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A subset of corals displaying wholesome coloration initially of the heat-stress assay following both the laboratory management or variable temperature therapy. Photos comparable to this had been taken each day in an effort to observe the development of bleaching through the heat-stress assay. Credit: Amanda Kirkland
Researchers apply disturbing temperature therapy to laboratory corals to spice up warmth tolerance.
A brand new examine led by researchers on the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science discovered that corals that underwent a disturbing temperature therapy within the laboratory for 90 days had been extra tolerant to elevated water temperatures.
These findings provide coral restoration scientists with a brand new strategy to doubtlessly improve the success charge of planting nursery-raised staghorn coral onto degraded reefs as local weather change continues to heat ocean temperatures, leading to extra frequent coral bleaching occasions. Staghorn coral (Acropora cervicornis) has died off all through South Florida and the Caribbean, and is listed as “threatened” on the Endangered Species Act.
While earlier “stress-hardening” experiments on corals have utilized exposures to short-term temperatures, the UM Rosenstiel School group assessed the impact of a long-term, variable therapy the place temperatures reached a disturbing degree for a short time period, twice per day.
“This ‘training’ regime is akin to an athlete preparing for a race,” mentioned the examine’s lead creator Allyson DeMerlis, a Ph.D. scholar on the UM Rosenstiel School. “We were able to demonstrate that this temperature treatment can boost the corals’ stamina to heat stress.”
Staghorn coral (Acropora cervicornis) maintained in an aquarium within the Experimental Reef Laboratory. Credit: Allyson DeMerlis
To conduct the experiment, DeMerlis and scientists on the National Oceanic and Atmospheric Administration’s (NOAA) Atlantic Oceanographic and Meteorological Laboratory, and UM’s Cooperative Institute for Marine and Atmospheric Studies, collected coral fragments from six distinct genetic people of Caribbean staghorn coral from the UM Rosenstiel School’s Rescue a Reef coral nursery and randomly assigned them to one in every of three teams: (1) discipline management, (2) laboratory management, and (3) variable temperature therapy. The laboratory management and variable temperature-treated corals had been subjected to a three-month therapy interval the place the laboratory controls had been stored at a continuing 28 levels Celsius while the variable temperature regime corals were subjected to fluctuating temperatures between 28 to 31 degrees Celsius, twice daily for three months.
The scientists then measured bleaching progression photographically as well as the number of days that a coral endured thermal stress before bleaching. They found that the variable temperature treatment significantly improved coral endurance in thermal stress, on the order of several days, in comparison to the untreated corals. In addition, they found that untreated corals were more likely to quickly succumb to disease-like signs of tissue loss.
The findings demonstrate the benefit of using a variable temperature treatment in the laboratory setting for maintaining staghorn coral over the traditional static temperatures. This may be translated in the field for restoration practitioners, specifically for identifying locations where their coral nurseries and outplanting sites can be exposed to more fluctuating temperatures.
“We have unfortunately reached the point where active intervention and restoration are necessary to ensure that valuable coral reefs are able to persist for generations to come,” said Ian Enochs, senior author of the study, a coral scientist at NOAA’s Atlantic Oceanographic and Meteorological Laboratory, Ocean Chemistry and Ecosystems Division. “We want to increase the efficiency and efficacy of these efforts, and ultimately ensure that the corals that are placed back out on a reef have the greatest chance of enduring the stressful conditions they will face in the future.”
“Our findings bring a glimmer of hope to the uncertain future of corals, as we identified a treatment in which we can enhance their tolerance to heat stress,” said DeMerlis.
Reference: “Pre-exposure to a variable temperature treatment improves the response of Acropora cervicornis to acute thermal stress” by Allyson DeMerlis, Amanda Kirkland, Madeline L. Kaufman, Anderson B. Mayfield, Nathan Formel, Graham Kolodziej, Derek P. Manzello, Diego Lirman, Nikki Traylor-Knowles and Ian C. Enochs, 23 February 2022, Coral Reefs.
DOI: 10.1007/s00338-022-02232-z
The study, titled “Pre-exposure to a variable temperature treatment improves the response of Acropora cervicornis to acute thermal stress,” was published on February 23 in the journal Coral Reefs. The study’s authors include: Allyson DeMerlis, Madeline Kaufman, Diego Lirman and Nikki Traylor-Knowles from the UM Rosenstiel School; Amanda Kirkland from the University of New Orleans; Anderson Mayfield, Nathan Formel and Graham Kolodziej from UM’s Cooperative Institute for Marine and Atmospheric Studies, Ian Enochs from NOAA’s Atlantic Oceanographic and Meteorological Laboratory, Ocean Chemistry and Ecosystems Division; and Derek Manzello NOAA’s Coral Reef Watch, Center for Satellite Applications and Research, Satellite Oceanography and Climatology Division.
The study was supported by a grant from the NOAA Coral Reef Conservation Program.
