Functional thermal limits are determined by rate of warming during simulated marine heatwaves

Marine heatwaves (MHWs) are increasing in both intensity and frequency against a backdrop of gradual warming associated with climate change. In the context MHWs, animals likely to experience sub-lethal rather than lethal effects, defining long-term limits survival and/or impacting individual population fitness. We investigated how functional track critical thresholds this relationship changes rate. To end, we monitored basic functioning, specifically ability right, feed assimilate energy, as well oxygen consumption rate common Antarctic sea urchin Sterechinus neumayeri. Water temperature experimental systems was increased at rates 1, 0.5 0.3°C d -1 , line characteristics MHW events previously experienced site where study urchins were collected on Antarctica Peninsula. Functioning assessed during simulation determined when degradation changed increased. Results suggest that thermal sensitivity varies between key biological functions measured, right having highest threshold. Functions deteriorated lower temperatures more rapid (1°C ), contrary thresholds, which reached slower (0.3°C ). MHWs their impacts extend far beyond Antarctica, context, our analyses indicate onset is determining an organism tolerate short-term elevated temperatures.