Acidification and overexploitation pushing marine life to mass extinction: IPSO
As per a report released by the International Programme on the State of the Ocean (IPSO) the increasing acidification of the oceans due to excessive absorption of carbon dioxide released mainly from burning fossil fuels and overfishing is exposing marine organisms to intolerable evolutionary pressure which may lead to their mass extinction. As per the report:
- The oceans are more acidic now than they have been for at least 300 million years which may result into a mass extinction of key species. Carbon dioxide in the atmosphere is absorbed by the seas — at least a third of the carbon that humans have released has been dissolved in this way.
- In absorbing carbon and heat from the atmosphere, the world’s oceans have shielded humans from the worst effects of global warming
- Overfishing and pollution are also imperilling marine life, on which billions of people depend for their nutrition and livelihood.
- This acidification is unprecedented in the Earth’s known history which has exposed organisms to intolerable evolutionary pressure.
- Increased acidity is specially impacting coral as it dissolves the calcium carbonate skeletons that form the structure of reefs, and rising temperatures lead to bleaching where the corals lose symbiotic algae they rely on.
- Current efforts of the world governments’ to curb carbon emissions are insufficient to save many reefs.
- There is a time lag of several decades between the carbon being emitted and the effects on seas, meaning further acidification and warming of the oceans are inevitable, even if emissions are drastically reduced.
- Corals are vital to the health of fisheries, because they act as nurseries to young fish and smaller species that provide food for bigger ones.
- The current ocean acidification is the highest for 300 million years from geological records.
- Governments should take measures to limit carbon concentrations in the atmosphere to no more than 450 parts per million of carbon dioxide equivalent.
- At least 70% of the world’s fish populations are overexploited. To tackle this, local communities should be given more control over their fisheries and favouring small-scale operators over large commercial vessels.
Tags: Current Affairs 2013