Effects of ocean acidification and warming on the behaviour of marine shelled molluscs’ early life stages

• Main Author: Fonseca, Joana Gomes
• Other Authors: Barroso, Carlos Miguel Miguez, Hinzmann, Mariana Fonseca, Oliveira, Susana Galante Correia Pinto de
• Format: Master Thesis
• Language: English
• Published: 2022
• Subjects: Climate change; Temperature; pH; Gastropods; Bivalves; Tritia reticulata; Venerupis corrugata; Locomotion; Mobility; Swimming; Feeding; Histology; Microscopy; Ocean acidification
• Online Access: http://hdl.handle.net/10773/30174

Over the last few decades the Earth’s climate change has been changing in an unprecedent way. The planet’s surface temperature has increased (Global Warming) due to the increasing emission of greenhouse gases from anthropogenic activities, especially carbon dioxide (CO2). Global changes have also affected the oceans causing an increase in its temperature – Ocean warming (W) – and a decrease in the seawater pH as a consequence of the increased concentration of CO2. Shelled gastropods and bivalves are potentially sensitive to OA-W since are calcifiers and have complex life cycles. These life cycles generally comprise a planktonic larval phase followed by a profound metamorphosis leading to a benthic way of life. In this way, early development stages may eventually be more susceptible to seawater acidification and warming. In order to assess the impact of OA-W on the behaviour and survival of the early stages of shelled molluscs, the larval phases of the gastropod Tritia reticulata (Linnaeus, 1758) – a necrophage essential in european coastal ecosystems – and of the bivalve Venerupis corrugata (Gmelin, 1791) – a filter-feeder and important fishery resource – were exposed to OA-W scenarios predicted by the Intergovernmental Panel on Climate Change (IPCC) for the end of this century. T. reticulata swimming and larval survival were negatively affected by the exposure to OA-W experimental conditions for 14 days. In addition to the synergistic effect of pH and temperature on the activity, velocity and distance traveled by T. reticulata veligers, there was evidence of morpho-histological damage of the foot epithelium with potential functional implications on both the larval and benthic phases. In turn, after 14 days of exposure to AO-W scenarios, the pullet carpet shell Venerupis corrugata showed greater larval survival and development, and no behavioural changes were observed. Despite the antagonistic effect of temperature and pH, their simultaneous occurrence may reduce the impacts of OA on natural populations’ ...