A team of U.S. scientists has documented the first transmission of the lethal phocine distemper virus from the Atlantic Ocean to a population of sea otters living along the coast of Alaska.

The presence of phocine distemper virus has been confirmed in nasal swabs take from live otters and through necropsies conducted on dead otters found along the Alaskan coast. The findings also indicate that the virus was passed between seal species across Northern Canada or Arctic Eurasia before reaching the otters in Alaska’s Kachemak Bay.

Prior to this study, PDV had never been identified as the cause of illness or death in the North Pacific Ocean and researchers suggest that diminishing Arctic sea ice may have opened a new migration route for both animals and pathogens.

The study was carried out by researchers from two California universities and the Alaskan branch of the U.S. Fish and Wildlife Service. It has been published in ”Emerging Infectious Diseases”, a journal published by the U.S. Centers for Disease Control and Prevention.

What is phocine distemper virus (PDV)?

Phocine distemper virus (PDV) is a paramyxovirus of the genus Morbillivirus. It is dangerous for pinniped species, especially seals, and is a close relative of the canine distemper virus (CDV).

PDV was first identified in 1988 when it caused the death of approximately 18,000 harbour seals, Phoca vitulina, and 300 grey seals, Halichoerus grypus, in northern Europe. In 2002, the North Sea lost approximately 21,700 harbour seals in new a PDV outbreak – estimated to be over 50% of the total population.

Infected seals normally develop a fever, laboured breathing and nervous symptoms.

The Department of Environmental Protection (DEP) has temporarily suspended shellfish harvesting from a portion of the Delaware Bay. The suspension began at August 19 after health officials had confirmed two cases of illness linked to oysters harvested from the bay. The illness was caused by Vibrio parahaemolyticus, a bacterium that can cause symptoms such as diarrhea, nausea, vomiting, abdominal cramps and, less frequently, headache, fever and chills. On rare occasions, an infection in the bloodstream can occur. Vibrio parahaemolyticus is especially prone to cause problems for people with compromised immune systems. Vibrio parahaemolyticus occurs naturally in coast waters. Since it thrives in warm waters, a majority of the cases occur during warm summer months when people consume sea food contaminated with the bacterium.

Delaware Bay is a large estuary outlet of the Delaware River on the Atlantic coast of the United States. The bay is bordered by the states New Jersey and Delaware. The entire bay is 782 square miles (2,030 km²) in area, but only about 130 square miles (337 km²) of Delaware Bay is affected by the suspension. If you wish to see a map of the affected area, take a look at this PDF-file:

http://www.state.nj.us/dep/wms/bmw/Closures_Revocations/HarvSusp20080818signed.pdf

The public notice has been posted on the DEP website: http://www.nj.gov/dep/newsrel/2008/08_0042.htm