Seawater carbonate chemistry and mortality, abnormality, morphology, respiration of Heliocidaris crassispi

• Main Authors: Dorey, Narimane, Maboloc, Elizaldy, Chan, Kit Yu Karen
• Format: Dataset
• Language: English
• Published: PANGAEA 2018
• Subjects: Abnormality; Alkalinity; total; standard deviation; Animalia; Anterolateral arm length; Aragonite saturation state; Arm length; postoral; Arm symmetry; Bicarbonate ion; Biomass/Abundance/Elemental composition; Body length; Bottles or small containers/Aquaria (<20 L); Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Copper; Echinodermata; EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Gap of anterolateral arms; Gap of postoral arms; Growth/Morphology; Heliocidaris crassispi; Identification; Inorganic toxins; Laboratory experiment; Larvae mortality; Larval density; Leung_Sheun_Wan; Mortality/Survival; North Pacific; OA-ICC; Ocean Acidification International Coordination Centre; Pacific; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.907717; https://doi.org/10.1594/PANGAEA.907717

Metallic pollution is of particular concern in coastal cities. In the Asian megacity of Hong Kong, despite water qualities have improved over the past decade, some local zones are still particularly affected and could represent sinks for remobilization of labile toxic species such as copper. Ocean acidification is expected to increase the fraction of the most toxic form of copper (Cu2+) by 2.3-folds by 2100 (pH =7.7), increasing its bioavailability to marine organisms. Multiple stressors are likely to exert concomitant effects (additive, synergic or antagonist) on marine organisms. Here, we tested the hypothesis that copper contaminated waters are more toxic to sea urchin larvae under future pH conditions. We exposed sea urchin embryos and larvae to two low-pH and two copper treatments (0.1 and 1.0 μM) in three separate experiments. Over the short time typically used for toxicity tests (up to 4-arm plutei, i.e. 3 days), larvae of the sea urchin Heliocidaris crassispina were robust and survived the copper levels present in Hong Kong waters today (≤0.19 μM) as well as the average pH projected for 2100. We, however, observed significant mortality with lowering pH in the longer, single-stressor experiment (Expt A: 8-arm plutei, i.e. 9 days). Abnormality and arm asymmetry were significantly increased by pH or/and by copper presence (depending on the experiment and copper level). Body size (d3; but not body growth rates in Expt A) was significantly reduced by both lowered pH and added copper. Larval respiration (Expt A) was doubled by a decrease at pHT from 8.0 to 7.3 on d6. In Expt B1.0 and B0.1, larval morphology (relative arm lengths and stomach volume) were affected by at least one of the two investigated factors. Although the larvae appeared robust, these sub-lethal effects may have indirect consequences on feeding, swimming and ultimately survival. The complex relationship between pH and metal speciation/uptake is not well-characterized and further investigations are urgently needed to detangle the mechanisms ...