After a year long study, a new report presents findings after investigating the deaths of starfish along the North Pacific Coast.
The study identified densovirus, a member of the parvovirus family, as the culprit behind the onslaught of deaths. The virus causes disease of varying severity in starfish, with the most pathogenic effects resulting in disintegration of these echinoderms. More interesting, however, is that this virus has existed in the ocean since 1942. Thus, the investigation forced researchers to wonder what had changed in order to allow the virus to cause such profound disease in starfish.
In order to confirm that densovirus was indeed responsible for the disease observed in starfish, the researchers isolated viruses from diseased tissue and added the viruses to tanks of healthy sea stars. The population of sea stars that were treated with viruses from diseased tissues became ill. The control group, tanks of sea stars treated with heat-killed virus, remained uninfected. Healthy sea stars inoculated with virus from diseased tissue also became ill, further providing evidence to suggest that densovirus is responsible for the disease.
Up until now, we have devoted little effort to understanding viral pathogens in marine environments. The recent outbreak of densovirus among the sea star population along the Pacific Coast has encouraged researchers to investigate marine pathogens more closely.
Nevertheless, researchers have yet to identify why the densovirus has suddenly become so virulent—no environmental factors have yet to be linked with the outbreak.