whole bay. The standard calls for a certain amount of coliforms, or less than a certain level, as if the bay is one place; yet you can walk along the beach and get a 10-fold change in coliforms over 100 m in some cases. Obviously, some improvements are still needed. We must be able to look at variability and patchiness, because regulation of these microorganisms requires understanding more about how they are moving and what kind of processes are controlling them.
One additional issue regards questions relating to pathogens of marine organisms. Although this is not my main area of expertise, I have heard people talk about epidemics among marine organisms, possibly including endangered species such as marine mammals. Almost certainly these are exacerbated by pollution or some other source that might have stressed the immune system of these animals.
As a separate issue, there is the question of marine organisms as a reservoir for human or terrestrial animal diseases. Here we are talking about viruses or perhaps bacteria that have a terrestrial animal source, which then enters the marine environment, infecting marine organisms and then returning to infect land organisms, possibly including humans. Usually, viruses have one species of host or closely related hosts. Some viruses, however, jump from host to host, such as from pigs to humans. Such jumping to or from marine animals is very poorly understood. Some recognized broad host-range examples include the caliciviruses that include Norwalk-like viruses. Some are reported to have remarkably wide host ranges, even including fish and mammals for certain serotypes. More work is needed before we can say whether the exact same strain jumps that far and might infect humans.
Recent examples of viruses jumping to marine mammals include reports of canine distemper in seals in Europe. If epidemics of marine mammals become more severe, one might imagine a higher probability of infections that jump across species lines. It might become a zoonotic concern to the human population if there is a reservoir in a marine environment that keeps reinfecting something that affects humans. As our population increases and moves closer to the coast, this virus jumping could worsen any problem that might exist.
Fuhrman JA. 1999 Marine viruses: Biogeochemical and ecological effects. Nature 399:541-548.