Smoke billows from a large steel plant in Inner Mongolia, ChinaOceans are becoming more acidic as a result of absorbing excess carbon dioxide gas released in the atmosphere by human activity. Fossil fuel emissions and deforestation are the two major sources for carbon pollution. The rapid destruction of warm water coral reefs is evidence that ocean acidification will affect marine life. Reef ecosystems have served as ‘cradles of evolution’ throughout Earth’s biological history. More marine species have originated in reef ecosystems than in any other.Image by Kevin Frayer / Getty Images
Scores of dead fish surface on the banks of the Guanabara Bay in Rio de Janeiro, BrazilAs the planet’s polluted atmosphere traps more heat, the oceans get warmer. Last year saw new highs of ocean temperature in the top 700 m and 2,000 m of water. Fish species known to hunt at depths are repeatedly floating to surface view today. The reason: Warm temperatures have knocked oxygen out of waters at great depths, making it difficult for the predators to breathe—let alone hunt—in deep waters. Insufficient oxygen in water reduces growth, increases disease, alters migratory behaviour and increases mortality of marine animals.Image by Ricardo Moraes / Reuters
A fish farm in Maoer Lake, Jiangsu Province of ChinaThe percent of seafood supplied by the aquaculture industry has risen from a mere 7 percent in 1974 to over 52 percent of all seafood consumed today. Dense aquaculture contributes to deoxygenation. Not only do densely kept animals use oxygen as they respire, but microbial decomposition of excess fish food and fish faeces also consumes oxygen. When this increased respiration and insufficient water flow occur at the same time in aquaculture pens, oxygen concentrations decline, leading to fish kills, a frequent occurrence in fish farms throughout East and Southeast Asia.Image by Zhou Haijun/ Visual China Group via Getty images
Garbage floats in the Ganga river along the ghats of Varanasi, IndiaA toxic soup of marine debris that gets swept into sewers, storm drains and waterways and eventually out to sea via rivers, has turned our oceans into floating garbage patches. Eight of the 10 ten rivers that carry 90 percent of the plastic that ends up in the ocean are found to be in Asia. What these rivers had in common: A vast population living along the banks, with a lack of incentive and infrastructure to recycle plastic waste. The Indus and the Ganga, carry the second and sixth highest amounts of plastic debris to the ocean.Image by Avishek Das / Sopa Images/ Lightrocket via Getty Images
