Development of ceramic settlement devices for coral reef restoration using <Emphasis Type="Italic">in situ</Emphasis> sexual reproduction of corals

A ceramic coral settlement device (CSD) was developed to raise juvenile corals in situ in preparation for transplantation. The CSD is designed to be deployed in the water before mass spawning of corals, allowing larvae to settle and grow on the CSD before it is fixed to the reef structure. CSDs were aggregated and fixed on 0.2-m² frames (either 648 or 720 CSDs per frame) and deployed in the Sekisei Lagoon around the full moons of April and May in 2002. Seven frames were collected in August 2002 and settled corals were counted in the laboratory. The maximum number of coral colonies settled on CSDs in one frame was 617, with 94% belonging to the genus Acropora. The aggregated CSDs successfully functioned as a coral settlement substratum, with more appropriate arrangement of CSDs on the frame, enabling greater exposure to sunlight and currents, which is expected to increase the amount of settlement.     

Herbivorous fishes and the potential of Caribbean marine reserves to preserve coral reef ecosystems

• 1. The development of macroalgae to the detriment of corals is now one of the major threats to coral reefs. Herbivorous fishes are partly responsible for algal regulation on coral reefs and their overexploitation favours the shift from scleractinian coral‐dominated systems towards macroalgae‐dominated systems.
• 2. Marine protected areas (MPAs) that have been established worldwide may benefit coral reefs through the maintenance of high densities of herbivorous fishes which regulate algal growth.
• 3. The paper assesses whether small MPAs in the Caribbean are able to enhance herbivorous fish stock and by controlling macroalgae help to maintain reef ecosystems. A visual census using band‐transects was undertaken around Guadeloupe island where marine reserves have been in place since 1979. The effects of MPAs on both benthic communities and herbivorous fishes are examined.
• 4. Inside MPAs, herbivorous fish biomass was almost twice as high as outside MPAs and macroalgal cover was significantly lower. Fish size class distributions revealed that large individuals occurred mainly inside MPAs and that few male individuals were found outside MPAs. Copyright © 2010 John Wiley & Sons, Ltd.

     

An index for the management of South African estuaries for juvenile fish recruitment from the marine environment

The release of fresh water from major impoundments to meet the requirements of estuaries has become a recognized need and methodologies to define appropriate release strategies have become an urgent priority in some parts of the world. A recruitment index for juvenile marine fish is presented, based on information relating to the preferred recruitment periods for 27 species, as well as the extent of dependency of these species on estuaries. The status of the estuary mouth (i.e. open or closed) and the longitudinal salinity differences (i.e. the difference between the salinity at the estuary head and the mouth) in the estuary are obtained from a hydrodynamic model of the estuary. The recruitment index integrates this information to provide an indication of potential recruitment (or recruitment opportunity). This index was applied in a case study of the Great Brak Estuary, South Africa, and a distinct decrease in the recruitment index was associated with a reduction in freshwater inflow. In the estuary modelled, annual run-off could be halved without an appreciable decrease in the fish recruitment index (FRI), but with a potentially sharp decline in fish recruitment thereafter. While the index represented recruitment opportunity rather than actual recruitment, it does at least provide an indication of where ecological risk is likely to increase substantially. Since the index integrates the current understanding with respect to the key processes which regulate recruitment of juvenile marine fish into estuaries, it is suggested that it has the potential to fulfil a vital role in identifying appropriate freshwater release policies for impoundments in South Africa.     

BOD测量方法及仪器进展

生化需氧量(BOD)是一项水质监测的重要指标,本文分析介绍了现有的BOD测量方法,同时分析介绍了适用于淡水、海水的BOD分析仪器。     

Hierarchical methods and sampling design for conservation monitoring of tropical marine hard bottom communities

• 1. A 4-year study developed methods for annual monitoring of shallow-water tropical marine benthic communities to detect changes in spatial patterning and benthic diversity. Two low-relief sponge/octocoral communities were selected from natural colour photography to gain a broader perspective on spatial variability in the benthic community structure of similar community types.
• 2. Changes in benthic spatial patterning were studied using four methods: (i) substrata and lifeform coverage characterization, (ii) species inventories, (iii) belt quadrat measurements of taxa-level (algae, sponges, octocorals and stony corals) density, area coverage and size, and (iv) belt quadrat measurements of species-level density, area coverage and area per individual or colony.
• 3. A sampling hierarchy of multiple parameters was utilized to detect changes in benthic community diversity. Substrata and lifeform characterizations (at the taxa-versus species-level) were the least sensitive and serve as indicators of catastrophic change in community structure.
• 4. Changes in spatial patterning of the benthos that may be attributed to low-level, chronic anthropogenic disturbances can be best studied utilizing belt quadrat measurements. The use of multiple study sites and a sampling hierarchy was useful in minimizing Type II errors and to determine the level of monitoring necessary to segregate natural rates of change from anthropogenic impacts.

     

海洋捕捞渔船分析系统的开发与应用

根据全国海洋捕捞渔船换证数据库,运用现代软件工程的方法,介绍了海洋捕捞渔船分析系统(M arine F ish ing Vessel Analysis System,以下简称MFVAS)。首先从实际需求出发,分析了MFVAS的功能,如数据处理、统计分析、信息查询、报表打印、系统管理等;其次介绍了MFVAS的系统设计,主要有系统结构设计、数据库设计、“层级”设计、图表设计等;同时简要说明了系统的实现,包括开发工具VB.NET、数据库系统SQL Server 2000等。最后概述了MFVAS的实际应用,指出了渔船管理存在的主要问题,同时讨论了MFVAS的发展趋势。     

Comparison of euphausiid population size estimates obtained using replicated acoustic surveys of coastal inlets and block average vs. geostatistical spatial interpolation methods

Because of their intense patchiness, euphausiid spatial distributions and stock sizes are often assessed using echosounder surveys. However, statistical error bars appropriate for individual survey results are not well known. We quantified these by examining the statistical repeatability of acoustic estimates of total euphausiid biomass within two enclosed fjords adjoining the Strait of Georgia, British Columbia. Within each inlet, paired and replicated `mirror image' zig-zag survey tracks provided sets of closely spaced backscatter profiles along the survey lines. Local stock density (biomass per unit area) was calculated by vertical integration across the euphausiid scattering layer. Total inlet population size was then estimated by horizontal interpolation and integration of the local measurements, both by block averaging and by geostatistical interpolation (kriging). By assuming no change in true population biomass over the short time interval separating replicate surveys, we could then estimate statistical precision by analysis-of-variance comparison among replicate survey grids. For the partial surveys (one or the other half of the mirror-image paired grid) multiplicative error bars were about a factor of 1.5 for Jervis Inlet and 1.7 for Saanich Inlet. Use of the full surveys (both parts of the mirror-image pair, roughly doubling the number of measurements in each estimate) reduced the error to about factor of 1.35 for Jervis but only to about 1.65 for Saanich. Statistical precision was similar for the block average vs. kriging interpolation and integration methods, however, kriging provided additional useful information about spatial pattern within the inlets.     

An assessment of the Prochilodus platensis Holmberg population in the Pilcomayo River fishery, Bolivia using scale-based and computer-assisted methods

Abstract. The catch from the fishery for the migratory Prochilodus platensis Holmberg on the Rio Pilcomayo shows considerable annual variation. Peaks were apparent in 1981 and 1982, followed by very low returns between 1983 and 1985 and a resurgence in 1986. The catch in 1986 was 1011t with the degree of annual variation probably lying between 500 and 2000t. In the Pilcomayo P. platensis is a rapidly growing short-lived fish with a maximum life expectancy of 6-7 years and an upper size approaching 61.5cm. The fish first migrate and appear in Bolivian' waters when they are 21/2-3 years old, having spent the first 2 years on the nursery grounds, probably on the Argentine/Paraguay section of the river. Although fish of this age were numerous in the 1986 catches, the optimal market size is rather larger, and older fish are taken preferentially. The fishery actually depends upon very few age classes. A comparison of growth and mortality rates obtained from scale reading and from length frequency analysis by ELEFAN programs showed a close agreement. The considerable fluctuations in the fishery are largely due to the highly variable flood regime of the river rather than to fishing pressure, with the flood determining recruitment in 2 years' time. Nevertheless, a combination of a sequence of poor flood years with sustained fishing pressure could seriously damage the fishery.     

唐山海洋牧场海域焦氏舌鳎生长特征与资源量评估

根据2016—2017年唐山市海洋牧场周围海域调查资料,分析了唐山市海洋牧场周围海域焦氏舌鳎(Cynoglossus joyneri Günther)的体长和体质量组成;求解焦氏舌鳎的体质量关系式和体长、体质量生长方程,对唐山市海洋牧场焦氏舌鳎的资源量进行了估算。根据基于体长结构的实际种群分析法,估算出唐山市海洋牧场附近海域焦氏舌鳎的资源生物量为50.996 t。     

Rarity of marine benthic species in Great Britain: development and application of assessment criteria

1. One consideration in assessing the nature conservation importance of a site is the presence of ‘rare’ species. How pragmatic concepts of ‘rarity’ can be applied to the marine benthos in a national context for conservation and coastal zone management purposes are considered. 2. A means of assessing rarity, based on the total number of units of area where the species is known to occur within the 3-mile limit of British territorial waters, has been developed. Coastal marine species can therefore be assessed quantitatively using a consistent methodology comparable to terrestrial assessments in Britain. 3. Application of the criteria has required the collation and analysis of data on a national scale and involved wide consultation. Examples are given of species considered to be nationally rare or scarce (using the technique). The way the information has been disseminated is described. 4. The reasoning behind the work is discussed and some of the applications and limitations of the criteria and results are examined. Apparently this is the first time that rarity criteria have been developed for application in the marine benthos on a national scale. ©1996 by John Wiley & Sons, Ltd.     

辽宁省海洋渔具渔法结构调整的研究

根据辽宁省海洋捕捞产量的统计资料,运用灰色关联法分析了拖网、围网、流刺网、钓具、定置网5种主要渔具渔法的产量与海洋捕捞总产量的关联度,运用改进的层次分析法确定了5种主要渔具渔法产量的权重。结果表明,海洋捕捞产量与定置网、拖网的产量的关联度高,与围网、钓具和流刺网的产量关联度低;拖网、围网、流刺网、钓具、定置网产量的计算权重分别约为23．3％、16．1％、31．1％、20．4％、9．1％。对辽宁省渔具渔法产量结构调整进行了讨论。     

夏季柘林湾-南澳岛海洋牧场营养盐的空间分布及其评价

柘林湾-南澳岛海洋牧场由网箱养殖区、贝类底播区、海藻养殖区和人工鱼礁区4个不同的功能区构成。根据2011年夏季（8月）海水营养盐的调查数据,分析其表层海水营养盐含量的空间分布特征,并对其污染现状进行综合评价。结果表明,氮、磷营养盐的空间分布均呈现由西北部柘林湾近岸海域向东南部海域递减的变化趋势。不同功能区中,无机氮（DIN）和活性磷酸盐（PO4-P）的高值出现在网箱养殖区,硅酸盐（SiO3-Si）的高值出现在贝类底播区,人工鱼礁区的营养盐水平均较低。单因子污染指数、污染物分担率和综合污染指数评价结果也表明,海洋牧场受到DIN和PO4-P污染的程度以及富营养化程度均呈现由西北海域向东南海域递减、近岸向离岸递减的变化趋势。网箱养殖区受DIN和PO4-P污染最重,呈现严重富营养化,其次为贝类底播区,而人工鱼礁区和对比区受到的污染程度均较轻。     

福建省海洋捕捞与渔业资源学科发展的思路

文章首先分析了国内外在海洋渔业资源的调查与评价、海洋渔业资源的保护与管理、海洋环境生态修复和海洋渔业资源的恢复等有关海洋捕捞和渔业资源学科研究的现状和发展趋势,探讨了目前我国海洋渔业面临捕捞过度、渔具选择性差,渔业资源日益衰退等主要问题,提出2个学科的战略目标与发展思路,最后建议目前可以开展的适宜捕捞力量研究、渔具选择...     

冷藏养殖大黄鱼指数腐败货架期模型的构建与评价

通过感官、化学、微生物学分析对0~10℃冷藏养殖大黄鱼鲜度和货架期进行研究,构建和验证了指数腐败货架期模型。结果表明,0~10℃冷藏养殖大黄鱼货架期终点时菌落总数、假单胞菌数、嗜冷菌数和产H2S细菌数分别为6.64~7.60、6.24~6.96、6.16~6.90、6.14~6.62 lg cfu/g,挥发性盐基氮和三甲胺分别为27.15~30.12 mg/100g和8.44~10.83 mg/100g。0、5、8和10℃冷藏大黄鱼的货架期分别为17.8±2.5、9.3±1.1、7.0和5.4±1.3 d,并用于构建指数腐败货架期模型。用0、3、7℃冷藏养殖大黄鱼货架期验证指数腐败货架期模型,相对误差为?6.1%~4.6%,显示该模型可以快速有效预测0~10℃冷藏养殖大黄鱼的剩余货架期。     

A new role for MSY in single-species and ecosystem approaches to fisheries stock assessment and management

In 1977, Peter Larkin published his now‐famous paper, ‘An epitaph for the concept of maximum sustained yield’. Larkin criticized the concept of single‐species maximum sustained yield (MSY) for many reasons, including the possibility that it may not guard against recruitment failure, and the impossibility of maximising sustainable yields for all species simultaneously. However, in recent years, there has been a fundamental change in the perception of the fishing mortality associated with MSY (F_MSY) as a limit to be avoided rather than a target that can routinely be exceeded. The concept of F_MSY as a limit is embodied in several United Nations Food and Agriculture Organization (FAO) agreements and guidelines, and has now been incorporated into the US Magnuson–Stevens Fishery Conservation and Management Act. As a result, the United States now requires the development of overfishing definitions based on biological reference points that treat the F_MSY as a limit reference point and must also define a lower limit on biomass below which rebuilding plans with strict time horizons must be developed. This represents a major paradigm shift from the previously mandated (but often unachieved) objective to simply maintain fishing mortalities at levels below those associated with recruitment overfishing. In many cases, it requires substantial reductions in current fishing mortality levels. Therefore, the necessity of the new paradigm is continually questioned. This paper draws on examples from several fisheries, but specifically focuses on the recent US experience illustrating the practical difficulties of reducing fishing mortality to levels below those corresponding to MSY. However, several studies suggest that even more substantial reductions in fishing mortality may be necessary if ecosystem considerations, such as multispecies interactions, maintenance of biodiversity and genetic diversity, and reduction of bycatch and waste, are taken into account. The pros and cons of moving beyond single‐species assessment and management are discussed. A US plan for improving stock assessments indicates that even a ‘basic’ objective such as ‘adequate baseline monitoring of all managed species’ may be extremely costly. Thus, the suggestion of Larkin (1983, 1997) that the costs of research and management should not exceed 10–20% of the landed value of the catch may preclude comprehensive ecosystem management. More importantly, neither single‐species nor ecosystem‐based fisheries management is likely to improve appreciably unless levels of fishing capacity are aligned with resource productivity, as is currently being promoted by FAO and several individual nations.