Science News - Oceans Will Take Thousands Of Years, Not Decades, To Recover From Abrupt Changes

[hatrack]

A 30-foot-long core sample of Pacific Ocean seafloor is changing what we know about ocean resiliency in the face of rapidly changing climate. A new study reports that marine ecosystems can take thousands, rather than hundreds, of years to recover from climate-related upheavals. The study's authors--including Peter Roopnarine, PhD, of the California Academy of Sciences--analyzed thousands of invertebrate fossils to show that ecosystem recovery from climate change and seawater deoxygenation might take place on a millennial scale. The revolutionary study is the first of its kind, and is published today in the Early Edition of the journal PNAS. The scientific collaborative--led by Sarah Moffitt, PhD, from the UC Davis Bodega Marine Laboratory and Coastal and Marine Sciences Institute--analyzed more than 5,400 invertebrate fossils, from sea urchins to clams, within a sediment core from offshore Santa Barbara, California.

EDIT

Moffitt emphasized the importance of using a large, 30-foot core sample from one portion of the seafloor, saying the team "cut it up like a cake" to analyze the full, unbroken record. In periods of fewer than 100 years, oceanic oxygen levels decreased between 0.5 and 1.5 mL/L. Sediment samples during these periods show that relatively minor oxygen fluctuations can result in dramatic changes for seafloor communities.

The study results suggest that future periods of global climate change may result in similar ecosystem-level effects with millennial-scale recovery periods. As the planet warms, scientists expect to see much larger areas of low-oxygen "dead zones" in the world's oceans.

"Folks in Oregon and along the Gulf of Mexico are all-too-familiar with the devastating impacts of low-oxygen ocean conditions on local ecosystems and economies," says Roopnarine. "We must explore how ocean floor communities respond to upheaval as we adapt to a 'new normal' of rapid climate change. We humans have to think carefully about the planet we are leaving for future generations."

EDIT/END

http://esciencenews.com/articles/2015/03/30/massive.study.first.explore.historical.ocean.response.abrupt.climate.change

[daleanime]

1. kick, kick, kick.....