Toward an Understanding of Technology Adoption: Risk, Learning, and Neighborhood Effects

Abstract

<h3>Abstract</h3> Ongoing climate change has caused rapidly increasing temperatures, and an unprecedented decline in seawater pH, known as ocean acidification. Increasing temperatures are redistributing species towards higher and cooler latitudes which are most affected by ocean acidification. Whilst the persistence of intertidal species in cold environments is related to their capacity to resist sub-zero air temperatures, studies have never considered the interacting impacts of ocean acidification and freeze stress on species survival and distribution. A full-factorial experiment was used to study whether ocean acidification increases mortality in <i>Mytilus</i> spp. following sub-zero air temperature exposure. We examined physiological processes behind variation in freeze tolerance using ¹H NMR metabolomics, analyses of fatty acids, and amino acid composition. We show that low pH conditions (pH = 7.5) significantly decrease freeze tolerance in both intertidal and subtidal populations of <i>Mytilus</i> spp. Under current day pH conditions (pH = 7.9), intertidal <i>M. trossulus</i> were more freeze tolerant than subtidal <i>M. trossulus</i> and <i>M. galloprovincialis</i>. Opposite, under low pH conditions, subtidal <i>M. trossulus</i> was more freeze tolerant than the other groups. We observed a marked shift from negative to positive metabolite-metabolite correlations across species under low pH conditions, but there was no evidence that the concentration of individual metabolites or amino acids affected freeze tolerance. Finally, pH-induced changes in the composition of cell membrane phospholipid fatty acids had no effect on survival. These results suggest that ocean acidification can offset the poleward expanding facilitated by warming, and that reduced freeze tolerance could result in a niche squeeze if temperatures become lethal at the equatorward edge.