2008 Mid-Atlantic Small Cetacean Unusual Mortality Event

An increasing number of small cetaceans have stranded along the Mid-Atlantic. An elevated number of common dolphin, Delphinus delphis (27), and Atlantic white-sided dolphin, Lagenorhynchus acutus (5), mortalities occurred from New Jersey to North Carolina from January 1 to April 15, 2008. The 24 of the 32 strandings were in February and March, with 17 occurring in Virginia. Several animals have stranded on the Outer Banks, NC where access is difficult or limited. Approximately one-third of the animals have stranded alive and most of the remaining animals have been fresh dead to moderately decomposed.

On April 3, 2008, a consultation was initiated with the Working Group on Marine Mammal Unusual Mortality Events following the procedures prescribed in 116 U.S.C. 1421(c), Section 404 of the Marine Mammal Protection Act to determine if an unusual mortality event was in progress and to receive guidance from the Working Group on the investigation. The Working Group concluded at least one of the seven criteria established for designation of a UME has been met. These mortalities are unusual because there is a marked increase in the magnitude or a marked change in the nature of morbidity, mortality or strandings when compared with prior records (criteria number one).

The investigation into this event is ongoing. Thorough necropsies have been performed on the majority of animals with no consistent findings being reported. The Northeast Region has the lead for this UME with consultation from the Southeast Region. Both regions are continuing to monitor the situation.

Short-Beaked Common Dolphin
(Delphinus delphis)
Photo: NMFS Southwest Fisheries Science Center