To find the cause of a massive fish kill in the Neuse River near New Bern, North Carolina, state officials and a river advocacy foundation sent samples to the National Centers for Coastal Ocean Science laboratory in nearby Beaufort for analysis.
Most of the dead fish exhibited large, open skin ulcers. Using molecular assays, the Beaufort scientists determined that the fish perished from ulcerative mycosiscaused by the water mold Aphanomyces invadans, a fungus-like pathogen of wild and cultured fish around the world. Although Aphanomycescauses skin ulcers in fish, it is rarely causes large fish kills.
The afflicted fish, menhaden, are commonly used for bait, fish oil supplements, and as feed for fish farms. They are an important part of the food chain, as major filter feeders of algae as well as an important prey for other valuable predator fish. While this event will not have a major effect on their population, a fish kill of this magnitude is a nuisance and expensive to clean up.
The North Carolina Department of Natural Resources and the Neuse Riverkeeper Foundation collected the fish for the NCCOS researchers.
The scientists gave the results of the molecular assays and a fact sheet about the water mold to state, NGO, and academic partners, who in turn shared the information with local news outlets, including the National Public Radio station.