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P. Tett
concern for ecosystem health, but they can help to manage sites for sustainability
by ensuring that conditions remain within the “safe” area in Fig. 1.8.
An indicator of sustainability is categorically different from indicators of pressures
and impacts. The latter are like thermometers: their readings help describe the
weather at a particular time, or show whether a human is well or sick from fever. A
sustainability indicator must take account of time and the overall state of the ecosystem. More precisely, if the symbol Y i refers to values of a particular impact indicator, {Y i } means the set of all relevant impact indicators, and f({Y i }) specifies a
function of the values of each member of this set, such as the function that converts
monitoring results into a WFD water quality status value. Then a sustainability
indicator is df({Y i })/dt, and a generalized EcoQO for sustainability requires that:
d f({Y i })/dt £ 0 for a given site, water body or regional sea.
To understand this, imagine a set of diagrams, similar to Fig. 1.8, for each of the
CSTT scales. To make things more concrete, let us consider the zone B scale water
body that is loch Creran. The known environmental pressures on this scale are from
nutrients, oxygen-demanding organic matter, and antifouling and anti-lice chemicals,
Box 1.1 Models for assimilative capacity in the ECASA project
ECASA stands for Ecosystem Approach for Sustainable Aquaculture. The
project, which ran from December 2004 through November 2007, was part of
the European Community’s 6th framework program and funded by a contract
from the Fisheries Directorate-General of the Commission of the European
Communities. Its aims included:
Assessing the applicability (efficiency, cost effectiveness, robustness, practicality, feasibility, accuracy, precision, etc) of selected indicators and developing
operational tools, e.g., models, establishing the functional relationship
between environment and aquaculture activities.
The models studied during ECASA include the following categories:
1. Models for the biology of a type of farmed organism, including mussels
and other shellfish, and salmon and sea bream. Some of these models can
be used for best management of the animals.
2. Zone A models for local impact of fish-farms, especially models able to
predict the pattern made on the sea-bed by sinking organic waste and its
effect on the sediment and benthos.
3. Zone B models for the water-body scale impact of finfish-farming, including effects on chlorophyll, transparency and deep-water oxygen that are
associated with eutophication, together with basin-scale models for shellfish production.
Further details may be obtained from the ECASA web site at http://www.
ecasa.org.uk, and details about the models can be found in the ECASA “toolbox”, at http://www.ecasa.org.uk/toolbox.
P. Tett
concern for ecosystem health, but they can help to manage sites for sustainability
by ensuring that conditions remain within the “safe” area in Fig. 1.8.
An indicator of sustainability is categorically different from indicators of pressures
and impacts. The latter are like thermometers: their readings help describe the
weather at a particular time, or show whether a human is well or sick from fever. A
sustainability indicator must take account of time and the overall state of the ecosystem. More precisely, if the symbol Y i refers to values of a particular impact indicator, {Y i } means the set of all relevant impact indicators, and f({Y i }) specifies a
function of the values of each member of this set, such as the function that converts
monitoring results into a WFD water quality status value. Then a sustainability
indicator is df({Y i })/dt, and a generalized EcoQO for sustainability requires that:
d f({Y i })/dt £ 0 for a given site, water body or regional sea.
To understand this, imagine a set of diagrams, similar to Fig. 1.8, for each of the
CSTT scales. To make things more concrete, let us consider the zone B scale water
body that is loch Creran. The known environmental pressures on this scale are from
nutrients, oxygen-demanding organic matter, and antifouling and anti-lice chemicals,
Box 1.1 Models for assimilative capacity in the ECASA project
ECASA stands for Ecosystem Approach for Sustainable Aquaculture. The
project, which ran from December 2004 through November 2007, was part of
the European Community’s 6th framework program and funded by a contract
from the Fisheries Directorate-General of the Commission of the European
Communities. Its aims included:
Assessing the applicability (efficiency, cost effectiveness, robustness, practicality, feasibility, accuracy, precision, etc) of selected indicators and developing
operational tools, e.g., models, establishing the functional relationship
between environment and aquaculture activities.
The models studied during ECASA include the following categories:
1. Models for the biology of a type of farmed organism, including mussels
and other shellfish, and salmon and sea bream. Some of these models can
be used for best management of the animals.
2. Zone A models for local impact of fish-farms, especially models able to
predict the pattern made on the sea-bed by sinking organic waste and its
effect on the sediment and benthos.
3. Zone B models for the water-body scale impact of finfish-farming, including effects on chlorophyll, transparency and deep-water oxygen that are
associated with eutophication, together with basin-scale models for shellfish production.
Further details may be obtained from the ECASA web site at http://www.
ecasa.org.uk, and details about the models can be found in the ECASA “toolbox”, at http://www.ecasa.org.uk/toolbox.