Anglers taking part in this year’s Salmon Spectacular are not only finding a lot of fish, but also a dangerous fish predator called Sea lamprey.

The sea lamprey is a large blood sucking predator. The invasive species got into Lake Huron and Georgian Bay when the Welland Canal was built in the early 1900’s.

In less than 20 years, the sea lamprey decimated the lake trout populations in the upper lakes.

With more than $150,000 in prizes up for grabs in the derby, all of the fish are carefully weighed, measured and checked over for scars from sea lamprey bites.  

About half of the fish being weighed in at the derby today have signs of lamprey attack.

The streams around the Great Lakes where sea lamprey spawn in are chemically treated every few years to help control the population, but the invasive species can never be totally eliminated.

“Sea lamprey populations vary in different areas so we try to treat those areas every three or four years to help keep those populations down,” said Ted Lawrence with “If we stop for even a year, sea lamprey populations will explode in those areas that we don’t treat and devastate the fish population in those areas,” he said.

Experts say sea lamprey prefer deep cold water over warm shallow water and are unlikely to latch onto swimmers.