Impact of near-future ocean warming and acidification on the larval development of coral-eating starfish Acanthaster cf. solaris after parental exposure

• Published in: Journal of Experimental Marine Biology and Ecology
• Main Authors: Hue, Thomas, Chateau, Olivier, Lecellier, Gaël J., Marin, Claire, Coulombier, Noémie, Le Dean, Loïc, Gossuin, Hugues, Adjeroud, Mehdi, Dumas, Pascal Paul
• Other Authors: Ecologie marine tropicale dans les Océans Pacifique et Indien (ENTROPIE Réunion ), Institut de Recherche pour le Développement (IRD)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Excellence CORAIL (LabEX CORAIL), Institut de Recherche pour le Développement (IRD)-Université des Antilles et de la Guyane (UAG)-École des hautes études en sciences sociales (EHESS)-École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de La Réunion (UR)-Université de la Polynésie Française (UPF)-Université de la Nouvelle-Calédonie (UNC)-Institut d'écologie et environnement-Université des Antilles (UA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Université de la Nouvelle-Calédonie (UNC), Centre de recherches insulaires et observatoire de l'environnement (CRIOBE), Université de Perpignan Via Domitia (UPVD)-École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), The authors are particularly grateful to Richard Farman, Director of the Aquarium des Lagons in Noumea, for hosting our experiments. We also wish to express our warmest thanks to the aquarium staff for their logistical support, in particular Sylvain Govan and Jeff Dubosc. We warmly thank Dr. Sven Uthicke for his valuable advices. Finally, we would like to warmly thank all the staff from the Adecal Technopole/Ifremer laboratory for their great help for the microalgae cultures.
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: Adult exposure; Crown-of-thorns starfish; Larvae; Ocean acidification; Ocean warming; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Pacific
• Online Access: https://hal.science/hal-03604068; https://hal.science/hal-03604068/document; https://hal.science/hal-03604068/file/S0022098121001751.pdf; https://doi.org/10.1016/j.jembe.2021.151685

International audience Outbreaks of crown-of-thorns starfish Acanthaster spp. (COTS) are among the most severe local threats to Indo-Pacific coral reefs. Despite intensive research, the factors triggering outbreaks remain unclear, though could involve enhanced COTS larval fitness due to ocean warming and acidification. Nevertheless, the effect of these combined stressors has never been tested on larval development and survivorship after parental exposure. We investigated the effects of ocean warming (+2 °C above ambient) and/or acidification (pH 7.75) on early COTS life-history stages of offspring after exposing the parental generation for 20 weeks to the same treatments. We hypothesized that prior adult exposure would modulate the effects measured in previous studies that omitted this phase, providing a more realistic scenario. Our results showed detrimental effects of elevated temperature towards lower gastrulation success and smaller advanced bipinnaria. Both elevated temperature and lower pH produced developmental delay from early to advanced bipinnaria, eventually translating into retarded achievement of mid-late brachiolaria. On average, larvae were significantly bigger in low pH treatments, independent of stages. We suggest a link between developmental delay and larger larvae due to acidification, where larvae could be blocked at a developmental stage but continue growing. Finally, we found that larval mortality was not impacted by treatments, potentially due to prior adult exposure. If adult COTS were able to acclimatize their reproductive physiology in 15 weeks to produce larvae withstanding warming and/or acidification, slow climatic changes might not affect survival at this life stage. However, the developmental delays displayed might elongate their fragile pelagic phase, potentially decreasing their chances to reach recruitment. We specified the natural spawning peak in New Caledonia, and show caution in directly linking high fertilisation rates with high larval success. Our study reinforces the ...