Management and Mitigation. Further development of the conservation objectives and the framework approach for determining bycatch thresholds is required. Such approaches allow the development of robust triggers and limits to enable the ASCOBANS specified conservation objectives to be met by allowing the impact of anthropogenic removal within and across Member States to be more fully assessed and effectively managed.
Management and Mitigation. As the direct risk is considered low, any management of this threat will depend on evidence of the need. Restriction of activities and/or adaptation of methods based on Environmental Impact Assessments may be an option if evidence of an increased risk is forthcoming. Level of risk: Given the weak evidence for this pressure (and therefore a need for further research) and the uncertainty as to its effects on the species, attention to this threat should have LOW PRIORITY. Environmental change Changes to ocean temperatures, conditions and therefore species movements which has knock on effects to predator/prey interactions and ecosystem function. Evidence Base: MODERATE There is clear evidence that environmental change is occurring and will impact the North-east Atlantic. Such changes have significant impacts on marine ecosystems including fluctuations in ocean temperature and chemical composition, primary productivity and the distribution and abundance of species (Xxxxxxx-Xxxxxxxx et al., 2019; Xxxxxx et al., 2020; Xxxxxx et al., 2020). Through a combination of changes in oceanic conditions and prey distribution and abundance, apex predators such as cetaceans are also impacted (Figure A2). However, the details of possible impacts upon cetaceans generally remain speculative. Figure A2: Schematic representation of climate change impacts on marine mammal populations. Taken from Gulland et al. (2022). The challenge is to relate changes in distribution and occurrence to the impacts of anthropogenic caused climate change as there are many confounding effects, including natural climate variability, human exploitation of the prey resources, etc. and any changes observed could simply be the result of the cetacean species responding to short-term regional variability in the prey resource rather than long-term anthropogenically driven climate change. Environmental change has the potential to result in a range expansion for harbour porpoise (XxxXxxx, 2009; xxx Xxxxxxx et al., 2021). Changes in prey distribution associated with the change in seawater temperature is considered to be the key driver of such change. For example, Xxxxxxxx et al. (2020) demonstrated that a change in the sandeel distribution when combined with the physiological requirements of harbour porpoise could result in a large shift in porpoise distribution, whilst the effects of changes in the xxxxxxx population indicated little change in porpoise distribution. Climate change may also result in an increas...
Management and Mitigation. The workshop discussed whether IMMAs could be used to support the development of mitigation measures, including proposals to re-route shipping lanes and information on where the shipping lane should be moved to. Participants noted that IMMAs often cover larger areas than those that might require management (e.g. in the Hauraki Gulf). Therefore they are a tool to highlight an area of concern but may not indicate exactly where management measures are needed. Instead a finer scale risk analysis within the IMMA area will frequently be required to identify possible management options. Similarly, a finer scale of spatial detail within an IMMA may be needed if they are to be included in voyage planning tools. Participants noted the need to avoid unintended consequences, e.g. if ships slow down in one place, they might speed up in others. Many IMMAs have buffer areas around them, added to support management and conservation considerations. For many IMMAs it is likely that the area immediately outside is less important, however this cannot be assumed when that area lacks data. In these instances there may be more scope for management measures (such as re-routing or slowing down) within the IMMA, where the best data exist. Some IMMAs have zones or specific areas highlighted within them, which may inform re-routing options and in some cases, it may be necessary to re-route shipping within an IMMA. A reduction in speed within an IMMA may also be an option where marine mammal distribution patterns are not predictable or detailed information is not available. Zones within an IMMA are sometimes marked on the maps associated with the IMMA but more often this information is part of supporting material that accompany each IMMA, along with information on threats, which may help to identify areas of high ship strike risk. Participants noted that some IMMAs are seasonal, in which case seasonal management measures could be considered. It was also agreed that modelling different scenarios could be useful to assess management options and to determine the potential impacts of these options. It was agreed that it would be useful to describe the levels of confidence in data and knowledge used to determine IMMAs with respect to possible ship strike risk analyses or mitigation measures. The workshop agreed that currently there are probably no quick technological fixes to avoid ship strikes on a real- time basis. Even if robust information on the presence and location of the whales can...
Management and Mitigation. Where a High Risk Area has been identified as requiring management action, the workshop recommends the following steps in developing a mitigation strategy: Recommend identifying and engaging with shipping “nodes” (e.g. big company “command centers”, port meetings, etc.). Recommend a collaborative approach with stakeholders, prior to going to the IMO (if warranted). Recommend maintaining a feedback loop with shipping will help encourage and sustain success.
Management and Mitigation
