Electronic tags implanted in juvenile salmon, tracking them from birthplace to ocean

Using tags surgically implanted into thousands of juvenile salmon, UBC researchers have discovered that many fish die within the first few days of migration from their birthplace to the ocean. “We knew that on average 10 to 40 million smolts leave Chilko Lake every year and only about 1.5 million return as adults two years later,” said Nathan Furey, researcher and a PhD candidate in the faculty of forestry. “It’s always been a mystery about what happens in between.” More than 2,000 salmon were tracked over four years and researchers found that survival was poor in the clear and slow-moving Chilko River, where predators were feeding intensely on the smolts. Once in the murky and fast-flowing Fraser River, the salmon travelled day and night, covering up to 220 km per day, and experienced nearly 100 per cent survival. The researchers believe that in these waters, predators have difficulty finding and getting to the fish. Video, read the rest here 10:58