British Divers Marine Life Rescue
British Divers Marine Life Rescue (photo: Steve Marsh)
British Divers Marine Rescue


2018-10-29 13:06:08

Beluga in the Thames update

Joint PLA / BDMLR media statement

The beluga whale continues to be highly mobile, providing limited sightings and swimming strongly and from what we can tell, it is exhibiting normal foraging. The sex and age are unknown but improved estimates of length now put it at around 3.5 metres (about eleven feet long).

Discussions have been held this week with whale experts and relevant agencies to share information and assess possible scenarios.  Beluga researchers and other experts abroad have been consulted and we will take into consideration their advice and knowledge of this enigmatic species

It is planned to place hydrophone equipment in the water this week to record the whale sounds so that experts can then analyse its behaviour. This may help confirm it is feeding.

The whale’s welfare is our shared priority and we are continuing to observe and protect it. The safety of the public is also paramount. The restriction on boat traffic in the local area remains in force.  We continue to ask that members of the public do not attempt to enter the water or bring boats or small craft close to the whale or overfly it using drones.

Update from BDMLR October 29th 2018

The Port of London Authority is updating its website with sightings of the beluga, so if you would like to check when it was last seen, please click the link here.

Sightings are quite sporadic and although the whale has been seen in the same stretch of the Thames, that doesn't mean that it's not moving out eastwards on a regular basis.  Here, there is little development and therefore fewer people that might see and report a sighting, so although it isn't being seen, it could be increasing its range but returning less frequently to Gravesend and Tilbury.  We now have good reason to believe that it may have been around for longer than originally thought, as we have received credible reports of potential sightings in the outer reaches of the Medway into the Thames estuary as far back as July.

From what we can tell, the beluga has adapted well to its surroundings and reports and photos have not suggested that its condition is deteriorating in any way.  As beluga live in shallow waters and estuaries for much of the year in their usual habitats, this is not really a surprise. It is also likely to remain in an area where there is a good food source and little competition, but we don't really know whether it would feel the need to head out into the North Sea and head North to the polar ice as most beluga make this migration as the temperature drops.

Results from the hydrophone have also been minimal, but the data has shown beluga click trains at periods and in areas where at the time, there were no physical sightings reported. This supports our belief that the whale may be around even though it is not being seen.  The click trains showed that the beluga was sending out clicks at a rate of ten per second - this shows normal, unstressed behaviour.  When the whale finds prey, these clicks increase to around 500 per second and are directed at its prey.  We are still hoping to pick up some of this activity but acoustics specialists have said that this is unlikely as the foraging clicks are probably pointed downwards towards bottom-living fish and crustaceans. This means that clicks would be absorbed or dissipated by the muddy seabed and therefore would not necessarily be picked up by the hydrophone. What has been confirmed though is that none of the click trains have shown any signs of distress by the animal and have been exactly what would have expected to hear from beluga living in their natural home.

It was announced last week that Gravesham Council had taken the decision to postpone the fireworks display (originally planned for Friday November 2nd) until such time as it was certain that the beluga had moved out of the area. BDMLR applaud this decision and would like to thank the council for recognising just how wildlife can be disturbed by such activity - it is always encouraging to see such moves being made out of good will and with real compassion.  The understanding of local people and their support for this decision has been incredible as well - it's good to know that the beluga (we still don't know if it's a Benny or a Belinda!) has so many friends who care so much about it.

We would also like to thank the Port of London Authority for all of their support and all the continued hard work they have been putting in behind the scenes to ensure that this unusual visitor gets all the protection and care it deserves.

Update 3rd May 2019. 16:15hrs

The last confirmed sighting of the whale was in December 2018, further downstream from Gravesend. Hydrophones have been placed in the water and can record noise produced by the whale – these have also not recorded any evidence of whale activity.

As the fish that were likely to be the preferred food source for the whale migrate out of the estuary early in the year, we conclude that the whale has moved on elsewhere.