Sea Lamprey is a primitive fish native to coastal watersheds of the Atlantic Ocean, but has become invasive since it was introduced to the Great Lakes. This
eel-like fish spends part of its life cycle in the ocean, but can also survive in freshwater.
They are native in the Atlantic coast from Labrador to the Gulf of Mexico
and Florida; but have become landlocked in the Great Lakes and several New York lakes. Sea lampreys are also found
along the Atlantic coast of Europe and Mediterranean Sea.
Sea lampreys are generally marine,
but ascend to freshwater rivers to spawn.
Sea lampreys resemble eels, but unlike eels, they are parasites of large
fish. Sea lampreys are members of an ancient family of jawless fish that
were around before the time of the dinosaurs. They grow to 30-50 cm (12-20
inches) long. They have dark- brown to black backs and light- yellow to
pale- brown bellies. Look for a feathery fin from their midsection down
and under the tail. Their sucking mouth is circular with circular rows
of teeth. They have large reddish eyes.
Sucking mouth of Lamprey
Construction and improvements of the Welland and Erie Canals (between
Lake Ontario and Lake Erie) around 1921 allowed sea lampreys to get from
the Atlantic Ocean and the St. Lawrence Seaway through the canal to the
rest of the Great Lakes. Sea lampreys can lay over 100,000 eggs when spawning,
many more than the native lamprey species such as the Ohio, silver and
Sea lampreys feed by sinking their disc-shaped mouth full of teeth into
a fish. They hold fast to the sides of their victims as they feed on blood
and body fluids. Large fish are better able to survive a lamprey attack
with just a circular scar left on their sides; however, small fish may
die immediately from the attack or from a wound infection.
Lamprey attached to Lake Trout
first arrived on the Great Lakes scene, they killed large numbers of sport
fish. People began to notice fewer large fish and scars on others. Lampreys
preyed on whitefish, lake trout, and chub populations in Lake Superior
and Lake Michigan. What followed was a collapse in these commercial fisheries
during the 1940s and 1950s, particularly in lakes Huron and Michigan,
and in eastern Lake Superior.
There are several current methods to control the spread and population
growth of sea lampreys.
a chemical (commonly known as TFM) added to the water that is effective
in killing young sea lampreys.
by sterilizing competitive males and placing them in the water, they
will spawn with females but conception will not occur.
barriers- the barriers keep lampreys from traveling upstream to nesting
building dams that are small enough for fish to leap over them, but
too high for lampreys to pass keeps the sea lamprey from traveling upstream
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