89. Climate Change-Driven Multistressor Impacts on a Shelf Ecosystem: The Gulf of Maine

Cynthia H. Pilskaln (1), Zhaohui A. Wang (2), David W. Townsend (3), Gareth Lawson (4), Joseph Salisbury (5)

1 School for Marine Science and Technology, University of Massachusetts Dartmouth, New Bedford, MA 02744, USA
2 Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
3 School of Marine Sciences, University of Maine, Orono, ME 04469, USA
4 Biology, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
5 Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH 03824, USA

Background
The Gulf of Maine on the Northwest Atlantic margin is experiencing substantial decadal changes in water column biogeochemical characteristics and planktonic-benthic ecosystem structure and function. Such transformations are believed to be the result of global anthropogenic forcing with acute effects on the North Atlantic region.

Methods
In order to examine linkages between drivers, stressors and specific impacts on the biogeochemical system and ecology, multiple chemical and biological data sets collected by numerous Gulf of Maine researchers from time-series moorings, research cruises and satellite surveys over the course of three decades, are integrated and summarized.

Findings and Conclusions
Recent freshening and warming of the North Atlantic/Gulf of Maine appear to be significant drivers of plankton and fish community regimes shifts, changes in carbon delivery rates, variations in benthic community life cycles and production, as well as driving potential impacts on CaCO3 precipitation/dissolution rates and near-bottom dissolved oxygen levels. Implications are that these trends will continue along their present trajectory into the future as a function of increasing atmospheric carbon dioxide levels and global temperature rise.