Tuesday, April 1, 2014

Fish Disease Hits Pequest Trout Hatchery

Raceway for fish at Pequest

Due to the re-occurrence of a fish disease that has affected a section of the Pequest Trout Hatchery in Warren County, the New Jersey Division of Fish and Wildlife announced  it is euthanizing a portion of its brook trout population that was scheduled to be stocked this spring and is taking other steps to protect the overall integrity of the facility.

This action is consistent with the Division of Fish and Wildlife’s Fish Health Policy, which was approved last week by the State Fish and Game Council following a public comment period and two public hearings. The plan states that fish found positive of pathogens, such as furunculosis, will not be stocked in state waters.

Furunculosis, a fatal disease caused by a bacterium known as Aeromonas salmonicida, mostly affects cold water species of fish such as trout. Laboratory tests last weekend confirmed the presence of the disease in brook trout in an upper portion of the concrete raceway system used to raise trout for stocking of New Jersey’s waterways.

It is important to note that no human health risks are associated with this bacteriumand that it is not transmissible to humans or other animal species.

Despite the loss of the large number of brook trout, the Division still will release healthy trout in state waters in time for the Opening Day of Trout Season scheduled for April 5, at 8 a.m. None of the trout being stocked this spring have the disease. Some may have been exposed to the bacterium that causes furunculosis but were effectively treated. Others that will be stocked have tested negative.

brook trout - NJDEP

The 114,000 trout to be euthanized are a portion of the more than 600,000 trout the Pequest Hatchery raises every year. The fish are being humanely euthanized by introducing carbon dioxide into the water.

Rainbow trout appear to be resistant to the disease, so the hatchery is increasing production of these species for stocking in future years. Brown and brook trout tend to be more susceptible and these fish will be vaccinated to provide protection against the disease. The Division also is considering acquiring brown and brook trout that have been bred for resistance to furunculosis.

The 31-year-old Pequest Fish Hatchery had its first outbreak of furunculosis last fall, likely transferred into the hatchery by birds. Osprey feeding on infected fish in the wild may have spread the bacteria through contact when feeding on fish in the affected pool at the hatchery. As a result, some 25,000 trout were euthanized last fall.

The Division of Fish and Wildlife utilizes robust measures to protect raceways at Pequest from bird infiltration, including wire deterrents strung over the raceways and air cannon. The division is continuing to investigate other options, including enclosing the raceways under fabric domes or barn-like structures. It also is exploring installation of extra wells to allow each raceway to have its own unique water supply for each group of fish.

For the short term, the affected areas of the hatchery will be drained, dried, steam cleaned, and disinfected before the next round of fish are introduced back into the raceway.

SOURCE: http://www.nj.gov/dep/newsrel/2014/14_0018.htm

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