To do marine disease impacts in context requires a wide perspective on the roles infectious agents have in the ocean. Parasites infect most marine vertebrate and invertebrate species,and parasites and predators can have comparable biomass density, suggesting they play comparable parts as consumers in marine food webs. Although some parasites might increase with disturbance, and most probably decline as food webs unravel. There are several ways to adapt epidemiological theory to the marine environment. In particular,because the ocean represents a three-dimensional moving habitat for hosts and parasites, models should open up the spatial scales at which infective stages and host larvae travel. In addition to open recruitment and dimensionality, or marine parasites are subject to fishing,filter feeders, dosedependent infection, or environmental forcing,and death-based transmission. Adding such considerations to marine disease models will form it easier to predict which infectious diseases will increase or decrease in a changing ocean.
Source: usgs.gov