Effect of increased <i>p</i>CO<sub>2</sub> on early shell development in great scallop (<i>Pecten maximus</i> Lamarck) larvae

Abstract

As a result of high anthropogenic emission of CO₂, partial pressure of carbon dioxide (<i>p</i>CO₂) in the oceans has increased causing a drop in pH, known as ocean acidification (OA). Numerous studies have shown negative effects on marine invertebrates, and that the early life stages are the most sensitive to OA. We studied the effects on embryo and larvae of great scallop (<i>Pecten maximus</i> L.), using mean <i>p</i>CO₂-levels of 477 (ambient), 821, 1184, and 1627 ppm. OA affected both survival and shell growth negatively after seven days. Growth was reduced with 5–10% when <i>p</i>CO₂ increased from ambient 477 ppm to 1627 ppm, and survival based on egg number was reduced from 40.4% in the ambient group to 10.7% in the highest <i>p</i>CO₂-group. Larvae/embryos stained with calcein one day after fertilization, showed fluorescence in the newly formed shell area indicating calcification of the shell already at the trochophore stage. Shell hinge deformities were observed at elevated <i>p</i>CO₂-levels in trochophore larvae after two days. After seven days, deformities in both shell hinge and shell edge were observed in veliger larvae at elevated <i>p</i>CO₂-levels. Although the growth showed a moderate reduction, survival rate and increased amount of deformed larvae indicates that <i>P. Maximus</i> larvae are affected by elevated <i>p</i>CO₂ levels within the range of what is projected for the next century

Life cycle and early development of the thecosomatous pteropod Limacina retroversa in the Gulf of Maine, including the effect of elevated CO2 levels

“…We found that early exposure of L. retroversa to elevated CO2 (1200 ppm) caused increased mortality relative to the ambient and 800 ppm treatments in two experiments. Increased mortality in response to OA exposure has been similarly observed in several previous studies with other larval molluscs, such as the bay scallop (1987 ppm;White et al 2013), and the great scallop (1599 ppm; Andersen et al 2013). In the only other study of the effects of OA on developing pteropods, Comeau et al (2010b) found that mortality of Cavolinia inflexa was not influenced by OA exposure.…”

“…In this study, we documented early calcification in L. retroversa through calcein staining paired with fluorescent, SEM, and confocal microscopy. Recently, calcein staining has been used to study the effects of OA on scallop larvae (Andersen et al 2013), as well as pteropod adults (Comeau et al 2009) and juveniles (Lischka et al 2011). Calcification by veligers of the pteropod Cavolinia inflexa was also observed under ambient and acidified conditions (Comeau et al 2010b), revealing the reduction or loss of shells during development when larvae were reared in acidified water.…”

High resolution microscopy reveals significant impacts of ocean acidification and warming on larval shell development in Laternula elliptica

“…Reduced shell integrity could drastically impair function in larvae (see [27,29]), and subsequently reduce settlement and recruitment success. Additionally, larvae may have experienced trade-offs in muscle and tissue development in order to maintain calcification, resulting in a weaker animal [44].…”

“…Examinations of shell structures using scanning electron microscopy (SEM) have revealed abnormal development of hinge and valve structures [27], abnormal calcification [28], reduced shell integrity [25] and shell dissolution [28]. Deformities in shell hinges and valve edges may significantly reduce larval survival, while reduced shell integrity could increase susceptibility to injuries [25,27,29]. Increases in such abnormality rates are frequently observed in the SEM under ocean acidification, and it is likely that they are underestimated in studies that examine morphology using lower resolution techniques (e.g.…”

A SHORT-TERM SURVIVAL EXPERIMENT ASSESSING IMPACTS OF OCEAN ACIDIFICATION AND HYPOXIA ON THE BENTHIC FORAMINIFERGLOBOBULIMINA TURGIDA

“…In multi-generation experiments, coccolithophores have been shown to adapt to OA by increasing growth rates (Lohbeck et al, 2012). Larval molluscs had lower survival and growth rates when exposed to enriched pCO 2 (Andersen et al, 2013;Gobler et al, 2014). In sum, while most calcareous organisms have lower net calcification rates in response to lower pH, some taxa can be have higher net calcification rates while growing in more acidic waters (Ries et al, 2009).…”