Sea urchins are key components of rocky reef ecosystems and valuable fishery resource in many coastal regions. Their management is challenging because they can act both as ecological drivers, influencing algal cover and habitat state, and as harvested resources whose overexploitation may compromise population viability and fishery sustainability. Conservation and fishery objectives are often addressed separately, although both depend on maintaining sea urchin populations within ecological, demographic and socio-economic limits.

Here, we present a review of sea urchin management worldwide, integrating evidence from fisheries, habitat conservation and population dynamics within a three-threshold framework. We screened 562 studies, of which 137 addressed management actions across 23 Exclusive Economic Zones. The reviewed evidence was strongly dominated by fishery-oriented studies, which accounted for >80% of the total, whereas culling, restocking and combined actions were much less represented. We further assessed the knowledge base across 29 marine biogeographic regions to evaluate how evidence is distributed among three key dimensions: fishing sustainability, habitat condition and population viability.

Our results identify only a few reference systems providing useful models of integrated management, while the strongest combined evidence of scientific knowledge across the three thresholds emerged from the Western Mediterranean, California Coast and Northwest Atlantic. Many marine regions remain poorly represented, and in general management approaches rarely integrate ecological thresholds, demographic limits and socio-economic constraints within a common framework.

This review highlights the need to move beyond single-objective management of sea urchins as either ecosystem stressors or fishery resources. A three-threshold approach can support adaptive and ecosystem-based management by identifying the safe operating space within which sea urchin populations, fisheries and rocky reef habitats can persist. Such an integrated framework is particularly relevant for Mediterranean systems, where commercial harvesting, habitat conservation and population resilience increasingly interact under cumulative anthropogenic and climatic pressures.