Pilot whales 'highly unusual' sighting in River Thames
British Divers Marine Life Rescue has responded to reports
Last updated 18th Sep 2026
British Divers Marine Life Rescue has responded to reports of pilot whales seen swimming in the River Thames.
Reports were made yesterday (Thursday 17 September 2026) with 'multiple whales present' today (Friday 18 September).
The group said the presence of pilot whales in the Thames and southern North sea region is 'highly unusual'.
Whilst the public are being told to report sightings, it is important to note that increased crowds, noise, and vessel activity can cause additional stress and disrupt natural behaviour, potentially 'putting them at risk of stranding'.
In a statement online on Thursday (17 September) British Divers Marine Life Rescue said:
"The whales’ movements, behaviour and condition are being closely monitored by our team of experienced Marine Mammal Medics. This is a developing incident, and further updates will be shared here: https://bdmlr.org.uk/news periodically.
"As a precaution, specialist whale rescue equipment is being prepared with support from neighbouring regional teams should the whales strand. Marine Mammal Medics will continue to monitor the pod, with teams ready to respond should the situation change.
"Long-finned pilot whales typically favour cooler temperate waters offshore beyond the continental shelf in the Atlantic ocean. They form exceptionally close family bonds and several pods may come together temporarily, creating vast “super-pods” numbering in the hundreds often seen in countries such as New Zealand.
"The presence of pilot whales in the Thames and southern North sea region is highly unusual, although currently reported to be calm. Whales seen swimming in shallow or enclosed waterways are not necessarily in trouble, however they are at an increased risk of stranding from changing tides, vessel traffic and disturbance.
"Because of this, we are asking people in the area not to attempt approaching the whales from the land, water, launch drones or attempt to intervene."
Vessels nearby are being told to:
- Slow down to a no-wake speed
- Keep 100m distance away where possible
- Avoid travelling through or separating the group
- Avoid cutting across their direction of travel
BDMLR is asking members of the public to avoid sharing the whales’ location online while the incident is ongoing to help reduce the potential impacts on them from crowds gathering or launching vessels and watercraft to see them.
The group added: "Increased crowds, noise, and vessel activity can cause additional stress and disrupt natural behaviour, potentially putting them at risk of stranding. Their welfare must remain a priority whilst they remain in the Thames estuary and wider region. Cetaceans (whales and dolphins) are protected by law in the UK from intentional or reckless disturbance under the Wildlife and Countryside Act."
If you see the whales, you are asked to report the sighting directly to BDMLR’s rescue hotline on 01825 765546, providing their location, direction of travel and any notable behaviour.
The Port of London Authority and Civil Air Support are currently supporting British Divers Marine Life Rescue with this ongoing incident.