- Report from the Zoological Society of London reveals unusual species in the river
- But the results paint a ‘worrisome picture’ as far as climate change is concerned
- The Thames has also experienced a rise in temperature and a rise in water levels.
Scientists have conducted the first complete ‘health check’ of the River Thames since it was declared ‘biologically dead’ more than 60 years ago.
The results of the assessment, led by the Zoological Society of London (ZSL), reveal some surprising species living in the river including seahorses, eels and seals.
The River Thames is also home to various species of sharks, such as the tope, starry smooth hound, and spurdog.
Despite the abundance of wildlife, the new results also show that climate change has caused a 0.34 °F (0.19 °C) increase in summer temperatures in the Thames since 2007, as well as a rise in water levels.
Plastic waste is scattered around the world in the form of bottles and containers in the famous river, as well as ‘mounds’ of thrown wet wipes.
The results of the assessment, led by the Zoological Society of London (ZSL), reveal some surprising species living in the river, including seahorses, eels and seals.
The River Thames was so polluted that it was declared ‘biologically dead’ by the Natural History Museum in 1957. Now, a new report shows that species living in the Thames include seahorses, eels, seals and even sharks, including tope, starry smooth hound and spurdog. , Pictured, A Harbor Seal (Phoca Vitulina) by Thames
A juvenile short-toed seahorse (Hippocampus hippocampus) was found in Greenwich in 2017 during a juvenile fish survey. This species is believed to inhabit Tems.
Pictured, common smooth hound shark (Mustellus mustellus), found swimming in the Thames
Shark Species in the Thames
Several shark species have been discovered in the River Thames, including:
A long and slender shark, up to two meters in length, with a brown upper body and a white belly
starry smooth hound
A small, long, slender shark that can be up to 1.4 meters in length
Also known as the spiny dogfish, the spurdog is a predator that can grow up to 92 cm in length.
In 1957, the Thames was so polluted that it was declared ‘biologically dead’ by the Natural History Museum. Now, the ZSL has unveiled the first State of the Thames report to determine the river’s environmental health and trends.
Dr Andrew Terry, director of conservation and policy at ZSL, said in the preface to the report, “This report is what changed in those 60 years, as the Thames was almost devoid of life.”
‘We highlight some reduction in pressure and improvements in key species and habitats, and set benchmarks for indicators of how the river is used.
‘At ZSL, we work towards a wilder and more diverse UK that is full of wildlife. That means continuing to engage with communities about the positive benefits of easing stress, restoring species and the healing Thames.’
For the report, experts used 17 different ‘indicators’ to assess the health of the natural environment of the Thames, including water temperature, dissolved oxygen, plastic pollution and the presence of fish, birds and marine mammals.
He concentrated the specimens in the Tidal Thames, the part of the Thames that is subject to tides (from Teddington Wear in west London towards the Thames Estuary).
A European eel (Anguilla anguilla) found in Tilbury, in the borough of Thurrock, Essex. It is a yellow eel, which is one of the later maturation stages of the eel.
The researchers studied the Tidal Thames, the part of the Thames that is subject to tides (from Teddington Wear in west London towards the Thames Estuary)
Marine Species in the Thames
– Juvenile Short-Toothed Seahorse
– Harbor seal (Phoca vitulina) and gray seal (Halichoerus grypus)
– European fish (Anguilla anguilla)
– European Flounder (Platichthys phallus)
– River Shrimp (Gammarus pulex.)
– Chinese kitten crab (Eriochir sinensis)
– Melt (Osmerus aperlanus)
– European sea bass (Dicentrarchus labrax)
– Smooth Hound Shark (Mustellus mustellus
The results show an increase in bird species, marine mammals and a range of natural habitats such as carbon-capturing saltmarsh – an important habitat for a range of wildlife.
The Tidal Thames has two resident marine mammal species – the gray seal and the harbor seal, both of which use the estuary for habitat and food. Harbor seals also use it as a place to give birth to their puppies.
A more recent report from the ZSL found that the combined numbers of both species have declined by 12 percent since 2019, although they are still top predators in ‘key ecological hotspots’.
The new report says the Thames is a ‘complex habitat’ where large numbers of live oysters and dead shells form a shelter structure for a wide variety of organisms, such as juvenile fish, crabs, mollusks and sponges.
Since the early 1990s, there has been a slight decline in the number of fish species found in the tidal areas of the river, although further research is needed to determine the cause.
Interestingly, the Tidal Thames also hosts invasive non-native species, including zebra mussels, quagga mussels, and Chinese mitten crab (Eriochir sinensis).
‘While some introduced species cause no apparent damage to the ecosystems they occupy, others may be associated with harmful effects such as disease introduction and hybridization of species,’ the report said.
Juvenile European flounder (Platichthys flesus) found in the Thames. The flounder is roughly oval in shape, with both eyes on the right side of its head and a small mouth and pointed snout
Harbor seal (left and right, foreground) and a gray seal (middle) retrieved on the Thames foreshore
Bird Species in the Thames
– Redshank (Tringa Totnes)
– Avocet (Recurvirostra avoceta)
– Hen Harrier (Circus…