Adaptive strategies of sponges to deoxygenated oceans
Loading...
Files
Accepted Version
Supplementary Material
Date
2021-12-01
Authors
Micaroni, Valerio
Strano, Francesca
McAllen, Rob
Woods, Lisa
Turner, John
Harman, Luke
Bell, James J.
Journal Title
Journal ISSN
Volume Title
Publisher
John Wiley & Sons, Inc.
Published Version
Abstract
Ocean deoxygenation is one of the major consequences of climate change. In coastal waters, this process can be exacerbated by eutrophication, which is contributing to an alarming increase in the so-called ‘dead zones’ globally. Despite its severity, the effect of reduced dissolved oxygen has only been studied for a very limited number of organisms, compared to other climate change impacts such as ocean acidification and warming. Here, we experimentally assessed the response of sponges to moderate and severe simulated hypoxic events. We ran three laboratory experiments on four species from two different temperate oceans (NE Atlantic and SW Pacific). Sponges were exposed to a total of five hypoxic treatments, with increasing severity (3.3, 1.6, 0.5, 0.4 and 0.13 mg O2 L−1, over 7–12-days). We found that sponges are generally very tolerant of hypoxia. All the sponges survived in the experimental conditions, except Polymastia crocea, which showed significant mortality at the lowest oxygen concentration (0.13 mg O2 L−1, lethal median time: 286 h). In all species except Suberites carnosus, hypoxic conditions do not significantly affect respiration rate down to 0.4 mg O2 L−1, showing that sponges can uptake oxygen at very low concentrations in the surrounding environment. Importantly, sponges displayed species-specific phenotypic modifications in response to the hypoxic treatments, including physiological, morphological and behavioural changes. This phenotypic plasticity likely represents an adaptive strategy to live in reduced or low oxygen water. Our results also show that a single sponge species (i.e., Suberites australiensis) can display different strategies at different oxygen concentrations. Compared to other sessile organisms, sponges generally showed higher tolerance to hypoxia, suggesting that sponges could be favoured and survive in future deoxygenated oceans.
Description
Keywords
Climate change , Dead zones , Eeutrophication , Evolution , Hypoxic events , Marine benthic hypoxia , Oxygen depletion , Phenotypic plasticity , Porifera , Sessile organisms
Citation
Micaroni, V., Strano, F., McAllen, R., Woods, L., Turner J., Harman, L. and Bell, J. J. (2022) 'Adaptive strategies of sponges to deoxygenated oceans', Global Change Biology, 28, pp. 1972-1989. doi: 10.1111/gcb.16013
Link to publisher’s version
Copyright
© 2021, John Wiley & Sons, Inc. This is the peer reviewed version of the following article: Micaroni, V., Strano, F., McAllen, R., Woods, L., Turner J., Harman, L. and Bell, J. J. (2022) 'Adaptive strategies of sponges to deoxygenated oceans', Global Change Biology, 28, pp. 1972-1989. doi: 10.1111/gcb.16013, which has been published in final form at https://doi.org/10.1111/gcb.16013. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.