Sample acidification significantly alters stable isotope ratios of sulfur in aquatic plants and animals

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 493:1-8 (2013) - DOI: https://doi.org/10.3354/meps10560 FEATURE ARTICLE Sample acidification significantly alters stable isotope ratios of sulfur in aquatic plants and animals Rod M. Connolly1,*, Thomas A. Schlacher2 1Australian Rivers Institute - Coast and Estuaries, and School of Environment, Gold Coast Campus, Griffith University, Queensland 4222, Australia 2Faculty of Science, University of the Sunshine Coast, Maroochydore DC, Queensland 4558, Australia *Email: r.connolly@griffith.edu.au ABSTRACT: Sulfur stable isotopes are increasingly being used as tracers of material processing in studies of both modern and historical food webs. Preparation of plant and animal material for isotope analysis routinely includes steps that remove inorganic material not normally assimilated by consumers. Whereas acidification of samples is known to assist with this for some elements (carbon), it can produce unwanted effects for others (nitrogen). Here we tested the effects of acidification on sulfur isotopes by comparing isotope ratios of paired acidified and non-acidified samples of seagrass, epiphytic algae growing on seagrass and animal consumers (3 types of crustaceans: amphipods, copepods and isopods). Acid treatment resulted in significant losses of elemental sulfur from the tissues and changes in sulfur isotope ratios of samples. The artificial depletion of the heavy sulfur isotope decreased sulfur isotope ratios by 2.6‰ on average, and by as much as 7.0‰ in individual samples. Acidification of samples prior to sulfur isotope analysis results in invalid ratios and should not be used. KEY WORDS: Acid digestion · Amino acids · Carbonate · DMSP · Seagrass · Stable isotope analysis Full text in pdf format Information about this Feature Article NextCite this article as: Connolly RM, Schlacher TA (2013) Sample acidification significantly alters stable isotope ratios of sulfur in aquatic plants and animals. Mar Ecol Prog Ser 493:1-8. https://doi.org/10.3354/meps10560 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 493. Online publication date: November 20, 2013 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2013 Inter-Research.