About Common Carp & Asian Carp

Carp are a freshwater fish species from the family Cyprinidae, a group of fish native to Europe and Asia. Carp are not new to Wisconsin; in fact, certain species have been living in our lakes since the 1890s! Despite their longtime presence, carp are still considered an invasive species with harmful impacts on native ecosystems.

Common Carp

Quick Facts:

• Common carp can be identified by their large, golden brown scales. They also have two small “whiskers” on each side of their mouth.
• Common carp can weigh up to 80 pounds and grow up to 5 feet in length. They live an average of 20 years in the wild, although they have been known to live up to 50 years in captivity.
• Common carp congregate in large numbers when spawning. Spawning takes place in the spring to early summer in shallow (2-3 feet deep) water. When they spawn, they disturb the lake bottom in shallow waters, causing the water to become murky.
• Female carp can produce hundreds of thousands of eggs during the breeding season.

How did they get here?

Believe it or not, common carp were actually brought intentionally into the U.S. by the Commission of Fish and Fisheries in the 1800s. Native to Europe, they were originally intended to be a game fish and source of food. Due to their ability to rapidly reproduce and tolerate a wide range of environments, they quickly spread into waterways throughout the country.

Are they in the Yahara Lakes?

The common carp can be found in all the Yahara lakes. They were intentionally introduced into our lakes in the 1890s. Despite various removal efforts, carp have spread and continue to disrupt natural areas throughout the watershed.

Why are common carp a problem?

Carp are notorious for altering natural ecosystems. They uproot and disturb submerged vegetation while searching for insect larvae to eat. Carp reduce water clarity and stir up bottom phosphorus-containing sediments, which contributes to algae blooms.

Common carp have a significant impact on water quality in the Yahara Lakes. as seen in a 2007 carp exclosure experiment in Lake Wingra. Note the dramatic contrast in water clarity between the carp-free zone and the rest of the lake, taken in the summer when blue-green algae is most abundant.

What is the Koi Herpes Virus?

The Koi Herpes Virus resulted in the death of hundreds of common carp in the Yahara lakes in fall of 2017. This was the first known occurrence of the Koi Herpes Virus in the Yahara watershed.

The virus works by suppressing the fish’s immune system, making it highly vulnerable to other infections. It affects common carp and koi; fortunately, it is not harmful to humans, or any other animals outside the carp family.

How are we managing carp in our lakes?

Due to their long life cycles, lack of natural predators, and rapid breeding, carp eradication can be both difficult and expensive. In partnership with the Wisconsin DNR, local groups have organized carp harvests to remove these fish from our lakes. Using radio telemetry to track carp movement and large nets to collect the fish, 523,616 pounds (256.8 tons) of fish have been removed from the lakes since 2008. Clean Lakes Alliance has been active in financially supporting these efforts.

Are carp safe to eat?

Carp can in fact be eaten! They have been used as a source of food throughout Europe for centuries, and were initially brought to America to serve the same purpose. Carp have developed a reputation as an unsavory fish in America, with people often preferring more well-known species.

Carp that inhabit certain Wisconsin waters may be contaminated with high levels of polychlorinated biphenyls (PCBs). PCBs are highly toxic industrial compounds which can build up in the fatty tissue of fish and pose serious health risks. To ensure that you are consuming carp and other fish in a healthy manner, please review the DNR guidelines.

Are there any alternative uses for harvested carp?

Yes! It turns out that carp can be used as an organic fertilizer! Private companies located throughout the Mississippi River basin have begun to aid in carp removal efforts by using the fish to make organic liquid fish fertilizer.

What can I do?

If you find dead carp on your property, remove the carcasses, which can be put in a dumpster, composted or buried for disposal. Wear protective gloves when handling to avoid contact with harmful bacteria.

Remember, never move live organisms from one lake to another! Dispose of unwanted bait in the trash, not the water. Wash your boat and never drain water from your boat into waterways.

Asian Carp

Asian carp are a non-native and invasive species of carp that are not currently found in the Yahara lakes. They are also a fish species from the  family Cyprinidae, a group of fish native to Europe and Asia. Flooding in the 1990s allowed this species to escape to the Mississippi river and migrate into the Wisconsin River.

Quick facts:

• Asian carp can grow as large as 110 pounds, though the average size is around 30-40 pounds.
• There are four species of Asian carp that are considered invasive to Wisconsin waters: the bighead, silver, grass, and black carp.
• Asian carp are voracious eaters; they can consume up to 20% of their bodyweight per day.
• Silver carp can jump up to 10 feet high out of the water when disturbed.
• See the ACRCC guide for identification and the next steps after catching an Asian carp.

Where do Asian Carp come from?

If you thought we learned our lesson from the invasion of common carp in the 1800s, think again. It turns out that Asian carp were also intentionally brought to the United States! These fish were imported into the Southern U.S. from Southeast Asia in the 1970s.

This time, the idea was to use Asian carp to manage the aquaculture and retention ponds of wastewater treatment facilities. However, flooding in the 1990s allowed these fish to escape into the Mississippi River and its surrounding waterways.

Are they in the Yahara Lakes?

The good news here is that Asian carp have yet to be found in the Yahara lakes. Individual fish have been found in the Wisconsin waters of the Mississippi River and Lower Wisconsin River. This does not mean we are out of the woods (or water, so to speak) when it comes to Asian carp. Since the Yahara watershed is part of the larger Mississippi drainage basin, we must proactively monitor the potential spread of Asian carp.

Why are Asian carp bad?

Asian carp eat a ton! Think of them as that friend that only saves you two slices of pizza and eats the rest all by themselves. Their voracious appetite leaves little food for native species, and they can significantly disrupt the local food chain.

Asian carp are filter-feeders that consume plankton and algae. They strip the water column of plankton, a crucial food source for many native species during their juvenile stages. They can feed on mollusks, which can disrupt native sturgeon and mussel populations.

What can I do?

If you catch an Asian carp species in Wisconsin waters, do not put it back in the water! The Wisconsin Department of Natural Resources asks that you take a picture of the fish, if possible, put the fish on ice, and bring it to your local DNR office.

$1 Million Annual Campaign

In 2018, Clean Lakes Alliance launched the $1 Million for Our Lakes Annual Campaign, building critical community support and funding for phosphorus reduction. We raised $965,000 in 2018 – that was 97% of our total goal! Help us reach our goal of $1 MILLION in 2019 by donating today!

This beginning-of-year renewal model will allow us to launch into important projects with full funding – from monitoring at all 25 beaches to conservation practices on farmland upstream. We encourage you to make or renew your annual donation today!

How you can help!

Become a Friend of Clean Lakes

Friends of Clean Lakes is the volunteer-led friend and fundraising arm of the Clean Lakes Alliance. This proactive group is dedicated to building a larger community of people who support our lakes through events, volunteerism and advocacy. Friends of Clean Lakes commit to a $35 or greater annual donation and receive FREE admission to Yahara Lakes 101 science café series.

Become a Lake Partner

Lake Partners are businesses and organizations that support Clean Lakes Alliance through donations made independent of events, sponsorships, or programs. As a thanks for your support, businesses who support our lakes as a Lake Partner receive:

• FREE access to one of 20+ scheduled corporate volunteer days in 2018
• FREE admission to our monthly Yahara Lakes 101 science café for all employees
• Marketing exposure on Clean Lakes Alliance’s website and social media accounts
• Donor recognition in the State of the Lakes Annual Report following the calendar year of donation
• Opportunity to advertise in the Greater Madison Lake Guide, with 75,000 copies distributed each May

Progress

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In 2018, we raised $965,000 – that was 97% of our total goal. Help us reach our $1 MILLION goal in 2019 by donating today!

In the meantime…

Become a Volunteer

Donate your time! Clean Lakes Alliance would love to connect you or your group with local volunteer opportunities.

Join us at a Clean Lakes Alliance Event

From educational talks and art contests, to bike races and swims, we have plenty of ways for you to get involved and have some fun. See you there!

Frozen Assets 5K Terms and Conditions of Entry

Conditions: All entrants must read and agree to this declaration

The Frozen Assets 5K is a fundraiser for Clean Lakes Alliance conducted with the assistance of partners. In these Terms and Conditions of Entry:

• The Event is the Frozen Assets 5K;
• The Event Organizer is Clean Lakes Alliance; and,
• You are the Participant or Run Participant.

These Terms and Conditions are designed to enable the Event to operate smoothly, safely and effectively. By registering to participate in the Event, you accept and agree to be bound by these Terms and Conditions of Entry in respect of yourself and any other persons, including any minors or children who you register. You further warrant that you have the capacity and authority to agree to these Terms and Conditions of Entry on behalf of all such persons whose registration you arrange. Please take the time to review these Terms and Conditions and understand your rights and obligations.

Safety

You understand that running on the ice is a potentially hazardous activity and involves the real and foreseeable risk of serious injury or death from matters including, but not limited to, accidents with other course users (whether other runners or vehicles), ice and weather conditions, and the effects of strenuous exertion and activity.

You agree to abide by the course rules, obey any directions of Event officials and run with all reasonable care, skill, diligence and consideration of other users and Event participants on the course. You attest and warrant that you are physically fit and prepared for competition prior to undertaking the Event.

During the Event you agree to wear, at all times:

• proper footwear with the appropriate traction; and,
• highly visible clothing and appropriate reflectors appropriate for weather conditions

Any children or minors accompanying Event participants must also wear appropriate clothing and be monitored for safety and comfort.

You release and indemnify each Event Organizer and their contractors, partners, employees, invitees and agents and all volunteers acting on behalf of the Event from:

• all claims for injury, personal or otherwise;
• any loss or damage of whatever kind you or persons who you registered to enter the Event may suffer or cause as a result of any act(s) or omissions whether negligent or otherwise of the Event Organizer, employees or agents in relation to the Event; and,
• any loss or damage that is suffered, caused or arises as a consequence of your participation in the Event or participation by persons who you registered to enter the Event.

Age Limitations

Minors must be accompanied onto the ice by an adult Run Participant who will be responsible for their welfare.

Photography of Participants, including Minors

By agreeing to these Terms and Conditions of Entry and participating in the Event, you consent to the taking of images or video footage of you and/ or your child during or at the Event or its authorized agents and authorize the use of such images or video footage of you and/or your child by the Event Organizer, its authorized agents and its sponsors in all forms of media without any further approval or compensation.

Limitations, Runner Directions or Event Suspension

By participating in the Event, you acknowledge that an Event official may, at any time during the conduct of the Event, in his or her absolute discretion, direct your withdrawal from the Event. If an Event official directs your withdrawal from the Event, you undertake to comply with this direction immediately, including by voluntarily returning to the finish area. You agree to indemnify the Event Organizer against any loss or damage resulting from your failure to comply with this condition.

Personal Responsibility

You are responsible for all personal property you bring onto the run course, area and sites and understand that the Event Organizer does not accept any responsibility whatsoever for any loss, damage or harm caused to your personal property whether caused by negligence or otherwise. The Event Organizer strongly recommends that you obtain personal accident insurance before taking part in the Event.

If, during the Event, you become ill or are injured, the Event Organizer will attempt to arrange medical transport, usually in an ambulance, but will not take responsibility for such transport being available nor the care provided. Any medical transport costs must be met by you. The waiver agreed to by you as a condition of entry to the Event does not cover Participants for liability to other persons for accidents or injuries caused by yourself or another runner. You are responsible for ensuring that you have adequately and appropriately prepared both physically and mentally for the Event, and have the appropriate equipment and clothing to do so. If you have any current or past health issues or doubts prior to the Event, the Event Organizer recommends that you seek appropriate medical advice before participating in the Event.

Cancellation & Weather

Except as otherwise stated in these Terms and Conditions of Entry and as required by law, the Event Organizer is under no obligation to refund monies or entry fees due to non-use, cancellation, failure to participate or dissatisfaction by the Participant. The Event Organizer may, in its absolute discretion and without giving reasons for its decision, accept or refuse an application for registration from participation in the Event.

In consideration of Clean Lakes Alliance permitting me to enter into and participate in the Frozen Assets 5K Run event I fully release, indemnify and hold harmless Clean Lakes Alliance, its partners and agents from all claims for injury, loss or damage of whatever kind I might suffer as a result of any acts or omissions whether negligent or otherwise of the Alliance, its partners or agents in relation to the event.

Ice on for Lake Mendota!

Temperatures below the freezing mark, combined with cold water and low wind, helped Lake Mendota officially freeze on January 15, 2024, as declared by the Wisconsin State Climatology Office. Lake Mendota, the largest lake in the Yahara Watershed, froze a full 26 days after December 20^th, which is the median ice-on date for the largest lake in the Yahara River Watershed. The January 15^th freeze is the 3^rd latest freeze date since monitoring began over 170 years ago. The latest date ice-on has been declared is January 30^th, and that took place in 1932.

The Wisconsin State Climatology Office requires ice to hold for a period of 24 hours before a lake can officially be declared frozen over. The January 15^th freeze date is three weeks later than last year’s December 25^th freeze date. For statistics about determining the freeze date and the Madison ice record, see History of freezing and thawing of Lake Mendota and Madison lakes ice summary.

We have a winner!

For the 12th year in a row, Clean Lakes Alliance held its annual Mendota Freeze Contest, asking people to make a guess as to when the lake would officially freeze. Of the 2,100 people to enter the contest, 88 people guessed Lake Mendota would freeze on January 15th. Kathleen Maier of Madison was the randomly selected winner. She said she picked the 15th because it is a family member’s birthday. Maier will receive a $1,000 gift cards courtesy of Lands’ End as the grand prize.

Freeze statistics for Lake Mendota

• For insight into the Wisconsin State Climatology Office, which declares the lakes frozen each year, read more about lake ice records from Wisconsin State Climatology Office
• The Wisconsin State Climatology Office makes the official determination as to whether the lake is frozen. The climatologists use the same guidelines they have used for decades. This allows for a continuity in data collection. Read more: Determining ice cover on Madison’s lakes.
• For statistics about determining the freeze date and the Madison ice record, see History of freezing and thawing of Lake Mendota and Madison lakes ice summary.
• To test your knowledge of our lakes in the winter, take the frozen lakes quiz.

A look back at the 2022-23 season

For the 11th year in a row, Clean Lakes Alliance held its annual Mendota Freeze Contest, asking people to make a guess as to when the lake would officially freeze. Frigid air temperatures, combined with cold water and low winds, helped Lake Mendota officially freeze on December 25th, 2022. The declaration came from the Wisconsin State Climatology Office. Lake Mendota, the largest lake in the Yahara Watershed, froze five days after December 20th. December 20th is the median ice-on date for the largest lake in the Yahara River Watershed. The Christmas Day freeze date is over a month shy of January 30th – which is the latest date that ice-on has ever been declared (1/30/1932).

Contest Rules

Only one guess per individual. Multiple entries will be automatically disqualified. Official rules and regulations can be found here.

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