Dave Garey

Correspondent

When the white Ford Ranger pulled up on a residential street in Chester on a recent Friday morning, it could have been mistaken for invited company bringing what appeared to be a large ice chest.

The cooler was actually a fish tank containing several thousand fathead minnows and banded killies. Before the day was through, the tiny fish would all be placed in ponds and woodland pools deemed troublesome mosquito-breeding sites by the Morris County Division of Mosquito Control.

Once in their new habitats, the fish would feast on mosquito larvae, helping minimize the population of the potentially dangerous pests, and reducing the need for insecticide spraying.

The truck's first stop on this particular day was the home of Frank and Lucille Hunkele, of Chester, whose five-and-a-half acre property abuts a portion of the Black River Wildlife Management Area.

"It was a wet, cool spring, so there were a lot of mosquitoes," said homeowner Frank Hunkele. "If you have a dry year, you might not have any."

Hunkele said his main motivation for contacting the Division of Mosquito Control was the safety of his four grandchildren.

"They love coming here. I want them to be able to go outside and play."

After two sprayings earlier this season, the mosquito problem had subsided.

"Right now, I hardly have any," Hunkele said.

Since the Hunkele property has a 25-foot by 15-foot pond — a ripe location for the incubation of mosquitoes — it was recommended that fish be utilized, leading to the stocking of the pond on this hot July morning with 1,000 minnows and killies.

The fish are a welcome addition, said Hunkele, a retired Public Service Electric and Gas Company maintenance supervisor, who praised the work of the division's staff. "They were extremely nice. They walked the property, walked along the preserve and checked the pond to see if it was suitable for the fish."

The Division of Mosquito Control, previously a separate agency known as the Morris County Mosquito Commission, was renamed earlier this year after it became a division of the county's Department of Planning and Public Works.

The arsenal

The division's arsenal of fish — all produced at the nearby Charles O. Hayford State Fish Hatchery in Hackettstown — also includes the gambusia affinis, more commonly referred to as gambusia or mosquitofish.

Selecting which fish to use depends on the water site.

The guppy-sized gambusia, with its ability to penetrate vegetative growth containing mosquito larvae and pupae and withstand extreme hot and cold temperatures — even poorly oxygenated water — is considered the most efficient, cost-effective mosquito battler.

Unlike the killies and minnows, which generally survive no longer than a single March-to-October mosquito season in such settings, the hearty gambusia quickly adapts and makes it through winter. Its reproduction cycle allows the live-bearing fish to maintain a presence for several years without the need to restock.

The sole drawback, however, is that the gambusia is a non-native species that also eats other fish — a scenario that could compromise an existing ecosystem, limiting the locations where the mosquito-eating fish can be placed.

An ideal water site for the gambusia is "self-contained, with no reasonable expectation of escape," says biologist Kristian McMorland, the division's nine-year director.

After McMorland's crew determines a mosquito-breeding site is viable for gambusia, the N.J. Office of Mosquito Control Coordination — part of the state's Department of Environmental Protection — must first make an onsite inspection.

"We either get the yea or nay from them. Then we'll coordinate with the fish hatchery," McMorland said. "If the spot is not appropriate for gambusia, it could be appropriate for the native species (minnows and killies), so we'll throw some of them in there."

Stocking sites in Morris

So far, the Division of Mosquito Control reports that nine Morris County sites have been stocked with fish during the 2014 season — three with gambusia and six with a minnows/killies mixture — totaling nearly 14,000 fish. Going back to 2006, some 81 sites have received fish, at least half of which are still active.

After stocking the Hunkeles' pond, mosquito identification specialists Mike Rosellini and Russell Berger had two remaining afternoon appointments — including checking up on a retention basin at the Craigmeur Recreation Complex in Rockaway Township.

The body of water had last been stocked with gambusia in 2010. All these seasons later, the news still was good.

"There are way more of them now than we originally put in," said Berger, estimating the gambusia count at around 5,000.

Elsewhere on the scenic Craigmeur grounds, a naturally occurring woodland pool not approved for gambusia received 1,500 minnows and killies.

"We don't have to go back there for the rest of the summer because we know the fish will be doing their job," McMorland said.

Hotspot for mosquitoes

In Denville, a woodland pool surrounded by leaf litter at the bottom of a sloping, well-shaded parcel of property near Morris Catholic High School was determined to be a mosquito-breeding hotspot.

"There was an abundance of mosquito larvae when we checked yesterday," said Berger, who relied on a dipper to measure the density of larvae population. Several water samples each yielded between five and 10 larvae.

Although the owner of the property that lies between Kitchell Road and Morris Avenue was not immediately known, the Division of Mosquito Control had authority to take action on its own.

"If there are mosquitoes here, it's our jurisdiction," Rosellini said.

If not eliminated in their aquatic stage of development, the state's 60-plus varieties of mosquitoes are much more difficult to control, making the role of mosquito-consuming fish all the more vital.

"If you can treat them in the larvae stage, you're taking away that nuisance factor," Rosellini explained.

While the state has been producing mosquito-eating fish for distribution among its counties since 1990, Morris County had previously obtained the fish from private suppliers since at least the 1970s, McMorland said.

Still, the gambusia remains a novelty to many - and quite the celebrity - as portable fish tanks showcasing gambusia are a popular attraction brought by the Division of Mosquito Control to events throughout the county.

County residents are advised to regularly check the www.morrismosquito.org website for locations of scheduled sprayings and other mosquito-related information. To report mosquito problems, call 973-285-6450. There is no charge for onsite inspections or any work necessary to control mosquitoes.

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FOR MORE INFO:

Morris County Division of Mosquito Control

Website:www.morrismosquito.org

Tel: 973-285-6450