Ecomare

Viruses possess genes and evolve by natural selection, just like organisms. However, they don't have a cellular structure, which is usually seen as a necessity for life. Viruses cannot multiple outside of living cells. So is a virus a form of life or an organic structure that interacts with life forms? Experts still don't agree in which category they should be classified. The presence of viruses in the sea is very important ecologically. For example, they play a role in decomposing the foam algae Phaeocystis. Every liter of North Sea water contains ten billion viruses. Fortunately, most are not dangerous for man. A few well known (land) viruses cause Hoof and Mouth disease in hoofed animals, avian influenza in birds, myxomatosis and Rabbit Hemorrhagic Disease in rabbits and PDV in seals. Even our everyday flu is a virus. Viruses spread in numerous manners, from insects, to sneezing, coughing, kissing, sexual contact and blood transfusions.