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The management strategy evaluation (MSE) approach was used to evaluate management strategies based on the current method of stock assessment for rock lobster (Jasus edwardsii) off Victoria, Australia, and decision rules inferred from the management plan for Victorian rock lobster and past practice when selecting total allowable catches, TACs. The results are expressed in terms of whether it is possible to keep stocks above limit reference points with high probability and recover over‐exploited stocks to the target level. Three categories of management strategy were examined using the MSE, which differed in whether assessments were conducted, and TACs set, by management zone or by region within management zone. A management strategy based on conducting assessments and setting TACs by management zone is most similar to the way assessments are currently conducted and management regulations implemented for rock lobster off Victoria. However, this management strategy performed poorest in recovering stocks to target levels. Alternative management strategies which involved conducting assessments and setting TACs by region performed better, but may have practical limitations. The assessment method was found to be generally relatively accurate and precise, although estimation performance was poor/imprecise on occasion. 相似文献
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Southern rock lobster (Jasus edwardsii) support significant commercial and recreational fisheries in Tasmania, Australia. Since the mid 1990s the number of persons holding recreational lobster licences increased by over 80%, with c. 15 500 persons licensed in 2002/03. Assessment of the recreational fishery has been undertaken periodically since 1996 using a telephone‐diary survey method. The fishery was concentrated off the south‐east and east coasts of Tasmania and characterised by strong seasonality in catch and effort, which peaked markedly early in the fishing year (November‐January). Although pots were the most popular fishing method, daily catch rates by divers were more than double those for pots. Divers selectively harvested larger lobsters than those taken by pots and more frequently attained the daily bag limit of 5 lobsters. The estimated recreational harvest increased significantly since 1996/97 and in 2002/03 effectively reached a management trigger level of 10% of the total allowable commercial catch, flagging a review of recreational management arrangements. 相似文献
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The missing layer: Geo-technologies, communities, and implications for marine spatial planning 总被引：6，自引：3，他引：3
The assessment and management of marine resources is an increasingly spatial affair dependent upon emerging geo-technologies, such as geographic information systems, and the subsequent production of diverse layers of spatial information. These rapid developments are, however, focused on biophysical processes and data collection initiatives; the social landscape of the marine environment is undocumented and remains a “missing layer” in decision-making. As a result, the resource areas upon which stakeholders and communities are dependent are neither mapped nor integrated into planning processes. We report on a participatory method to map the presence of fishing communities at-sea. The lessons learned concerning the spatial representation of communities informs not only fisheries, but other sectors struggling to incorporate similarly the human dimensions of the marine environment in assessment and planning. 相似文献
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《Marine Policy》2015
Commercial vessel traffic through the Bering Strait is increasing. This region has high biological and cultural significance, to which commercial shipping poses several risks. For this environment, these risks include ship strikes of whales, noise disturbance, chronic pollution, and oil spills. Indigenous Chukchi, Iñupiaq, St. Lawrence Island Yupik, Siberian Yupik, and Yup’ik peoples may be affected by proximity between small hunting boats and large commercial vessels leading to swamping or collisions, through displacement of animals or impacts to food security from contaminants, and through loss of cultural heritage if archeological sites and other important places are disturbed by wakes or an increase in people spending time on shore. Several measures are available to govern shipping through the region, including shipping lanes, Areas to Be Avoided (ATBAs), speed restrictions, communications measures, reporting systems, emissions controls, oil spill prevention and preparedness and salvage, rescue tug capability, voyage and contingency planning, and improved charting. These measures can be implemented in various ways, unilaterally by the U.S. or Russia, bilaterally, or internationally through the International Maritime Organization (IMO). Regulatory measures can be established as voluntary measures or as mandatory measures. No single measure will address all risks, but the framework presented herein may serve as a means of identifying what needs to be done and evaluating whether the goal of safe shipping has been achieved. 相似文献
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均衡态:动力-沉积-地貌系统的跨尺度联系 总被引：2，自引：2，他引：0
潮汐汊道P-A关系、岸线轮廓、浅海沙波剖面轮廓等3个海洋动力地貌学案例,属于能够同时满足"沿程能耗率处处相等,输沙率沿程递变处处相等,沉积速率处处相等"规律的动力-沉积-地貌系统均衡态。这种在流体力学、沉积动力学和动力地貌学时空尺度跨度很大的交集中涌现的均衡态,为引导出动力-沉积-地貌系统跨尺度联系,实现动力-沉积-地貌系统的跨尺度模拟,留下宝贵的理论研究与应用检验窗口。 相似文献
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Interpretation of seismic reflection data reveal evidence of a Cenozoic fault (Walkers Cay Fault) north of Little Bahama Bank.
This fault strikes N15–30°E, perpendicular to the adjacent bank margin and offsets a late Oligocene reflector by as much as
100 m. The origin of this near-surface fault is uncertain, but its location and strike are nearly coincident with an independently
mapped basement fault. Walkers Cay Fault may be the result of recurrent faulting, implying intermittent basement fault movement
during the post-rift history of the northern Bahamian continental margin. 相似文献
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Manned or unmanned, towed, tethered, or acoustically remote-controlled underwater vehicles are the necessary tools of deep-ocean exploration as well as the exploitation of the continental shelf mineral resources. It is possible to identify categories of tasks for which a type of vehicle is best suited, and in each of those categories, the Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), the French agency for ocean research, has designed new sophisticated vehicles, giving to scientists and engineers a set of tools to fulfill most of their needs. SAR is a broad-range high-resolution side-scan sonar designed for detailed acoustic surveys; NAUTILE is a 6000-m capability manned submersible; SAGA is a large autonomy lock-out 600-m submersible. Finally, ELIT will be a totally autonomous vehicle for inspection of oil underwater structures. 相似文献
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New three-dimensional ray-acoustics expressions for the amplitude, eikonal, and phase along a ray path are derived. These expressions clearly indicate the numerical calculations that must be performed in order to evaluate these functions. The ocean medium is characterized by a three-dimensional random index of refraction which is decomposed into deterministic random components 相似文献
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Chris M. C. Woods 《新西兰海洋与淡水研究杂志》2013,47(4):881-888
This investigation examines aspects of reproductive output in brooding wild male seahorses, Hippocampus abdominalis, from Wellington Harbour, New Zealand. Previously undocumented, such information is crucial to the management and protection of this species in relation to the CITES Appendix II‐listing of all seahorse species. Brooding males (n = 46) were captured and kept captive until the release of their juveniles, whereupon the number of juveniles was counted and sampled for standard length (SL) and dry weight (DW). SL (mean ± 1SE) of brooding males was 18.1 ± 0.6 cm and wet weight (WW) 17.6 ± 1.6 g. Number (mean ± 1SE) of juveniles released per brood was 271.2 ± 27. The number of juveniles produced was positively correlated with parent SL, WW, and brood pouch volume. Brood pouch volume was positively correlated with male SL. SL (mean ±1SE) of juveniles released was 16.7 + 0.2 mm and DW 1.2 ± 0.1 mg. Mean SL and DW of juveniles were not correlated with the number of juveniles per brood, parent male SL or parent male pouch volume. The percentage of pouch contents which were non‐viable (i.e., premature or non‐viable eggs) upon juvenile release was low (1.1 ± 0.2%; mean ±1SE of the total pouch contents). Based on findings in this study it is suggested that the CITES 10 cm minimum height restriction, which can be used in lieu of non‐detriment findings to allow sustainable exploitation of seahorses, is not suitable for H. abdominalis from Wellington Harbour as it would appear to only protect small males that produce low numbers of juveniles. 相似文献
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《Ocean & Coastal Management》2000,43(10-11):927-936
The perspectives of an efficient coastal management organization for the Tamaulipas Coastal Zone in Mexico are analyzed. With seven coastal municipalities, Tamaulipas has nevertheless 430 km of littoral and the largest estuarine area in the country (231,200 ha). The main activities there are: cattle breeding, fisheries and local manufacturing and urban development is actively increasing, concentrating in the Tampico-Ciudad Madero “Metropolis.” All of this affects significantly the many important natural ecosystems present. Following a comprehensive literature search and field visits to the area, it was made clear that the State's coastal zone is largely unknown scientifically. The organization of the Country Administration for its management of natural resources is overviewed and the criteria for the selection of the nine areas considered prioritary for ecological protection or conservation are explained. The main challenges facing the area with respect to an efficient coastal management are: (1) to close the gap in its scientific knowledge and make available all existing and future information to interested parties, (2) to modify the Administration organization to make the application of legal tools more efficient (3) to encourage open discussion, exchange of ideas and interactive forums among the different sectors (scientific, administrative, public and private organizations). 相似文献
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A diagnostic of coastal erosion and shoreline retreat occurring at a 7-km long sandy beach (Littoral Cell III) located in Todos Santos Bay (Baja California, Mexico) is performed trough the analysis of aerial photographs. Around 82,000 m2 of this sandy beach have been lost in a 20 year period (1985–2005), at a beach loss rate of 2,100 m2 per year. This indicates that coastal erosion is becoming a hazard to human lives and coastal infrastructure. Due to the latter, the implementation of a Shoreline Erosion Management Plan (SEMP) is proposed as the best management approach to deal with the problem. The Littoral Cell III SEMP considers four core policies, eight management strategies and a group of specific measures. 相似文献
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海洋生态系统服务非市场价值评估是将生态系统服务的效用价值量化为货币价值的过程。通过将无形的生态系统效益转化为有形的经济价值,非市场价值评估有利于提高海洋生态系统管理决策的科学性和有效性。然而现有研究对于评估对象的界定以及评估技术的使用缺乏统一的标准,导致评估结果不具有可比性。本文从内涵、技术与准则三个层面构建了海洋生态系统服务非市场价值评估框架:首先,系统分析了生态系统功能、生态系统服务以及生态效益的区别和联系,明确了非市场价值从生态系统到社会经济系统的转化路径;其次,对比阐释了非市场价值评估技术的差异性与适用性,识别出不同评估方法的技术特征;最后,提出了非市场价值评估的应用准则,确保评估过程的有效性和评估结果的可靠性。 相似文献
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The basic approaches, methods, and procedures for collecting and analyzing samples of microplastics in a marine environment are briefly described. 相似文献