2015-11-10 - P&O Agenda - Item 7, Attach 1 - Historical Ecology of the Noosa Estuary Fisheries

Introduction

Historical ecology

Humans have lived adjacent to, and relied upon food and other resources from
our rivers and coasts for millennia (Erlandson et al. 2008). Yet in recent decades
levels of exploitation and alteration of these ecosystems has occurred at
unprecedented rates, resulting in widespread ecological degradation (Myers and
Patz 2009). Our ability to recognise (and potentially reverse) this degradation is,
however, hampered by a lack of information on past conditions. In many cases
we simply do not know what ecosystems looked like, or how abundant fish and
shellfish populations were prior to the commencement of exploitation and
coastal development. This lack of long-term knowledge is reinforced by
contemporary ecological datasets, which commonly span just a matter of years
or at most a few decades in length, and which therefore only provide us with
information on ecosystems after major changes have already occurred (Jackson
et al. 2001).


A lack of information on historical conditions results in a phenomenon called the
‘shifting baseline syndrome’ (Pauly 1995). Shifting baselines describes a
situation where we fail to appreciate the environmental changes that occurred
prior to our lifetimes. The older generation may recall past environments that
look quite different to today, but this knowledge does not necessarily get
translated to younger generations (Sáenz-Arroyo et al. 2005; Fig. 1). Likewise,
many older individuals are probably unaware of changes that occurred prior to
their lifetimes, and so forth. Therefore, with each subsequent generation a shift
occurs in what is perceived to be a ‘natural’ environment. This applies to both
terrestrial and coastal changes: it can affect what we perceive to be a ‘normal’
abundance of mangroves along the river, or a ‘healthy’ fish resource. The shifting
baseline syndrome is a problem for resource management as without an
appreciation of past change, we are less likely to recognise continuing
degradation or attempt to halt further adverse effects.




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