Poisonous sharks swim across London

Researchers examined the Thames and made surprising discoveries in the process. But there is also cause for concern.

For centuries, the Thames has been one thing above all else for Londoners: a practical way to get rid of all kinds of excrement and litter. The city owes a lot to its river, not least to its foundation. The Romans settled here once after crossing the Thames on ships. However, in the 20th century, large parts of the river were still polluted, and in 1957 it was declared “biologically dead”.

Now the Zoological Society of London (ZSL) has done a health check on the Thames and discovered amazing things. As scientists announced on Wednesday. The report stated that the overall picture of the investigation was “positive”. There are indications that more birds and marine mammals are living in and around the river. Additionally, one encounters “amazing” species of animals, including “seahorses, eels, seals, and even sharks.”

Sharks that are seen include the dog shark, the smoothie shark, and the dog shark. The latter reaches a length of 90 cm and can emit a light venom with spines near the dorsal fin when attacked. The poison can cause swelling and mild pain.

‘One of our neglected and threatened ecosystems’

In total, according to the report, there are more than 100 species of fish in the Thames. However, some of them are becoming less and less. Scientists at the Zoological Society of London also found other findings of interest. Climate change is causing the river’s water temperature to rise.

Even if the Thames is cleaner today than it was before, large amounts of sewage still flow into the river. A new canal system called the Thames Tideway aims to prevent 39 million tons of untreated sewage from entering the Thames each year.

Estuaries such as the Thames are, according to Alison Debney of the Zoological Society of London, “one of our neglected and threatened ecosystems”. BBC said the world: “They provide us with clean water, protect us from floods, and are an important nursery for fish and other wildlife.” The report submitted now shows “how far the Thames has come to recovery since it was declared biologically dead”.