Abstract

1. Over the last four decades coral disease research has continued to provide reports of disease states, the occurrence and severity of disease outbreaks, and associated disease signs however nomenclature and protocols for microscopic disease descriptions have yet to be implemented. Histopathology using systematic protocols is a gold standard for the microscopic assessment of diseases in veterinary and medical research. Increasing disease outbreaks on coral reefs as human impacts intensify highlights the need to also establish standardised diagnostic terminology and methodology for coral disease research. 2. Here we apply a systematic approach to collating, reviewing, and evaluating histopathological methods used to study white diseases in hard coral taxa and map research effort in this field spanning study design, sample processing and analysis in the 33 publications identified between 1984 and 2022. 3. We find that studies to-date have not uniformly detailed methodologies, and terminology associated with histopathological reporting and disease description is inconsistent between studies. Combined these limitations reduce study repeatability, limiting the uptake of histopathology in coral disease research and the capacity for researchers to compare disease reports. 4. A primary outcome of this study is revision of the most widely used terminology applied to coral tissue and development of recommendations for standardised reporting procedures with the aim of increasing accessibility and uptake of histopathology in addition to allowing for ongoing comparative analysis through living systematic reviews for the coral disease field.