Biofouling is one of the most serious problems in the maritime industry and aquaculture development. In the marine environment, submerged surfaces are often colonized by marine organisms that have come to be called biofoulers, which are marine organisms that attach to submerged surfaces. Biofoulers increase the weight, drag and surface corrosion of ships, and lead to huge costs to maintain mariculture systems and seawater pipelines. Antifouling compounds are used as biocides in marine paints that are coated on the submerged surfaces to control the preponderance of biofoulers. 

Butenolide [5-octylfuran-2(5H)-one] is a very promising anti-marine-fouling compound. The antifouling compound 5-octylfuran-2(5H)-one (here referred to as butenolide) was synthesized by Medicilon.

Reference:

Yi-Fan Zhang, et al. Acute toxicity of the antifouling compound butenolide in non-target organisms. PLoS One. 2011;6(8):e23803. doi: 10.1371/journal.pone.0023803.