Effects of ocean acidification (pHtotal~7.8) on calcification, photosynthesis, carbon and nitrogen contents and carbon isotopic signatures on Halimeda opuntia grown at tropical carbon dioxide seeps (NERP TE 5.2, AIMS)

• Other Authors: Australian Institute of Marine Science (isOwnedBy)
• Format: Dataset
• Language: unknown
• Published: data.gov.au
• Subjects: Halimeda opuntia; calcification; marine; ocean acidification; Milne Bay; Ocean acidification
• Online Access: https://researchdata.edu.au/effects-ocean-acidification-52-aims/1942071; http://data.gov.au/dataset/8242201e-3769-4f71-9cab-1abfc9a9bf19

This dataset consists of one csv data file from field derived experiments at tropical carbon dioxide seeps in Papua New Guinea, measuring the response parameters: calcification, photosynthesis, carbon and nitrogen contents and carbon isotopic signatures on Halimeda opuntia grown under ocean acidification conditions. \n\nThe aim of this study was to investigate the effects of ocean acidification on Halimeda opuntia grown under ocean acidification conditions at tropical carbon dioxide seeps. Therefore we tested several response parameters to try to understand how the calcareous alga is capable of growing under ocean acidification conditions.\n\n\nMethod:\n\nAt several locations in Milne Bay Province, Papua New Guinea, volcanic CO2 is seeping out of the seafloor (Fabricius et al. 2011). The seep sites are located at Dobu Island and Upa-Upasina (Normanby Island) close to the shore in shallow water of ~1¿15 m depth and extend over an area of ~20 by 100 m with different intensities of bubble activity within this area. Control reefs were allocated several hundred meters away from the seep sites with no impact of the seep activity on their seawater carbonate system. The bubbles, which consist of pure CO2, ascend to the surface and mix with the ambient seawater, changing the carbonate chemistry. This study was confined to areas where seawater chemistry was altered to levels projected for a vast part of the globe for the end of this century (¿representative concentration pathway¿ RCP6.0 to RCP8.5 scenarios) (Moss et al. 2010).\n\nCalcification rates in the light and dark, as well as net photosynthesis and respiration rates, were measured in-situ at control (pHtotal = 8.17) and seep sites (pHtotal = 7.77). Branches 5 ¿ 8 cm in height and with ~20 phylloids of H. opuntia were collected and retained at the site of collection until incubations commenced. Light incubations were conducted in-situ at 5 m water depth at midday. Specimens were placed into 0.5 L clear Perspex chambers, simultaneously at control and seep sites, by ...