In addition to controlling the environment as a means to inhibit growth, efficient monitoring and protective measures should be conducted. First, sampling sites should be constantly monitored to assess whether microbial communities are changing, and microbial contamination on shipwreck surfaces should be physically removed on a regular basis. Second, and more importantly, it is necessary to use efficient and low-toxicity biocides to repress the growth of dominant fungi in order to mitigate biodeterioration. Existing commercial agents used to prevent microbial damage to cultural heritage artefacts often involve considerable amounts of potentially hazardous agents and even materials that are poisonous to artefact-protecting personnel and the environment32. The high value of cultural heritage protection is such that the risks of any inhibitory agents that are used should be assessed. Biocides that are used should be non-toxic to personnel and to the public and cause no harm to the cultural materials. Although isothiazolinones proved effective to inhibit the activity of Fusarium in our laboratory analyses, further testing will be required to ensure that their usage meets the above criteria and will also be compatible with future conservation methods and materials.