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Asian Carp: Invasive Species & Ecosystem Impact

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Asian Carp Reading
Adapted from the NPS “Asian Carp Overview”
What are carp?
Carp are a family of fish that is native to Europe and Asia. The common carp
(Cyprinus Carpio) has been in the United States for over 100 years. The newest
carp invaders, bighead carp, black carp, grass carp, and silver carp —collectively
known as "Asian carp"— however, are causing trouble in the freshwater
ecosystems of the Mississippi River area. The Asian carp were introduced to the
U.S. in the 1970's to control algae, weed, and parasite growth in aquatic farms.
These captive fish eventually escaped into the Mississippi River and established
breeding populations. Asian carp are slowly making their way up the Mississippi
River and its tributaries and have been found as far north as Minnesota. These
invasive species (animals or plants from another region of the world that don’t
belong in their new environment) represent a threat to our valued aquatic
ecosystems.
Guiding Questions:
1. Why were Asian Carp brought to the United States?
They were brought to the US in order to control the algae, weeds, and parasite
growth.
Why are carp a problem?
Asian carp cause serious damage to the native fish populations in the lakes and
rivers that they infest because they out-compete other fish for food and space.
Carp are also thought to lower water quality, which can kill off sensitive organisms
like native freshwater mussels. Asian carp have been known to dominate entire
streams, effectively pushing out the native species.
Some Asian carp, known as Silver carp are known to jump out of the water to
escape threats. This behavior, by such large fish, can injure boaters, skiers, and
damage boats and onboard equipment.
Experts are worried that if these fish get into the Great Lakes, they may negatively
affect the area's $7 billion/year fishing industry and if they spread further north,
they could threaten the resort and sport fishing industry. By out-competing native
fish species for food and habitat, carp may reduce the populations of native fish
that are so important to anglers (a person who fishes with a rod and line).
Guiding Questions:
2. The Asian carp “out-compete other fish for food and space”. What does
this mean?
The Asian Carp is taking all the space and the food. This means that other fish
aren’t able to live because they don’t have food to eat and space to swim.
3. What population(s) in the ecosystem are Asian Carp affecting?
The Asian Carp is affecting native fish populations, water quality, and native
species.
How do carp spread?
Asian carp, especially silver carp, may be capable of jumping over some barriers,
including low dams. High water often creates an "open river" condition as
Mississippi River dams open their gates, which may allow invasive carps to move
past what is otherwise a barrier. Flooding can spread these fish as well, because
flooding can connect water bodies that aren't normally connected.
Invasive carp are also spread by humans. The release of live bait (food used to
attract animals) containing young carp has introduced these fish to other bodies of
water.
Silver carp jumping out of the water.
Photo: Ted Lawrence, Great Lakes Fishery Commission
Releasing even a few carp into a body of water can become a huge problem. While
the adult carp prefer slow moving water, they look for high, fast-moving water
when laying eggs (spawning). They lay hundreds of thousands of eggs at a time,
which means populations grow and spread quickly. Because of this, they can
quickly out-compete native species, and put ecosystems in danger.
Guiding Questions:
4. Why is the population of Asian carp increasing?
They lay hundreds of eggs at a time and they are provided with the high fastmoving water that they need for laying eggs.
5. Do you think Asian carp are considered a biotic or abiotic factor of an
ecosystem? Explain.
I think that Asian carp are considered as a biotic factor of the ecosystem because
it is a living animal that continues to reproduce.
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