The International Union for Conservation of Nature (IUCN) Red List classifies species into categories of risk of extinction. Assessments are mostly based on quantitative data and evaluate if the population of a given species is either declining or stable. Species for which insufficient data are available to make an assessment of extinction risk are termed ‘Data Deficient’. The groupers are commercially important marine fishes for which approximately one-third of species are data deficient. However, since species in the Data Deficient category could fall into any of the other Red List categories of risk, conservation programs may neglect genuinely threatened species due to their uncertain conservation status. In a new paper published in Conservation Letters, Osmar led a team of researchers from the Quantitative Ecology and Evolution and Marine Ecology and Conservation groups at Macquarie University to analyze the biological traits of grouper species that were classified into a risk category and generated a statistical model to predict in which category each of the Data Deficient species is more likely to be classified. Among 50 Data Deficient grouper species, seven stand out either as vulnerable to extinction or as endangered. This model provides a way to prioritize the so often limited resources available for the conservation of poorly-known species.