The marine ecosystem, which makes up around two-thirds of the planet’s sur-
face, suffers from aggressive heavy metal contamination, especially in the last
few years. This pollution causes shifting in many marine life forms threatening
our fisheries and human health. The natural sources of marine heavy metal pol-
lution are rock erosion, and volcanic dust, while the artificial sources are related
to human attitudes like sewage, ship accidents, industrial wastes, and agricultural
wastes. Because they are so common in nature, microorganisms also predomi-
nate in locations where heavy metals have been contaminated. Heavy metals are
easily changed by them into harmless forms. Microorganisms have two respond-
ing mechanisms of heavy metal contamination that comprise enzymatic break-
down of the target contaminants and/or heavy metal resistance. In this chapter we
will discuss marine heavy metal contamination sources, their risks to the marine
life forms, and different responses of marine fungi to heavy metal
contamination.