Matthew’s interest in environmental and aquatic issues is well known and he took an opportunity during the Easter recess to visit the Game and Wildlife Conservation Trust (GWCT) Salmon counting project in Dorset. Each year the GWCT count the number of Salmon smolts emigrating from the River Frome using a Bio-Acoustic Fish Fence. This is a curtain of bubbles that diverts the fish through a fluvarium tank where the smolts are counted as they pass through a Rotary Screw Trap.
When juvenile salmon reach between 10 and 24 cm in length, they experience a remarkable transformation, usually in the spring, known as smoltification. Their bodies change in preparation for their entry into salt water, where they may spend years before embarking on a treacherous ocean voyage to return to their home rivers to spawn. Researchers believe that the early part of ocean life is especially hazardous for salmon smolts as they are at risk from the stresses of the river, including fluctuating temperatures, an array of predators, pollution, disease, parasites, and an uncertain food supply. Most do not survive this early stage.
The GWCT has reported evidence that salmon from the River Frome and presumably other south coast rivers in England feed off the coast of Greenland. The epic migratory journey to the North Atlantic was confirmed on 6 October 2009 when a fish was recorded at a Fish Market in Sisimuit on the west coast of Greenland. The fish was picked up during a sampling programme organised by the North Atlantic Salmon Conservation Organisation (NASCO). The distance between the GWCT location and Sisimuit is 2,070 miles. Because it was caught in late 2009, this fish would have been destined to be a multi-sea winter fish rather than a grilse, had it successfully made the return journey to Dorset.
Matthew said: “The GWTC is a charity that aims to promote the study and application of freshwater biology to advance freshwater science and encourage as many people as possible to adopt it as the best way to understand, protect and manage the country’s precious water resources. The impact of this goes way beyond the management of fish stocks as it provides an in-sight into the ecology of our waterways, which reflect upon the environment at large.”
Photo: Matthew is joined by Gemma, a volunteer from the Weymouth Sea Life Park, in measuring Salmon smolts