Hydrogen Therapy Shows Promise for Protecting Coral Reefs from Heat Stress
- Authors
- Malte Ostendarp, Mareike de Breuyn, Yusuf C. El-Khaled, Neus Garcias-Bonet, Susana Carvalho, Raquel S. Peixoto, Christian Wild
- Journal
- PLoS One
- Year
- 2025
- DOI
- 10.1371/journal.pone.0308894
- Study Type
- Coral
- Outcome
- Positive
- Peer Reviewed
- Yes
- Country
- Germany
- Health Condition
- Coral Bleaching
- Body System
- Photosynthetic System
TL;DR
Adding molecular hydrogen to water may help some corals withstand hot temperatures better, although it can be harmful at normal temperatures.
Key Finding
Molecular hydrogen increased photosynthetic efficiency in heat-stressed Acropora corals by 28%, but impaired photosynthesis in both coral species at normal temperatures, indicating its effects are temperature-dependent.
Summary
Researchers tested whether molecular hydrogen (a gas with antioxidant properties) could help two types of hard corals survive heat stress. They exposed corals to normal ocean temperature (26°C) and elevated temperature (32°C), with and without hydrogen added to the water over 48 hours. Hydrogen helped one coral species (Acropora sp.) maintain better photosynthetic function (the ability to convert light into energy) when exposed to heat, but surprisingly, adding hydrogen at normal temperatures actually harmed both coral species' photosynthesis.
Practical Takeaway
This laboratory study in corals suggests hydrogen may have protective potential during heat stress, but the findings are preliminary—conducted over only 48 hours in controlled conditions with no human application. Much longer-term research is needed to understand whether hydrogen could realistically help coral reefs survive warming oceans, and the temperature-dependent effects raise questions about when and how it should be applied.
Abstract
Coral reefs are increasingly threatened by mass bleaching events due to global ocean warming. Novel management strategies are urgently needed to support coral survival until global efforts can mitigate ocean warming. Given the strong antioxidant, anti-inflammatory and anti-apoptotic properties of molecular hydrogen, our study explores its potential to alleviate the negative effects of heat stress on corals. We investigated the ecophysiological responses of two common hard corals (Acropora sp. and Pocillopora verrucosa) from the Central Red Sea under ambient (26 °C) and elevated seawater temperatures (32 °C), with and without hydrogen addition ( ~ 150 µ M H2) over 48 h. Our results showed that at 32 °C without hydrogen addition, P. verrucosa exhibited high temperature tolerance, whereas Acropora sp. showed significant reductions in photosynthetic efficiency and maximum electron transport rate compared to the ambient condition (26 °C). The addition of hydrogen at 32 °C increased the maximum electron transport rate of Acropora sp. by 28%, maintaining it at levels compared to those at 26 °C. In contrast, the addition of hydrogen at 26 °C caused a significant decrease in the photophysiology of both Acropora sp. and P. verrucosa. This suggests that the short-term response of the coral holobiont to molecular hydrogen is temperature-dependent, potentially benefiting the coral holobiont under heat stress, while impairing the photophysiology under ambient temperatures. Our findings therefore provide the foundation for future long-term studies uncovering the mechanisms behind molecular hydrogen, potentially informing the development of new management strategies to enhance coral resilience to ocean warming.