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7 Ecosystem Health in the Context of Fisheries and Aquaculture…
systematic way of analyzing what makes the system more or less governable, and
what governing interventions may therefore be required.
Before delving in any further, we would like to fi rst acknowledge that the word
‘ecosystem’ evokes multiple connotations, even within the scienti fi c community. It
generally refers to a complex system that relates living organisms and physical
factors in an environment. One of the most widely accepted de fi nitions of the term
is provided by Convention on Biological Diversity. Accordingly, ‘ecosystem’ means
a dynamic complex of plant, animal and micro-organism communities and their
non-living environment interacting as a functional unit (CBD 1993 [1992]).
2
However, some elements of the concept may be understood from different perspectives. For instance, where or how the limits of an environment can be located may
constitute a controversial issue, because natural systems are globally interrelated.
Another relevant issue, perhaps the most important for our aims, is how the role of
human societies in ecosystems can be conceptualized. For some authors it is evident
that humans have a clear, dominating role in the recent evolution of ecosystems in
our planet (Vitousek et al. 1997 ) . Others even argue for the use of a ‘human ecosystems’
concept for those ecosystems where humans constitute a central agent (Stepp et al.
2003 ) . As posited by Vitousek et al., “It is clear that we control much of Earth, and
that our activities affect the rest. In a very real sense, the world is in our hands - and
how we handle it will determine its composition and dynamics, and our fate” ( 1997 ,
498–499). This position looks increasingly clear after considering all of the accumulated evidence on how humans induce ecosystem transformations in the world,
as is the case with climate change.
Next, de fi ning what a healthy ecosystem is may be subject to debate. System
evaluators may have different opinions about the baseline, because ecosystems are
continuously changing. Moreover, based on their experiences, each generation may
have a very different perspective of the state of a healthy ecosystem. Finding pristine ecosystems without clear human impact, whether it is at sea or on land, is no
longer possible. Even remote areas are being exploited directly by humans or indirectly by other activities (Kulbicki 2005 ) , including through processes like climatic
change.
Well-functioning ecosystems are crucial not only for fi sheries productivity
(Chuenpagdee et al. 2005 ) , but also for other functions. The capacity of the sea to
absorb CO 2 , for instance, is a key factor in assimilating climate change. Ocean currents are also essential for climate stability in many areas of the world. The extent
to which human societies depend on ecosystem services, speci fi cally on marine
ecosystems, may not be completely known. Yet, humans may very well be the only
species on earth to have unprecedentedly impacted ecosystem health far beyond
recovery. This is perhaps due to con fi dence in our ability to develop technologies
to control the natural realms. However, such ability is increasingly contested by
2 The relevance of this concept even conduces to detailed legal de fi nitions, for instance as “a
dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit” (Commonwealth of Australian Law 1999 , 466).
7 Ecosystem Health in the Context of Fisheries and Aquaculture…
systematic way of analyzing what makes the system more or less governable, and
what governing interventions may therefore be required.
Before delving in any further, we would like to fi rst acknowledge that the word
‘ecosystem’ evokes multiple connotations, even within the scienti fi c community. It
generally refers to a complex system that relates living organisms and physical
factors in an environment. One of the most widely accepted de fi nitions of the term
is provided by Convention on Biological Diversity. Accordingly, ‘ecosystem’ means
a dynamic complex of plant, animal and micro-organism communities and their
non-living environment interacting as a functional unit (CBD 1993 [1992]).
2
However, some elements of the concept may be understood from different perspectives. For instance, where or how the limits of an environment can be located may
constitute a controversial issue, because natural systems are globally interrelated.
Another relevant issue, perhaps the most important for our aims, is how the role of
human societies in ecosystems can be conceptualized. For some authors it is evident
that humans have a clear, dominating role in the recent evolution of ecosystems in
our planet (Vitousek et al. 1997 ) . Others even argue for the use of a ‘human ecosystems’
concept for those ecosystems where humans constitute a central agent (Stepp et al.
2003 ) . As posited by Vitousek et al., “It is clear that we control much of Earth, and
that our activities affect the rest. In a very real sense, the world is in our hands - and
how we handle it will determine its composition and dynamics, and our fate” ( 1997 ,
498–499). This position looks increasingly clear after considering all of the accumulated evidence on how humans induce ecosystem transformations in the world,
as is the case with climate change.
Next, de fi ning what a healthy ecosystem is may be subject to debate. System
evaluators may have different opinions about the baseline, because ecosystems are
continuously changing. Moreover, based on their experiences, each generation may
have a very different perspective of the state of a healthy ecosystem. Finding pristine ecosystems without clear human impact, whether it is at sea or on land, is no
longer possible. Even remote areas are being exploited directly by humans or indirectly by other activities (Kulbicki 2005 ) , including through processes like climatic
change.
Well-functioning ecosystems are crucial not only for fi sheries productivity
(Chuenpagdee et al. 2005 ) , but also for other functions. The capacity of the sea to
absorb CO 2 , for instance, is a key factor in assimilating climate change. Ocean currents are also essential for climate stability in many areas of the world. The extent
to which human societies depend on ecosystem services, speci fi cally on marine
ecosystems, may not be completely known. Yet, humans may very well be the only
species on earth to have unprecedentedly impacted ecosystem health far beyond
recovery. This is perhaps due to con fi dence in our ability to develop technologies
to control the natural realms. However, such ability is increasingly contested by
2 The relevance of this concept even conduces to detailed legal de fi nitions, for instance as “a
dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit” (Commonwealth of Australian Law 1999 , 466).