Euromal 2021 – 9th European Congress of Malacological Societies, Prague
Date: 5 – 9 September, 2021
Hosted by: Czech University of Life sciences Prague

Date: 7 September 2021
Time: 2:35 pm
Title: Biological impacts of ocean warming and acidification on cephalopods: a meta-analysis
Presenter: Franscisco Borges
Description:
Cephalopods hold a relevant ecological role in the world’s oceans, being widely known for their cognitive and behavioural prowess. Found in almost all habitats, these molluscs play an important role as both predator and prey, while also being economically valuable. The existing literature suggests that this group may be able to cope or even thrive under the ocean’s novel conditions, due to their phenotypic flexibility and environmental plasticity. Notwithstanding, a growing body of literature has revealed potentially negative impacts of climate change for several species. In this context, the peer-reviewed literature was surveyed for articles featuring a sustained (≥24h) and controlled exposure of cephalopod species to increased temperature, reduced pH, reduced oxygen levels, and their combination. A comprehensive array of sequential meta-analyses was conducted over 211 control-treatment comparisons, from 57 suitable articles, using a standardized comparative framework to address the potential global effects of these stressors, across lineages (cuttlefishes, octopuses, and squids), climates (tropical and temperate), and life stages (embryo, paralarvae, juvenile, and adult). This analysis was also performed across specific response categories (e.g. Survival, Development, etc.). Temperature was the most influential factor, with significant effects for most categories. Reduced pH exhibited a significant, although comparatively smaller resulting effect size. Despite relatively low article and comparison number, the combination of both stressors further increased the effect size, suggesting potential synergy between both stressors. Overall, the existing literature suggests that temperature and low pH can have significant and pervasive effects on cephalopods, across lineages and life stages. This study also highlights the need for further research in certain taxa (e.g. Sepiida and Oegopsida), and emphasizes the current knowledge gaps on the effects of experimental deoxygenation, and of full factorial designs evaluating the effects of the ‘deadly trio’ in this class of molluscs.
Euromal, 6 September 2021. More information.