Taxonomic composition,abundance and biomass of mesozooplankton in the Zhelin Bay-an estuary with intensive aquaculture

1 IntroductionMesozooplankton (0.2 ~20 mm) are hetero-trophic animals that inhabit almost every type of ma-rine environment (Goswami and Padmavati, 1996;Uye et al., 1996). They are major secondary pro-ducers, grazing on phytoplankton and providing foodfor…     

A review of the feasibility, costs, and benefits of platform-based open ocean aquaculture in the Gulf of Mexico

Platform-based open ocean aquaculture (or mariculture) is a fledgling industry with a unique set of risks and uncertainties. In the past two decades, several commercial and experimental platform-based mariculture projects have been launched in the United States, however, all these projects failed or were abandoned because of operational problems or legal issues. The oil and gas infrastructure in the Gulf of Mexico is well suited for mariculture systems as these platforms are large, sturdy and long lasting, and designed to operate in the offshore environment. The purpose of this paper is to discuss the costs and benefits of a open ocean aquaculture industry in the Gulf of Mexico with particular focus on platform-based aquaculture. The opportunities for the use of idle oil and gas structures for open ocean aquaculture are limited, but the reuse of previously removed structures may have more promise.     

长江口北支近期河势演变与航道资源开发研究

从实测资料出发,分析长江口北支近期岸线与主流线的变化,并就滩涂围垦对北支河势的影响进行深入探讨.认为目前北支航道500 t级船舶基本可以达到全潮通航,1 000 t级船舶乘潮保证率也可达90%,若采取一定的工程措施,对局部浅段进行疏浚和整治,早日开辟北支1 000 t级航道是可行的.     

Another perspective on challenges in open ocean aquaculture development

Moving to open ocean locations will require the aquaculture industry to fundamentally change the way it develops installations due to increased environmental loads and longer distances from shore. With reference to the same technical issues faced by the oil producing offshore industry, technical and engineering challenges that are likely to face the aquaculture industry are identified with an emphasis on conditions off the east coast of Canada. Requirements are discussed with a view toward identifying areas where the aquaculture industry can borrow technology from the oil industry and areas where the Canadian aquaculture industry faces challenges unique to itself.     

Effects of irradiance on benthic and water column processes in a Gulf of Mexico estuary: Pensacola Bay, Florida, USA

We examined the effect of light on water column and benthic fluxes in the Pensacola Bay estuary, a river-dominated system in the northeastern Gulf of Mexico. Measurements were made during the summers of 2003 and 2004 on 16 dates distributed along depth and salinity gradients. Dissolved oxygen fluxes were measured on replicate sediment and water column samples exposed to a gradient of photosynthetically active radiation. Sediment inorganic nutrient (NH₄⁺, NO₃⁻, PO₄³⁻) fluxes were measured. The response of dissolved oxygen fluxes to variation in light was fit to a photosynthesis–irradiance model and the parameter estimates were used to calculate daily integrated production in the water column and the benthos. The results suggest that shoal environments supported substantial benthic productivity, averaging 13.6 ± 4.7 mmol O₂ m⁻² d⁻¹, whereas channel environments supported low benthic productivity, averaging 0.5 ± 0.3 mmol O₂ m⁻² d⁻¹ (±SE). Estimates of baywide microphytobenthic productivity ranged from 8.1 to 16.5 mmol O₂ m⁻² d⁻¹, comprising about 16–32% of total system productivity. Benthic and water column dark respiration averaged 15.2 ± 3.2 and 33.6 ± 3.7 mmol O₂ m⁻² d⁻¹, respectively Inorganic nutrient fluxes were generally low compared to relevant estuarine literature values, and responded minimally to light exposure. Across all stations, nutrient fluxes from sediments to the water column averaged 1.11 ± 0.98 mmol m⁻² d⁻¹ for NH₄⁺, 0.58 ± 1.08 mmol m⁻² d⁻¹ for NO₃⁻, 0.01 ± 0.09 mmol m⁻² d⁻¹ for PO₄³⁻. The results of this study illustrate how light reaching the sediments is an important modulator of benthic nutrient and oxygen dynamics in shallow estuarine systems.     

河海分界与河海区域的综合管理

河海区域是大江、大河与海洋的交汇之处,是社会、经济、文化高度发达的区域.随着我国经济社会的快速发展,河海区域在我国经济发展中的重要地位日益显现.然而,在河海区域开发利用带来巨大经济收益的同时,也出现了一些亟待解决的问题:管理政出多门,执法各自为政;产业布局失衡,生态环境恶化;围海造地无序,采沙挖沙失控;海上走私猖獗,治安纠纷不断等.众所周知,我国在河海区域管理上实行各行业部门分散管理的行政体制,一个部门在制定相关管理法规或条例时,缺少与其他部门的沟通协商,没有形成综合统一的管理体系,以致在执法管理中出现土地、水利、海洋、环保、渔政、交通等部门"各自为政、多头管理"的局面.由此所发生的各种问题和引起的各种纠纷,以及随之而来的有关河海界线划分的争议,已成为社会各界关注的焦点.所提出的"打破管理上各自为政的局面,构建统一协调的河海区域管理体系,组建集中统一的多功能多专业联合执法队伍"设想,符合我国河海区域可持续发展战略,有助于实现资源与环境、经济和社会的可持续发展.     

Economic feasibility of using offshore oil and gas structures in the Gulf of Mexico for platform-based aquaculture

The increasing global demand for animal protein is a major ecological concern due to its impacts on land use, climate change, global grain supply and fisheries. One method for harvesting animal protein is to grow marine fish. This is widely practiced in coastal environments, but also leads to environmental problems associated with habitat loss and nutrient loading. One alternative is to move marine aquaculture further offshore, away from coastal land-use conflicts and towards ocean currents, which can efficiently dispose wastes. This concept creates a logistical challenge, however, since operators have to transport large amounts of food, fish and fuel to and from offshore cages on a regular basis and in varied weather conditions. In this paper, we discuss the economic feasibility of using offshore oil and gas platforms as bases for open ocean aquaculture in the Gulf of Mexico. We develop net-present value models of a platform-based operation and describe sensitivity analysis of the model output. We conclude that offshore platform-based mariculture may be commercially viable under favorable assumptions, that its viability requires economies of scale and depends principally on the yield per unit of cage volume achieved. The limitations of the analysis are described.     

上游水库群运行对长江口淡水资源的影响及未来趋势分析

上海市饮用水主要来自长江口的3大水源地——陈行水库、青草沙水库和东风西沙水库,盐水入侵是长江口淡水资源利用的重要威胁。随着以三峡工程为代表的长江上游水库群的建成和运行,入海流量发生变化。在分析及预测长江入海流量的基础上,通过长江口实测盐度数据及数学模型,以淡水资源面积占比、水源地取水口平均盐度为指标,对长江口盐水入侵受上游水库群运行的影响开展研究,并对未来变化趋势进行分析。研究结果表明：三峡蓄水后入海流量小于15 000 m³/s的频率明显减少,而小于10 000 m³/s的极低流量几乎不再发生。未来10 a枯季入海流量较现在大体仍为增加趋势,尤其是12月平均流量增量可达2 400 m³/s。三峡工程的运行并未使得长江口盐度时空分布特征发生根本性变化,但盐度场会有一定改变。在三峡水库蓄水的影响下,除11月外其他枯季月份南支、南港、北港淡水资源面积均有增大,南支1、2月增量超过南支面积的40%,南北港则在3月增量最为明显;在11月水源地取水口盐度约有0.05‰的升高,其他月份均为下降,1月变化最为明显,3大水源地取水口盐度下降0.4‰~0.5‰。在未来10 a中,12月盐水入侵与现状相比将会有进一步减弱,水源地取水口盐度进一步下降0.2‰左右。研究可为未来长江口水源地运行提供参考和依据。     

Export market influence on the development of the Pacific shrimp fishery of Sonora,Mexico

The Pacific shrimp fishery is the most economically important and ecologically impactful fishery in Mexico. Strong export markets have had a tremendous influence on the technological development and structure of this fishery. This article describes the historical development, current status, ecological impacts and management of the open ocean trawling component of the shrimp fishery in the Sonoran waters of the Gulf of California. We trace the economic factors influencing the development of the Mexican Pacific trawler-based shrimp fishery, with a focus on the port of Guaymas, Sonora, and summarize the events leading to the current overcapitalized and inefficient state of that fishery. The Sonoran shrimp fishery is characterized by high rates of by-catch and a decline in catch per boat trends. A review of economic factors indicates that the decision-making process in this fishery is driven by export markets and does not adequately consider the local ecosystems and fishing communities impacted by shrimp trawling. Management priorities for the fishery include fleet size reduction, habitat protection and alternative technology development. Successful management depends on the participation of powerful export–import companies, along side producers, government resource management agencies, NGOs and scientists. This paper describes recent efforts in collaborative management and calls for the expansion of these efforts.     

Fishermen responses on marine protected areas in the Baltic cod fishery

Much of the research that concerns the impacts of management measures in the eastern Baltic cod fishery has focused on fish stock rather than understanding fishermen's attitudes towards regulations. Hence, there is little information available on fishermen's responses although they are the ones whom the regulations affect most profoundly. This study analyses the views of fishermen towards management measures with an emphasis on fishing closures (marine protected areas, MPAs). Swedish log-book data from 1996 to 2005 were used to describe MPA induced fishing effort displacements. Fishermen argued that MPAs have been inefficient in conservation of cod stock. The enlargement of Bornholm MPA in 2005 caused substantial effort displacement towards areas dominated by smaller sized fish. This contributed to the increased discarding of juvenile cod. Enlarged MPAs also intensified competition between different fleet segments and reallocated fishing areas. To reduce fishing mortality, fishermen suggested days-at-sea (effort) regulation and an effective landings control system for all fleets that exploit cod stocks in the Baltic Sea Main Basin. These measures would better motivate fishermen for mutual rule compliance, which is a prerequisite for a sustainable cod fishery.     

Seasonality and interannual variability of freshwater inflow to a large oligohaline estuary in the Northern Gulf of Mexico

Quantity, timing, duration, and fluctuation of freshwater inflow are important factors affecting the development and health of aquatic and adjacent wetland ecosystems in coastal estuaries. This study assessed six decades of freshwater inflow from the Amite River, Tickfaw River, and Tangipahoa River watersheds to Lake Pontchartrain, a large oligohaline estuary in the Northern Gulf of Mexico, whose flood waters caused recent damage to the city of New Orleans in the aftermath of Hurricane Katrina. By utilizing the long-term (1940–2002) river discharge and climatic data from the three major tributary watersheds, monthly and annual freshwater inflows have been quantified and their spatial and temporal variations have been analyzed. On average, the three rivers discharged (±standard error) 0.27 ± 0.04 km³ freshwater monthly and 3.29 ± 0.15 km³ freshwater annually into the lake estuarine system, with the highest inflow from the Amite River (0.16 ± 0.03 m³ mon⁻¹, and 1.91 ± 0.09 km³ yr⁻¹) and the lowest inflow from the Tickfaw River (0.03 ± 0.00 km³ mon⁻¹, and 0.34 ± 0.02 km³ yr⁻¹). A distinct seasonality was evident with over 69% of the total annual inflow occurring during December and May (wet months) and with a low flow period from August to November (dry months). The monthly inflow during the wet months was positively correlated with the monthly precipitation (r² = 0.64), while the monthly inflow during the dry months was subject to evapotranspiration. Furthermore, the study found a 20-year low flow period from 1954–1973 (2.76 ± 0.24 km³ yr⁻¹) and a 24-year high flow period from 1975–1998 (3.84 ± 0.24 km³ yr⁻¹), coinciding with both the climate variation and population growth in the watersheds.     

Spatial management of small-scale fisheries on the west coast of Baja California Sur, Mexico

To understand small-scale fisheries in Mexico, the spatial and temporal distribution of the landed catch of several species was analyzed, including abalone, clams, snails, octopus, squids, lobsters, shrimps, blue crabs, sharks, rays and finfish along the 349 km of the Gulf of Ulloa coast. Data reported by fishers from 1998 to 2009 on catch volume and value per group of species and per fishing locality, together with the number of landing events, were used to define fishing zones and the relative importance of each fishery. Finfish turned out the primary fishery in the region, but the other fisheries showed relevant spatial changes that should be considered when establishing management goals and fishing regulations according to resource availability, fleet efficiency, processing capacity, commercialization of fishing products and profit distribution.     

墨西哥湾天然气水合物矿产资源预测模型及其应用

墨西哥湾是世界上研究天然气水合物较深入的海区,调查资料丰富,已在50多处采集到天然气水合物样品,具备建立天然气水合物矿产资源预测模型的条件。选择34处已知天然气水合物矿点和34处已知无矿点作为训练区,建立矿点存在与否的预测模型。模型的相关系数值表明墨西哥湾天然气水合物与盐底辟关系密切。将该模型应用于整个墨西哥湾北部,初步获得了天然气水合物存在可能性概率分布图;概率大于0.7的预测单元包含已知矿点中的30个,利用该阈值圈定了墨西哥湾天然气水合物潜在资源分布区。     

论海洋资源开发法律制度

我国早已提出了实施海洋开发的战略决策。我国虽已具备实施该战略的经济基础,但确保该战略的关键为完善海洋资源开发法律制度。为此,文章在指出国际、区域、双边相关法制的特点后,阐释了我国海洋法律体系,并提出了完善我国海洋资源开发法制的具体措施。     

Institutional designs of customary fisheries management arrangements in Indonesia, Papua New Guinea, and Mexico

There are considerable efforts by governments, non-governmental organizations (NGOs), and academia to integrate marine conservation initiatives and customary practices, such as taboos that limit resource use. However, these efforts are often pursued without a fundamental understanding of customary institutions. This paper examines the operational rules in use and the presence of institutional design principles in long-enduring and dynamic customary fisheries management institutions in Papua New Guinea, Indonesia, and Mexico. Rather than a “blue print” for devising long-enduring institutions, this study relies on the design principles as a starting point to organize an inquiry into the institutional diversity found in customary governance regimes. Three important trends emerged from this comparative analysis: (1) despite it being notoriously difficult to define boundaries around marine resources, almost 3/4 of the cases in this study had clearly defined boundaries and membership; (2) all of the customary institutions were able to make and change rules, indicating a critical degree of flexibility and autonomy that may be necessary for adaptive management; (3) the customary institutions examined generally lacked key interactions with organizations operating at larger scales, suggesting that they may lack the institutional embeddedness required to confront some common pool resources (CPR) challenges from the broader socioeconomic, institutional and political settings in which they are embedded. Future research will be necessary to better understand how specific institutional designs are related to social and ecological outcomes in commons property institutions.     

浙江省海洋旅游资源开发研究的若干建议

21世纪被称为海洋经济时代,人们越来越关注沿海地区的发展及其资源的合理利用程度.以浙江省为例,着重探讨了海洋旅游的不同类型与特点,海洋旅游资源的开发要点.在日本和浙江相近沿海地区资源的比较与研究基础之上,分析了沿海地区的旅游规划与发展所面临的问题以及挑战,论述了浙江沿海地区旅游资源的开发和管理的可持续发展模式,并对浙江海洋资源开发的多样化发展提出了若干具体的建议.     

Integrating science and management on coastal marine protected areas in the Southern Gulf of Mexico

The coastal zone of the State of Campeche have some of the Gulf of Mexico’s richest ecosystems characterized by extensive seagrasses, mangrove forests, low-land tidal wetlands, a broad deltaic environment, including the Usumacinta/Laguna de Terminos estuarine ecosystem, and extensive low salinities and brackish wetlands in the Petenes region. Commercial and artisanal fishing, maritime transport, agriculture and cattle grazing in low-land areas, urban expansion, building of highways, and tourism, are important economics activities that are increasing in the State of Campeche. However, the growth needs to occur in a sustainable manner with adequate protection of the coastal ecosystems. The theoretical approach and conceptual basis of the integrated coastal management plan are based on 20 years of scientific research in the region; and from 1990 to the present, a number of projects have been completed which serve as case studies of coastal management coupling science, technology, public participation, and policymaking in the southern Gulf of Mexico. After developing seven “study case” integrating science into policymaking, a management approach was developed considering four main actions: promotion of institutional arrangements, so that the multi-sectorial planning approach be considered in coastal resources development; strengthening of public awareness related to coastal resources management policies and capabilities; gathering, analysis and dissemination of information related to coastal resources development; and provision of technical solutions to coastal resources uses in conflict. Finally this is a case study where science played a significant role in the politics of the policy process, both in protecting key estuarine ecosystem and the planning process defining the ICZM plans.     

大西洋鲑在封闭循环水养殖模式下的生长和性腺发育研究

本研究探讨了在封闭循环水养殖模式下大西洋鲑(Salmosalar)的生长发育模式,对封闭循环水系统养殖的大西洋鲑重要生长数量性状进行生物学测量,并跟踪性腺发育状况。本研究自2012年1月通过封闭循环水系统进行大西洋鲑养殖,经过周年养殖,体质量平均达到1194.42g,体长平均达到417.00 mm,体高平均达到100.58 mm,体宽平均达到53.52 mm,少数个体在养殖10个月后性腺发育较快,性腺质量达到9.76 g,性腺指数达到1.31%。本研究的研究结果为建立大西洋鲑标准化循环水养殖系统积累资料。     

海岸带资源资产化管理与可持续发展

资源问题是人类所面临的几个重大的全球性问题之一。“可持续发展”是国际社会在研究全球环境与发展问题时所取得的共识,其实质就是以自然资源的持续利用为前提的发展模式。目前,陆地上的自然资源已无法满足人类发展的需求,有的资源已经开始衰退。为了解决陆地资源紧张的问题,人们开始将目光投向占地球表面积71％的海洋,而且首先把目光集中在海岸带。