Seawater carbonate chemistry and larval settlement of Sea urchin larvae

• Main Authors: Espinel-Velasco, Nadjejda, Agüera, Antonio, Lamare, Miles
• Format: Dataset
• Language: English
• Published: PANGAEA 2020
• Subjects: Alkalinity; total; Animalia; Aragonite saturation state; Bicarbonate ion; Bottles or small containers/Aquaria (<20 L); Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Calculated using SWCO2 (Hunter; 2007); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Condition; Echinodermata; Evechinus chloroticus; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Laboratory experiment; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; pH; standard error; Registration number of species; Reproduction; Salinity; Settlement; Single species; South Pacific; Species; Substrate type; Temperate; Temperature; water; Time in hours; Treatment; Type; Uniform resource locator/link to reference; Zooplankton; New Zealand; Pacific; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.925182; https://doi.org/10.1594/PANGAEA.925182

Extensive research has shown that the early life stages of marine organisms are sensitive to ocean acidification (OA). Less is known, however, on whether larval settlement and metamorphosis may be affected, or by which mechanisms. These are key processes in the life cycle of most marine benthic organisms, since they mark the transition between the free swimming larval stage to the benthic life. We investigated whether OA could affect the larval settlement success of the sea urchin Evechinus chloroticus, a key coastal species with ecological, economic and cultural importance in New Zealand. We performed four settlement experiments to test whether reduced seawater pH (ranging from 8.1 to 7.0, at an interval of ∼0.2 pH units) alters larval settlement and metamorphosis success. Our results show that settlement success was not significantly reduced when the larvae were exposed to a range of reduced seawater pH treatments (8.1–7.0) at time of settlement (direct effects). Similarly, when presented with crustose coralline algae (CCA) pre-conditioned in different seawater pH of either pH 8.1 or 7.7 for 28 days, larval settlement success remained unaltered (indirect effects). We conclude that competent larvae in this species are resilient to OA at time of settlement. Further research on a range of taxa that vary in settlement selectivity and behaviour is needed in order to fully understand the effects of OA on the life cycle of marine invertebrates and the consequences it might have for future coastal marine ecosystems.