Preview

PDF 147566 - Amelio...pdf | Download (819kB) | Preview

Abstract

Concurrent anthropogenic global climate change and ocean acidification are expected to have a negative impact on calcifying marine organisms. While knowledge of biological responses of organisms to oceanic stress has emerged from single-species experiments, these do not capture ecologically relevant scenarios where the potential for multi-organism physiological interactions is assessed. Marine algae provide an interesting case study, as their photosynthetic activity elevates pH in the surrounding microenvironment, potentially buffering more acidic conditions for associated epiphytes. We present findings that indicate increased tolerance of an important epiphytic foraminifera, Marginopora vertebralis, to the effects of increased temperature (±3°C) and pCO2 (~1,000 µatm) when associated with its common algal host, Laurencia intricata. Specimens of M. vertebralis were incubated for 15 days in flow-through aquaria simulating current and end-of-century temperature and pH conditions. Physiological measures of growth (change in wet weight), calcification (measured change in total alkalinity in closed bottles), photochemical efficiency (Fv/Fm), total chlorophyll, photosynthesis (oxygen flux), and respiration were determined. When incubated in isolation, M. vertebralis exhibited reduced growth in end-of-century projections of ocean acidification conditions, while calcification rates were lowest in the high-temperature, low-pH treatment. Interestingly, association with L. intricata ameliorated these stress effects with the growth and calcification rates of M. vertebralis being similar to those observed in ambient conditions. Total chlorophyll levels in M. vertebralis decreased when in association with L. intricata, while maximum photochemical efficiency increased in ambient conditions. Net production estimates remained similar between M. vertebralis in isolation and in association with L. intricata, although both production and respiration rates of M. vertebralis were significantly higher when associated with L. intricata. These results indicate that the association with L. intricata increases the resilience of M. vertebralis to climate change stress, providing one of the first examples of physiological buffering by a marine alga that can ameliorate the negative effects of changing ocean conditions.

Item Type:	Article
Authors/Creators:	Doo, SS and Leplastrier, A and Graba-Landry, A and Harianto, J and Coleman, RA and Byrne, M
Keywords:	foraminifera, ocean acidification, physiological buffering, macroalgae, Laurencia, Marginopora
Journal or Publication Title:	Ecology and Evolution
Publisher:	John Wiley & Sons Ltd
ISSN:	2045-7758
DOI / ID Number:	https://doi.org/10.1002/ece3.6552
Copyright Information:	Copyright 2020 The AuthorsThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium,provided the original work is properly cited.
Related URLs:	Google Scholar: Graba-Landry, A
Item Statistics:	View statistics for this item

Actions (login required)

Item Control Page