How much more fishing, nutrient pollution and climate change can the world’s coral reefs endure?
Photo: Azote/Bent Christensen
This year’s coral bleaching event that destroyed vast tracts of valuable coral reefs, due to El Niño and climate change, was the most widespread in recorded history. Many now ask how much more warming in combination with overfishing, pollution and other human pressures the world’s coral reefs can endure?
The current state of knowledge is, for the first time ever, synthesised at a global level in a new article published in Frontiers in Ecology and the Environment by GEDB director Carl Folke and PhD student Jean-Baptiste Jouffray together with colleagues at the Stockholm Resilience Centre and elsewhere.
Safe operating spaces
“Ensuring that reefs and the many benefits they provide to human societies endure will require that fishing, water quality, and climate change stay within acceptable levels or ‘safe operating spaces’,” says lead author Albert Norström, Stockholm Resilience Centre.
Defining these safe levels is challenging because coral reefs in different parts of the world will respond differently to human pressures. There is also a lack of data and studies on how much reef organisms will be able to adapt to change.
"The values we provide should be regarded as guidelines, which will become more accurate with further studies and greater understanding," Norström continues.
The concept of safe operating spaces follows the precautionary principle with the aim to confine human pressures far enough from really dangerous levels, or thresholds, that might trigger abrupt and permanent coral reef degradation. The team of scientists chose this approach because despite the importance of thresholds, and recent advances in predicting them, they are extremely hard to generalise globally.
The authors hope that a better understanding of safe operating spaces might help bring issues of coral reef sustainability to the international negotiating tables. This is important because local management efforts alone will not be able to keep pace with the escalating speed of social, technological and ecological changes that challenge these safe operating spaces, they say.
“Conventional approaches like marine protected areas can offer local socioeconomic and ecological benefits, but are usually far too narrow in scope and small in scale, and often suffer from weak compliance and enforcement,” explains Magnus Nyström, Stockholm Resilience Centre.
“Coral reef scientists around the world should engage more with the international policy arena to work toward sharp reductions in greenhouse-gas emissions and the implementation of the Sustainable Development Goals,” adds Jean-Baptiste Jouffray
Norström, A., M. Nyström, J. Jouffray, C. Folke, N. Graham, F. Moberg, P. Olsson, and G. Williams. 2016. Guiding coral reef futures in the Anthropocene. Frontiers in Ecology and the Environment 14(9):490–498