Extinctions on land are often inferred from sparse sightings over time, but this technique is ill-suited for wide-ranging species. We develop a space-for-time approach to track the spatial contraction and drivers of decline of sawfishes. These iconic and endangered shark-like rays were once found in warm, coastal waters of 90 nations and are now presumed extinct in more than half (n = 46). Using dynamic geography theory, we predict that sawfishes are gone from at least nine additional nations. Overfishing and habitat loss have reduced spatial occupancy, leading to local extinctions in 55 of the 90 nations, which equates to 58.7% of their historical distribution. Retention bans and habitat protections are urgently necessary to secure a future for sawfishes and similar species.

The status of tropical inshore dolphins is a literature review for policy makers. Australia’s tropical inshore waters are some of the least impacted by human activities on a global scale but also a hotspot for marine mammal extinction risk. Knowledge of dolphin distribution, abundance, trends, habitat use and population structure applies only to discrete areas for some species. Anthropogenic threats align with those ranked as the greatest to marine systems globally: habitat loss and degradation via coastal development; bycatch in fishing gear and shark nets; climate change, including ocean warming, acidification and extreme weather events. Assessing conservation status remains challenging without estimates of abundance in unsurveyed areas. Scenario modelling/sensitivity analysis of the number of mature individuals in the national ‘population’ of each species should be conducted. The integration of multiple data sources will inform conservation listings in the face of uncertainty.