This blog has documented a number of the most important threats facing fisheries and marine ecosystems, including over-exploitation, ocean acidification, harmful fish farming practices, invasive species, and climate change. A new report (PDF) put out by the United Nations Environment Program does a good job of summarizing all of these, as well as providing a good overall picture.
Major conclusions of the report make for sober reading:
- Half the World catch is caught in less than 10% of the ocean
- With climate change, more than 80% of the World’s coral reefs may die within decades
- Ocean acidification will also severely damage cold-water coral reefs and affect negatively other shell-forming organisms
- Coastal development is increasing rapidly and is projected to impact 91% of all inhabited coasts by 2050 and will contribute to more than 80% of all marine pollution
- 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% 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
- Primary fishing grounds are likely to become increasingly infested by invasive species, many introduced from ship ballast water
- The worst concentration of cumulative impacts of climate change with existing pressures of over-harvest, bottom trawling, invasive species, coastal development and pollution appear to be concentrated in 10–15% of the oceans concurrent with today’s most important fishing grounds
- 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
- Substantial resources need to be allocated to reducing climate and non-climate pressures. Priority needs to be given to protecting substantial areas of the continental shelves. These initiatives are required to build resilience against climate change and to ensure that further collapses in fish stocks are avoided in coming decades
There is still some debate about which generation will experience the first reeling blows from climate change. It is increasingly clear that the young people of today will be alive to see the collapse of the world’s fisheries and coastal ocean ecosystems.