European Cetacean Bycatch banner loading

"Man is but a strand in the complex web of life"

Internal links buttons



BDMLR’s Veterinary Director reports on harbour porpoise stranding - Colchester - UK
10th May 2003

BDMLR Essex coordinator, Faye Archell received a call concerning a harbour porpoise stranded in a river at Hythe, Colchester at approximately 11.30 am. At the time, she was attending the mass stranding exercise on the Isle of Sheppey, north Kent. Faye, Lucie White, Duane Kirk and James Barnett made the two-hour journey to Colchester while Leon Woodrow and Andy Rutson Edwards made their way from north Essex.

Leon and his team arrived with the animal at
12 noon. The Colchester fire brigade
(Bluewatch) and RSPCA inspector Jim Farr
were in attendance, and the former rigged up
a walkway over the mud.
The animal was moved off the mud into a
dinghy and cooling and wetting with water
from the creek commenced.

From left
Lucie White [ BDMLR National Co-ordinator ]
Faye Archell BDMLR, Duane Kirk BDMLR

Photo courtesy BDMLR

When the team from Kent arrived at approx. 1.30 pm, James started an assessment of the animal, while the others assisted with support. The animal was a female harbour porpoise between 1.5 and 1.6 metres in length. She was in moderate to good body condition and had a rather distended ventral abdomen and thus the possibility that she was in the later stages of pregnancy could not be ruled out (harbour porpoises calving generally in June/July).  A number of minor superficial cuts and abrasions were found on her ventral abdomen and tail stock, probably arising from contact with some of the numerous sharp objects present in the mud.  An old, narrow, diamond shaped scar was present on the left side of her chest.  
However, her breathing rate was markedly elevated (10-12 breaths/minute) and her blowhole, flipper withdrawal and palpebral reflexes were poor.  Her lungs sounded rather harsh on auscultation, but as usual, interpretation was hampered by the explosive nature of the breathing.  Periodically she arched her tail and also she was hot to the touch. A rectal temperature of only 35.8oC was obtained with a digital thermometer and this was unlikely to be representative. A thermistor probe was not available.  No discharges were noticed from the blowhole or any other orifice, her mucous membrane colour was satisfactory, her skin generally was in good condition and her eyes were partially open. In summary, she was obviously a very stressed animal, and underlying lung pathology could not be ruled out. However, due to the position in which she was stranded, a muddy, polluted creek where supporting in water was impossible, the decision was taken to move her to a beach with open water to reassess her.

James stomach tubed her with approximately 350 mls of Zoolyte rehydration solution and a hose was connected up to a fire hydrant by the fire brigade, so cooling could commence with clean, cool water. An air mattress was placed underneath her in the dinghy, to give her extra support.

After a few minutes to allow her to stabilise after tubing, a sling was positioned underneath
her and a crane used to lift her the 20 feet to the quayside and into the back of an open Landrover.

Here she was again positioned on the air mattress
and Duane, Faye and Lucie supported her and
monitored her en route to West Mersea, leaving
at approx. 3.30 pm. Her breathing rate during
the journey remained between 9 and 10 breaths
per minute. Arriving at West Mersea at 4 pm,
she was moved in a boat along the shore to a
quiet location and support in the water
commenced at 4.30 pm.
James Barnett (front left)

Photo courtesy BDMLR

Initially, her response was quite favourable, as she made strong, powerful movements of her tail fluke in the water.  Her breathing rate, however, remained high at between 9 and 11 breaths per minute, although it did dip on one occasion to 6 breaths per minute. Blood samples were taken by James half an hour after arrival and an antibiotic, enrofloxacin was administered (long acting antibiotics were intended to be used, but the bottle smashed in the boat). A triangular depression was now noted under her head, where the skin was rather wrinkled and dry, and occasionally discoloured brown.  One possible explanation is that she had come in contact with a caustic material as she lay in the mud in Colchester.  Attempts were made periodically to see how well the animal supported herself in the water: each time she was able to support herself without listing, but appeared disorientated, often turning towards shore and her swimming movements were not coordinated. The breathing rate remained high and her eyes were now closed and she developed a slight list to one side. Her reflexes remained rather sluggish and her jaw tone was rather slack.  Her mucous membrane colour remained satisfactory.

At 7pm, James administered an anti-inflammatory (carprofen) due to increasing concerns over possible muscle damage, despite stranding on soft mud, and to see if this made any noticeable difference to her behaviour. The animal did appear possibly to make more coordinated movements after this point, but it is impossible to say if this was directly an effect of the drug. The breathing rate, however, remained high at 10-13 breaths/minute and now the animal was exhibiting mild muscle tremors over the chest. At 7.15 pm, due to concerns over the time of day, with little more than an hour’s good light left, the persistently high breathing rate and the perceptible decline in the animal’s condition, a final assessment was made of the animal, with a view to euthanasia if this was not positive. Again, hands were withdrawn and she was observed unsupported: her swimming did appear a little stronger, although she again veered round to point towards the beach. It was at this point that the animal caught everyone unawares and put in a strong spurt of swimming, getting way from her handlers and it was impossible to retrieve her.

A watch was mounted for the next hour and a half and she was observed tacking up and down parallel to the shore, over a hundred metres out, diving often for over a minute at a time. She was lost from sight in the failing light and the watch had to be called off. Ian Black of English Nature, who had accompanied us through the event, agreed to check the beach that night and in the morning. On Sunday, despite extensive searches of the sandbanks and shore by walkers and boats, she was not found again.  Results of blood samples revealed no evidence of muscle damage, but she was a little anaemic.  There was no evidence of infection, but the normal white blood cell counts do not necessarily rule out a bacterial lung infection, as work in the States has illustrated that an effective immune response to chronic lung infections often is not mounted.
BDMLR is grateful particularly for the hard work put in by the fire brigade and the support received from the crane driver, English Nature and the RSPCA. However, there was little confidence amongst those involved that this animal was a suitable candidate for release at the stage she was ‘released’ and it was unfortunate that she had got away from her handlers at the time she did.  A great deal was learned from the episode, however. In particular, this stranding highlighted the need to be able to assess and treat stranded cetaceans in a controlled environment over a much longer period of time than many refloatations allow.  The need to have thermistor probes readily available even for animals as small as an adult harbour porpoise also was emphasised and this is being addressed.  Although this animal had a characteristic scar on its chest wall, the event also highlighted the need to be able to tag an animal even for short term monitoring. Biodegradable ribbon has been obtained, but attempts to assess its suitability by trialling it on captive pinnipeds have not yet commenced. This will be chased up.
James Barnett
BDMLR Veterinary Director