CETACEANS IN THE EVENT OF AND OIL SPILL IN THE MORAY FIRTH
This document provides the best current advice for dealing with cetaceans in the event of an oil spill in the Moray Firth. The guidance covers a range of scenarios involving cetaceans and oil, such as dealing with stranded cetaceans, cetaceans surrounded by oil in confined areas, and circumstances where cetaceans may need to be treated in locations which are also easily accessible to the general public.
The guidelines recognise that cetaceans are only one of a number of factors that need to be taken into account during the contingency planning process and oil spill clean-up response.
Under the “Habitats Directive”, Council Directive 92/43/EEC, a large part of the inner Moray Firth has been proposed as a candidate Special Area of Conservation (cSAC) on account of the international importance of the resident bottlenose dolphin population (Figure 1). The status of part of the Moray Firth as a cSAC ensures that all local and national authorities with responsibilities in the marine environment must exercise their duties to secure the favourable condition of the bottlenose dolphin population.
FIGURE 1. The Moray Firth, including the area of the candidate Special Area of Conservation.
Oil spill contingency plans should include up to date information on the occurrence and usage of the Moray Firth by cetaceans.
There are a number of references about seeking specialist advice in these guidelines. As part of any forward planning, it will be essential for contingency planners to identify in advance those groups or individuals who are qualified and likely to be available to provide specialist advice in the event of an incident.
A tiered response is recommended depending on the size of the spill and the importance of the area for cetaceans . Notification and advice on implications for cetaceans will need to be sought for all spills within the cSAC.
1. Small operational spills at jetties or terminals. Reported but managed and cleaned up by operator.
2. Medium sized spills, either at or in the vicinity of a facility , which cannot be handled by the facility operator alone. Personnel and equipment support will be required either from other port users or from a local or regional oil spill co-operative.
3. Large spills, either at or remote from a facility that are beyond the capability of local and regional resources. They will require the National Contingency Plan to be invoked and national resources to be mobilised.
I. Areas for which there have been occasional sightings of cetaceans (ie. once or twice a year)
II. Areas with regular sightings of cetaceans for the time of year (ie. once or twice a month)
III. Areas used intensively by cetaceans or which are designated for cetaceans.
A Seek advice
C Call out
ASSESSING PRESENCE & RISK TO CETACEANS FOLLOWING A SPILL Reconnaissance
Areas where cetaceans are likely to be present, (eg. because of time of year or known resident groups) and good look out points with easy access are shown in Figure 2. A network of suitable sites for shore-based monitoring in the event of a spill needs to be identified. Early reconnaissance teams (land, aerial and water-based) investigating the nature of the incident should be requested to report any sightings of cetaceans. Dedicated cetacean reconnaissance teams are recommended for any spills in or likely to enter areas intensively used by cetaceans. Dedicated reconnaissance should only be carried out under the supervision and guidance of country agency staff or the marine mammal specialist(s) as poorly managed observation may miss the collection of some useful information and sea-based reconnaissance could cause unnecessary disturbance to the animals.
The contingency plan should clearly indicate how information gathered during reconnaissance will be conveyed to any clean-up teams and/or the Marine/Shoreline Response Centres. Remote methods, such as the deployment of sonar buoys or hydrophones in areas known to be well used by cetaceans should be considered. Sonar buoys are particularly useful to determine if cetaceans are present in an area when weather and sea conditions make sightings difficult. Hydrophones are already deployed in the area of the Kessock Bridge but may need to be switched on.
Information held by the clean-up teams and/or the Shoreline/Marine Response Centres on the spill (size, direction, condition etc.) should be passed to those assessing the risk to cetaceans. Good communication between cetacean reconnaissance and sightings teams and the clean-up teams and/or the Shoreline/Marine Response Centres is essential.
FIGURE 2. Areas intensively used by bottlenose dolphin and recommended visitor look-out points
Cetacean sightings in the Moray Firth (F- frequent, R- regular, O-occasional, RA - Rare)
Bottlenose dolphin (F)
Killer whale (O)
Harbour porpoise (F)
Risso’s dolphin (O)
White-beaked dolphin (R)
Common dolphin (O)
Minke whale (R)
Northern bottlenose whale (RA)
Atlantic white-side dolphin (O)
Humpback whale (RA)
Long-finned pilot whale (O)
Where sightings are made the species, numbers, direction of travel and any indications of condition of the animals should be recorded and information passed to marine mammal specialists to assess the risk to cetaceans. Video footage will be useful if it can be obtained and may provide vital information for later determination of any effects of the spill on cetaceans. Rapid and intensive effort to collect data on any cetaceans in the area will be essential if such a determination is to be possible. If conditions allow, therefore, specialists survey teams should ideally be put together to go into the field to make a first-hand assessment. Dedicated aerial surveys will need to be undertaken in the case of large spills where cetaceans are likely to be present and thought to be at risk. The local land based dolphin sightings network should be mobilised to provide sightings information. Good land-based vantage points which can be used by the sightings network are shown in Figure 2.
In the event of an oil spill in the Moray Firth, the media and general public will be seeking information about the presence of, and risk to cetaceans, and any actions being taken to minimise the risk or to treat affected animals. It is recommended that a marine mammal specialist be appointed to liaise with the nominated press officer/press office and be available to give knowledgeable briefings on the subject. The principal message may be that no effective action can be taken and therefore knowledge of the issues will be all the more important in explaining the case in a situation where there can be considerable pressure to take action.
Public and Press on location
As far as possible the media should be directed to land based observation points as this will reduce the potential for disturbance to cetaceans and avoid the risk of conflict with clean-up operations at sea. If land-based observation is unlikely to result in satisfactory coverage for the media then a specific vessel should be designated to take press representations on location.
Control of craft, including media craft, in the air and on the water may be required as part of the health and safety aspects of dealing with an incident. This will also be necessary if actions are being taken to treat stranded cetaceans or to encourage cetaceans to move from contaminated areas.
While it is possible to establish an exclusion zone around an incident it will be difficult to do the same around cetaceans because of their mobility. It must be made clear that it is an offence to deliberately disturb cetaceans in UK waters. In order to minimise disturbance to the dolphins, the “Dolphin Space Programme” code of conduct must be adhered to by water users seeking to observe the dolphins in the area.
DEALING WITH LIVING CETACEANS
Relocation of threatened cetaceans
Capture and removal of live, healthy, cetaceans away from the contaminated area is prohibited without licence under UK law. Although potentially feasible such action would be dangerous and is undesirable because of the likelihood of causing stress to healthy animals and therefore risk ill-effects on animals the action is trying to protect.
Keeping cetaceans away from oil spills
Vessels and booms placed around an oil slick are unlikely to deter cetaceans from entering the contaminated zone. This approach is therefore not considered to be a useful deployment of personnel and vessels dealing with cetacean concerns. Attaching marine mammal deterrents, such as “seal scarers” and other acoustic devices to booms might however be an option to consider.
The physical presence of boats and associated noise have been used to drive cetaceans into open water away from locations where they are at risk of becoming stranded. If safety considerations permit, this may be a useful option to consider in situations where spills are concentrated and under control, particularly in enclosed areas where cetaceans may be at risk of getting trapped, within or behind oil slicks (e.g. at the entrance to the Cromarty Firth and enclosed sections of the inner Moray Firth).
Any such operation will be a major undertaking and must be tightly controlled with good communication during the operation if there is any chance of it succeeding. If used this approach will be most valuable if it can prevent cetaceans from inhaling the volatile fractions evaporating from the surface of the oil as it is these which present the most significant health risk to cetaceans following an oil spill. At the same time, for some species and in some locations, it must be weighed up against the risk of driving the cetaceans to strand themselves during such an operation.
The idea of playing cetacean or other sounds through hydrophones, as a deterrent or attractant, has been tried or considered as an option to encourage trapped or refloated animals to move out of an area. As very little is known about what is required to be successful with this technique and because background noise from vessel and aircraft traffic dealing with the spill might be considerable, the likelihood of success is difficult to gauge.
Coastal watches and beach search parties should be asked to report any stranded animals. If live strandings are reported, specialist advice must be sought from Scottish Agricultural College Veterinary Services as soon as possible and the organisation/individuals leading the rescue effort should be clearly identified.
A variety of measures can be taken to treat and refloat live strandings. The likelihood of success will depend on the species, condition of the animal and speed of response. In-situ treatment is likely to be the only realistic option for large cetaceans. For small cetaceans rehabilitation may be an option. In some cases it may be necessary to hold animals in specially deployed temporary pools on site after administering first aid, until conditions are suitable for refloatation. Clean release areas will need to be identified and the teams caring for the cetaceans given regular updates on the condition and location of the spill so treated animals are not released into contaminated areas. In other cases euthanasia may be the most humane action.
Decisions on the best course of action must be taken by individuals with specialist expertise on this subject and any treatment or procedures under the guidance of individuals who are trained to deal with cetaceans in these circumstances.
The presence of cetaceans on the shore will elicit public interest. The attendance of the police at the scene is likely to be needed to keep the public away from animals being treated and enable veterinarians to do their work. There may also be a need to call out the fire brigade to assist with treatment of stranded animals (eg. hosing down animals to keep them cool).
It is important to avoid over flying an area with stranded cetaceans (as this is known to cause further distress to weakened and disoriented animals undergoing treatment) and to control vessel traffic.
OIL SPILL COUNTER-MEASURES
The effects of the use of dispersants on cetaceans are not known therefore a precautionary approach is recommended. Dispersants are least likely to be a problem in open sea environments. Spraying directly on to cetaceans should not be permitted and the observer present on craft undertaking dispersion should be notified of this. If there are likely to be significant numbers of cetaceans in an area to be sprayed then no spraying should be permitted.
Propeller action from standby vessels to disperse slicks could cause physical injury to nearby cetaceans if the animals are lethargic or suffering from other effects of inhaling volatiles. Operators should be alerted to look out for any such animals and propeller action should not be used if cetaceans are in the immediate vicinity.
No information is available on the effects on cetaceans of in-situ burning of oil. In situ burning is not recommended in the Moray Firth.
Deployment of physical barriers to contain oil are not likely to have any effects on cetaceans in the vicinity of an oil spill and are therefore not considered to be an issue of concern.
Vessel and air traffic noise will be detected by nearby cetaceans however this type of noise is likely to have short term effects so should not be a major issue during clean-up operations. Taking no action, in order to avoid noise disturbance, is likely to be more of a problem to wildlife in the long run (but see exception above for stranded cetaceans).
LONGER TERM CONSIDERATIONS
Information collected prior to, during, and after an oil spill will improve understanding of how cetaceans are affected by oil. Regular monitoring is essential to understand natural patterns of change and distinguish these from any changes following unusual events such as an oil spill. It would be particularly useful to look for any changes in the behaviour of animals in the vicinity of a spill as well as pathology following a spill. Continued careful and consistent documentation of marine mammal strandings will be important as well as checking whether these were animals seen in the vicinity of the spill, and data on tissue hydrocarbon levels. This should be obtained from stranded animals wherever possible as background reference points so that pathological and toxicological findings in marine mammals recovered in or near a spill can by interpreted more meaningfully.
Follow up research programmes will need to be instigated in areas known to be important for cetaceans or where animals were seen near spills during the incident. This may include follow up observations of particular animals, changes in abundance and behaviour of cetaceans in the area, and analysis of archived tissues taken from stranded animals.