Marine gastropods are key items in small-scale fisheries worldwide, generating employment and high economic value in international markets. In North Patagonian Gulfs (Southwestern Atlantic), gastropods are landed as by-catch in bivalve artisanal fisheries, and thus no official statistics are reported. Recently, the first regulation of marine gastropod catches was established based on size at maturity for some edible species. However, additional biological-fishery data are necessary for developing a management plan if a regulated small-scale fishery is to be established. We provide the first preliminary estimation of the harvestable stock and other basic biological parameters of gastropods in the San José Gulf (SJG), a Natural Protected Area in Northern Patagonia. Density assessments are usually carried out using dredges or trawl nets that damage marine substrata, and thus we used data from non-destructive, drifting underwater visual census in transects, integrated with a Geographic Information System. We estimated the biomass, density, CPUE and the harvestable stock of Odontocymbiola magellanica and Buccinanops cochlidium, the main species currently landed in SJG. Visual surveys were conducted in 85,000 m², where both species were present in depths ranging from 5 to 20 m depth. For O. magellanica, the maximum densities were 0.02–0.04 individuals m⁻² with maximum CPUE of 12.8 kg diver⁻¹ 15 min⁻¹ and estimated harvestable biomass of 837.05 kg (S.D. = 189.96), whereas for B. cochlidium densities were 0.32–0.60 individuals m⁻² with maximum CPUE of 9.25 kg diver⁻¹ 15 min⁻¹ and 365.12 kg (S.D. = 81.86) of harvestable biomass. The delayed maturity and reproductive strategies of both species, among other biological parameters, require a precautionary approach. The total exploitable biomass estimated in our work clearly highlights the need for a very selective, small-scale fishery, operating under a well enforced management plan regulating their capture to ensure its sustainability in a Natural Protected Area.

海洋腹足动物是全球小规模渔业的关键项目，在国际市场上创造就业机会和高经济价值。在北巴塔哥尼亚湾（西南大西洋），腹足类动物是双壳类手工渔业的副渔获物，因此没有官方统计数据。最近，首次根据一些可食用物种的成熟大小对海洋腹足动物的捕捞量进行了规定。但是，如果要建立受监管的小规模渔业，则需要额外的生物渔业数据来制定管理计划。我们对巴塔哥尼亚北部自然保护区圣何塞湾 (SJG) 的腹足动物可收获种群和其他基本生物学参数进行了首次初步估计。密度评估通常使用破坏海洋底层的挖泥船或拖网进行，因此我们使用了来自横断面的非破坏性漂流水下视觉普查数据，并与地理信息系统集成。我们估计了生物量、密度、CPUE 和可收获的存量SJG目前登陆的主要物种Odontocymbiola magellanica和Buccinanops cochlidium 。^{在 85,000 m 2}进行了视觉调查，这两种物种都存在于 5 到 20 m 深度的深度范围内。对于O. magellanica，最大密度为 0.02-0.04 个体 m ^-2，最大 CPUE 为 12.8 kg 潜水员^-1 15 min ^-1，估计可收获生物量为 837.05 kg (SD = 189.96)，而B. cochlidium密度为 0.32 –0.60 个人 m ^-2最大 CPUE 为 9.25 kg 潜水员^-1 15 min ^-1和 365.12 公斤 (SD = 81.86) 可收获的生物量。除其他生物学参数外，这两个物种的延迟成熟和繁殖策略都需要采取预防措施。在我们的工作中估计的总可开发生物量清楚地强调了对非常有选择性的小规模渔业的需求，该渔业需要在执行良好的管理计划下进行管理，以确保其在自然保护区内的可持续性。