Winter marine heatwaves alter bacterial carbon uptake in Macrocystis pyrifera ecosystems

In winter, ambient water temperatures are limiting planktonic bacterial carbon incorporation rates in kelp forests, and MHW events stimulate increased carbon turnover. Increasing bacterial metabolism during winter may affect kelp forest ecosystem services through altering turnover and maintenance of organic carbon within kelp forests and annual carbon cycling patterns. We suggest that temperature is not limiting bacterial carbon uptake at the algal surface, and other stressors are driving carbon uptake patterns in M. pyrifera biofilms.