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Effects of low pH on the coral reef cryptic invertebrate communities near CO2 vents in Papua New Guinea

December 15, 2021

Small cryptic invertebrates (the cryptofauna) are extremely abundant, ecologically important, and species rich on coral reefs. Ongoing ocean acidification is likely to have both direct effects on the biology of these organisms, as well as indirect effects through cascading impacts on their habitats and trophic relationships. Naturally acidified habitats have been important model systems for studying these complex interactions because entire communities that are adapted to these environmental conditions can be analyzed. However, few studies have examined the cryptofauna because they are difficult to census quantitatively in topographically complex habitats and are challenging to identify. We addressed these challenges by using Autonomous Reef Monitoring Structures (ARMS) for sampling reef-dwelling invertebrates >2 mm in size and by using DNA barcoding for taxonomic identifications. The study took place in Papua New Guinea at two reef localities, each with three sites at varying distances from carbon dioxide seeps, thereby sampling across a natural gradient in acidification. We observed sharp overall declines in both the abundance (34–56%) and diversity (42–45%) of organisms in ARMS under the lowest pH conditions sampled (7.64–7.75). However, the overall abundance of gastropods increased slightly in lower pH conditions, and crustacean and gastropod families exhibited varying patterns. There was also variability in response between the two localities, despite their close proximity, as one control pH site displayed unusually low diversity and abundances for all invertebrate groups. The data illustrate the complexity of responses of the reef fauna to pH conditions, and the role of additional factors that influence the diversity and abundance of cryptic reef invertebrates.

Publication Year 2021
Title Effects of low pH on the coral reef cryptic invertebrate communities near CO2 vents in Papua New Guinea
DOI 10.1371/journal.pone.0258725
Authors Laetitia Plaisance, Kenan O. Matterson, Katharina Fabricius, Serguei Vyacheslavovich Drovetski, Christoph F. J. Meyer, Nancy Knowlton
Publication Type Article
Publication Subtype Journal Article
Series Title PLoS ONE
Index ID 70226871
Record Source USGS Publications Warehouse
USGS Organization Eastern Ecological Science Center