Please note this site is currently in beta mode while we finalise the data and test for bugs.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 is 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 1-3 below.
Table 1 - Tolerance categories for FEAST sensitivity matrix
Tolerance category descriptions | ||||
Tolerance (Resistance) | Benthic habitats and species | Birds | Mammals (individual-based assessments) #plus some fish* | Geodiversity |
None | 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). | 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. | Mortality of the individual. | Complete destruction or removal of the feature. |
Low | Significant mortality of key and characterising species with some effects on physic-chemical character of habitat. A significant decline/ reduction relates to the loss of 25%-75% of the extent, density or abundance of the selected species or habitat element e.g. loss of 25-75% substratum. | 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. | 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. | Widespread disruption to the feature’s surface or stratigraphy. |
Medium | 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. | 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. | 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. | Partial and localised damage to the feature’s surface or stratigraphy. |
* Please see the fish section below for more specific details on tolerance scoring for fish assessments
Table 2 - Recovery category descriptions for FEAST sensitivity matrix
Recovery Category Description | |||
Recovery (Resilience) | Benthic habitats and species, Birds, Mammals and Fish | Geodiversity Please note recovery categories are named differently | |
Very Low | Negligible or prolonged recovery possible; at least 25 years to recover | None | No potential for regeneration over decadal to centennial timescales (e.g. relict or extremely inactive feature). |
Low | Full recovery within 10-25 years | Low | Partial regeneration over decadal to centennial timescales. |
Medium | Full recovery between 2- 10 years | Medium | Full regeneration over decadal to centennial timescales |
High | Full recovery within 2 years | High | Full regeneration over sub-decadal timescales |
Table 3 - Final sensitivity scoring matrix: Combining tolerance and recovery. Adapted from Tyler-Walters et al. (2018)
Tolerance | ||||
Recovery | None | Low | Medium | High |
Very Low | High | High | Medium | Low |
Low | High | High | Medium | Low |
Medium | Medium | Medium | Medium | Low |
High | Medium | Low | Low | Not Sensitive |
Note for individual based sensitivity assessments (mammals and some fish) 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
Confidence Description | |||
Biodiversity features | Geodiversity features | ||
Confidence score | Recovery/Tolerance | Recovery | Tolerance |
Low Confidence | 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. | 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. | 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 sea bed. |
Medium Confidence | There is some specific evidence or good proxy information on the sensitivity of the feature to the relevant pressure. | 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. | 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 sea bed. |
High Confidence | There is good information on the sensitivity of the feature to the relevant pressure. The assessment is well supported by the scientific literature. | 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. | 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 sea bed. |
Table 5 Final confidence scoring matrix: Combining tolerance and recovery confidence
Tolerance Confidence | |||
Recovery Confidence | Low | Medium | High |
Low | Low | Low | Low |
Medium | Low | Medium | Medium |
High | Low | Medium | High |
There are some slight differences between the methods used for different categories of marine feature, for details see below.