Digging Deep: Managing Social and Policy Dimensions of Geoduck Aquaculture Conflict in Puget Sound,Washington

Shellfish aquaculture can result in conflicts among stakeholders who perceive impacts and tradeoffs regarding sense of place, aesthetic, recreational, economic, and ecological values. Pacific geoduck clams (Panopea generosa Gould 1850) are grown in intertidal plots using gear- and labor-intensive techniques that result in a high value export product. A confluence of issues has resulted in on-going social and legal tensions surrounding geoduck aquaculture in southern Puget Sound, Washington (WA), USA. Using interviews and document analysis, we explored stakeholder perspectives and policy issues related to geoduck aquaculture in southern Puget Sound. Twenty-three stakeholders were interviewed, including state agency employees, representatives of the aquaculture industry, nongovernmental organizations, landowners, a tribal member, and an academic. Nine state hearings board decisions on challenges to aquaculture permits were also analyzed. Stakeholders articulated a variety of perspectives regarding aesthetic, recreational, land-use, ecological, political, regulatory, and economic aspects of geoduck aquaculture activities. Hearings board cases addressed similar issues (aesthetic, ecological, and recreational), as well as challenges to restrictions on aquaculture. Potential strategies for managing this conflict include emphasizing best management practices, identifying and incorporating best available science, joint fact-finding approaches, and initiating and improving communication among all stakeholders.     

10万吨级深远海养殖平台总体技术研究

深远海海域具有水质优良、远离陆源性污染与病害等特点,适合开展深远海养殖。本文围绕深远海养殖的技术需求,开展深远海养殖平台总布置研究、关键参数选取、航速选择、稳性校核和新能源利用等总体技术研究,形成集规模化养殖、繁育、加工及渔船补给、物流等功能的10万吨级深远海养殖平台总体技术方案。文中还介绍了深蓝渔业航母船队的构建理念,梳理了深远海养殖平台的功能区划,论证了该项目的各项关键指标,其结果满足设计及相应规则的要求。该项目紧扣海洋强国战略,以绿色高效的工业化养殖新模式实现深远海养殖装备跨越式发展,对我国深远海养殖平台建设具有重大的参考价值,并将对去船舶工业过剩产能、提升深远海养殖装备水平产生深远影响。     

海上养殖平台系泊系统耦合动力响应与疲劳计算

以某管架式海上养殖平台为例,计算平台-系泊系统耦合时域动力响应与系泊系统疲劳寿命,分析锚链拉力统计特性、平台运动规律、疲劳损伤成分比例等因素的影响。研究发现系泊系统动力响应具有明显的非线性特征,定常漂移力对本平台系泊系统极限载荷有重要影响,而波频振荡是产生疲劳损伤的主要因素。计算结果表明,系泊缆能够有效限制平台运动,且疲劳寿命满足设计要求,可为类似平台的设计和安全性评估提供参考。     

Factors Controlling the Development of the Aquaculture Industry in New Zealand: Legislative Reform and Social Carrying Capacity

The New Zealand aquaculture sector, consisting of mainly mussel, oyster, and salmon farmers, has been expanding over the last two decades. The increasing demand for water space for marine farming has prompted a process of community consultation and legislative reform resulting in the Aquaculture Reform Act 2004. Despite efforts to develop more effective legislation and improve the application process, marine farmers have often been relatively unsuccessful at gaining the water space that they desire for the expansion of the industry. However, social factors such as landscape and amenity values, recreational and navigational use, and alienation of public space are the most frequently cited reasons for the refusal of marine farm consent applications. An analysis of resource consent decision records from the past decade demonstrates this conclusion that the main factor limiting the further expansion of the aquaculture industry in New Zealand is the social carrying capacity, in the context of a period of legislative transition.     

Integrated Environmental Modeling and Assessment of Coastal Ecosystems: Application for Aquaculture Management

This article presents an approach that couples coastal ecosystem modeling with integrated environmental assessment methodologies to support coastal management. The focus is to support the development of an ecosystem approach to aquaculture management including interactions with watershed substance loading. A Chinese bay, with intense aquaculture and multiple catchment uses, and where significant modeling efforts were undertaken is used as a case study. The ecosystem model developed for this bay is used to run scenarios that test the local management strategy for nutrient reduction. The corresponding ecological and economic impacts of the managers’ scenarios are analyzed by means of the Differential Drivers-Pressure-State-Impact-Response (ΔDPSIR) analysis. Emphasis is given to the analysis of the eutrophication process in the bay including present eutrophic condition and the expected changes due to the simulated scenarios. For this purpose, the Assessment of Estuarine Trophic Status (ASSETS) screening model is a valuable tool to interpret and classify the data and model outputs regarding eutrophication condition and to evaluate the manageable level of the nutrient loading entering in the bay.     

Numerical and experimental study of submerged supple nets: Applications to fish farms

Our aim is to investigate the behavior of submerged supple nets. This work generates many problems owing to the discontinuous and highly flexible nature of the nets. Only the action of external forces can bring an infinitely flexible structure like a net into a definite shape. When considering supple nets immersed in a fluid, these external forces themselves depend on the net geometry. A numerical method to solve this fluid-structure coupling problem is proposed, and is applied to fish farms. In order to validate the calculation model of the hydrodynamic forces on the mesh sides, we measured the hydrodynamic forces on a plane panel of netting spread across a transverse current. We thus proved that the Landweber model modified according to the Richtmeyer formula as regards friction gives good results. The calculated shape of the fixed net cage is qualitatively in accordance with flume tank observations. We have adapted the algorithm to the study of the dynamic behavior of floating fish farms.