ecosystem dynamics - unsustainable use of natural resources

Question 1

unsustainable use

Answer 1

-using a resource more quickly than it can naturally be restored
-has a huge effect on biodiversity

Question 2

overharvesting

Answer 2

-harvesting a species at a rate that exceeds the replenishing rate of the population
-organisms with low reproductive rates are especially vulnerable due to this
-because new individuals from birth + immigration do not outweigh the ones lost from death + emigration

Question 3

sustainability & fishing

Answer 3

-4000+ species of fish live in australian waters, and 1/4 are not found anywhere else
-high competition for their use (e.g. food, recreation, transport, commercial livelihood etc)
-commercial harvesting has reduced the number of many species
-this impacts the food chains, for example seals/penguins must compete with the fishing industry

Question 4

by-catch

Answer 4

-undersized & oversized fish caught and being discarded causes problems as populations of fish decrease, there are fewer fish reaching reproductive age to sustain population growth

Question 5

bottom trawling

Answer 5

-destructive to ocean ecosystems, involves dragging a large net across the seafloor
-deep-sea fish are targeted globally, but it also damages non-target species, including habitat forming deep sea corals & sponges

Question 6

management strategies: creating & monitoring protected areas

Answer 6

-in WA, recreational fishing licenses and fishing seasons are mandatory to control fishing levels