Faculty Candidate Seminar - Allison Smith

01/19/2016 - 12:30pm

DATE:    January 19th

LOCATION:  Hubbs Hall 4500 at 12:30pm (SIO)
(2nd seminar 1/20 at 10:30am in 1103 Muir Biology - main campus)
SPEAKER:   Allison Smith, Ph.D.
 University of Washington

TITLE:  Predicting where, when, and why: tuna species response to global environmental change
Better predictions of the effects of climate change on living systems are needed so that policymakers can develop plans to sustain living resources. Mechanistic models can improve predictions by incorporating underlying physical, chemical, and biological principles. I use mechanistic models to determine the effects of temperature and oxygen on the physiology of marine species in the global ocean. Global climate models show that waters with low concentrations of oxygen are predicted to shoal and, as a result, the portion of the water column available to aerobic marine communities will become smaller resulting in a compression of habitat. However, the extent of habitat compression will vary among species depending on oxygen tolerance thresholds. A key physiological trait that determines the tolerance of marine species for low oxygen is the oxygen affinity of blood pigments, hemoglobin and hemocyanin. Shifts in blood-oxygen binding rates due to temperature cause species with the same blood-oxygen binding rates in the surface ocean to have different blood-oxygen binding rates at deeper depths. Closely related tuna species have different blood-oxygen binding characteristics, which suggest that tuna species may have different responses to changes in oxygen and temperature.  My analysis predicts that the greatest habitat compression for all tuna species will occur in the North Pacific. Compression of southern bluefin tuna habitat in the South Pacific is also predicted to occur. The effect of temperature on blood-oxygen binding of tuna determines whether there will be predicted expansion of regions with habitat compression.  Geographic analyses of blood-oxygen binding provide mechanistic insights into the effects climate change will have on tuna habitats and potentially tuna fisheries by the end of the century. 
Faculty Host:    Lisa Levin (llevin@ucsd.edu)
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Event Calendar: 
Hubbs Hall 4500