Turf wars: Ocean acidification and feedback loops lock in turf algal systems

February 16, 2021

Tsukuba, Japan - It's tough out there in the sea, as the widespread loss of complex marine communities is testament to. Researchers from Japan have discovered that ocean acidification favors degraded turf algal systems over corals and other algae, thanks to the help of feedback loops.

In a study published this month in Communications Biology, researchers from the University of Tsukuba have revealed that ocean acidification and feedback loops stabilize degraded turf algal systems, limiting the recruitment of coral and other algae.

Oceans are undergoing widespread changes as a result of human activities. These changes take the form of regime shifts - major, sudden and persistent changes in ecosystem structure and function. An example is the replacement of coral reefs and kelp forests with degraded turf algae communities. These shifts result in the loss of not only marine biodiversity, but also ecosystem services, which are of value to humans and contribute to their wellbeing.

"We looked at whether the turf algal state is being maintained by stabilizing feedback loops and hysteresis," says lead author of the study Professor Ben P. Harvey. "We predicted that certain changes in the physical/chemical environment and microbial community may prevent other large algae species from establishing, and function as a feedback loop that supports turf algal persistence."

Feedback loops (control mechanisms in a system) are important in regime shifts because of their ability to both stabilize and de-stabilize states in ecosystems. Hysteresis is the circumstance in which a system has passed a tipping point and moved into a new state, and the original state cannot simply be recovered by reversing the environmental conditions. Instead, the conditions must be reversed past the tipping point. Feedback loops are necessary for hysteresis to occur.

"We found that ocean acidification favors turf algae over corals and other large algae species" says Harvey. "Our results also suggest that hysteresis may be exhibited by this ecological shift - in which case it would be especially difficult to turn around."

This work contributes to an understanding of the processes underlying coastal regime shifts. Knowledge of how marine ecosystems are stabilized by species interactions is needed to mitigate or reverse these shifts, which are predicted to increase as a result of local and global causes. Such work will help to provide for improved science-based adaptive management of these shifts to better conserve coastal ecosystem services.
The article, "Feedback mechanisms stabilise degraded turf algal systems at a CO2 seep site," was published in Communications Biology at DOI:
University of Tsukuba

Related Ocean Acidification Articles from Brightsurf:

For red abalone, resisting ocean acidification starts with mom
Red abalone mothers from California's North Coast give their offspring an energy boost when they're born that helps them better withstand ocean acidification compared to their captive, farmed counterparts, according to a study from the Bodega Marine Laboratory at the University of California, Davis.

Ocean warming and acidification effects on calcareous phytoplankton communities
A new study led by researchers from the Institute of Environmental Science and Technology of the Universitat Autònoma de Barcelona (ICTA-UAB) warns that the negative effects of rapid ocean warming on planktonic communities will be exacerbated by ocean acidification.

Sentinels of ocean acidification impacts survived Earth's last mass extinction
Two groups of tiny, delicate marine organisms, sea butterflies and sea angels, were found to be surprisingly resilient--having survived dramatic global climate change and Earth's most recent mass extinction event 66 million years ago, according to research published this week in the Proceedings of the National Academy of Sciences.

Great Barrier Reef 'glue' at risk from ocean acidification
Scientists have suspected that increasing ocean acidity would weaken and thin the structures underpinning tropical reefs.

Ocean acidification causing coral 'osteoporosis' on iconic reefs
Scientists have long suspected that ocean acidification is affecting corals' ability to build their skeletons, but it has been challenging to isolate its effect from that of simultaneous warming ocean temperatures, which also influence coral growth.

Arctic Ocean acidification worse than previously expected
Arctic Ocean acidification worse than previously expected.

Protecting bays from ocean acidification
As oceans absorb more man-made carbon dioxide from the air, a process of ocean acidification occurs that can have a negative impact on marine life.

Ocean acidification prediction now possible years in advance
CU Boulder researchers have developed a method that could enable scientists to accurately forecast ocean acidity up to five years in advance.

Ocean acidification impacts oysters' memory of environmental stress
Researchers from the University of Washington School of Aquatic and Fishery Sciences have discovered that ocean acidification impacts the ability of some oysters to pass down 'memories' of environmental trauma to their offspring.

Coral 'helper' stays robust under ocean acidification
A type of algae crucial to the survival of coral reefs may be able to resist the impacts of ocean acidification caused by climate change.

Read More: Ocean Acidification News and Ocean Acidification Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.