation

conservation- wise management of the environment

benefits of conservation:
-maintain biodiversity
- the use of small fish nets results in small fish being caught, before they can reproduce
- pollution of rivers and lakes ~ takes many years to regenerate fish stocks

Conservation practices in fisheries:

Problems associated with the fishing industry:
-overfishing has reduced the number in fish stocks
- the use of small fish nets result in small fish being caught before they can reproduce
-pollution of rivers and lakes ~ takes many years to regenerate fish stocks

Regulation of net size ~ nets should be of large net size to allow young immature fish to escape the net and reach breeding age, to maintain the species
-apply quotas ~ use fish quotas to ensure only fixed amount of fish are caught so fish can survive and breed
-restocking ~ restocking rivers and lakes coupled with a ban on fishing for species low in numbers allows breeding to take place and fishing population can recover numbers

Constant monitoring is essential to identify any potential problems:

in fish farms regular monitoring for parasites and water quality
checking fishing nets and equipment
sampling to check fish stocks/numbers