Acidification effects on the benthic metabolism and trophodynamics

• Grant number: 10/20350-8
• Support Opportunities: Research Program on Global Climate Change - Regular Grants
• Start date: September 01, 2011
• End date: August 31, 2014
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Biological Oceanography
• Principal Investigator: Paulo Yukio Gomes Sumida
• Grantee: Paulo Yukio Gomes Sumida
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated researchers: Vivian Helena Pellizari

Abstract

Growing concentrations of atmospheric CO2 is affecting the oceans in two important modes: 1) Increase in the mean temperature and 2) pH reduction. The former may impact the biology and ecology of marine species in different ways, such as changing niche breadth or causing coral bleaching and diseases. The latter is modifying a characteristic that has been stable for the last 25 million years and may have dramatic effects over the biota. Calcium carbonate forming organisms may suffer tremendous losses resulting from changes in the chemical equilibrium of sea water due to the absorption of anthropogenic CO2, which have reached ca. 30%. The vast majority of studies on acidification encompass organism level research and very little is known about the effects of acidification on ecosystem services, i.e. on the marine ecological processes. Among these, benthic remineralization and flux rates are fundamental, since marine sediments are the main depositories of organic matter (OM) in the ocean. Benthic organisms degrade OM and supply nutrients that estimulate benthic and planktonic primary production. This process is of paramount importance in continental shelves that receive a substantial proportion of OM and keep a tight benthic-pelagic coupling owing to the shallower depths. The present proposal is an experimental study on the possible effects of ocean acidification on the sediment OM remineralization and benthic organic carbon foodweb pathways. Experiments will be carried out in shallow waters off Ubatuba-SP (10-20 m depth) through SCUBA diving for in situ measurements and sediment sampling for laboratory experiments. Analyses include sediment-water nutrient flux measurements and pulse-chase experiments to determine benthic trophodynamics. We intend to test the following hypotheses: 1) Ocean acidification (OA) significantly reduces OM degradation and, consequently, nutrient fluxes from the benthos to the water column; 2) OA alters organic carbon pathways in the benthic system; and 3) Under lower pH there is a shift in the sediment procariont community composition. The results will serve not only to measure unknown present day fluxes but also to evaluate the possible impacts of OA in a important process for the carbon cycle in the ocean. Direct and unequivocal data on the herbivore/detritivore food chain will also be generated, which will be unvaluable for understanding how climate change will affect the marine ecosystem. (AU)

Scientific publications

(5)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

MIES, M.; CHAVES-FILHO, A. B.; MIYAMOTO, S.; GUTH, A. Z.; TENORIO, A. A.; CASTRO, C. B.; PIRES, D. O.; CALDERON, E. N.; SUMIDA, P. Y. G.. Production of three symbiosis-related fatty acids by Symbiodinium types in clades A-F associated with marine invertebrate larvae. CORAL REEFS, v. 36, n. 4, p. 1319-1328, DEC 2017. (10/20350-8)

MIES, MIGUEL; VAN SLUYS, M. A.; METCALFE, C. J.; SUMIDA, P. Y. G.. Molecular evidence of symbiotic activity between Symbiodinium and Tridacna maxima larvae. SYMBIOSIS, v. 72, n. 1, p. 13-22, MAY 2017. (10/20350-8)

MIES, M.; GUTH, A. Z.; TENORIO, A. A.; BANHA, T. N. S.; WATERS, L. G.; POLITO, P. S.; TANIGUCHI, S.; BICEGO, M. C.; SUMIDA, P. Y. G.. In situ shifts of predominance between autotrophic and heterotrophic feeding in the reef-building coral Mussismilia hispida: an approach using fatty acid trophic markers. CORAL REEFS, v. 37, n. 3, p. 677-689, SEP 2018. (10/20350-8)

MIES, M.; VOOLSTRA, C. R.; CASTRO, C. B.; PIRES, D. O.; CALDERON, E. N.; SUMIDA, P. Y. G.. Expression of a symbiosis-specific gene in Symbiodinium type A1 associated with coral, nudibranch and giant clam larvae. ROYAL SOCIETY OPEN SCIENCE, v. 4, n. 5, MAY 2017. (10/20350-8)

MIES, M.; GUTH, A. Z.; CASTRO, C. B.; PIRES, D. O.; CALDERON, E. N.; POMPEU, M.; SUMIDA, P. Y. G.. Bleaching in reef invertebrate larvae associated with Symbiodinium strains within clades A-F. Marine Biology, v. 165, n. 1, JAN 2018. (10/20350-8)