Veterinary conservation work with seals

Seals are a common sight around the UK coast, and with rising public use of beaches and coastal areas, seals and humans are regularly sharing the same spaces. Seal disturbance and injury are becoming more commonplace with these increasing interactions, particularly in less remote areas popular with tourists and dog walkers. Members of the public may call local veterinary surgeries requesting advice when they find or see a seal that looks unwell or is injured. This article describes the natural history of seals native to the UK, some of the work that medic volunteers at the British Divers Marine Life Rescue (BDMLR) do with seals and, most importantly, who to call or direct members of the public to if a seal needs help.

Seals in the UK

There are two species of seal native to the UK: the common seal (Phoca vitulina), otherwise known as the harbour seal, and the grey seal (Halichoerus grypus). The major distinguishing features between these species are their size and head shape. The smaller common seal (adults weigh 80 to 100kg) looks quite cat-like and has a shorter nose with angled nostrils that form a “V” shape when closed. The larger grey seal (adult males can weigh over 300kg and females around 150 to 200kg) is more dog-like in its looks, with a longer muzzle and nostrils that are more parallel. Male grey seals also develop a pronounced long “Roman” nose.

Grey seals have mottled fur coats which range from beige to brown, light grey and black. Each seal’s coat pattern is unique, enabling researchers such as the Cornwall Seal Group Research Trust to identify individual animals and track their progress over their lifetime (grey seals can live for up to 40 years). Common seals have more generic coat patterns of spots on a background of blonde to brown or grey to black.

Each seal’s coat pattern is unique, enabling researchers […] to identify individual animals and track their progress over their lifetime

Both species are listed as “least concern” on the International Union for Conservation of Nature (IUCN) red list and are thought to have relatively stable populations globally; however, the grey seal is one of the rarest seal species. They have a global population of around 316,000 individuals (Bowen, 2016), over a third of which are thought to live around the UK coastline (SCOS, 2020). The common seal population in the UK is smaller, estimated at 44,000 individuals (SCOS, 2020).

Lifestyle and behaviour of UK seals

Seals are semi-aquatic, splitting their time between land and water. They forage for food at sea but return to the shore (“haul out”) to rest, breed, give birth and moult their fur coats. Seals can spend long periods foraging at sea, diving for fish, sand eels, shellfish, crabs and squid. They will often nap while in the water, either floating upright with their noses pointing up (“bottling”) or floating flat and face-down in the water (“logging”) – they can do this for minutes at a time. Grey seals tend to forage a little further from their (changeable) haul-out sites than common seals. They can travel for hundreds of kilometres but stay mostly within 100km of their haul-out sites. Common seals, in comparison, tend to stay closer to home, within 40 to 50km of their haul-out sites.

Pups and newborns

Both species of seal are polygynous and pup on land. The season for grey seal pupping changes around the coast of the UK, with the first pups of the season usually being born between August and October in the southwest. Average pupping dates then seem to move around the coast, with seals in north and west Scotland pupping around September to November and those in the east of the UK pupping in November or December. Common seals generally pup in June or July.

The pups of both species have white coats (Figure 1), but only the grey seals are born with them. Common seal pups moult their white coat while still in utero and are born with their adult coat. Grey seal pups’ long white coats are moulted in the first few weeks of life, with their adult coats predominating by weaning at two to three weeks.

While newborn common seals are proficient swimmers, grey seal pups are not and won’t voluntarily enter the water before they are a few days old. These pups rely entirely on their mother for food (milk) until they wean and can often be seen on a beach or rocky outcrop alone. If the mother is disturbed during this time, she may not return to the area to feed her pup.

Behaviour

Seals are naturally vigilant and can never turn off completely; they will keep some of their brain awake at all times, especially when sleeping at sea. This means that they are easily disturbed by sounds, sights and smells. A poorly rested seal can become exhausted and unable to forage sufficiently. Furthermore, maternally dependent pups abandoned after their mothers are scared away are unlikely to survive without intervention. It is vital that anyone who spots a seal keeps their distance, keeps quiet and keeps any dogs on a lead, and any photographs should be taken with a zoom lens. If a seal is looking at dogs or people, it is an indicator they are too close and that the seal has already been disturbed.

If a seal is looking at dogs or people, it is an indicator they are too close and that the seal has already been disturbed

Conservation and veterinary intervention

What to do if you find an abandoned or injured seal

If a seal pup has definitely been abandoned (this can be confirmed by monitoring from a distance for several hours) or is obviously injured or in distress, then intervention may be necessary. It is not advisable, however, to approach a seal unless you are trained in the methods of doing so. Capture must be quick, to avoid an injured seal being scared back into the sea, and safe for both the seal and those restraining it. It is important to remember that seals have sharp teeth and claws (and are very adept at using them) with strong shoulders and telescopic necks. The BDMLR provides training in seal restraint to teams of volunteer medics which includes vets and vet nurses.

Anyone reporting an injured or abandoned seal should, in the first instance, be referred to the BDMLR (call 01825 765546 or visit its website) or RSPCA/SSPCA (0300 123 4999/03000 999 999) who will be able to provide advice and assistance.

Veterinary care and first aid

Once assessed in situ, some seals need emergency first aid and/or veterinary care (Figure 2). The BDMLR has its own dedicated vet who works as the veterinary support coordinator and runs its seal hospital in Cornwall, as well as several specialist veterinary consultants and a team of volunteer vets and vet nurses trained as BDMLR medics who are happy to help when the need arises. Anyone can volunteer and train to be a medic with the BDMLR and provide an essential service to marine mammals countrywide. For vets and veterinary nurses there is access to further training and resources to enable them to put their veterinary skills and experience to use helping the seals around the UK coast. Sometimes, when no qualified vet medics are available to assist, help is requested of veterinary practices close to the site of the emergency. Any vets willing to help will always be under the direction of the incredibly experienced veterinary coordinator and the BDMLR team who will provide support and advice.

In Cornwall, BDMLR also has its own seal hospital which helps to take in seal pups and provide medical attention and care when the larger local rescue centres are full; pups are then moved on to these centres for rehabilitation as space becomes available.

Often seals resting in public places are just exhausted and if they can be left alone to rest will recover and move on; however, sometimes first aid is required

Often seals resting in public places are just exhausted and if they can be left alone to rest will recover and move on; however, sometimes first aid is required. This can include help with disentangling them from plastic bags, fishing nets and flying rings, etc, or treating superficial wounds. Common reasons for admission to the seal hospital and other rehabilitation centres include malnutrition (Figure 1), hyperthermia, traumatic lesions to eyes, mouth, flippers or skin, severe diarrhoea and respiratory conditions (Barnett et al., 2000). Gastrointestinal and respiratory conditions are often parasitic in origin, with the lungworm Otostrongylus circumlitis causing quite distressing clinical signs.

Lungworm

Lungworm (primarily Otostrongylus circumlitis) can cause significant morbidity and mortality in seals in the UK (Barnett et al., 2019). Pups with lungworm often present with a high respiratory rate, coughing up blood and worms. They can become seriously unwell and often need intensive care and treatments including anthelminthics, mucolytics, antibiotics (for secondary pneumonia) and steam baths (Figure 3). Parasiticides must be administered carefully due to an increased immune response to dead worms.

Conclusion

It is our responsibility to try to reduce the effect that we have on our native wildlife when our habitats overlap theirs, and working with charities such as the BDMLR allows veterinary personnel to get involved at the sharp end of local conservation work.