Biofouling is a major problem that affects the heat transfer efficiency of marine and coastal heat exchangers. The reduced heat exchanger efficiency results in energy loss and thereby affects the overall energy efficiency in the marine industry segment. Additional energy is required to compensate for the energy loss leading to increased fuel consumption which in turn contributes to global environmental issues like climate change. The current industrial methods of biofouling mitigation or removal from heat exchanger surfaces increase both operational and maintenance expenditure causing further environmental damages. This paper presents two models to provide an overview of the major environmental and economic impacts due to biofouling in marine heat exchangers. The study results suggest the need for sustainable biofouling prevention techniques to improve the energy and resource efficiency of marine heat exchangers.