Impacts Of Sea Lamprey On Lake Trout

Sea Lamprey Affects on the Lake Trout in the Great Lakes

 

WHO – Sea lampreys are an eel like fish native to the northern Atlantic Ocean and the Baltic, western Mediterranean and Adriatic seas.  Adult sea lampreys are 30 to 76 centimetres long; they have a grey/dark brown leathery skin with dark blotches and a lighter belly.  They do not have scales but they have very sharp teeth.  The sharp teeth radiate around their raspy tongue at the centre of their large sucker mouth.  Sea lamprey larvae are 18 centimetres long, with a black/pale grey body and light belly.  They are blind and wormlike.

Large fish species in the Great Lakes such as lake trout were affected by the invading sea lampreys.  Sea lampreys affected the population of lake trout during the 20th century.

 

WHAT – Sea lampreys are affecting the existence of lake trout fish species in the Great Lakes.  Sea lamprey attacks have resulted in reduced stocks of lake trout in the Great Lakes. 

 

WHEN – Sea lampreys invaded the Great Lakes in the early 20th century through shipping canals.

 

WHERE – Sea lampreys invaded the Great Lakes in Ontario through shipping canals.

 

WHY – This is an issue because the sea lampreys in the Great Lakes are very hard to eliminate.  The sea lampreys suck and kill large fish in the Great Lakes, which affect the food chain.  Sea lampreys do not attack small fish, so a population change may occur in the Great Lakes due to the sea lamprey.  Sea lampreys also had devastating impacts on Aboriginal fisheries.

 

HOW – The sea lamprey attacks large fish by attaching itself to the body of the fish with its sucker mouth, sharp teeth and rasping tongue.  During this process the sea lamprey sucks the fish’s blood, if the fish survives the attack it is left with a large open wound that often leads to its death because of infection.  Sea lampreys destroy an average of 18 kilograms of fish during their parasitic stage.