No, it’s not because of lack of oxygen this time.
The New Jersey Department of Environmental Protection (DEP) and its Division of Fish and Wildlife are actively investigating menhaden mortalities reported in Raritan Bay and the Navesink River of Monmouth County during the spring and winter of 2021. Similar mortalities were reported in New Jersey last fall and in other parts of the Northeastern United States.
“Dead and dying bunker, erratic swimming behavior,” is how Jeff Brust, chief at the Bureau of Marine Fisheries explained it during a January meeting of the New Jersey Marine Fisheries Council. “Sampling has ruled out some of the normal culprits,” Brust said, explaining that oxygen deprivation was not the culprit this time.
In a statement from Larry Hajna with the DEP press office on April 6, the Division had preliminarily identified an undetermined species of bacteria in the Vibrio family of bacteria as the cause of the mortalities in menhaden, and that more laboratory work was being done to determine the specific species of bacteria. The DEP is also working with the Atlantic States Marine Fisheries Commission (ASMFC) to better understand the mortalities.
The Division noted that Vibrio species are quite diverse and common in marine habitats, and it appears that the only fish species being impacted appears to be menhaden. “There is nothing to suggest human health or other fish, shellfish or wildlife are at risk,” Hajna said, noting that the Division is recommending people do not handle or collect any dead fish or those showing signs of disease.
