112 research outputs found
Developing FeAST for mobile marine species.
Background
The Feature Activity Sensitivity Tool (FeAST) is hosted on the Marine Scotland (MS) website
and supported by Scottish Natural Heritage (SNH) and the Joint Nature Conservation
Committee (JNCC). Its purpose is to enable high-level assessment of the sensitivity of
features of conservation value, present in Scottish seas, to different pressures resulting from
human activities. The overall aim of this project is to enable the FeAST methodology to be
adapted for mobile marine species and to consider for which species sensitivity assessment
at an individual level, as opposed to the population level, was more appropriate, and why.
Main findings
Existing approaches to Sensitivity Assessment, including FeAST, Marine Evidence-based
Sensitivity Assessment (MarESA) and Highly Mobile Species Sensitivity (HMSS)
methods, entail the estimation of changes in population expressed as a percentage of the
existing population. They assess the sensitivity of a hypothetical population and are not
site-specific.
It was difficult to define, categorically, when it is most appropriate to use an individualbased rather than population-based approach to sensitivity assessment. Accordingly, two
sets of indicators were identified which tended to favour such an approach.
We suggest that Individual-based Sensitivity Assessment (IBSA) should be applied in
species where the loss of a single individual (or small number of individuals) has the
potential to affect the survival of the population adversely or where legislation protecting
the species is implemented on an individual level. Such species are likely to be Kstrategists that are slow to reproduce with a long lifespan, slow growth rates, late
reproduction, high parental investment in their young, low fecundity and, probably, small
population sizes.
We identified those species with legislative protection at an individual level, in Scotland,
from criteria and species lists set out in the Wildlife and Countryside Act (W&C) 1981, the
Habitats Directive and the Marine (Scotland) Act 2010.
All the cetaceans, seals, marine reptiles, sharks and rays listed under W&C 1981 and as
European Protected Species would be suitable for IBSA using this approach, together
with the otter and notable fin-fish, i.e. the Atlantic sturgeon, Allis shad, Twaite shad and
European river lamprey.
RESEARCH REPORT
Summary
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In addition, the sharks and rays listed as mobile PMFs are also suitable, together with the
Atlantic halibut, blue ling, European eel, orange roughy, and round-nose grenadier. A list
of another seven fin-fish requires further consideration. The remaining fin-fish listed as
PMFs are probably not suitable under our suggested indicators.
However, the life history characteristics examined represent a short review of the
characteristics that influence population recovery and do not take into account
larval/juvenile mortality, recruitment, population dynamics, or restricted breeding sites
such as nursery areas in fish or rivers and estuaries in anadromous fish. In addition, the
cut-off values for life history characteristics are subjective rather than definitive.
Further study is required to expand and test the application of the above list of indicators
and the IBSA approach to a wider range of species than considered here.
An individual-based tolerance scale is suggested. We avoided a binary scale (dead/alive)
and suggested a scale from ‘dead’ through different levels of impairments due to physical
injury and behavioural changes. We slightly amended the existing FeAST recovery scale
to emphasize its application to the recovery of individuals rather than that of populations.
The FeAST sensitivity matrix was also amended slightly to highlight the fact that no
recovery was possible from direct mortality. The existing FeAST scales for ‘confidence’
and ‘evidence’ were adopted.
The suggested individual-based approach was tested on two pilot species: Risso’s
dolphin and the harbour seal. Contrary to initial concerns, the suggested scales did not
result in binary scores, that is, just mortality or no mortality. Both pilot assessments gave
a range of scores for tolerance, recovery and, hence, sensitivity.
Assessing on an individual level was found to simplify the assessment of tolerance. It
was often very straightforward to assess whether an individual was likely to suffer injury
or mortality from an impact.
The suggested individual-based approach does not take the likelihood of the impact
occurring or the extent of the impact into account at any point. Many of the pressures to
which the assessed species are highly sensitive may be very unlikely to have a
population level impact, due to their low likelihood of occurrence.
It should also be noted that the revision of benchmarks and scales for highly mobile
species in FeAST means that the resultant sensitivity assessment will differ from those
generated under the MarESA and HMSS approaches, and that their sensitivity scores for
the same species will not be directly comparable.
Overall, the suggested Individual-based Sensitivity Assessment (IBSA) approach was used
successfully to assess the sensitivity of two highly mobile species. More species need to be
assessed to test the approach fully and to develop examples and guidance on the
application of the individual-based tolerance scale to other highly mobile specie
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