Geoscience Reference
In-Depth Information
The key thing for management today is to pro-
tect environments from further avoidable change
(i.e. caused by human actions), and to allow
them to adjust to ongoing forces of change, i.e.
sea-level rise. Hence, management is about stop-
ping issues such as land loss and contaminant
input, and providing for other needs, such as
increased sediment to compensate for negative
budgets and the freeing up of land to allow it to
respond to sea-level rise. To do this, it is neces-
sary to determine what the anthropogenic forces
of change are. Viles & Spencer (1995) present
a case study relating to wetland loss on the
Mississippi delta, in which they cite a range of
management issues. These are split into three
categories: 'origin and evolutionary development';
'degradation and loss'; and 'human activities'.
The former includes issues such as storm activ-
ity and channel switching, which it could be
argued are natural processes that form part of
the ongoing evolution of the delta. The second
contains management issues that arise from
the first, such as loss of sediment due to channel
switching. The final category contains the impacts
of human activities, such as dam building, land
claim and drainage. In terms of management
approaches, the final and to some extent the
second categories are management problems,
but the first is not. It is common, however, and
not just in the Mississippi, that the first category
becomes a management issue because these
processes affect human development. In other
words, it is necessary for processes of natural
system evolution to be managed purely because
if such evolution were permitted, it could have
an impact on human activity.
This then puts the earlier point of whether
to conserve or preserve into another context.
Frequently the overriding strategy for manage-
ment is that although it is considered a good
thing, it is only good if it does not inconvenience
human activity. For estuaries and deltas, and to
a great extent coastlines, this is a critical issue
because often management and remediation
cannot progress according to the best environ-
mental reasons because of the human interest
in an area. It is relatively easy to manage some
human activities based on our knowledge of
their impacts. For contaminants and pollutants
(see section 7.5.1), abatement and input reduc-
tion can be achieved easily providing that we are
able to identify what these inputs are, and where
they originate from (see previous discussion on
contaminant reworking, and Case Study 7.3).
Other aspects of human interference are more
difficult. The reversal of land claim in order to
facilitate sea-level rise is a case in point because
freeing up land, often in areas where land use is
intense, cannot be facilitated easily. Hence, in
many cases, management will fail purely because
managers cannot undo the legacy of the past and
it may ultimately be that this legacy facilitates
the demise of many estuarine and delta envir-
onments. One important criterion, however, is
that whatever management we use, it should be
aimed at facilitating a natural system, and not
at managing natural processes that will further
disrupt the system.
7.5.1 Managing for the prevention of
environmental change
One of the main difficulties with management
relates to where the management responsibility for
such actions lies. One argument is that it should
lie with interest groups and various government-
based environmental authorities. With such an
approach, however, there is significant potential
for conflicting approaches to management. For
example, an electricity generating company may
manage a dam and its lake, but the water which
emerges from that lake becomes the responsibil-
ity of a river authority. Hence, is the release of
water based on the demand for electricity gener-
ation, or is it on the basis of what the estuary or
delta downstream needs to support extraction,
fish populations, or sufficient quantities of water
to dilute permitted waste discharges? Such issues
demand an overall management strategy cover-
ing rivers, estuaries and coasts. However, such
systems are generally thought of as unwieldy and
unworkable. Hence, smaller units of manage-
ment have to be used.
The Estuary Management Plan (EMP) can
provide for development and general land-use
planning in the estuary (or delta); it cannot
