Mold Removal and Rehousing of the Ichthyology and Herpetology Skeletal Collections at the Natural History Museum of Los Angeles County

Infection by fungal spores and hyphae is an acute problem that may cause damage or loss of specimens in natural history collections. Most Ichthyology and herpetology collections are fluid-preserved whole animals, stored in glass jars, but collections frequently also maintain dried specimens of skin or bones, which are vulnerable to fungus. An Infection of Aspergillus fungus was discovered in the ichthyology and herpetology skeletal collections at the Natural History Museum of Los Angeles County (LACM) in October of 2003. Within our collections, 12% of fish and 4% of herpetological skeletons were visibly Infected. We elected to use 70% ethanol as a fungicide because It is non-toxic, effective, inexpensive, and produces minimal damage. A total of 688 infected specimens were cleaned, and all 7,987 specimens were rehoused between June 2005 and May 2007. Treatments were carried out by a commercial fungus remediation firm, and the process was monitored by an environmental consultant. Treated specimens were stored in new plastic boxes, housed in one of four ways: sealed bags; sealed bags with desiccant; desiccant only; or no bag or desiccant. Skeletons not visibly contaminated were brushed clean, catalogued, and rehoused in sealed plastic bags and plastic boxes. Periodic agar plate sampling showed no fungal growth in a subset of the four rehousing groups over the course of two years. Among all disinfected specimens, only one displayed a recurrence of fungal growth two years after treatment. We recommend treatment of fungus-infested natural history collections with 70% ethanol, and storage in polyethylene boxes and polystyrene or polypropylene bags, to prevent infection and to contain the spread of Infection If it does occur.