Emerging Marine Diseases
In a recent article in Science magazine Professor Drew Harvell and other biologists present an overview of recent trends in marine ecology. Major groups of marine animals have suffered disease outbreaks and mass die offs1. Reports of epidemics in corals and some marine mammals have increased. A dramatic increase in coral bleaching around the world occurred in 1997-98 coinciding with increased sea surface temperatures due to that year’s El Niño.
It is thought that environmental stresses may compromise animals’ resistance to disease and increase the frequency of opportunistic diseases. Human-caused stresses include pollution and increasing sea surface temperatures as a result of global warming.
Disease outbreaks can occur when a disease causing organism changes its host. For example, the HIV retrovirus that causes AIDS in humans probably originated in apes, and flu often comes to us from birds. Disease can also move into new geographic regions either when the disease organism changes or the environment changes. Malaria for example is expected to move into more temperate regions in the future as global climate warms. These patterns of disease movement and host shifting also occur in the oceans, however marine scientists have only recently begun to study them systematically. We spoke with Professor Harvell about marine diseases and what we need to do to understand them better.