Feeling the heat: helping populations build thermal tolerance

Climate change is a major threat to biodiversity and important species on our planet. A potential solution to prevent vulnerable species from being lost is improving their thermal tolerances, making them better adapted to warmer temperatures and climates. University of Melbourne Masters student Kristal Sorby and co-authors tried to improve survival of individuals to extreme heat events within and across generations using a brine shrimp (Artemia franciscana) as a test animal. In combination with serotonin, methionine or neither, brine shrimp were exposed to ‘heat hardening’ over two generations and their thermal tolerances were recorded. While treatments did not increase their upper thermal limit, serotonin and methionine-treated shrimp outperformed control shrimp for thermal performance traits. Some effects were also present across generations, suggesting that heat hardening could provide resilience and stability in populations vulnerable to increasing temperatures.