A busy month of whale entanglements in Scottish inshore waters

In recent weeks the Scottish Entanglement Alliance (SEA) has documented three fatal whale entanglements around the coast of Scotland.

23rd April 2019

The first of these was a juvenile male humpback whale (Megaptera novaeangliae) that washed ashore at Tyninghame near Dunbar. This animal had first been reported entangled two months earlier by a concerned fisherman, who had spotted the whale with rope caught around it’s pectoral fin and towing a buoy in the Forth. Despite several further reports from the local fishing community and best attempts by British Divers Marine Life Rescue’s (BDMLR, www.bdmlr.org.uk) large whale disentanglement team to free it,  a rescue was not possible.

The entangled whale towing a buoy, which was first spotted in the Forth in February 2019. Image credit: Ronnie Mackie. The animal was reported dead two months later, washed up at Tyninghame. Image credit: East Lothian Countryside Rangers

With the help of Dunbar RNLI crew, East Lothian Countryside Rangers, the Civil Nuclear Constabulary and local farmers, the whale carcass was moved to allow the Scottish Marine Animal Stranding Scheme team (SMASS, www.strandings.org) to perform a necropsy the following morning. The necropsy concluded that this whale had suffered a chronic entanglement. This means the animal had been dragging the entangling ropes for a prolonged period of time, and these lines had cut deep into the blubber layer causing scarring in the underlying tissues, in particular around the pectoral fin where this had caused a severe infection.

  

Some of the tissue damage and lesions sustained by this humpback as a result of becoming entangled. Image credit: SMASS

This case highlighted the grim realities of entanglement in large baleen whales, such as changes in behaviour and disruptions in energy budgets. Once the whale had become entangled, it would have had to spend much more energy dragging the ropes and any attached gear with it through the water. The rope was stretched tight over the back just behind the head, which probably prevented the animal from feeding normally. As a result the whale was in poor body condition making it more susceptible to the effects of infection and parasitism, which debilitated it further. The animal had a very high parasite burden in the intestine and eventually drowned, either through sheer exhaustion or as a result of becoming entangled further.

  

A very sad ending for this young animal. Image credits: SMASS

7th May 2019

Two weeks later a juvenile minke whale (Balaenoptera acutorostrata) was reported, this time off the coast of Iona in the Inner Hebrides. The animal was discovered dead at sea entangled in creel lines which were anchoring it to the seabed.

 

The minke whale was discovered entangled around the head. The animal had been dead for a couple of days at the time these images were taken, hence the tongue has inflated like a sail (this process is normal in baleen whale cases). Image credits: Hannah Elizabeth Fisher

Minke whales are much smaller than humpbacks and therefore less able to swim away or reach the surface to breath once entangled. In contrast to the humpback whale, this animal suffered an acute entanglement meaning that it likely died very quickly after becoming caught. This is evident from the apparent absence of tissue damage associated with the ropes. Though rapid drowning is perhaps a kinder end than enduring the suffering caused by a chronic entanglement, this does highlight how difficult it is to help in some cases where an immediate response is required.

  

The whale was cut free and subsequently made landfall on the Isle of Mull. Image credits: Hannah Elizabeth Fisher.

19th May 2019

This weekend the SEA team received reports of a third animal, again a minke, spotted alive but entangled off the west coast of Barra by a group of local kayakers. One kayaker entered the water with the whale and was able to pull a section of rope from its mouth and capture some very useful video footage. However despite their best efforts the damage was already done and later the same evening the animal washed ashore and quickly died, possibly through exhaustion. This case again highlights the welfare implications of entanglements, for example it appears that this whale has suffered a fractured jaw. Although we cannot say for certain, it is plausible based on the severity of the injuries that at one point this animal was anchored by the entangling ropes to the seabed, and in attempting to free itself, has sustained significant damage which almost certainly would have prevented it from feeding.

A still from video footage captured by Barra Surf Adventures of the animal still alive, shortly after they had removed a piece of rope from the animal’s mouth. Entering the water with an entangled animal is something we never recommend doing, for your safety and that of the animal. These are wild animals that can be very dangerous and unpredictable. Image credit: Chris Denehy

 

Photographs captured by a member of the SMASS volunteer network reveal the extent of this entanglement, which was not only around the mouth but also the tail. The injuries suggest that someone else had attempted to free the animal by cutting away other entangling lines, which were no longer present by the time the kayakers encountered it. This whale is to be further examined tomorrow and numerous tissue samples will be collected for analysis by SMASS. From samples taken from the rope lesions we will be able to gain valuable insight in to what this animal was entangled in and the chronicity of this (i.e. how long it was entangled for).

   

The minke whale live stranded on Barra on Sunday evening and subsequently died. The full extent of its injuries are now visible. Image credits: Bruce Taylor and Kirsty Macdonald

14th May 2019

SEA partners received yet another call about an entangled whale, again a minke but thankfully this time live and  seemingly uninjured near Gairloch. BDMLR’s large whale disentanglement team were immediately dispatched and subsequently spent two days pursuing the animal. Fortunately the entanglement does not seem to be hindering this whale, though this meant that it was moving too quickly for the disentanglement team to attempt to free it. The team have now stood down but continue to monitor the situation and local fishing and wildlife watching boats are also keeping a look out of this animal.

 

The minke whale reported entangled off Gairloch. This animal is moving freely but a rope is clearly visible across its back. Image credit: Noel Hawkins

Entanglements are thought to be a relatively rare occurrence in Scottish waters, however based on data collected by SMASS and through the SEA project, the incidence and range of affected species does seem to be increasing. As highlighted in the aforementioned cases, entanglements can interfere with an animal’s ability to move and feed, cause horrific injuries, and if many animals get entangled, the morbidity and mortality effects can have an impact at a population or even species level. On top of this entanglements can pose a threat to human safety and have a significant financial impact on individual fishers through damage to their gear and lost fishing time. However it is vital to remember that no entanglement is deliberate, and more often than not it is fishermen who are more upset and affected by these incidents than anyone. It is also important to remember that it is often fishermen who come to the rescue of these stricken animals, and fishermen have played an integral role in the successful disentanglement of numerous whales around our coast.

Entanglements aren’t just a Scottish problem, they occur globally wherever marine animals and fishing gear overlap but these cases highlight the need for projects such as SEA. SEA partners are working with and supporting fishermen to better understand the scale and impacts of marine animal entanglements, and find solutions to minimise these risks whilst allowing fishermen to continue earning their living from the sea. To date over 100 Scottish creel fishermen have been involved in the SEA project, sharing their knowledge and expertise surrounding these unfortunate incidents and their ideas of how these may be prevented. This is already leading to some exciting developments which would not be possible without the industry’s continued support and participation. The SEA project continues to receive a massively positive response from the creel fishing community, and it is crucial that we and the public appreciate these efforts and recognise that fishers are the solution to this issue, not the problem.

If you are a creel fisherman and would like to learn more about the SEA project or get involved in this, or if you ever come across an animal entangled in your gear, please contact the SEA project coordinator Ellie MacLennan on 01463 246048, 07393 798153 or at ellie.maclennan@sac.co.uk.

Any information you choose to share will be treated positively, sensitively and confidentially.

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