Although there is a range of environmental conditions in which an animal can survive, there is an even smaller range of conditions in which it can thrive.
New research from the national Marine Environmental Observation Prediction and Response (MEOPAR) Network finds that low oxygen levels may stress, or even kill, a number of marine fish and invertebrates off Eastern Canada in the next 50 years.
The Eastern Canadian fisheries of the Gulf of St. Lawrence and the Scotian Shelf are globally important fisheries. But the effects of climate change, such as increasing temperatures,increasing acidity, and lowered oxygen levels, are placing stress on marine fish and invertebrates,which could affect the fisheries’ future viability.
The study, led by Dr. Catherine Brennand while a MEOPAR-funded postdoctoral fellow at Dalhousie University, used computers to model currents and physical characteristics, such as salinity and temperature,of the Gulf of St. Lawrence and Scotian Shelf.
The study concludes that if the current trends of increasing temperature and
decreasing oxygen continue, “many species will encounter unsuitable temperature or
oxygen conditions within the next century,” and that some will do so in the next 50 years.
“Each species has a thermal limit, a maximum temperature above which they are not able to
thrive,” explains Brennan. “For example, Atlantic Cod, which inhabit the western Scotian Shelf,
are at the upper boundary of their thermal limit, so any bit of warming that occurs in
this region is going to be too warm for them.”
The researchers hope others will use and expand the open access data-set they
compiled to better our understanding of the regional effects of climate change.
The study, Putting Temperature and Oxygen Thresholds of Marine Animals in Context of
Environmental Change: A Regional Perspective for the Scotian Shelf and Gulf of St. Lawrence,
was published in open access journal PLOS ONE, here. To access the dataset, go to the supporting information of the paper.
MEOPAR is a national Network of Centre of Excellence hosted at Dalhousie University that sees academic researchers and students, government scientists, and partners in the private, NGO and community sectors working together to reduce vulnerability and strengthen opportunity in Canada’s marine environment.