Sunday, September 13

Invasion of the Asian Carp

We discussed a little about the interactions and keystone species in the last class, about how the removal of starfish resulted in reduced biodiversity. The addition of alien species wreaks havoc too.

Sometime ago, I read about the invasion of Asian carp in the Illinois River (“Asian Carp Ground Zero”). The species of Asian carp (silver carp) were introduced into the river by accident. The silver carp is native to the Pacific in Eastern Asia and the Amur river in Russia. In the early 1970s, they were used to control the growth of algae in catfish farms in the South. The Mississippi floods of 1993 spread the species to other bodies of water, and as they prefer colder waters, they moved quickly up north. They are almost in the Great Lakes- but installed in the Chicago Shipping Canal is the “last line of defense”, an electrical fence made to repel anything that moves in the water.

The silver carp does not have as many predators here in US waters as it would in its native habitats. The large size of the carp (it can grow up to 1m/ 3.3feet long and 27 kg / 59.5 lbs), even the young ones, makes it difficult for native predators in the Illinois River to prey on them, hence the overwhelming growth in numbers.

As it feeds on plankton in copious amounts (up to half of its body weight a day), it breeds quickly and crowds out the native species of fish, such as the gizzard shad and largemouth buffalo. Apart from invading the rivers (90% of the fish in Illinois River are silver carp), the carp pose a danger to boaters by jumping out of the water when their boats pass, breaking their noses, bruising arms, et al.

Jumping carp video

Scientists working with the USDA are trying to solve this problem... and here are some of the solutions that might work. 3 uses for the invasive carp:
  • Animal Feed- The Saint Louis zoo is looking to use the carp as food for its animals
  • Entertainment - Redneck Fishing Tournament in Bath, IL. The annual tournament sees people/ rednecks trying to catch these silver carp sans fishing rod. Some use baseball bats.
  • Food- We can eat them! Fishermen suggested that a change in its name might make it more appealing to consumers. I wonder how it tastes like grilled with garlic sauce.
-georgi p

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