Quantifying coral-algal interactions in an acidified ocean: Sargassum spp. exposure mitigates low pH effects on Acropora cervicornis health

IF 2.8 2区生物学 Q1 MARINE & FRESHWATER BIOLOGY

Frontiers in Marine Science Pub Date : 2025-02-28 DOI:10.3389/fmars.2025.1487102

Johann D. Lankes, Heather N. Page, Amanda Quasunella, Jaclyn F. Torkelson, Clöe Lemaire, Robert J. Nowicki, Lillia Blasius, Emily R. Hall

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引用次数: 0

Abstract

Increasingly frequent large-scale pelagic Sargassum algae blooms in the Atlantic have become a problem for coastal ecosystems. The mass decay of these blooms reduces water quality for coastal flora and fauna. However, the effects of living Sargassum blooms on seawater quality and consequently coral reef ecosystems that rely on delicately balanced carbonate chemistry are more ambiguous. Future oceans are predicted to be more acidic as additional anthropogenic CO2 emissions are absorbed, potentially tipping the balance in favor of algal blooms at the cost of coral survival. This study aimed to simulate the indirect interaction between pelagic Sargassum spp. and Acropora cervicornis coral fragments from the Florida Reef in current-day and future ocean pH conditions over the course of 70 days in a mesocosm experimental system. Measurements of coral growth and health via buoyant weight and Pulse Amplitude Modulated (PAM) fluorescence measurements reveal an unexpected coral-algal interaction. After 1 month, coral growth was significantly reduced under ocean acidification conditions and exposure to Sargassum; at the same time quantum yield and maximum electron transport rate of photosynthesis were increased relative to control counterparts in ambient and future pH scenarios by up to 14% and 18% respectively. These improvements in photosynthetic efficiency did not translate to significant differences in growth by the final measurement time point. In addition, the presence of Sargassum spp. did not raise seawater pH in the system, raising questions about how it benefited photosynthetic efficiency in exposed corals. Heterotrophy of detrital algal matter is suspected to compensate for impaired photosynthesis of pH stressed corals. Therefore, despite their current negative reputation, Sargassum blooms could provide short term localized benefits to corals in present and future ocean conditions.

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来源期刊

Frontiers in Marine Science Agricultural and Biological Sciences-Aquatic Science

CiteScore

5.10

自引率

16.20%

发文量

2443

审稿时长

14 weeks

期刊介绍： Frontiers in Marine Science publishes rigorously peer-reviewed research that advances our understanding of all aspects of the environment, biology, ecosystem functioning and human interactions with the oceans. Field Chief Editor Carlos M. Duarte at King Abdullah University of Science and Technology Thuwal is supported by an outstanding Editorial Board of international researchers. This multidisciplinary open-access journal is at the forefront of disseminating and communicating scientific knowledge and impactful discoveries to researchers, academics, policy makers and the public worldwide. With the human population predicted to reach 9 billion people by 2050, it is clear that traditional land resources will not suffice to meet the demand for food or energy, required to support high-quality livelihoods. As a result, the oceans are emerging as a source of untapped assets, with new innovative industries, such as aquaculture, marine biotechnology, marine energy and deep-sea mining growing rapidly under a new era characterized by rapid growth of a blue, ocean-based economy. The sustainability of the blue economy is closely dependent on our knowledge about how to mitigate the impacts of the multiple pressures on the ocean ecosystem associated with the increased scale and diversification of industry operations in the ocean and global human pressures on the environment. Therefore, Frontiers in Marine Science particularly welcomes the communication of research outcomes addressing ocean-based solutions for the emerging challenges, including improved forecasting and observational capacities, understanding biodiversity and ecosystem problems, locally and globally, effective management strategies to maintain ocean health, and an improved capacity to sustainably derive resources from the oceans.