Close up of the Green Lake, Minnesota (Kandiyohi County) shoreline showing zebra mussels washed up on shore, October 2021
What are zebra mussels and why should we care about them?
Zebra mussels are an invasive, fingernail-sized mollusk that is native to fresh waters in Eurasia. Their name comes from the dark, zig-zagged stripes on each shell.
Zebra mussels probably arrived in the Great Lakes in the 1980s via ballast water that was discharged by large ships from Europe. They have spread rapidly throughout the Great Lakes region and into the large rivers of the eastern Mississippi drainage. They have also been found in Texas, Colorado, Utah, Nevada, and California.
Zebra mussels negatively impact ecosystems in many ways. They filter out algae that native species need for food and they attach to--and incapacitate--native mussels. Power plants must also spend millions of dollars removing zebra mussels from clogged water intakes.
Related
How can the spread of zebra mussels be prevented? How can the spread of zebra mussels be prevented?
The USGS documents the zebra mussel's geographic distribution and studies its behavior and biology. The resulting information is critical in helping to develop strategies aimed at containing and controlling the mussel's spread. Meanwhile, catching and transporting zebra mussels for use as bait, food, and aquarium pets is highly discouraged. We also encourage good boat hygiene: Wash your boat off...
What are snakeheads? What are snakeheads?
Snakeheads are air-breathing freshwater fishes that are not native to North America. In scientific terms, snakeheads are divided into two distinct genera: Channa (snakeheads of Asia, Malaysia, and Indonesia) Parachanna (African snakeheads) In the summer of 2002 and again in late spring 2004, Channa argus, the northern snakehead, generated national media attention when anglers caught this fish in a...
What is an Asian swamp eel and what does it look like? What is an Asian swamp eel and what does it look like?
Swamp eels are freshwater fish, but they are not closely related to other living eels or snake-like marine and freshwater fishes. In addition to the name swamp eel, other English common names used for members of this group of fish include rice eel, rice-paddy eel, and belut. The swamp eel family includes more than a dozen species. Asian swamp eels may be confused with a number of native animals...
What are Invasive Carp? What are Invasive Carp?
Carp are not native to North American waters, but various carp species have been introduced here since the mid-1800s, much to the detriment of native fish. Although carp eradication measures have been active for over 100 years, long-established species, like the common carp, are present in almost every state. Invasive carp (bighead, black, grass, and silver carp) were imported to the United States...
What is an invasive species and why are they a problem? What is an invasive species and why are they a problem?
An invasive species is an introduced, nonnative organism (disease, parasite, plant, or animal) that begins to spread or expand its range from the site of its original introduction and that has the potential to cause harm to the environment, the economy, or to human health. A few well-known examples include the unintentional introduction of the West Nile virus, chestnut blight, the South American...

Close up of the Green Lake, Minnesota (Kandiyohi County) shoreline showing zebra mussels washed up on shore, October 2021
Ohio River at Ironton, OH - staff removing zebra mussels from the equipment
Ohio River at Ironton, OH - staff removing zebra mussels from the equipment
During a National Water Quality Network (NWQN) sampling trip in May to the St Lawrence River, Hydrologic Technician Dave Knauer finds a batch of Zebra mussels attached to the boat anchor.
During a National Water Quality Network (NWQN) sampling trip in May to the St Lawrence River, Hydrologic Technician Dave Knauer finds a batch of Zebra mussels attached to the boat anchor.
The zebra mussel (Dreissena polymorpha) is a small, non-native mussel originally found in Russia. In 1988, this animal was transported to North America in the ballast water of a transatlantic freighter and colonized parts of Lake St. Clair. In less than ten years, zebra mussels spread to all five Great Lakes.
The zebra mussel (Dreissena polymorpha) is a small, non-native mussel originally found in Russia. In 1988, this animal was transported to North America in the ballast water of a transatlantic freighter and colonized parts of Lake St. Clair. In less than ten years, zebra mussels spread to all five Great Lakes.
Zebra Mussel, Lake Huron specimens.
Zebra Mussel, Lake Huron specimens.
Zebra Mussel, Lake Huron specimens.
Zebra Mussel, Lake Huron specimens.
Zebra mussels are small, averaging about an inch long. Two inches is approximately the maximum size.
Zebra mussels are small, averaging about an inch long. Two inches is approximately the maximum size.
Zebra Mussel (Dreissena polymorpha) vs Quagga Mussel (Dreissena rostriformis bugensis). The only two dreissenid mussels known to have been introduced into the US. Both the quagga mussel and zebra mussel are prolific breeders possibly contributing to their spread and abundance. The introduction of both dreissenid species into the
Zebra Mussel (Dreissena polymorpha) vs Quagga Mussel (Dreissena rostriformis bugensis). The only two dreissenid mussels known to have been introduced into the US. Both the quagga mussel and zebra mussel are prolific breeders possibly contributing to their spread and abundance. The introduction of both dreissenid species into the
United States Register of Introduced and Invasive Species United States Register of Introduced and Invasive Species
Zebra and Quagga mussels in the United States—Dreissenid mussel research by the U.S. Geological Survey Zebra and Quagga mussels in the United States—Dreissenid mussel research by the U.S. Geological Survey
Invasive species research—Science for prevention, detection, containment, and control Invasive species research—Science for prevention, detection, containment, and control
U.S. Geological Survey invasive species research—Improving detection, awareness, decision support, and control U.S. Geological Survey invasive species research—Improving detection, awareness, decision support, and control
Quagga and zebra mussels: biology, impacts, and control Quagga and zebra mussels: biology, impacts, and control
The National Nonindigenous Aquatic Species Database The National Nonindigenous Aquatic Species Database
USGS Zebra Mussel Monitoring Program for north Texas USGS Zebra Mussel Monitoring Program for north Texas
Procedures for conducting underwater searches for invasive mussels (Dreissena sp.) Procedures for conducting underwater searches for invasive mussels (Dreissena sp.)
Zebra mussels in the eastern United States Zebra mussels in the eastern United States
Related
How can the spread of zebra mussels be prevented? How can the spread of zebra mussels be prevented?
The USGS documents the zebra mussel's geographic distribution and studies its behavior and biology. The resulting information is critical in helping to develop strategies aimed at containing and controlling the mussel's spread. Meanwhile, catching and transporting zebra mussels for use as bait, food, and aquarium pets is highly discouraged. We also encourage good boat hygiene: Wash your boat off...
What are snakeheads? What are snakeheads?
Snakeheads are air-breathing freshwater fishes that are not native to North America. In scientific terms, snakeheads are divided into two distinct genera: Channa (snakeheads of Asia, Malaysia, and Indonesia) Parachanna (African snakeheads) In the summer of 2002 and again in late spring 2004, Channa argus, the northern snakehead, generated national media attention when anglers caught this fish in a...
What is an Asian swamp eel and what does it look like? What is an Asian swamp eel and what does it look like?
Swamp eels are freshwater fish, but they are not closely related to other living eels or snake-like marine and freshwater fishes. In addition to the name swamp eel, other English common names used for members of this group of fish include rice eel, rice-paddy eel, and belut. The swamp eel family includes more than a dozen species. Asian swamp eels may be confused with a number of native animals...
What are Invasive Carp? What are Invasive Carp?
Carp are not native to North American waters, but various carp species have been introduced here since the mid-1800s, much to the detriment of native fish. Although carp eradication measures have been active for over 100 years, long-established species, like the common carp, are present in almost every state. Invasive carp (bighead, black, grass, and silver carp) were imported to the United States...
What is an invasive species and why are they a problem? What is an invasive species and why are they a problem?
An invasive species is an introduced, nonnative organism (disease, parasite, plant, or animal) that begins to spread or expand its range from the site of its original introduction and that has the potential to cause harm to the environment, the economy, or to human health. A few well-known examples include the unintentional introduction of the West Nile virus, chestnut blight, the South American...

Close up of the Green Lake, Minnesota (Kandiyohi County) shoreline showing zebra mussels washed up on shore, October 2021
Close up of the Green Lake, Minnesota (Kandiyohi County) shoreline showing zebra mussels washed up on shore, October 2021
Ohio River at Ironton, OH - staff removing zebra mussels from the equipment
Ohio River at Ironton, OH - staff removing zebra mussels from the equipment
During a National Water Quality Network (NWQN) sampling trip in May to the St Lawrence River, Hydrologic Technician Dave Knauer finds a batch of Zebra mussels attached to the boat anchor.
During a National Water Quality Network (NWQN) sampling trip in May to the St Lawrence River, Hydrologic Technician Dave Knauer finds a batch of Zebra mussels attached to the boat anchor.
The zebra mussel (Dreissena polymorpha) is a small, non-native mussel originally found in Russia. In 1988, this animal was transported to North America in the ballast water of a transatlantic freighter and colonized parts of Lake St. Clair. In less than ten years, zebra mussels spread to all five Great Lakes.
The zebra mussel (Dreissena polymorpha) is a small, non-native mussel originally found in Russia. In 1988, this animal was transported to North America in the ballast water of a transatlantic freighter and colonized parts of Lake St. Clair. In less than ten years, zebra mussels spread to all five Great Lakes.
Zebra Mussel, Lake Huron specimens.
Zebra Mussel, Lake Huron specimens.
Zebra Mussel, Lake Huron specimens.
Zebra Mussel, Lake Huron specimens.
Zebra mussels are small, averaging about an inch long. Two inches is approximately the maximum size.
Zebra mussels are small, averaging about an inch long. Two inches is approximately the maximum size.
Zebra Mussel (Dreissena polymorpha) vs Quagga Mussel (Dreissena rostriformis bugensis). The only two dreissenid mussels known to have been introduced into the US. Both the quagga mussel and zebra mussel are prolific breeders possibly contributing to their spread and abundance. The introduction of both dreissenid species into the
Zebra Mussel (Dreissena polymorpha) vs Quagga Mussel (Dreissena rostriformis bugensis). The only two dreissenid mussels known to have been introduced into the US. Both the quagga mussel and zebra mussel are prolific breeders possibly contributing to their spread and abundance. The introduction of both dreissenid species into the