Posted Monday, July 11th, 2016



The State Department of Environmental Protection is providing increased resources to county mosquito commissions throughout New Jersey – including $500,000 in grants for mosquito control expenditures, more than 20,000 mosquito dunks and traps, and more than 500,000 mosquito larvae-eating fish – to aggressively combat the threat of Zika and other mosquito-borne diseases.

Muskie Fish 1

DEP Commissioner Bob Martin at Pequest Fish Hatchery

Morris County is working closely with the state, so far stocking 17,650 mosquito-eating fathead minnows in eight locations in five municipalities. These sites vary but are mainly old mine pits, small ponds and even an abandoned swimming pool — all potential breeding grounds for millions of mosquitoes.

The county are expecting to pick up at least another 10,000 state-bred mosquito-eating fish from the DEP’s fish hatchery in Warren County this year to use in the county’s program.

“The nicest part about fish is that once you stock them, you really don’t have to worry about that spot anymore since the fish will generally take care of the mosquito population,” said Kristian McMorland, Director, Morris County Division of Mosquito Control. “They tend to work best in self-contained bodies of water that do not have an existing fish population.  Perfect sites are abandoned swimming pools, old ornamental ponds, old foundations etc…

McMorland and Morris County Health Officer Carlos Perez will provide a public update on the Zika Virus at 10 a.m. Wednesday at the Morris County Board of Freeholder’s meeting in Morristown. The meeting will be held in the County Administration and Records Building at 10 Court Street in Morristown, on the 5th floor. 

Mosquito-eating fish at Pequest Hatchery

Mosquito-eating fish at Pequest Hatchery

DEP’s Office of Mosquito Control Coordination and the State Mosquito Control Commission work closely with all 21 county mosquito commissions and agencies to reduce mosquito breeding habitats.

“While the presence of the mosquito that carries the Zika virus is extremely rare in New Jersey, we are taking every precaution to protect our residents and visitors from this and other disease-carrying mosquitoes,” said DEP Commissioner Bob Martin said. “The Christie Administration is committed to providing our county mosquito control partners with the best possible means to monitor and reduce mosquito populations throughout the state.”

To date this year, DEP has:

  • Offered $500,000 in grants to county mosquito control units for reimbursements incurred for mosquito control, monitoring and identification efforts, as well as supplies and additional staffing.
  • Purchased and provided to all counties 21,000 mosquito dunks – ecologically safe tablets placed in standing water to destroy mosquito larvae before they hatch into adult mosquitos.
  • Purchased 42 motor-powered mosquito traps – two per county – which are used to capture hundreds of mosquitos for future identification and testing of viruses.
  • Raised and stocked more than 150,000 fish that eat mosquito larvae – with another 400,000 fish to be raised and stocked statewide over the course of the summer.
  • Purchased four distribution tanks to assist in the transport of mosquito-eating fish throughout the state.
  • Purchased five holding tanks that temporarily hold mosquito-eating fish to assist in counties in their distribution of the fish.
Aedes albopictus, or Asian Tiger Mosquito

Aedes albopictus, or Asian Tiger Mosquito

Aedes aegypti is the mosquito most known for carrying the Zika virus. It is found in tropical climates and is unable to survive New Jersey’s winter conditions. McMorland said that the Asian Tiger mosquito, or Aedes albopictus, has been identified as the lost likely potential carrier of Zika in New Jersey.

The federal Centers for Disease Control and Prevention is investigating the extent to which the Asian tiger mosquito, which is found in New Jersey, can spread Zika. In April, the Pan American Health Organization and World Health Organization reported that Mexico had identified Asian Tiger mosquitos carrying Zika.

Zika is a viral infection that is usually spread by the bite of an infected Aedes mosquito, which also spreads dengue and chikungunya. Outbreaks typically occur in tropical Africa and southeast Asia. In May 2015, Brazil reported the first outbreak of Zika in the Americas. Zika is now present in Central and South America, and the Caribbean. To date, there has been no local transmission in the continental United States.

About one in five people develop symptoms and infection is usually mild. The most common symptoms are fever, rash, joint pain or red eyes. The biggest concern is for pregnant women because Zika can cause birth defects.

“As mosquito season continues in New Jersey and families travel this summer, residents should protect themselves from mosquito bites wherever they go,” said State Health Commissioner Cathleen Bennett. “It is important to apply EPA-registered insect repellent, use screen and air conditioning, wear long sleeves and pants, and stay informed.”

Muskie Fish 2New Jersey’s 21 county mosquito control agencies employ a variety of methods for mosquito control, including aerial spraying, application of approved insecticides, water management programs, public awareness campaigns and use of natural predators, such as fish that eat mosquitos and their larvae.

The use of larvae-eating fish, also known as biocontrol, is common in New Jersey. Since its inception in 1991, the Division of Fish and Wildlife’s Hayford Fish Hatchery has stocked more than 4.4 million mosquitofish in New Jersey.

Counties stock the fish in places of the greatest attraction to the 63 varieties of mosquitoes which are native to the state. This summer, in response to concerns about Zika and mosquito-transmitted viruses, the hatchery is raising and distributing more than 500,000 fish, more than double a normal season.

“Our fish program has been a key component of mosquito control for years and their usefulness is only increasing as the threats increase,” said Division of Fish & Wildlife Director Dave Chanda. “These fish help control the mosquito population by eating their young and preventing them from growing, biting and most importantly, reproducing.”

Five breeds of mosquito-eating fish are bred at Hackettstown for mosquito control; the fathead minnow (Pimephales promelas), the freshwater killifish (Fundulus diaphanus), the pumpkinseed sunfish (Lepomis gibbosus), the bluegill sunfish (Lepomis macrochirus) and the Gambusia affinis, also known as the mosquitofish, for biological control. The fish are raised at the Hayford Hatchery and distributed, at no charge, to county mosquito control agencies.

The first four fish species are native to New Jersey, but the Gambusia originates from Central and South America. They are placed in water bodies with no resident fish, and no natural or manmade water outlets. They are not stocked in lakes or ponds, but in standing water sources which cannot be drained.

Remove standing water from your property to eliminate muskie breeding areas

Remove standing water from your property to eliminate muskie breeding areas

“We are using the fathead minnow in Morris County as compared to the Gambusia affinis because the fathead is a native species that allows us a little more freedom where we place them,” said McMorland.  “The Gambusia on the other hand is a non-native fish that has some stricter protocol’s to follow to ensure that feral populations are not created.  Both species are very good at what they do under the right circumstances.

Morris County and the DEP encourage residents, business owners and contractors to follow these steps to help reduce mosquito populations on their properties:

  • At least once or twice a week, empty water from flower pots, pet food and water dishes, birdbaths, swimming pool covers, buckets, barrels and cans.
  • Check for clogged rain gutters and clean them out. Downspout elbows can also hold small amounts of water that can serve as breeding grounds for mosquitos.
  • Remove discarded tires, and other items that could collect water.
  • Be sure to check for containers or trash in places that may be hard to see, such as under bushes or under your home.

For more information on Zika and how DEP is addressing the potential threat please  or

For information on the State’s Mosquito Control Commission, please

For information on the Morris County Mosquito Control Division, visit:

For a podcast featuring a discussion of mosquito control and the Zika virus with DEP Deputy Commissioner David Glass and Dr. Arturo Brito from the state Department of Health, visit: