Sixty years ago the Thames Estuary was regarded as “biologically dead” and largely devoid of wildlife but, in recent years seals have returned to the Thames as well as to the coastal and low-lying lands bordering the estuary. Marine biologists will be keeping their eyes peeled for new arrivals as the first-ever survey of seal pups in the Thames Estuary goes into action into action.
Led by international conservation charity ZSL (Zoological Society of London), this year’s study – running from 1-4 July – will for the first time count seal pup numbers in key colonies along the Kent and Essex coasts, shedding further light on the importance of this critical habitat for the UK’s native harbour seals (Phoca vitulina).
Conducted via a combination of aerial, shoreline and boat-based surveys, the inaugural harbour seal breeding survey will also look for impacts of a range of emerging threats to these animals – ranging from wildlife disease and pressures from coastal construction projects, to plastic pollution and inter-species competition for food/habitat.
Commenting on this year’s Thames seal survey, ZSL conservation biologist Thea Cox said: “The outer Thames Estuary has long been known as an important habitat for adult harbour seals – now, our first survey specifically of pupping in the outer Thames Estuary will hopefully also show how vital this habitat is as a breeding habitat for these charismatic marine mammals.
“Last year, we estimated populations of 1,104 harbour seals and 2,406 grey seals across the Estuary – an increase of 14% and 19% respectively against 2016’s figures. These positive findings support the idea that today’s Thames is not the same polluted, biologically dead ‘open sewer’ it was in the 1950s, but is in fact thriving with wildlife once again. There’s still a lot of work to do, however, so launching our first-ever pupping count this year should yield further invaluable evidence to support the ongoing renaissance of London’s river as a living, breathing ecosystem.”