Barriers to marine conservation

Question 1

Main threats to ecosystems

Answer 1

• Pollution
• Habitat destruction
• Invasive species
• Major climate change
• Overexploitation

Question 2

Possible solutions (universal and specific)

Answer 2

Universal...
• Reduce C emissions
• Don't destroy habitats
-difficult with such a large pop size 
More particular...
• Sustainable exploitation of fisheries
• Balancing social, economic and ecological needs

Question 3

The barriers to conservation…

Answer 3

1. The ‘inexhaustible seas’ paradigm
2. Perceptions of extinction risk in marine taxa
3. Management of common resources

Question 4

The inexhaustible seas paradigm

Answer 4

Going back to 1880s - fishing technology reached a point where they thought it may be damaging
Thomas Henry Huxley led research into this, deciding there are so many fish - fishermen aren’t doing any harm.

Question 5

Perceptions of extinction risk in marine taxa

Answer 5

Low extinction risk…
• Lower in fossil record (hard to test)
• Too fecund to go extinct - not a good predictor
• Large geographic ranges and high dispersal, but do get endemics and well-structured pops
• Rare species lose value - but can also increase
• Depleted populations recover - only sometimes
• Marine populations more variable & resistant than terrestrial -acc vary as much as birds and mammals
• Few recorded marine extinctions <20 IUCN, >800 terrestrial
Overall - little evidence to support this.

Question 6

Management of common resources

Answer 6

‘Tragedy of the commons’
• Resource not owned, but open to many to exploit
-resources will decline and go extinction, but benefit in mean time by taking as much as possible
• When costs shared by everyone, but few benefit = tragedy of commons
• More likely if not ownership

Question 7

International fisheries management

Answer 7

Put in place to help tragedy of commons
Internation council for exploitation of the sea (ICES) 1902
• UN food and agriculture organisations keep updated stats on this
•Fisheries science investigates no. and how they vary & catching at different ages
-important for pop ecology
•Helped to find max sustainable yield - good yield for long-term = no population crashes (~50% of virgin biomass)