Category Archives: Climate Change

By Richard A. Ingebrigtsen, Department of Arctic and Marine Biology, University of Tromsø - Own work, GFDL, https://commons.wikimedia.org/w/index.php?curid=12614179

Keeping Things the Same

The elemental composition of organic matter is remarkably constant throughout the world’s oceans, but phytoplankton are known to take up nutrients and carbon in quite variable ratios depending on light and nutrient conditions.

In a paper published online in the journal Global Biogeochemical Cycles last month, Darwin Project researchers David Talmy (MIT), Christopher Hill (MIT), Anna Hickman (Univ. of Southampton, England), and Mick Follows (MIT), in a collaboration with Adam Martiny (Univ. of California, Irvine), report on their work  seeking to understand what ecosystem factors could cause the elemental composition of organic matter to remain stable and relatively constant (homeostatic), even when the phytoplankton can have quite variable composition. Continue reading

Dutkiewicz, S., J.J. Morris, M.J. Follows, J. Scott, O. Levitan, S.T. Dyhrman, and I. Berman-Frank, 2015, Impact of Ocean Acidification on the Structure of Future Phytoplankton CommunitiesNature Climate Change, doi: 10.1038/nclimate2722

 

NO3, Fe, and diazotroph biomass - observations (left) and model (right) over top 50 m - from Fig 1, Dutkiewicz et al, 2014

Life on the Edge – How shifting marine province boundaries could provide a new metric for global change

In their new competition theory paper, appearing in the 2014 issue of Biogeosciences, Dutkiewicz et al examine the sensitivity of the biogeography of nitrogen fixers to a warming climate and increased aeolian iron deposition in the context of a global earth system model. Continue reading

Publication

Death, R., J.L. Wadham, F. Monteiro, A.M. Le Brocq, M. Tranter, A. Ridgwell, A., S. Dutkiewicz, and R. Raiswell, (2014) Antarctic Ice Sheet fertilises the Southern OceanBiogeosciences, 11, 2635-2643, doi: 10.5194/bg-11-2635-2014

osm2014_245

Darwin goes to Ocean Sciences 2014

Leaving the cold of a New England February behind, the Darwin team will be in full attendance at this year’s Ocean Sciences conference taking place February 23-28 in Honolulu, Hawaii.

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800px-Phytoplankton_-_the_foundation_of_the_oceanic_food_chain

Winners and losers in a warming ocean

by Alli Gold Roberts (MIT Joint Program on the Science and Policy of Global Change)
Read this story at MIT News

Phytoplankton — small plant-like organisms that serve as the base of the marine ecosystem — play a crucial role in maintaining the health of our oceans by consuming carbon dioxide and fueling the food web. But with a changing climate, which of these vital organisms will survive, and what impact will their demise have on fish higher up the chain?
Stephanie Dutkiewicz, a researcher with the MIT Joint Program on the Science and Policy of Global Change, and her colleagues developed a model that investigates the potential effects of climate change on phytoplankton.

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On the potential role of marine calcifiers in glacial-interglacial dynamics

Ice-core measurements reveal a highly asymmetric cycle in Antarctic temperature and atmospheric CO2 over the last 800,000 years. Both CO2 and temperature decrease over 100,000 years going into a glacial period, then rise steeply over less than 10,000 years at the end of a glacial. There does not yet exist wide agreement about the causes of this cycle or about the origin of its shape. In this article, recently accepted in the journal Global Biogeochemical Cycles, Darwin researchers Anne Wilem Omta, Mick Follows and co-authors, explore the possibility that an ecologically driven oscillator may play a role in the dynamics.

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