Water quality
In dead water: merging of climate change with pollution, over-harvest, and infestations in the world’s fishing grounds
The impacts of climate change, over-fishing and pollution on the world's oceans
Authors:
C. Nelleman (ed); S. Hain (ed); J. Alder (ed)
Publisher:
United Nations [UN] Environment Programme , 2008
The world’s oceans are already under stress as a result of overfishing, pollution and other environmentally-damaging activities in the coastal zones and now on the high seas. Climate change is presenting a further and wide-ranging challenge with new and emerging threats to the sustainability and productivity of a key economic and environmental resource. This rapid response report attempts to focus the numerous impacts on the marine environment in order to assess how multiple stresses including climate change might shape the marine world over the coming years and decades.
The headline findings from the report include:
- half the World catch is caught in less than 10 per cent of the ocean
- with climate change, more than 80 per cent of the World’s coral reefs may die within decades
- climate change may slow down ocean thermohaline circulation and continental shelf “flushing and cleaning” mechanisms crucial to coastal water quality and nutrient cycling and deep-water production in more than 75 per cent of the World’s fishing grounds
- increased development, coastal pollution and climate change impacts on ocean currents will accelerate the spreading of marine dead zones, many around or in primary fishing grounds
- over-harvesting and bottom trawling are degrading fish habitats and threatening the entire productivity of ocean biodiversity hotspots, making them more vulnerable to climate change
- a lack of good marine data, poor funding for ocean observations and an ‘out of sight – out of mind’ mentality may have led to greater environmental degradation in the sea than would have been allowed on land.
