According to a United Nations Environment Program (UNEP) commercial fish stocks around the world could collapse within decades. The report, In Dead Water, states that 2.6 billion people rely on these stocks for protein, which could be destroyed through a combination of climate change, overfishing and pollution.
At least three quarters of the planet’s key fishing grounds may become seriously impacted by changes in circulation as a result of the ocean’s natural pumping systems fading and falling they suggest.
According to the United Nations Food and Agriculture Organization (FOA), several Canadian commercial fish stocks are over-exploited and depleted, including Atlantic Cod, Haddock and North Pacific Hake.
Wild salmon stocks in Canada are also under threat from pollution and sea lice resulting from salmon farms at or near wild salmon migration routes.
Climate change has compounded previous problems such as over-fishing, as rising temperatures kill coral reefs, threaten tuna spawning grounds, and shift ocean currents and with them the plankton and small fish which underpin ocean food chains.
The report, the work of UNEP scientists in collaboration with universities and institutes in Europe and the United States, was launched today during UNEP’s Governing Council/Global Ministerial Environment Forum taking place in Monaco.
It draws on a wide range of new and emerging science including the latest assessment report of the Intergovernmental Panel on Climate Change-the 2,000 plus panel of scientists established by UNEP and the World Meteorological Organization.
Other contributions have come from organizations and institutions including the University of Plymouth; the Norwegian Institute for Nature Research; the University of British Columbia; the Institute of Zoology; Princeton University; the University of Barcelona and the Sustainable Europe Research Institute.
In Dead Water Key Findings:
- 80 per cent to 100 per cent of the world’s coral reefs may suffer annual bleaching events by 2080 under global warming scenarios.
- Those at particular risk are in the Western Pacific; the Indian Ocean; the Persian Gulf; the Middle East and in the Caribbean
- Over 90 per cent of the world’s temperate and tropical coasts will be heavily impacted by 2050.
- Increasing concentrations of C02 in the atmosphere are likely to be mirrored by increasing acidification of the marine environment.
- Increasing acidification may reduce the availability of calcium carbonates in sea water, including a key one known as aragonite which is used by a variety of organisms for shell-building.
- Cold-water and deep water corals could be affected by acidification by 2050 and shell-building organisms throughout the Southern Ocean and into the sub-Arctic Pacific Ocean by 2100.
- Climate change may slow down the ocean thermohaline circulation and thus the continental shelf 'flushing and cleaning' mechanisms which are crucial to water quality and nutrient cycling and deep water production in at least 75 per cent of the world’s major fishing grounds.
- Dead zones, area of de-oxygenated water, are increasing as a result of pollution from urban and agriculture areas. There are an estimated 200 temporary or permanent ’dead zones’ up from around 150 in 2003.
- Up to 80 per cent of the world’s primary fish catch species are exploited beyond or close to their harvesting capacity.
- Alien invasive species, which can out-compete and dislodge native ones, are increasingly associated with the polluted, over-harvested and damaged fishing grounds.
The report comes in the wake of findings issued last week by a team led by the National Center for Ecological Analysis and Synthesis which estimates that over 40 per cent of the world’s oceans have been heavily impacted by humans and that only four per cent remain relatively pristine.
'The question is not whether we should stop fishing but to address climate change, which is creating a degree of impact we’ve not seen before,' said lead author of the UNEP report, Christian Nellemann.
The Executive Summary of the Report is available here.
The Full report is available here.