In 2018, scientists made an incredible observation that harbour seals were breeding in river Thames. In a conclusive tally released by UK-Wide Seal Monitoring, from photos taken by a light aircraft while the seals were resting, showed that there were 138 pups born in the river in 2018.
Despite the river being declared biologically dead 60 years ago, the report indicated that Thames is home to both harbour and grey seals. The pup-data obtained also was an indication that only harbour seals had the ability to breed in this ecosystem.
According to Thea Cox a conservative biologist, this finding was undisputed proof of how far the river’s ecosystem had thrived, since it was declared biologically dead 60 years ago. He further expounded that the harbour seal pups would not be able to survive in the river if it didn’t provide a reliable food source.
Additionally, Anna Cucknell a project manager for ZSL’s Thames conservation pointed out that harbour seal pups can swim just within a few hours of their birth, making them well adapted for tidal estuaries ecosystems.
For over the last decade, both harbour and grey seals population has been on the increase in Thames. However, scientists are yet to determine whether this increase in number is as a result of the mammals breeding in the river, or due to migration of adult seals from other places.
The river also supports more than 100 species of fish such as endangered European eel, sharks, and short-snouted seahorses just to mention a few.
This is an indication that there is still hope for the river that was once declared biologically dead.