Friday, September 27, 2013

The emerging synthesis of evolution with ecology in fisheries science

[ This post is by Dylan Fraser of Concordia University, Montréal; I am just posting it for him.  –B. ]

It is both a harrowing and hopeful time to be a conservation biologist: harrowing in the sense that our species is, of course, rapidly altering and diminishing the Earth’s biodiversity and ecosystems. But there is hope: the present and next generation of conservation biologists really do have the opportunity to help stem the incoming tide of rapid species loss and habitat change, and to contribute substantially towards more effective conservation strategies for retaining the services that species provide to humanity. Why am I optimistic that we can accomplish this? In part, our science is getting better. It is becoming more integrative and closer to biological reality. In particular, as many of the postings on this blog indicate, we are currently witnessing the emergence and crystallization of a true (and long-awaited) synthesis of evolutionary with ecological perspectives in the scientific literature.

The implications of this ecological-evolutionary synthesis for how we manage our own activities are profound. Perhaps this is nowhere more apparent than in fisheries and its associated activities. No other vertebrates are tinkered with more by us than fishes, save for lab mice and farm animals. Intentionally or unintentionally, we harvest vast numbers of fish in marine and freshwater, we rear and release them in enormous numbers in nature for aquaculture or to bolster natural populations, we block fish migrations when we build our dams, we routinely pollute their environments, and we regularly introduce fishes to new environments. As I summarize in a recent perspective paper in the Canadian Journal of Fisheries and Aquatic Sciences, such activities regularly generate rapid changes to population abundance, density, and (or) mortality. Under such conditions, evolutionary dynamics might strongly influence ecological dynamics and vice versa within fish populations, and within the communities and ecosystems they inhabit. Indeed, the evidence is accumulating that human-induced evolutionary changes in fisheries-related activities can elicit a rich array of ecological changes on short time scales, in some cases equal to or exceeding the changes brought on by classical ecological effects.

These changes are not merely of academic interest. They matter to everyone because they can and do affect the persistence, recovery and productivity (and profitability) of exploited fishes, and hence the services that fishes provide to us for our own survival and health. Once again, there are profound implications of applying ecological-evolutionary science to manage our own activities, as exemplified by a growing number of studies in fisheries science.

I am certainly not the first person to plead for more consideration of evolutionary perspectives with ecological ones in fisheries management (or any other natural resource management sector). I have found other such pleas in the literature going back at least two decades. The reality, though, is that despite such pleas, and although I firmly sense that conservation/applied biology has become more oriented toward the ecological-evolutionary perspective in many instances, management decision-making often has not (as was raised by the one of the reviewers of my paper). Why is this? Is it that evolution is still often viewed as happening too slowly to be of relevance to many management timescales? Perhaps increased recognition of evolutionary change may reveal that the current way of doing things needs tweaking, but isn’t that consistent with adaptive management? I am optimistic that the growing arsenal of studies demonstrating the significance of evolutionary change to managed species’ demography and productivity will eventually lead to more, and more positive, management decision-making change. So for those of you with a genuine interest in conducting and applying combined ecological-evolutionary science for conservation and natural resource management: keep at it! And get the message out!


Fraser, D. J.  (2013).  The emerging synthesis of evolution with ecology in fisheries science.  Canadian Journal of Fisheries and Aquatic Sciences 70(9), 1417-1428.  DOI: 10.1139/cjfas-2013-0171

Photos provided by D. Fraser.

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