Using “bright spots” to study coral reefs


A “mandarin fish”

Amid a sea of depressing news on coral reefs, examples of healthy reef fish populations could help drive new understanding for conservation efforts. A comprehensive study published in Nature  earlier this year found that some coral reefs have a higher than expected abundance of fish given relatively high exposure to human activity. What can we learn from these special cases? The novel research method carried out by Cinner et. al., calls these areas “bright spots”, and seeks insights into why they exist.

Where are these bright spots? The map below shows bright spots in yellow and corresponding “dark spots” in black. The authors of this study used the abundance of reef fish per hectare as the unit of measure, so the yellow circles show where reef fish abundance is higher than expected and vice versa for black.


Bright spots- areas of higher than expected reef fish abundance

The table below gives a summary of the countries home to bright spots vs. dark spots.


What factors were present in bright spots? The authors found many to be socio-cultural, and not all are what you might expect. The following were significant:

  1. Taboos / tenure: The authors cite the following example: ” In one bright spot, Karkar Island, Papua New Guinea, resource use is restricted through an adaptive rotational harvest system based on ecological feedbacks, marine tenure that allows for the exclusion of fishers from outside the local village, and initiation rights that limit individuals’ entry into certain fisheries.” This is an example of where indigenous rights, rituals, and code are well aligned to the sustainable management of an ecosystem.
  2. Local Engagement in the Management Process. The opposite of local engagement in the management process would be oil extraction in the middle east or diamond mines in Africa. Who are the real decision-makers in those scenarios? Not the locals.
  3. High Dependence on Coastal Resources: This factor was interesting to me because one could imagine this going both ways. Perhaps a recognition of the dependence on the ecosystem coupled with a tenure arrangement and code of conduct that allows locals to manage the resource sustainably is a key combination… I’d love to see more on this.
  4. Proximity to Deep Water: This is an environmental variable that was associated with bright spots, and the authors speculate that the deep water offers a refuge for fish.

The above social factors (1-3) could give insight into where conservation funding and strategy should be deployed and shaped. Land tenure, local engagement, and the dependence on the health of the resource are all important factors in bright spots. Perhaps the presence of these factors tip management practices in favor of ensuring the long term ecological integrity of the resource rather than short term gains. However, when I take a step back and think if I’d like my society to be truly dependent on a resource such as a coral reef, it gets more complicated. We should be careful in calling that kind of dependence “a good thing” outside the context of putative positive ecosystem management.

More broadly for the field of conservation biology, the approach of using bright spots in this context is interesting because its a relatively novel technique for this discipline. It is routinely used in medicine, and there is no reason why conservation biologists shouldn’t study outliers in the same way that doctors study people who have survived lethal diseases. The authors say that this approach could “expand the conservation discourse from the current focus on protecting places under minimal threat, towards harnessing lessons from places that have successfully confronted numerous or severe stressors.”

Citation of the full scientific article

Cinner, J. E., Huchery, C., MacNeil, M. A., Graham, N. A. J., McClanahan, T. R., Maina, J., … Mouillot, D. (2016). Bright spots among the world’s coral reefs. Nature, advance online publication. Retrieved from


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