Urban Marine Environments as Coupled Human and Natural Systems


Over the last decade, a growing faction of scientists in the world of ecology and conservation biology has pushed the idea that most ecosystems on Earth are now comprised of coupled human and natural components.  They’ve come up with a variety of different names of these entities, but the one that I like most is “Coupled Human and Natural Systems,” or CHANS.  The idea is that although we’ve spent decades studying natural ecosystems, we have to take a step back and include humans before we can really understand how ecosystems function.

The literature describes several key qualities of coupled human and natural systems.  They are structured in a hierarchical manner and consist of complex networks of interactions.  These interactions are commonly reciprocal, with humans acting in ways that influence natural components, and natural components in turn influencing humans.  They also may involve positive or negative feedback loops that can accelerate or decelerate key processes.  Coupled human and natural systems exhibit emergent properties, which differ from the properties of individual system parts.  They exhibit nonlinearity in their dynamics, and may shift between multiple states or equilibria when certain thresholds are exceeded or system resilience is reduced.

If that sounds like Greek, don’t worry, I’m not here to drone on about models or theories.  I simply wanted to introduce the idea of CHANS.  By definition, CHANS are systems in which natural and human components interact. It’s undeniable then that urban marine ecosystems qualify.  Graphical model of human and natural interactions in urban marine ecosystemsThey are created out of long, intense interactions between humans and nature. Does the theory above then  give us insight into how urban marine ecosystems function? Do urban marine ecosystems evolve over time according to the theoretical framework for CHANS?

As I explore urban marine ecology in posts and research, I will do my best to highlight the coupled human and natural components of the system.  This may come in the form of historical information about interactions between humans and urban marine environments, explorations of the ecosystem services urban marine environments provide, and evaluations of these systems through the lens of resilience theory.  It may seem tangential at times, but the bottom line is that urban marine ecosystems are not just comprised of the marine organisms we encounter underwater.  Humans are very much a part of the ecological processes in urbanized marine habitats, and we may not be able to understand these processes or habitats until we have fully integrated ourselves into the ecological picture.