Revealing the Widespread Bias of Extinction Risk in the Antarctic and the Southern Ocean

ABSTRACT

Accelerating environmental change in the Antarctic and Southern Ocean (ASO) necessitates robust extinction risk assessments to inform conservation priorities. Nevertheless, no systematic, region‐wide baseline of extinction risk currently exists for tracking ASO biodiversity responses to ongoing change, a significant barrier to global biodiversity monitoring. Here, we conducted the first ASO‐wide synthesis of current extinction risk knowledge for plants, animals and Fungi. This included examining biases in current assessments, the distribution of Threatened species and their associated threats. Using a data‐inclusive workflow, we compiled 8908 assessments representing 4970 species, more than doubling the number of ASO species assessed compared with any single source. As expected, assessments were heavily biased towards vertebrates (58% assessed), while invertebrates, despite their ecological prevalence, were markedly underrepresented (6% assessed). Among vertebrates, mammals had the highest proportion of Threatened species (26%). Birds within the ASO were disproportionately Threatened (25%) compared to the global average (11%), with the greatest threat for ASO species being ‘Biological Resource Use’. The sub‐Antarctic Islands had the highest density of both Threatened species and assessment effort, whereas many Antarctic species remain unassessed. Additionally, Threatened species have the lowest protected area coverage of any conservation status. These pronounced assessment biases highlight the need for more balanced, representative and data‐inclusive extinction risk assessments to be able to effectively detect conservation status change. This work represents an important step in ensuring ASO representation in global biodiversity monitoring frameworks, strengthening the capacity of these frameworks to detect, attribute and respond to future biodiversity changes.