Humpback whales live in oceans all over the world and are renowned for their epic migrations. Yet it’s only in the last few years that these magnificent creatures have started to appear off the Cornish coast. So why are they showing up now? Cornwall Wildlife Trust Marine Conservation Officer Rebecca Allen has some ideas.
‘We’ve got a few different theories on why the whales are showing up on our coastlines, and it’s really quite impossible to know for sure,’ Rebecca explains. ‘One of the things is the humpback populations in general, we think, are increasing because nobody’s hunting them anymore.’
Humpback whale populations have rebounded since hunting them in international waters was banned in 1986 by the International Whaling Commission. Rebecca believes this recovery is allowing ‘young individuals to come back into the population, and they’re traveling around, exploring and coming back into waters where they probably were at one point.’
Another possible reason for their return is shifting food availability.
‘We’ve seen quite a lot of changes in species that were in our coastal waters over the last few years… so they could be coming in search of food that’s not available elsewhere,’ says Rebecca.
Humpback whales are known for their epic seasonal migrations, with Atlantic populations typically following a well-established pattern.
‘What humpbacks should be doing through the summer months is feeding in northern, polar waters, where it’s really rich and productive,’ Rebecca explains. ‘Then traveling through the autumn down into tropical waters, where they rest and breed during the winter.’
But the sightings of humpback whales off Cornwall’s coast don’t quite align with this usual rhythm. ‘We’re seeing individuals in the winter here, and that is a bit odd,’ Rebecca points out. One possible explanation is that the whales aren’t managing to store enough energy during their summer feeding season. ‘They might be stopping off on their migration to find extra food because generally, when they go down to the tropics, they don’t feed.’
This raises intriguing – and potentially troubling – questions about the conditions in their northern feeding grounds. ‘It could be they’re not getting enough, and they’re coming here to feed up more when they really should be going on further down south,’ Rebecca says. Shifting distributions of prey species, potentially driven by changes in ocean temperature or ecosystem dynamics, could be playing a role. And whilst Rebecca is delighted to see humpbacks in Cornwall, she hopes it is for positive reasons.
For wildlife enthusiasts, winter in Cornwall now brings the chance to glimpse these majestic visitors. ‘Last winter, we had quite a few sightings in Newquay, which is where I live, which was very exciting,’ says Rebecca. Other hotspots include St Ives Bay and Land’s End. ‘They’ll come in quite shallow, so people have got some pretty spectacular sightings just from the coast,’ Rebecca says.
‘When they arrive, they tend to stay in that locale for a little bit.’ This means that once a whale has been spotted in a certain area, there’s often a short window of opportunity for others to catch sight of it before it moves on.
The season usually begins in early December and continues through January and February. After that, the whales tend to move on, disappearing from Cornish waters for the rest of the year.
Despite increasing sightings, it’s still unclear how many individual whales visit Cornwall. To answer this, Dan Jarvis, a fellow researcher, is building an ID catalogue to track them. ‘Dan’s been matching them up with photographs. We get people to send in pictures they’ve seen, and then we match them with scars on their body, or their tail fluke patterns,” Rebecca explains. This technique helps distinguish between repeat sightings of the same whale and encounters with new individuals.
As part of this project, members of the public are encouraged to report sightings of humpbacks and other cetaceans they spot off the Cornish coast. Ideally with images, but also without if they aren’t available. If you spot a humpback you can notify researchers at seaquest@cornwallwildlifetrust.org.uk. This information helps researchers to understand their needs, how to protect them and how to support their population growth, around the Cornish coast and beyond.
Respecting our ocean visitors
As humpbacks become regular winter visitors, it’s vital to admire them responsibly. 'Don’t try to approach, don’t try and get closer,' Rebecca emphasises. This is especially important for those on small craft like paddleboards. 'They don’t deliberately go around doing any harm, but people have been hurt in the past by being landed on or vessels being landed on,' she warns.
For motorised vessels, DEFRA’s code of conduct recommends staying at least 100 metres away. 'If you happen to be motoring and see a humpback, the advice is to keep your course and speed and let them do their own thing,' Rebecca advises. Harassing or disturbing whales is not only dangerous but also illegal under UK law.
The rise of whale-watching tourism is another consideration. 'As soon as something becomes regular, you can build an industry of getting people to go out on boats and watch them,' Rebecca notes. 'That can be great – it’s brilliant for engagement and awareness. But if those animals are really busily trying to feed and then we start interfering with that, that could be bad for them.' Rebecca hopes that potential future tours will seek the guidance of Cornwall Wildlife Trust and other marine wildlife experts before launching such programmes. By doing so, we can safely enjoy these magnificent creatures and ensure Cornwall remains a welcome stop on their journeys.
Did you know?
Humpback whales are filter feeders that eat small fish and crustaceans.
They eat up to 1.5 tonnes of food a day by using hunting methods which include slapping their fins on the water, herding using sounds and creating “bubble nets” around their prey.
Humpbacks found in the Northern Hemisphere reach an average length of 50 feet, whilst southern humpbacks reach 60 feet. Females are larger than males.
Humpbacks are less solitary than other large whales. Even when they are on their own they are within communication range of other humpbacks, as their frequency spans up to 200 miles.
