The Manila clam (Ruditapes philippinarum, Adam & Reeve 1850) is a non-indigenous species that was illegally introduced in Europe (France) in the 1970s for commercial purposes, and reached Portugal in the 1980s. Currently, it occurs in several European coastal systems, from the Bay of Biscay to the north Mediterranean. In Portugal, it is present in estuarine systems and coastal lagoons from the north to south, such as Ria de Aveiro, Óbidos Lagoon and Sado estuary, but a sharp rise in the prevalence of this species in the largest Portuguese estuary, the Tagus, resulted in the exponential growth of the number of harvesters and, consequently, an increase in the illegal exploitation of this resource. At least 1700 harvesters were estimated in this system and an annual catch volume of between around 4,000 and 17,000 t which corresponds to an annual value around €10,000,000 to €23,000,000 of sales. There is a general failure to comply with current legislation, both in relation to harvesting and marketing, as well as constraints arising from spatial planning instruments in force on the estuary. The failure to comply with sanitary standards for the exploitation and trade of bivalve mollusks presents a risk to public health and a social-economic issue resulting from this activity. The goal of this study is to propose management models for this activity with the aim of contributing to createe a legal framework in which sustainable harvesting can be achieved, in the different systems where exploitation occurs. In order to accomplish this goal, the current state play, legal framework, regulation for harvesting and trade and relevant spatial planning instruments in Portugal are analysed. In order to ascertain an adequate national management strategy, a variety of case studies in France, Spain and Italy were studied. The outcome is a management model which includes a co-management strategy of concessions as well as a mixed regime with concession areas and free areas. The creation of specific regulations; implementation of a co-management model with the active participation of harvesters; science-based regulation of a closed season and maximum daily quotas and an improved surveillance of the activity are recommended.

中文翻译：

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被入侵的欧洲沿海系统中马尼拉蛤（菲律宾蛤蜊）渔业的管理模式

马尼拉蛤 (Ruditapes philippinarum, Adam & Reeve 1850) 是一种非本土物种，于 1970 年代出于商业目的非法引入欧洲（法国），并于 1980 年代到达葡萄牙。目前，它发生在几个欧洲沿海系统，从比斯开湾到地中海北部。在葡萄牙，它存在于从北到南的河口系统和沿海泻湖，如 Ria de Aveiro、Óbidos Lagoon 和 Sado 河口，但该物种在葡萄牙最大的河口塔霍河的流行率急剧上升，导致收割机数量呈指数级增长，因此非法开采该资源的行为也随之增加。该系统中估计至少有 1700 台收割机，年捕捞量在 4,000 到 17 之间，000 吨，相当于年销售额约 10,000,000 至 23,000,000 欧元。在采伐和销售方面普遍未能遵守现行立法，以及对河口生效的空间规划工具所产生的限制。未能遵守双壳贝类软体动物开发和贸易的卫生标准会对公共健康构成风险，并由此产生社会经济问题。本研究的目标是为这项活动提出管理模式，旨在帮助创建一个法律框架，在其中可以在发生剥削的不同系统中实现可持续收获。为了实现这一目标，当前的国家运作、法律框架、分析了葡萄牙的采伐和贸易法规以及相关的空间规划工具。为了确定适当的国家管理战略，对法国、西班牙和意大利的各种案例进行了研究。结果是一种管理模式，其中包括特许权的共同管理战略以及特许区和自由区的混合制度。制定具体法规；在收割者的积极参与下实施共同管理模式；建议对封闭季节和最大每日配额进行基于科学的监管，并改进对活动的监督。结果是一种管理模式，其中包括特许权的共同管理战略以及特许区和自由区的混合制度。制定具体法规；在收割者的积极参与下实施共同管理模式；建议对封闭季节和最大每日配额进行基于科学的监管，并改进对活动的监督。结果是一种管理模式，其中包括特许权的共同管理战略以及特许区和自由区的混合制度。制定具体法规；在收割者的积极参与下实施共同管理模式；建议对封闭季节和最大每日配额进行基于科学的监管，并改进对活动的监督。