The news, the evidence that supports it, and the warning that accompanies it could hardly be more dire.
The latest audit by an international team of marine scientists at the International Programme on the State of the Ocean (IPSO) found that the world’s oceans and marine life are facing an unprecedented threat by combination of industrial pollution, human-driven global warming and climate change, and continued and rampant overfishing.
According to the report, The State of the Ocean 2013: Perils, Prognoses and Proposals, the degradation of the ocean ecosystem means that its role as Earth’s ‘buffer’ is being seriously compromised. As a result, the authors of the report call for “urgent remedies” because the “rate, speed, and impacts of change in the global ocean are greater, faster, and more imminent than previously thought.”
Driven by accumulations of carbon, the scientists found, the rate of acidification in the oceans is the highest its been in over 300 million years. Additionally, de-oxygenation–caused by both warming and industrial runoff–is stripping the ocean of its ability to support the plants and animals that live in it.
The combined stressors, according to the report, are “unprecedented in the Earth’s known history. We are entering an unknown territory of marine ecosystem change, and exposing organisms to intolerable evolutionary pressure. The next mass extinction may have already begun.”
Professor Alex Rogers of Somerville College, Oxford, and Scientific Director of IPSO said: “The health of the ocean is spiraling downwards far more rapidly than we had thought. We are seeing greater change, happening faster, and the effects are more imminent than previously anticipated. The situation should be of the gravest concern to everyone since everyone will be affected by changes in the ability of the ocean to support life on Earth.”
Among the report’s comprehensive findings, the panel identified the following areas as of greatest cause for concern:
• De-oxygenation: the evidence is accumulating that the oxygen inventory of the ocean is progressively declining. Predictions for ocean oxygen content suggest a decline of between 1% and 7% by 2100. This is occurring in two ways: the broad trend of decreasing oxygen levels in tropical oceans and areas of the North Pacific over the last 50 years; and the dramatic increase in coastal hypoxia (low oxygen) associated with eutrophication. The former is caused by global warming, the second by increased nutrient runoff from agriculture and sewage.
• Acidification: If current levels of CO2 release continue we can expect extremely serious consequences for ocean life, and in turn food and coastal protection; at CO2 concentrations of 450-500 ppm (projected in 2030-2050) erosion will exceed calcification in the coral reef building process, resulting in the extinction of some species and decline in biodiversity overall.