Tilbury Fish Monitoring
In January 2006, ZSL in collaboration with partners launched a long-term project monitoring Thames fish.
The presence of fish in the Thames and their movements will be monitored adjacent to Tilbury Marshes, providing valuable information on which fish species are present in the Thames, including the interesting John Dory Zeus faber and snake pipefish, Entelurus aequoreus, and more common species, such as bass Dincentrachus labrax, Dover sole Solea solea and the pollution sensitive common smelt Osmerus eperlanus.
ZSL will be monitoring on a monthly basis and it is hoped that this will continue for many years providing a variety of important information, including the effects of pollution incidents and the overall water quality of the Thames, natural fluctuations in important commercial and recreational fish populations, and news of rare and interesting fish visitors.
Until recently, snake pipefish have been an inconspicuous presence in British waters, usually restricted to seaweed and seagrass beds around the coast. But now they can be found in extraordinary numbers throughout the coastline of Britain, including the Thames Estuary. However, the reason for such an increase in abundance is not known and could be a combination of factors such as a natural population boom and warmer waters.
Snake pipefish are members of the sea horse family, resembling slender, straightened seahorses, and like seahorses, it’s the males that carry the young. Snake pipefish have no teeth, and their jaws are locked together to make a snout, which is more than half its head length. The body, brown or yellowish in colour, is smoothly rounded with light coloured bands along most of its length.
Snake pipefish vibrate the long fin on their back to move, but can also use their whole body to move through the water. As a result, people often confuse them with snakes, which is why they got their name. They feed on a range of small creatures, including shrimp and juvenile fish and use their snouts like a straw to suck up their prey. However, they are fussy eaters, and often blow food that they don’t like back out.
As prey for other animals they are now causing a few problems. Sea birds that normally eat sand eels have tried taking advantage of the high numbers of snake pipefish. Unfortunately, due to their bony body, snake pipefish are often inedible to most birds and have proved disastrous as a food source for some young sea birds. Whether this population explosion is a result of warming waters or just a natural phenomenon it is too early to say.