Human impact on marine environment Flashcards
How do humans impact marine environment?
Destruction of habitats or pollution
Contaminant
Substance that is found at higher values than natural in the environment or that do not occur naturally in environment
Pollutant
Any substance that has negative or toxic effects on organisms
What is the difference between point and diffuse pollution?
Point: decreases with distance from source
Diffuse: has many sources
What are the main causes of marine pollution?
navigation and burning of fossil fuels
What are the two kinds of pollutants?
Organic and inorganic
What causes nutrient excess?
Urban residual waters and extensive fertilizer use lead to eutrophication and decrease of oxygen
what two words define decrease and absence of oxygen?
Hipoxia and anoxia
What are some important organic pollutants?
Polycyclic aromatic hydrocarbons
What is global distillation or grasshopper effect?
Evaporation of chemical substances in warm latitudes and deposition in cold regions, like poles or mountains, due to condensation
What is bioaccumulation?
Accumulation of contaminants in organisms
What is biomagnification?
Transfer of contaminants form prey to predators
What problems are related to fisheries?
Bycatch -fishing of unwanted, protected or endargered targeted and non targeted species
Ghost fishing- abandoned fishing gear
Habitat destruction
What is maximum sustainable yield and how is it estimated?
Maximum yield for which there is not too few and not too many individuals in a population
It can be estimated knowing the population growth rate and size
What fishes are more prone to overfishing and collapse?
Small pelagic fish or demersal fishes (that live on bottom)
