Ocean warming modulates the effects of limited food availability on Paracentrotus lividus larval development

Abstract

Oceans are becoming warmer due to climate change processes. Marine invertebrates live within a limited range of body temperatures, and functional constraints result at temperature extremes. Furthermore, interactions between temperature and other environmental stressors have the potential to narrow the thermal windows of species. This study assessed the interactive effects of current and predicted conditions of temperature and food availability on the survival, growth, and development of the sea urchin Paracentrotus lividus. Samples were collected from the Canary Islands (28°24′N, 16°18′W) in March 2011. Nine two-factor treatments of temperature (19, 20.5 and 22.5 °C) and food level (2000, 1000 and 500 cells mL−1) were tested in laboratory experiments. The temperature and food-level treatments were chosen based on current oceanographic data for seawater off the studied region and from values predicted for the next century in the subtropical eastern Atlantic region. Our results indicated that P. lividus larvae survival could be affected by increasing seawater temperatures, in ranges expected to occur over the next century. The negative effects of decreasing food availability on the development of P. lividus larvae will be significantly modulated, however, by increasing seawater temperature. These results show that surviving sea urchin larvae are capable of shifting their energy budget to successfully grow and develop under the stressful conditions presented by the combined effects of environmental factors.