Antagonistic interplay between pH and food resources affects copepod traits and performance in a year-round upwelling system

• Published in: Scientific reports 2020-01, Vol.10 (1), p.62-62, Article 62
• Main Authors: Aguilera, Victor M., Vargas, Cristian A., Dam, Hans G.
• Format: Article
• Language: English
• Subjects: 119/118; 14/63; 704/158/2455; 704/47/4113; 704/829/827; Acidification; Animals; Body Size; Carbon Dioxide - chemistry; Chlorophyll; Chlorophyll - chemistry; Chlorophyll - metabolism; Copepoda - growth & development; Copepoda - metabolism; Ecosystem; Egg production; Female; Humanities and Social Sciences; Hydrogen-Ion Concentration; Marine ecosystems; multidisciplinary; Oceans; Ovum - physiology; pH effects; Phenotypic variations; Resource availability; Science; Science (multidisciplinary); Seasons; Seawater - chemistry; Temperature; Upwelling
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-56621-6

Linking pH/ p CO 2 natural variation to phenotypic traits and performance of foundational species provides essential information for assessing and predicting the impact of ocean acidification (OA) on marine ecosystems. Yet, evidence of such linkage for copepods, the most abundant metazoans in the oceans, remains scarce, particularly for naturally corrosive Eastern Boundary Upwelling systems (EBUs). This study assessed the relationship between pH levels and traits (body and egg size) and performance (ingestion rate (IR) and egg reproduction rate (EPR)) of the numerically dominant neritic copepod Acartia tonsa , in a year-round upwelling system of the northern (23° S) Humboldt EBUs. The study revealed decreases in chlorophyll (Chl) ingestion rate, egg production rate and egg size with decreasing pH as well as egg production efficiency, but the opposite for copepod body size. Further, ingestion rate increased hyperbolically with Chl, and saturated at ~1 µg Chl. L −1 . Food resources categorized as high (H, >1 µg L −1 ) and low (L,  7.89) and future (>400 µatm p CO 2, pH