The oceans rise, even as they decline... so long, fish!
Two interesting, alarming reports this week about what's happening (no small thanks to us) to the dominant habitat on this watery planet. First, that habitat is becoming even more dominant: a paper in PNAS meticulously reconstructs global sea-levels over the past two millenia to show that the oceans have been steadily rising, in concert with climatic changes, and that their rise has accelerated in recent years. This figure ought to worry you:
Meanwhile, though, that dominant habitat is also becoming emptier of inhabitants, as we continue to deplete marine wildlife in alarming ways.
So concludes an international panel of marine scientists convened by the International Programme on the State of the Ocean (IPSO). Even though conservation biologists have a reputation for being alarmists, this statement from one of the panelists, should worry you:
"The findings are shocking," said Alex Rogers, IPSO's scientific director and professor of conservation biology at Oxford University.
"As we considered the cumulative effect of what humankind does to the oceans, the implications became far worse than we had individually realised.
"We've sat in one forum and spoken to each other about what we're seeing, and we've ended up with a picture showing that almost right across the board we're seeing changes that are happening faster than we'd thought, or in ways that we didn't expect to see for hundreds of years."
There's more:
"The rate of change is vastly exceeding what we were expecting even a couple of years ago," said Ove Hoegh-Guldberg, a coral specialist from the University of Queensland in Australia.
"So if you look at almost everything, whether it's fisheries in temperate zones or coral reefs or Arctic sea ice, all of this is undergoing changes, but at a much faster rate than we had thought."
But more worrying than this, the team noted, are the ways in which different issues act synergistically to increase threats to marine life.
Those "different issues" include, of course, overfishing, pollution - especially from nasty plastics - ocean acidification, and warming. All adding up to the next mass extinction, one we are living through, unprecedented in being caused largely by a single species - us. So what are we to do?
IPSO's immediate recommendations include:
- stopping exploitative fishing now, with special emphasis on the high seas where currently there is little effective regulation
- mapping and then reducing the input of pollutants including plastics, agricultural fertilisers and human waste
- making sharp reductions in greenhouse gas emissions.
Sounds simple enough, right? Clean up our act and take responsibility? So, we may know the way to back away from this rising, empty tide. Do we have the will?
Reference:
Kemp, A., Horton, B., Donnelly, J., Mann, M., Vermeer, M., & Rahmstorf, S. (2011). Climate related sea-level variations over the past two millennia Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.1015619108
