Global anthropogenic changes are rapidly disassembling the structure of natural ecosystems, leading to detrimental consequences for their functioning and services to human society (e.g., food production). In the Mediterranean Sea, fishing can reduce the abundance of coastal fish which feed on sea urchins, allowing these to increase uncontrolled, and overgraze marine macrophyte forests. These ecosystems are a biodiversity hotspot, supporting multiple species of marine organisms and the ecosystem services.

This trophic unbalance and its eventual cascading effects push the system to crossing resilience tipping points, beyond which intense grazing pressure facilitates a shift from a productive and healthy state (vegetated coastal marine habitat hosting high biodiversity) to a degraded one (bare rocky areas - barrens – hosting low biodiversity).

Additionally, the lack of fish generates ecological downgrading fishery that drives fishers to intensify the exploitation of alternative resources including invertebrates. Among them, sea urchins represent a relevant socio-economic resource in many Mediterranean regions.

Sea urchin fisheries further worsen the health of this socio-ecological system. In extreme cases, the overharvesting leads to the collapse of their fisheries and ultimately and eventually results in the abrupt decline of the population growth rate.

Guaranteeing food security from natural resources while maintaining healthy marine forest ecosystems and conserving biodiversity remains a complex challenge for managers. To accomplish this purpose, it is necessary to deeply understand the processes regulating the ecological and socio-economic systems including the sea urchin Paracentrotus lividus that plays a key role, both as one of the main Mediterranean herbivores controlled by fish and for its value as a highly prized delicacy.