The discovery of a colony of short-snouted seahorses (Hippocampus hippocampus) living in the Thames means that the London river is becoming cleaner, conservationists said today. Scientists from the Zoological Society of London (ZSL) have discovered five seahorses during routine conservation surveys in the Thames estuary in the past 18 months, evidence which they say indicates that a breeding population exists. The rare species, which is normally found in the Mediterranean and Canary Islands and also along the south coast of England, has been found at Dagenham in east London and Tilbury and Southend in Essex. The sea creatures thrive in shallow, muddy waters, estuaries or seagrass beds. Scientists at the ZSL say the presence of the seahorses in the Thames estuary is a good sign that river quality is improving, but warned that any disturbance to their habitats could be disastrous. The presence of a breeding population has been kept quiet to date as the species was not protected, the zoo said. But last month, the short-snouted and spiny seahorses, along with the water vole, angel shark and Roman snail, became the latest species to gain legal protection under the Wildlife and Countryside Act. The laws, which came into force today, mean that anyone found killing, injuring or taking any of these species from the wild faces a