![]() ![]() ![]() With every increment of global warming we face increasing climate hazards and multiple risks to ecosystems and people. ➡ the urgency of addressing the emissions gap - we are ![]() ➡ the gravity of human caused climate change that is causing adverse impacts and losses and damages, hitting the most vulnerable people and ecosystems. We are at the turning point to limit global warming and follow a more equitable and sustainable path to development. It’s Getting Harder for Fish in the Sea to Breathe | The Tyeeįor me this is the iconic figure of the #IPCC Synthesis Report: A child born now is likely to experience, on average, many times more extreme weather events in their lifetime than their grandparents. #research #diversity #fisheries #marine #oxygen But when researchers take the time to compare the three effects - warming, acidification and deoxygenation - the impacts of low oxygen are the worst. That’s obviously not good for marine life. Just this April, for example, headlines screamed that global surface waters were hotter than they have ever been - a shockingly balmy average of 21 C. Researchers complain that the oxygen problem doesn’t get the attention it deserves, with ocean acidification and warming grabbing the bulk of both news headlines and academic research. The tropics will empty as fish move to more oxygenated waters, says Pauly, and those specialist fish already living at the poles will face extinction. Our future ocean - warmer and oxygen-deprived - will not only hold fewer kinds of fish, but also smaller, stunted fish and, to add insult to injury, more greenhouse-gas producing bacteria, scientists say. “Deoxygenation is a big problem,” Pauly summarizes. Lack of ecosystem diversity means lack of resilience. Researchers expect many places to experience a decline in species diversity, ending up with just those few species that can cope with the harsher conditions. As the atmosphere warms, oceans around the world are becoming ever more deprived of oxygen, forcing many species to migrate from their usual homes. But the influx provides a peek at a bleak future for China and for the planet as a whole. The boom is making some people happy, since Bombay duck is perfectly edible. Fish species that can’t cope with less oxygen have fled, while the Bombay duck, part of a small subset of species that is physiologically better able to deal with less oxygen, has moved in. The reason for this mass invasion, says Pauly, is extremely low oxygen levels in these polluted waters. “It’s monstrous,” says University of British Columbia fisheries researcher Daniel Pauly of the explosion in numbers. When research ships trawl the seafloor off that coast, they now catch upwards of 440 pounds of the gelatinous fish per hour - a more than tenfold increase over a decade ago. Off the coast of southeastern China, one particular fish species is booming: the oddly named Bombay duck, a long, slim fish with a distinctive, gaping jaw and a texture like jelly. According to the Intergovernmental Panel on Climate Change’s 2019 special report on the oceans, from 1970 to 2010, the volume of “oxygen minimum zones” in the global oceans - where big fish can’t thrive but jellyfish can - increased by between three and eight per cent. ![]() Some patches are worse than others - the top of the northeast Pacific has lost more than 15 per cent of its oxygen. It’s Getting Harder for Fish in the Sea to Breathe: Oxygen levels in the world’s oceans have already dropped more than 2 per cent between 19, and they are expected to decline up to seven per cent below the 1960 level over the next century. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |