water pollution Flashcards
define pollution
means releasing substances into the environment in amounts that cause harmful effects and in which natural biological processes cannot easily remove
key feature is the amount
define pollutants
waste materials released into the environment usually as a result of human activities
list the two types of water pollution
freshwater and marine
what are the three main pollutants of freshwater pollution
nitrates from fertilisers, organic waste and detergents
where does the oil come from?
super tankers damaged in a number of ways resulting in release of vast quantities of crude oil
oil leaks from offshore oil drilling rigs and pipelines that bring oil to land from oceans
how does the oil negatively impact
oil floats forming huge slicks and sometimes can be driven onto beaches killing much of the plant and animal life there
oils slicks in the sea block oxygen and light killing marine life
how is oil spills dealt with
sometimes dispersed by using detergents which breaks oil into smaller droplets so disperses more easily
this also breaks up the natural skin feathers, and lipids in cell membrane
makes it easier for animals to absorb increasing its toxicity
where is organic waste derived from
untreated sewage from housing, ships and farms
how does organic waste affect the environment
pollutes coastal waters
lead to eutrophication
causes numerous diseases such as typhoid cholera dysentery among people who drink and use the contaminated water
excreta often contains pathogens
how is organic waste broken down
by bacteria which multiply rapidly and use up oxygen
lack of oxygen causes fish and other marine organisms to die
surviving anaerobic bacteria then continue to break down the waste and release foul smelling gases such as methane and hydrogen sulfide
what is solid waste
referred to as trash or garbage
consists of a large range of products and materials such as cups, plastic bottles and bags
how does solid waste affect the environment
endangers safety and livelihood of fishermen and recreational waters by blocking waterways and causing flooding
seabirds become entangled in marine debris
some birds feed on plastic pellets resembling eggs but have little nutritional value so weakened and die
leather back turtle frequently swallow plastic bags mistaking them for jellyfish
if ingested plastic can prevent assimilation of nutrients and make turtles too buoyant to dive for food
fish and crabs entangled in nets
juvenile crabs enter plastic bottles such for life as they grow and cannot crawl out
what are the heavy metals
mercury acid wastes heavy metal products
where do heavy metals originate
industrial plants
how do heavy metals affect the environment
become concentrated in fatty tissues of animals along food chains such as tuna and shark
estimated to take 100 years for mercury to make its way out of an ecosystem
