Draft
These pages are still under construction.
Classification
where does it fit in the classification tree ?
this will be a gliffy diagram only
Definition
"Total biomass of surveyed species is a conservative property of an ecosystem; as species are fished and their biomass reduced, other species increase in abundance and “replace” these species in the foodweb. With the removal of top predators lower trophic levels can be expected to increase. Thus changes in total biomass can be reflective of changes in ecosystem productivity." (methods details page of http://www.indiseas.org/).
Indicator summary
| Indicator use | !! need a name for this column....!! | Category of indicator | Direction of change | Robustness or variability | Management objective/direction | Stakeholder/Public acceptability |
|---|---|---|---|---|---|---|
| To measure biomass trend over time | D | Species-based | Decreasing | Resource Potential | Widely accepted | |
Demonstrable (D) or Aspirational (A) | Pick one of the following:
| Pick on of the following:
or should it be deteriorating, improving, stable, unclear
| what error level or variability is there? | Pick one of the following:
| Pick one of the following:
|
Indicator use
what does it indicate?
"Ecosystem indicators are generally accepted as tools for evaluating ecosystem status and trends (e.g. Shin & Shannon 2010, Shin et al. 2010a,b), identifying key ecosystem processes (e.g. Ojaveer & Eero 2011), serving as signals that something is happening beyond what is actually measured (NRC 2000), and assessing the impacts of human activities and climate forcing (e.g. Coll et al. 2010, Link et al. 2010b, Ojaveer & Eero 2011)." (Fu et al 2012).
second column - name??
“Biomass” was not used to characterise the ecosystem state since survey data does not provide absolute estimates of biomass and thus is not comparable between species or ecosystems (due to differences in species catchability and surveys).
is it demonstrable or not?
ideally want them all to be demonstrative rather than aspirational ...
demonstrable = this definitely shows this by these studies, data sets, etc.
aspirational = this may show this we think but have no data or studies to back it up..which just think that it is a link that can be made.
Category of indicator
size-based, species-based, trophodynamics or environmental
others????/
environmental drivers are are most likely related to total system biomass and biomass of specific biological groups variables, (Fu et al 2012).
trophodynamic drivers are most relevant to the mean trophic level of community and the demersal-to-pelagic biomass ratio (Fu et al 2012).
Direction of change (Reference points, trajectories or directions for indicator)
what was it like in an undisturbed/unexploited system?
how would it be expected to change?
which way is the indicator showing a population is going in? decreasing or increasing ??
The trend associated with meeting an operational objective can be a limited or target reference point, trajectory or direction.
Target stock use in management plans has a tradition of setting reference points (Jennings 2005). In other fields a reference point can not be made therefore a trajectory or reference direction is used instead. See figure below frmo Jennings 2005 for an example of points, trajectories and directions. The unexploited, target, precautionary and limit are reference points where as the green arrows are the trajectories or reference directions. These are all measurement of progress of the management performance.
"Reference points that might support management decision making are: 1, reference points for no impaxct, 2. limit reference points fr the values of indicators associated with serious or irreversible harm, and 3, target reference points for preferred values of the indicators. As indicator values include error, precautionary reference points may be used to guarantee a high (preferably specified) probability of avoiding a limit" (Jennings 2005).
Robustness or variability? not sure which title yet...
what error level or variability is there?
what factors contribute to variability?
is there were could include discussion about type I and II errors...or are we talking statistical errors in calculating the indicator? or both?
Management strategies and/or objectives
define a standard set of management objectives?? ie from Indiseas
- Conservations biodiversity
- Ecosystem stability and resistance to perturbations
- ecosystem structure and functioning
- resource potential
has it been used in a management strategy? if so how?
relationship to management strategies/ objectives
Acceptability with stakeholders
- by all stakeholder
- by the public
- understandable to the stakeholders
Associated links
Hyperlinks to organisations, databases, webportals, and ID books, that are associated with this indicator, if appropriate.
Indicators for the Seas - http://www.indiseas.org
People
Not sure if I want this here yet...who would I actually link to?? scientist? mangers? both?
References
A list of references referred to on this page.
Methods details page http://www.indiseas.org/, accessed 20/08/2012.
Background reading
Other references that would be useful to read in regard to the indicator referred to on this page.
Citation
Please cite this page as:
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Page created by:Shavawn Donoghue
Last modified on: Aug 20, 2012 16:28
Versions: 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1
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