Marine heatwaves and upwelling shape stress responses in a keystone predator. Issue 1991 (25th January 2023)

• Record Type: Journal Article
• Authors: Rühmkorff, Sarah; Wolf, Fabian; Vajedsamiei, Jahangir; Barboza, Francisco Rafael; Hiebenthal, Claas; Pansch, Christian
• Is Part Of: Proceedings. Volume 290:Issue 1991(2023)
• Publication Date: 2023-01-25
• Subjects: climate change -- environmental fluctuations -- extreme events -- ecological memory -- cross-stress tolerance -- starfish; Biology -- Periodicals; 570.5
• DOI: 10.1098/rspb.2022.2262
• Languages: English
• ISSNs: 0962-8452

Abstract

Abstract : Climate change increases the frequency and intensifies the magnitude and duration of extreme events in the sea, particularly so in coastal habitats. However, the interplay of multiple extremes and the consequences for species and ecosystems remain unknown. We experimentally tested the impacts of summer heatwaves of differing intensities and durations, and a subsequent upwelling event on a temperate keystone predator, the starfish Asterias rubens. We recorded mussel consumption throughout the experiment and assessed activity and growth at strategically chosen time points. The upwelling event overall impaired starfish feeding and activity, likely driven by the acidification and low oxygen concentrations in the upwelled seawater. Prior exposure to a present-day heatwave (+5°C above climatology) alleviated upwelling-induced stress, indicating cross-stress tolerance. Heatwaves of present-day intensity decreased starfish feeding and growth. While the imposed heatwaves of limited duration (9 days) caused slight impacts but allowed for recovery, the prolonged (13 days) heatwave impaired overall growth. Projected future heatwaves (+8°C above climatology) caused 100% mortality of starfish. Our findings indicate a positive ecological memory imposed by successive stress events. Yet, starfish populations may still suffer extensive mortality during intensified end-of-century heatwave conditions.