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Methods
Below is a summary of the methods used when assessing the sensitivity of marine features to anthropogenic pressures.
Sensitivity scoring methods summary
Sensitivity assessments use the best available evidence to assess the likely response of a marine feature to anthropogenic pressures. This is done by considering a feature’s tolerance (ability to absorb or resist change or disturbance) to a pressure (such as abrasion) and its likely ability to recover, should the pressure be stopped.
A list of human induced marine pressures are used, each with a clear definition and impact benchmark (where possible) at which feature sensitivities are assessed. This ensures the assessments are consistent. The marine pressures list was adapted from an inventory and prepared and agreed by the OSPAR Joint Assessment Monitoring Programme.
Each marine feature is scored for tolerance and recovery separately and then combined to give a single sensitivity score – see Tables 1 to 3.
For mobile species, there are two approaches used in FeAST, these are population-based sensitivity assessments (PBSAs) and individual-based sensitivity assessments (IBSAs). Two sets of indicators are used to determine which method a feature is assessed by. The first set is based on the legislative criteria used to identify species that qualify for individual based protection and addresses their population status. The second set of indicators address the potential vulnerability of species to human activities based on their life history characteristics. For further details please see the report ‘Developing FeAST for mobile marine species’ (Sinclair et al., 2020).
Table 1. Tolerance categories for the FEAST sensitivity matrix.
| Tolerance category descriptions | |
Tolerance | None |
Benthic habitats and species | Key functional, structural, characterising species severely decline and/or physico-chemical parameters are also affected e.g. removal of habitat causing change in habitat type. A severe decline/ reduction relates to the loss of 75 % of the extent, density or abundance of the selected species or habitat element e.g. loss of 75 % substratum (where this can be sensibly applied). |
Birds and fish (population-based assessments) | A severe decline (>50 %) in the estimated size of the local population as a result of increased mortality, reduced reproductive success, displacement or any other mechanism. |
Mammals and some fish, e.g. flapper skate, basking shark, and sturgeon (individual-based assessments) | Mortality of the individual. |
Geodiversity features | Complete destruction or removal of the feature. |
Tolerance | Low |
Benthic habitats and species | Significant mortality of key and characterising species with some effects on physico-chemical character of habitat. A significant decline/ reduction relates to the loss of 25 to 75 % of the extent, density or abundance of the selected species or habitat element e.g. loss of 25 to 75 % substratum. |
Birds and fish (population-based assessments) | A significant decline (>10 and ≤50 %) in the estimated size of the local population as a result of increased mortality, reduced reproductive success, displacement or any other mechanism. |
Mammals and some fish, e.g. flapper skate, basking shark, and sturgeon (individual-based assessments) | Significant sub-lethal effects: Behavioural response resulting in e.g. significantly increased energy expenditure, significantly reduced food intake, significant increase in susceptibility to disease or significant increased vulnerability to predation. Physical impairment with significant energetic or health consequences. Likely effects on fertility rate. Possible effects on probability of individual survival. |
Geodiversity features | Widespread disruption to the feature’s surface or stratigraphy. |
Tolerance | Medium |
Benthic habitats and species | Some mortality of species (can be significant where these are not keystone structural /functional and characterising species) without change to habitat type. Some mortality refers to the loss of 25 % of the species or element. |
Birds and fish (population-based assessments) | A moderate decline (loss of up to 10 %) in the estimated size of the local population as a result of increased mortality, reduced reproductive success, displacement or any other mechanism. |
Mammals and some fish, e.g. flapper skate, basking shark, and sturgeon (individual-based assessments) | Behavioural response resulting in some increased energy expenditure, some reduced food intake, some increase in susceptibility to disease or some increased vulnerability to predation. Possible effects on fertility rate. Unlikely to affect the probability of individual survival. |
Geodiversity features | Partial and localised damage to the feature’s surface or stratigraphy. |
Tolerance | High |
Benthic habitats and species | No significant effects to the physico-chemical character of habitat and no effect on population viability of key/characterising species but may affect feeding, respiration and reproduction rates. |
Birds and fish (population-based assessments) | No population decline is expected within the site. Effects affecting key functional and physiological attributes of the species (e.g. food intake rate, energy expenditure rate) may occur but are buffered from feeding through to changed rates of reproduction or mortality and hence population size by virtue of species’ flexibility to respond to the pressure e.g. by redistribution, dietary shifts, increased foraging effort, etc. |
Mammals and some fish, e.g. flapper skate, basking shark, and sturgeon (individual-based assessments) | Behavioural response resulting in little increased energy expenditure, little reduced food intake, little increase in susceptibility to disease or little increased vulnerability to predation. No significant change to the reproductive rate of the individual. No impact on probability of individual survival. |
Geodiversity features | Negligible change to the feature. |
Table 2. Recovery category descriptions for the FEAST sensitivity matrix.
Recovery | None |
Benthic habitats and species, birds and fish (population-based assessments) | Score not applicable to assessment type. |
Mammals and some fish, e.g. flapper skate, basking shark, and sturgeon (individual-based assessments) | No recovery due to mortality. |
Geodiversity features | No potential for regeneration over decadal to centennial timescales (e.g. relict or extremely inactive feature). |
Recovery | Very Low |
Benthic habitats and species, birds and fish (population-based assessments) | Negligible or prolonged recovery possible; at least 25 years to recover. |
Mammals and some fish, e.g. flapper skate, basking shark, and sturgeon (individual-based assessments) | Negligible or prolonged recovery possible. At least 25 years to recover fertility and survival rates to pre-impact level. |
Geodiversity features | Score not applicable to assessment type. |
Recovery | Low |
Benthic habitats and species, birds and fish (population-based assessments) | Full recovery within 10 to 25 years. |
Mammals and some fish, e.g. flapper skate, basking shark, and sturgeon (individual-based assessments) | Full recovery of fertility and probability of survival to pre-impact level within 10 to 25 years. |
Geodiversity features | Partial regeneration over decadal to centennial timescales. |
Recovery | Medium |
Benthic habitats and species, birds and fish (population-based assessments) | Full recovery between 2 to 10 years. |
Mammals and some fish, e.g. flapper skate, basking shark, and sturgeon (individual-based assessments) | Full recovery of fertility and probability of survival to pre-impact level between 2 to 10 years. |
Geodiversity features | Full regeneration over decadal to centennial timescales. |
Recovery | High |
Benthic habitats and species, birds and fish (population-based assessments) | Full recovery within 2 years. |
Mammals and some fish, e.g. flapper skate, basking shark, and sturgeon (individual-based assessments) | Full recovery of fertility and probability of survival to pre-impact level within 2 years. |
Geodiversity features | Full regeneration over sub-decadal timescales. |
Table 3. Final sensitivity scoring matrix: Combining tolerance and recovery.
| Tolerance | |
Recovery | Very Low/None |
None | High |
Low | High |
Medium | Medium |
High | Low |
Recovery | Low |
None | High |
Low | High |
Medium | Medium |
High | Low |
Recovery | Medium |
None | Medium |
Low | Medium |
Medium | Medium |
High | Low |
Recovery | High |
None | Medium |
Low | Low |
Medium | Low |
High | Not Sensitive |
Note for individual-based sensitivity assessments (IBSAs) any tolerance score of none – represents mortality, from which there is no possible recovery.
Final sensitivity scores do not take into account the intensity, frequency or cumulative impacts from activities taking place at specific locations, but provide a consistent approach to measuring sensitivity, which then needs to be interpreted and applied to the situation the sensitivity information is being used for. Information about the sensitivity scores and their definitions can be found in the glossary.
The confidence in the assessments are also scored for both the tolerance and recovery evidence (Table 4), which are then combined using the confidence matrix to give an overall confidence score (Table 5) for the final sensitivity.
Table 4. Confidence category descriptions for all FeAST assessments with the exception of birds.
| Species and habitat features | |
| Geodiversity features | |
Confidence score | Low confidence |
Recovery/Tolerance | There is limited or no specific or suitable proxy information on the sensitivity of the feature to the relevant pressure. The assessment is based largely on expert judgement. |
Recovery | Low level of confidence in the assigned judgement of how the feature is likely to recover from disruption. Reflects a poor level of knowledge about the feature under consideration either in terms of the processes behind its inception and/or whether it is currently active or relict. |
Tolerance | Low level of confidence in the assigned judgement of feature resistance to specified pressure reflecting a poor understanding of either the morphological characteristics of the mapped feature and/or an incomplete understanding how the specified pressure may disturb the seabed. |
Confidence score | Medium confidence |
Recovery/Tolerance | There is some specific evidence or good proxy information on the sensitivity of the feature to the relevant pressure. |
Recovery | Reasonable level of confidence in the assigned judgement of how the feature is to likely to recover from disruption. Reflects some knowledge gaps with regards to either the processes behind its inception and/or whether the feature is currently active or relict. |
Tolerance | Reasonable level of confidence in the assigned judgement of feature resistance to specified pressure reflecting a generally sound understanding of the morphological characteristics of the mapped feature and the extent to which the specified pressure may disturb the seabed. |
Confidence score | High confidence |
Recovery/Tolerance | There is good information on the sensitivity of the feature to the relevant pressure. The assessment is well supported by the scientific literature. |
Recovery | High level of confidence in the assigned judgement of how the feature is to likely to recover from disruption. Reflects a good level of knowledge about the feature under consideration in terms of both the processes behind its inception and whether it is currently active or relict. |
Tolerance | High level of confidence in the assigned judgement of feature resistance to specified pressure reflecting a good understanding of the morphological characteristics of the mapped feature and the extent to which the specified pressure may disturb the seabed. |
For bird assessments, separate confidence scores were determined for both Recovery and Tolerance scores.
The confidence for the Tolerance score was based on the evidence base and an evidence confidence score was assigned for each species and pressure pairing (Table 5). The three criteria for assessing confidence scores were evaluated separately and combined for an overall confidence score. This method is different to the FeAST approach and was created during the 2019 assessment updates for the seabird conservation strategy as it provided a clear guide to reach a definitive score. Scores greater than 12 resulted in a ‘High’ confidence score, if scores fell between 6 and 12, a ‘Medium’ confidence score was given, and if scores were less than 6, a ‘Low’ confidence score was given.
For the confidence for the Recovery score, all species were likely to receive a ‘High’ confidence score for recovery score because the key information on marine bird breeding and survival is established (cf. Robinson, 2005; Woodward and Humphreys, 2018). The confidence would be ‘Medium’ or ‘Low’ if it were not possible to access evidence for the majority of aspects of the recovery score. The tolerance confidence score was ‘Low’ if proxy species statements were used or if only general species statements were applicable instead of species-specific information within the evidence base. The confidence scores for the Recovery and Tolerance scores were combined to produce a final sensitivity confidence score (Table 6).
Table 5. Criteria and levels for confidence scores for bird assessments only.
Confidence assessment of evidence* | Low |
Quality of Information Sources | Based on expert judgement, which is not clearly documented. Score = 1 |
Applicability of evidence | Assessment based on proxies for pressures, e.g. natural disturbance events. Score = 1 |
Degree of Concordance | Evidence does not agree on concordance or magnitude. Score = 1 |
Confidence assessment of evidence* | Medium |
Quality of Information Sources | Based on some peer reviewed papers but relies heavily on grey literature or expert judgement on feature or similar features. Score = 3 |
Applicability of evidence | Assessment based on similar pressures on the feature in other areas. Score = 3 |
Degree of Concordance | Evidence agrees on direction but not magnitude of impact. Score = 3 |
Confidence assessment of evidence* | High |
Quality of Information Sources | Based on Peer Reviewed papers (observational or experimental) or grey literature reports by established agencies on the feature. Score = 5 |
Applicability of evidence | Assessment based on the same pressures arising from similar activities, acting on the same type of feature in comparable areas (i.e. Ireland, UK). Score = 5 |
Degree of Concordance | Evidence agrees on the direction and magnitude of impact. Score = 5 |
* The final rank is given based on the summed scores across the three components of the assessment i.e. quality, applicability and concordance: Maximum combined score 15; Minimum score 3.
Table 6. Final confidence scoring matrix: Combining tolerance and recovery confidences.
| Tolerance confidence | |
Recovery confidence | Low |
Low | Low |
Medium | Low |
High | Low |
Recovery confidence | Medium |
Low | Low |
Medium | Medium |
High | Medium |
Recovery confidence | High |
Low | Low |
Medium | Medium |
High | High |
Additional details
There are some slight differences between the methods used for different feature categories, as described below.