Meet Greg Bennett a researcher for the environmental agency in the Devon Area. Most of his time he is working on the river Tamar near the town Gunnislake, South West of England. The river tamar is equipped with a fish passage that also doubles as a fish counting station. One or twice a day the fish that want to pass are trapped in by closing the fish passage off.
Greg counts the fish they have caught. When Greg arrive on site he lowers the water level of the fish passage, just enough that the caught fish can still swim around but are much easier to handle. Greg lifts the fish out of the water onto a wooden plank with a measuring tape on it. Besides measurements, the name of the species is written down, scale samples are taken and he looks at the overall health of the fish. Before releasing the final step, weighing the fish. Release happens a but more upstream and fish get cradled until the have the power swim off again.
This practice is going on for roughly 80 years. This sheer amount of data has given de Tamar the right to be one of the index rivers in the UK. An index river is used to see the changes over the decades in fish species population.
Rob Price, catchment coordinator, use this data to build a better place for people and also for wildlife. Working with different partners to bring together skilled people and good information, like found in the river tamar, to invest in things like fish passages.
Fish passages are extremely important to help fish navigate around man-made structures that provide England with hydropower or in the instance of the Tamar River, abstracting drinking water for the 250.000 people in the city of Plymouth. Helping those fish to swim from the atlantic, through the estuaries and up to the spawning ground in the upper rivers.
All kinds of fish species are using fish passages but the main focus are the fish that are England considers protected. Fish species like salmon, sea trout and eels.
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