Jurassic records warn of risk to marine life from global warming

February 19, 2013, University of Plymouth
This shows Early Jurassic ammonite. Credit: Plymouth University

Researchers at Plymouth University, UK, believe that findings from fieldwork along the North Yorkshire coast reveal strong parallels between the Early Jurassic era of 180 million years ago and current climate predictions over the next century.

Through geology and palaeontology, they've shown how higher temperatures and lower oxygen levels caused drastic changes to marine communities, and that while the Jurassic seas eventually recovered from the effects of , the that returned were noticeably different from before.

The results of the Natural Environment Research Council-funded project are revealed for the first time in this month's scientific journal.

Professor Richard Twitchett, from the University's School of Geography, Earth and Environmental Sciences, and a member of its Marine Institute, said: "Our study of fossil marine ecosystems shows that if global warming is severe enough and lasts long enough it may cause the extinction of marine life, which irreversibly changes the composition of marine ecosystems."

Professor Twitchett, with Plymouth colleagues Dr Silvia Danise and Dr Marie-Emilie Clemence, undertook fieldwork between Whitby and Staithes, studying the different sedimentary rocks and the they contained. This provided information about the environmental conditions on the sea floor at the time the rocks were laid down.

The researchers, working with Dr Crispin Little from the University of Leeds, were then able to correlate the ecological data with published data on changes in temperature, sea level and oxygen concentrations.

Dr Danise said: "Back in the laboratory, we broke down the samples and identified all of the fossils, recording their relative abundance much like a would do when sampling a modern environment. Then we ran the ecological analyses to determine how the marine seafloor community changed through time."

The team found a 'dead zone' recorded in the rock, which showed virtually no signs of life and contained no fossils. This was followed by evidence of a return to life, but with new species recorded.

Professor Twitchett added: "The results show in unprecedented detail how the fossil Jurassic communities changed dramatically in response to a rise in sea level and temperature and a decline in .

"Patterns of change suffered by these Jurassic ecosystems closely mirror the changes that happen when modern marine communities are exposed to declining levels of oxygen. Similar ecological stages can be recognised in the fossil and modern communities despite differences in the species present and the scale of the studies."

The NERC project – 'The evolution of modern marine ecosystems: environmental controls on their structure and function' – runs until March 2015, and is one of four funded under their Coevolution of Life and the Planet research programme.

Explore further: Trove of sea turtle and other marine fossils found along ancient new jersey coast

More information: dx.plos.org/10.1371/journal.pone.0056255

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1.7 / 5 (12) Feb 19, 2013
"...warn of risk to..." same as maybe, might, could, etc. The verbiage of doomster alarmism.
4.5 / 5 (4) Feb 19, 2013
"...warn of risk to..." same as maybe, might, could, etc. The verbiage of doomster alarmism.

"The only things certain in life are death and taxes, and I'm not that certain about death."
If your looking for a different verbiage, you simply don't understand science. Nothing in life is certain. The only people who will give you definitive answers are those trying to sell you something, like politicians or used car salesmen.
Budding Geologist
5 / 5 (2) Feb 19, 2013
It would be nice to know more details about the Jurassic warming being studied, such as temperature change and what the time it took for the warming to occur, so I could more easily relate it to today's climate change.
3.7 / 5 (6) Feb 20, 2013
Geologic changes are typically very slow (by our standards), today's decade-level temperature changes are rapid; by geological timescales almost instantaneous.
3 / 5 (6) Feb 20, 2013
There exists a certain class of people, who are incapable of accepting evidence that contradicts their political ideology.

That class of people spend their lives lying to themselves, and internally deploying diversionary tactics that allow them to avoid thinking about aspects of reality that they find inconvenient and a challenge to their ideology.

For them, Death is the only cure for a life of self imposed ignorance.

DeaTard is such a person.

"The verbiage of doomster alarmism." - DeaTard
2.3 / 5 (6) Feb 20, 2013
Budding Geologist as I read the article my first thought was about the speed of the change. That's a very important fact left out of this. Climate change deniers always seem to forget that we are changing the climate faster than at any time in modern history. It would really make a parallel if this change occured as fast as it is changing today because that is the crux of the problem with global warming. If we had 50,000 years for the change to occur then plant and animals could adapt. My guess is that the only things that will adapt well at our current rate of change is the single celled organisms, who can evolve through thousands of generations in fifty years time. http://rawcell.co...capture/

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