Thriving seal population calls River Thames home

The number of seals in the Thames is proof that the river is teeming with life, according to conservationists, despite a dip over the past two years.

The river was home to 2,866 grey seals and 797 harbour seals following the most recent pupping season, researchers from the Zoological Society of London found. In 2019, they counted 3,243 grey seals and 932 harbour seals.

Conservationists use the mammals as a barometer of river health, with stable numbers indicating good water quality and reliable fish stocks. They say the wildlife shows how far the Thames has come since it was declared “biologically dead” in the 1950s.