In mid-May the Division of Fish and Wildlife conducted a preliminary fish health study in the South Branch Raritan River, specifically the Ken Lockwood Gorge, in response to a fisherman capturing an apparently diseased rainbow trout from the river. 

Pictures of the diseased fish showed skin and muscular lesions, consistent with clinical disease signs of furunculosis. 

Confirmation of furunculosis was not possible by the Division's Fish Pathologist because the fish was released by the fisherman back into the trout conservation stretch of the river.

Anglers catching apparently diseased fish, even those caught in catch and release areas, are asked  to call the Fish Pathology Laboratory at the Pequest Trout Hatchery in Oxford at (908) 637-4173 (extension 120) or after hours contact the DEP Hotline (877) 927-6337, so arrangements can be made to acquire the fish for testing.

A study is being conducted at Ken Lockwood Gorge to determine the prevalence of furunculosis. 

The goals of the research project includes determining the prevalence of this bacterium within the Ken Lockwood Gorge, understanding the genetics of the fish affected by the bacterium, and fully characterizing the strains of the bacterium found in the river.

Furunculosis is an endemic disease caused by the bacterium Aeromonas salmonicida subspecies salmonicida. 

The bacterium does not pose any human health risks. 

Although the bacterium is endemic in North America and has been known to exist in the state for a long period of time, clinical disease in wild or stocked trout in the environment has not been documented in New Jersey until this year.

The state's Pequest Trout Hatchery suffered an outbreak of furunculosis in September of 2013. 

A strict fish health policy was followed to avoid the introduction of fish affected with furunculosis or suspected carriers of the bacterium into trout waters, like Ken Lockwood Gorge. 

No fish with a history of furunculosis were released from Pequest into any state trout waters.

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