Corals can be 'trained' to tolerate heat stress
Researchers apply stressful temperature treatment to laboratory corals to boost heat tolerance

Date:
March 2, 2022
Source:
University of Miami Rosenstiel School of Marine & Atmospheric
Science
Summary:
A new study found that corals that underwent a stressful temperature
treatment in the laboratory for 90 days were more tolerant to
increased water temperatures.



FULL STORY ==========================================================================
A new study led by researchers at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science found that corals that underwent
a stressful temperature treatment in the laboratory for 90 days were
more tolerant to increased water temperatures.


========================================================================== These findings offer coral restoration scientists with a new approach to potentially increase the success rate of planting nursery-raised staghorn
coral onto degraded reefs as climate change continues to warm ocean temperatures, resulting in more frequent coral bleaching events. Staghorn
coral (Acropora cervicornis) has died off throughout South Florida and the Caribbean, and is listed as "threatened" on the Endangered Species Act.

While previous "stress-hardening" experiments on corals have utilized
exposures to short-term temperatures, the UM Rosenstiel School team
assessed the effect of a long-term, variable treatment where temperatures reached a stressful level for a brief period of time, twice per day.

"This 'training' regime is akin to an athlete preparing for a race,"
said the study's lead author Allyson DeMerlis, a Ph.D. student at
the UM Rosenstiel School. "We were able to demonstrate that this
temperature treatment can boost the corals' stamina to heat stress."
To conduct the experiment, DeMerlis and scientists at 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 individuals of Caribbean staghorn coral from the UM Rosenstiel
School's Rescue a Reef coral nursery and randomly assigned them to one
of three groups: (1) field control, (2) laboratory control, and (3)
variable temperature treatment. The laboratory control and variable temperature-treated corals were subjected to a three-month treatment
period where the laboratory controls were kept at a constant 28 degrees
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 and 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.

The study was supported by a grant from the NOAA Coral Reef Conservation Program.

========================================================================== Story Source: Materials provided by University_of_Miami_Rosenstiel_School_of_Marine_&
Atmospheric_Science. Original written by Diana Udel. Note: Content may
be edited for style and length.


========================================================================== Related Multimedia:
* Coral_growth ========================================================================== Journal Reference:
1. Allyson DeMerlis, Amanda Kirkland, Madeline L. Kaufman, Anderson B.

Mayfield, Nathan Formel, Graham Kolodziej, Derek P. Manzello,
Diego Lirman, Nikki Traylor-Knowles, Ian C. Enochs. Pre-exposure
to a variable temperature treatment improves the response of
Acropora cervicornis to acute thermal stress. Coral Reefs, 2022;
DOI: 10.1007/s00338-022-02232-z ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/03/220302185947.htm

--- up 2 days, 10 hours, 51 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)