Fish kill culprit verifiedPublished 8:06pm Friday, October 19, 2012
Water samples from Blounts Bay have turned up positive for A. invadans.
According to Heather Jacobs Deck, Pamlico-Tar River riverkeeper, the naturally occurring fungus is responsible for the massive fish kills seen in the Neuse, Pamlico and Pungo river regions over the past several weeks. The fungus has, so far, only affected juvenile menhaden (known as bait fish), with no yet apparent impact on other fish populations.
“(It) is most likely impacting more fish species than just menhaden, but at this point we are still only seeing menhaden die,” Deck wrote in a press release.
The first reports about the fish kills came in from fishermen and waterfront property owners two weeks ago. Deck has estimated that the numbers of dead fish could reach into the upper hundreds of thousands to millions — and the reports of more fish kills continue. Friday, Blounts Creek and Broad Creek were added to the list of locations where kills were sighted.
Recent data from the Neuse River shows low to zero oxygen levels in the bottom water of the rivers and creeks, which is probably contributing to the menhaden kills, according to Deck.
“It is very likely we too have lower oxygen levels in the bottom waters,” Deck explained. “Menhaden, stricken by this fungus become weak and very susceptible to low oxygen or other fish- related diseases. It is also probable that we continue to see algal blooms that could be contributing to the low oxygen level … this is tied in part to nutrient pollution.”
At this time, water samples from Crystal Beach and Blounts Bay that were tested at the Department of Environmental and Natural Resources lab did not show the presence of any potentially toxic algal bloom.
Deck stressed the importance of the public to continue to call in reports of fish kills, especially if other species of fish are being affected, as it would indicate change is occurring and more rigorous testing and investigation is needed. She did receive a report of a few dead pinfish Friday though the fish were without the signature A. invadans mark: lesions.
As a precaution, Deck advises that people and pets should stay away from waters where a visible fish kill is occurring.
“There are types of blue-green algae that can be a public health concern and best to avoid when we may not know the culprit,” Deck added. “Also, as always, anyone with wounds, cuts, abrasions, et cetera, should avoid contact with natural waterbodies at any point, because naturally occurring bacteria could pose a health risk — especially for those who may already have a weakened immune system.”