The bamboo coral Isidella elongata is a Mediterranean near-endemic octocoral able to form unique marine animal forests on muddy bottoms between ca. 120 and 1600 m depth. This deep-sea coral ecosystem plays a fundamental ecological role, providing shelter and representing nursery, feeding and spawning area for several species. Until fifty years ago, I. elongata was the most common coral of the Mediterranean bathyal zone, where it overlaps with important stocks of fishing resources including the shrimps Aristeus antennatus and Aristaeomorpha foliacea. With the relentless development of trawl fishing technologies in the last century, I. elongata forests almost completely disappeared. The species has been classified as critically endangered, and the General Fisheries Commission for the Mediterranean recognised bamboo coral forests as Vulnerable Marine Ecosystems. Despite the need to take action to ensure the conservation of I. elongata forests, crucial information regarding life-history traits such as age, growth rate, and life span is still limited. Following the incidental catch of 751 I. elongata in South-Adriatic Sea during experimental trawl fishing surveys from 2012 to 2023, and after a Remotely Operated Vehicle survey, this study provides new life-history traits of this emblematic deep-sea species. Population size structure by means of imaging and species growth model through thin sections and radiocarbon analysis were performed. The species’ lifespan in the study area was predicted to be from 57.5 to 59 years. The species showed an exponential growth with significant difference between two groups of age data (<12 and >48.8 years). Ageing and population insights of I. elongata is critical in determining the species' long-term population dynamics and recovery capacity from an ecosystem-based fishery management perspective, particularly in an area where a Fishery Restricted Area has been just implemented.