基于人口特征的城市生态游憩空间配置——以常熟市为例

生态游憩空间配置是休闲城市建设的重要内容,对城市生态文明建设、城市优质生活环境营造具有重要意义。本文以国家休闲城市综合标准试点市——常熟市为研究对象,以人口特征为切入点,对该市不同功能区内各年龄段人口数量、可进行生态游憩的时间、生态游憩意愿、对不同生态游憩空间的偏好,以及全市不同功能区人口对生态游憩空间的配置需求进行了调查研究。人口特征影响城市生态游憩空间的配置需求,全市不同功能区的人口特征有显著差异,因此对各类生态游憩空间的配置需求不同。在人口量、人口平均生态游憩可能性、人口生态游憩空间类型偏好等因素的影响下,商业活动区内人口对各类生态游憩空间的配置需求指数均最高,其次为生活居住区、商务办公区、工业生产区;全市不同功能区内人口对草地游憩空间的配置需求指数均最高,其次为水域和林地。可根据城市不同功能区人口数量、类型、分布特征,以及对各类生态游憩空间的配置需求来指导城市规划建设中生态游憩空间的配置实践。     

The Geography of Fish: The Use of Remote Sensing and Spatial Analysis Tools in Fisheries Research

Rather than seeing the oceans as an expansive void, researchers using acoustic technologies can detect the heterogeneity of biological resources and view the marine environment as a three-dimensional landscape. Underwater remote sensing, using acoustics, provides high resolution maps of the spatial distribution of organisms in aquatic ecosystems. Analyzing the spatial pattern of species distribution within the water column and the impact of that organization on ecological processes bridges the fields of fisheries and spatial analysis. Tools and concepts familiar to geographers, such as remote sensing, GIS, and landscape ecology, contribute to the investigation of large lake and marine ecosystems.     

Book Reviews

Rosa Ainley (ed.) New Frontiers of Space, Bodies and Gender David Bell and Gill Valentine (eds.) Consuming Geographies: We Are What We Eat Ruth Fincher and Jane M. Jacobs (eds.) Cities of Difference Richard Grant and Jan Nihman (eds.) The Global Crisis in Foreign Aid Martin Kellman and Rosanne Tackaberry Tropical Environments: The Functioning and Management of Tropical Ecosystems Glenn R. McGregor and Simon Nieuwolt Tropical Climatology Martin Oppermann (ed.) Sex Tourism and Prostitution: Aspects of Leisure, Recreation, and Work Keith Smith and Roy Ward Floods: Physical Processes and Human Impacts     

我国水库渔业对水质的影响及其生态控制对策

我国水库资源丰富,水质优良,是极佳的淡水养殖水体;实施科学合理的渔业可降低水库氮磷营养负荷,是合理利用水面和生物资源的需要.我国水库渔业自1950年代起步,1979年后快速发展,水库养殖面积迅速扩大、养殖产量显著增加、养殖品种多样化,先后发展形成6种不同的渔业模式.由于片面追求水库渔业的产量,大量施肥和投饵带来过量外源氮、磷等营养元素导致水库水体的富营养化,水质下降,有的水库甚至暴发了蓝藻水华.针对库区水质保护的要求,数项生态控制对策被提出以降低水库渔业对水质的负面影响.     

基于深度学习和时空特征融合的海洋渔船密度预测方法

为了从海量渔船轨迹数据中挖掘隐含的信息和知识,进而为渔业行政主管部门的决策提供科学依据,本研究以AIS渔船轨迹数据为研究对象,提出了一种基于深度学习和面向时空特征融合的海洋渔船密度预测方法：首先,利用渔船轨迹数据集对渔船行驶区域进行网格划分;其次,筛选出渔船高密度区域进行研究,避免数据稀疏性问题;再次,根据渔船轨迹数据的时空分析,构建三维时空融合矩阵;最后,通过卷积循环神经网络模型捕获渔船分布的时间和空间特征,并利用卷积神经网络的堆叠加强对空间特征的学习。实验通过东海海域渔船真实轨迹数据进行具体测试,结果表明渔船密度预测值与真实值非常接近,平均绝对误差为4×10-4,模型较好地拟合了渔船密度分布特征,有效地提高了渔船捕捞热点预测的准确性和鲁棒性。     

Challenges for New Zealand's individual transferable quota system: Processor consolidation,fisher exclusion, & Māori quota rights

This paper identifies three management initiatives in New Zealand's Individual Transferable Quota system that facilitated consolidation of the processing sector and limited market access for fishers, even those with quota rights. They are: (1) the placement of responsibility onto a Māori trust in 1992 and tribes (iwi) in 2004 to manage a limited amount of quota to benefit all Māori, fishers and non-fishers, which increased the use of quota as an investment asset; (2) the creation of Annual Catch Entitlement (ACE) as a fish access right separate from the quota ownership right, which made it possible to overcome consolidation limits by leasing ACE; (3) the 1997 Licensed Fish Receiver Act that made it illegal for fishers to sell fish off the boat without food safety certification. This account of the fishery policy environment in New Zealand explains why, despite owning significant portions of New Zealand's fishing quota, few Māori are fishing, processing, or selling fish caught by Māori quota.     

An indicator-based adaptive management framework and its development for data-limited fisheries in Belize

Decisions regarding the selection and implementation of management strategies that constrain fishing pressure can be among the most difficult choices that fisheries managers and stakeholders must make. These types of decisions often need to be confronted in a data-limited context, where few if any management measures are currently in place or fisheries are managed independent of adequate scientific advice. This situation can sometimes create a high risk of overfishing and potential loss of economic and social benefits. To address this situation, simple model-free indicator-based frameworks have the potential to be effective decision-making platforms for fisheries where quantitative estimates of biomass and fishing mortality based reference points are lacking. In this paper, a multi-indicator framework is developed that enables decision-makers to proceed with management decisions in data-limited situations. Model-free indicators are calculated using trends in observed data, rather than stock assessment derived estimates of biomass and fishing mortality. The framework developed is adaptive so that adjustments to catch or effort are recursive and can respond to changing environments, socioeconomic conditions, and fishing practices. Using stakeholder-defined objectives as a foundation, indicators and reference points of fishery performance are chosen that can be evaluated easily by undertaking analyses of available data. Indicators from multiple data streams are used so that uncertainty in one indicator can be hedged through careful interpretation and corroboration of information from alternative indicators. During the adaptive management cycle, managers and stakeholders evaluate each indicator against the associated reference points to determine performance measures, interpret the results using scientific and local knowledge, and adjust fishery management tactics accordingly using pre-defined harvest control rules. The framework facilitates the interpretation of situations in which performance measures suggest divergent stock abundance or productivity levels. A case study is presented on this framework's development for conch and lobster fisheries of Belize.     

How subsidies affect the economic viability of small-scale fisheries

This article presents the first bottom-up analysis of the proportion of global marine fisheries subsidies to small-scale fisheries (SSF). Using existing data, the reported national subsidy amounts are split into the fraction that goes to small- and large-scale fishing sectors. Results reveal a major imbalance in subsidy distribution, with SSF receiving only about 16% of the total global fisheries subsidy amount of $35 billion in 2009. To bring this into perspective, a person engaged in large-scale fishing received around 4 times the amount of subsidies received by their SSF counterparts. Furthermore, almost 90% of capacity-enhancing subsidies, which are known to exacerbate overfishing go to large-scale fisheries, thus increasing the unfair competitive advantage that large-scale fisheries already have. The developmental, economic and social consequences of this inequity are huge and impair the economic viability of the already vulnerable small-scale fishing sector. Conclusions indicate that taxpayers' money should be used to support sustainable fishing practices and in turn ocean conservation, and not to foster the degradation of marine ecosystems, often a result of capacity-enhancing subsidies. Reducing capacity-enhancing subsidies will have minimal negative effects on SSF communities since they receive very little of these subsidies to begin with. Instead, it will help correct the existing inequality, enhance SSF economic viability, and promote global fisheries sustainability.     

A United States shark fin ban would undermine sustainable shark fisheries

A proposed nationwide ban on the sale of shark fins within the United States would undermine sustainable shark fisheries, would have little effect on global shark mortality, and would perpetuate the misconception that the shark fin trade is the only threat facing sharks. Instead, placing a priority on policies focusing on sustainable shark fisheries management is preferred for meeting the goals of shark conservation.     

Research and management priorities for Atlantic marine recreational fisheries in Southern Europe

Marine Recreational Fishing (MRF) is an important activity in Europe, with 9 million fishers and generating annually € 6 billion in direct expenditures. However, there is a lack of data and understanding of MRF in Europe, particularly in Southern countries, which prevents a number of fish stocks from being effectively assessed and managed. In November 2016, a participatory workshop on MRF was held in Vigo (Spain) to identify challenges and opportunities for data collection, and to diagnose key research gaps and management issues for MRF in the Southern European Atlantic. Experts from a wide range of disciplines (researchers, policy makers, fisheries managers and commercial and recreational fishers) highlighted that the management of MRF is a challenge due to complex and dispersed legal frameworks, with multiple administrations involved, and overlapping uses of space with commercial fishing, aquaculture, navigation and tourism, among others. The lack of strong and representative fishing associations hampers research and management initiatives. Effective communication between recreational fishers, researchers and fisheries managers is also lacking. Despite the ecological, social and economic relevance of MRF, there is no systematic and comprehensive collection of information on fishing effort, recreational catches, expenses, social profile and access conditions of European recreational fishers. These data would be useful to avoid biases in the assessment of recreational fisheries due to the great diversity of ecosystems, species and typologies of users. Strategic recommendations and research priorities were also identified to address knowledge gaps and are discussed in the context of the management of MRF across Europe.