We now have a number of scientific studies that tell us how climate change is altering coral reef ecosystems, but how will these changes impact the human communities that depend on them for their livelihood? According to Joshua Cinner of James Cook University in Australia and colleagues from around the world, that answer depends more on the community capacity for adaptation than its location.
Fishery-dependent communities in Kenya are not in a great situation. Their reefs were heavily affected by a massive bleaching event in 1998 that has been linked to an extreme El Niño event and have not necessarily recovered as well as we might hope, and Kenyan reefs are likely to face increasing amounts of climate-related stress into the future. Across three years, Cinner and co surveyed 15 ecological sites associated with 10 coastal communities along the Kenyan coast. Using a range of ecological indicators of vulnerability of these reefs, they linked up the ‘health’ of the ecosystems with the vulnerability of the human communities that depend on them.
The authors found only a marginal difference in the vulnerability of reefs that were heavily fished, under community co-managed fisheries closures, or no-take National Marine Parks, with heavily fished reefs looking like they may be most vulnerable. How this impacted on their associated human-communities varied considerably, with some communities faring better than others. Some of this variability depended on the type of species fishers were targeting, with fishers using traps and beach seine nets are expected to see a decline in their catch. But we are an adaptable species, and some coral creatures – particularly herbivorous fish – may increase in abundance as a response to changes in the reef*.
But not every community is able to adapt to the changing conditions well. There are a whole host of reasons why a community may not be able to adapt. For the fishers themselves, switching gear to catch a different species isn’t necessarily that easy. Fishing equipment isn’t cheap, and these guys aren’t exactly rolling in it. Then we have whole communities that are almost solely dependent on reef fisheries. For these guys, their adaptive capacity is even more limited, because there simply isn’t the option to switch to another source of livelihood. In essence, communities that are more ‘generalist’ are better able to adapt to changing conditions than those which are ‘specialist’.
So where does this leave the Kenyan communities when having to deal with the changing conditions they are facing? The authors maintain that “adaptive capacity is perhaps the component of vulnerability most amenable to influence, and may be a useful focus for adaptation planning”. This is a good point. We can’t necessarily halt the degradation that reefs have experienced on a time-scale that is meaningful to these communities, but we can work towards supporting communities increase their capacity to adapt to change.
Lumping 'poor communities' together when thinking about climate change impacts doesn't really cut it - even within the same geographic area there is considerable variation with regards to the impacts of climate change and more importantly how those communities can respond to that change.
The paper is published in the open access journal PLoS ONE – you can have a read of the paper here http://dx.doi.org/10.1371/journal.pone.0074321
* Herbivorous fish may increase because algae often grow over dead coral. So, as reefs become degraded and the coral dies off, there will be more food for herbivorous fish and we may very well see a shift in the state of the ecosystem in those areas. Nothing is certain though, and we will have to wait to see how that scenario actually plays.
Image: Fishers in Mwabungu, Kenya. Credit Javier/Flickr (CC BY-NC-ND 2.0)