A population of seahorses have recently been found living in an area of the Thames between Essex and Kent.
Zoological Society of London (ZSL) scientists found the Short-snouted seahorses, Hippocampus hippocampus, during routine wildlife monitoring in 2006 but kept the details secret as they were waiting for legislation to be put into place to protect them.
The species is now protected under the Wildlife and Conservation Act of 1981.
Scientists are taking the presence of the seahorses as an indication of the improving water quality in the Thames as the species is usually found only in shallow muddy waters, estuaries and seagrass beds.
Fifty years ago the river was declared biologically dead due to the pollution produced by industrialisation and the increased urbanisation. Now there are more than 120 fish species recorded between Fulham and Tilbury.
ZSL s Marine and Freshwater Conservation Programme Manager, Alison Shaw, is quoted as saying on the ZSL website:
These amazing creatures have been found in the Thames on a number of occasions in the last 18 months during our regular wildlife monitoring work. It demonstrates that the Thames is becoming a sustainable biodiverse habitat for aquatic life.
It is not clear how endangered Short-snouted seahorses are because there is little data known, particularly in the UK, so every scrap of information is valuable. Now they are protected conservationists are more relaxed about telling the world they are there.
The Short-snouted seahorse is typically found on the shallow coastal waters of France, Spain, the Mediterranean and along the northern coast of Africa, but has been reported elsewhere.
According to the ZSL, this seahorse has previously only been found occasionally in deep water around the Channel Islands and off the Sussex coast, although in the last two years the area where they have been found has increased to include all of the south coast and parts of Ireland.
This protection provided by the Wildlife and Conservation Act means that it will be illegal to take short and long snouted seahorses from the wild, to possess them or to damage or obstruct their habitat or place of shelter.
Also protected at the same time were water voles Arvicola terrestris, Angel sharks Squatina squatina and Roman snails Helix pomatia.