Transcript The Sea Lamprey

By: Daniel Bassani, Michael Morassutti,
Anastasiya, and Younos
What Is a Sea Lamprey?
 An eel-like fish native to the Atlantic Ocean, Baltic
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Sea, Mediterranean Sea, and Adriatic Sea
Adapted to fresh water bodies such as the Great Lakes,
but do not grow as big in size as they do in salt water
Spend from 1-2 years feeding on fish
Uses its sucker mouth, sharp teeth and tongue to
attach itself to the body of a fish and suck its blood
Fish is left with a circular wound that can get infected
and kill it
What is the Sea Lamprey Cont.
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Cylindrical bodies are 30 to 76 centimetres long
Can be dark brown or green/black colour
A sea lamprey can destroy up to 18kg of fish
About 1 in 7 fish can survive a Sea Lamprey attack
They feed on lake trout, salmon, rainbow trout,
whitefish, chubs, burbot, walleye, catfish
 Entered the great lakes through man-made shipping
canals in the 1940s
 Have been living in the ocean for hundreds of millions
of years
How Does It Grow/Reproduce?
4. Parasitic fish grow a
suction cup mouth with
sharp, hooked teeth. They
migrate to open lakes
where they prey on fish.
1. Spawning phase, sea
lamprey migrate into streams
and build nests from rocks.
They spawn, and then die.
3. Larvae
transforms into
parasitic fish.
2. Larvae burrow into the
river bottom and live there
for several years.
Equipment Used to Find and Track
the Sea Lamprey
 In the earliest attempts to control the Lampreys,
American scientists tested thousands of chemicals
before finding one that could kill Lampreys and not
harm other species
 Today a similar chemical is used to kill Lampreys and
not harm other species. It is called Lampricide
 Lampricide is used to kill the larvae or reduce their
population before they get to their parasitic phase
 About 175 lakes and streams are regularly treated with
lampricide to reduce their population
Equipment for Tracking Cont.
 Small dams can be used to block Lampreys because they are
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weak swimmers and fish can jump over them
Electric barriers and fast moving currents can also stop them
because they are weak swimmers
They sterilize males so they can’t reproduce as quickly
Method called electrofishing removes Lampreys from their
burrows, in 250 of the 440 streams where lampreys are known to
live
Mobile science labs are used to monitor Lampreys in 40
Canadian streams
Barriers are used to stop up-stream migration, but do allow other
fish to pass through
The sea lampreys are trapped in traps. They are then used in
research and testing
Equipment for Tracking Pictures
(Above) Shows a
barrier to stop upstream migration
of Sea Lamprey
(Above) Shows tracking of Sea
Lamprey in Great Lakes
(Left) Shows
Electrofishing
to remove
Lamprey from
burrows
(Below) Show
distribution of
Lampricide in a stream
Effect Species has on Humans
 Damages the great lakes fishery by reducing fish
populations
 Attacks lake trout, steelhead, perch and other species
of fish
 Fish have little defence against sea lamprey attacks and
often die from their wounds, which has a profound
affect on the ecosystem
 From the 1940s to the early 1960s, growing sea lamprey
populations we hard to control without modern
methods of extermination
How Does the Sea Lamprey Affect
Food Webs?
 The sea lamprey eats large fish which are at the top of
the food web in the Great Lakes
 Populations of the smaller fish increase because the
large fish aren’t there to eat them
 The producers’ population will decrease because the
increased population of the smaller fish will eat all of
the producer
 Eventually it will leave the small fish without food and
the whole food web will collapse
Video
 http://youtu.be/9JQ6oHjpeqU
 Start at 0:11
 End at 1:22
Sea Lamprey