SFU researcher finds 50% decline in coral reefs capacity since 1950s

Coral reef capacity decline has direct implications on the lives of surrounding Indigenous communities

Coral reef under water
PHOTO: Quentin Hanich / SFU

By: Tamanna T., Staff Writer 

Andrés Cisneros-Montemayor, assistant professor in the School of Resource and Environmental Management, recently published a new study on coral reef capacity. He and a team of multi-institutional researchers found coral reef capacity and coral cover have decreased up to 50% globally since the 1950s. This has reduced the ability of coral reefs to provide essential habitats for aquatic animals. The research also noted the impact felt by many Indigenous communities in coastal regions. 

The study emphasizes the effect of this decline on the food consumption of Indigenous communities as they have “a high dependence on coral reef fisheries, for both traditions and food sovereignty,” said Cisneros-Montemayor.

“Food security is a big part of it, but just as importantly, food sovereignty — choosing what species you want to eat and which one is culturally desirable is a really important part of their daily lives and traditions.”

Coral reefs, like the Great Australian Barrier Reef, are aquatic structures in which corals, a type of cnidarian animal, reside. Coral cover refers to the amount of surface area the structures can cover. 

The lack of living coral reef capacity causes a decline in the fish species around the area. “Living reefs have way more biodiversity and way more abundance of species associated with them.” This reduction in living coral reefs can be caused by multiple factors such as pollution, climate change, and human activity.  

Cisneros-Montemayor compared the significance of the reduced coral reef capacity in Indigenous and frontline communities to its commercial importance, and stated the former are affected more than just financially. “It’s very difficult to convey to people that some of these impacts that are happening through climate change [ . . . ] have a much deeper implication than just losing income,” said Cisneros-Montemayor. 

While some have proposed solutions such as relocation or changing practices, “in places where Indigeneity is intimately tied to the practice of fishing, to physically being and living your life in these reefs, those solutions don’t work.”     

The impact of climate change on the coral reefs is related to the warming of the oceans. Cisneros-Montemayor said, “Corals live in a symbiosis with the animal and algae. When water gets too warm, the symbiosis is broken and over time, that coral will just die.” 

Dead coral reefs are still effective and “useful for a lot of fish,” he explained , but “living coral [reefs] are associated with more species.” 25% of fish species depend on coral reefs, signifying their importance.

Cisneros-Montemayor reveals another effect of climate change on coral reefs: ocean acidification. “Corals, to build these structures that create the reef itself, they need to precipitate calcium carbonates. So what happens with acidification is the ocean chemistry actually changes in ways that make it a lot more difficult for corals to make a reef.”

He pointed out a challenging aspect of his research involves convincing the general public the issues affecting Indigenous communities deserve attention and resources.    

Cisneros-Montemayor hoped to convey the importance of capacity of coral reefs is directly proportional to the plight of surrounding frontline communities. “It really comes down to educating people [ . . . ] and bringing to light these really current Indigenous relationships; these aren’t things of the past.”