南沙群岛重点岛礁潟湖微型浮游动物的群落结构与摄食

潟湖是岛礁生物多样性演变的重要环境场,在岛礁水生态系统的物质循环和能量流动中发挥重要作用,而微型浮游动物的生态功能研究是解析南沙群岛岛礁水域潟湖生态系统初级生产力组成、流向、能量流动效率的重要研究内容之一。实验通过对南沙群岛重点岛礁渚碧礁、美济礁与永暑礁潟湖表层水域中微型浮游动物与生态环境调查,研究了其群落结构及其与环境因子的关系,并通过稀释培养实验研究了微型浮游动物的摄食压力。结果显示,调查水域共发现微型浮游动物20种,总丰度的范围为320～1 460个/L,以无壳纤毛虫丰度最高。无壳纤毛虫在渚碧礁潟湖西部水域（ZB-1）丰度最高,砂壳纤毛虫峰值则出现在永暑礁潟湖中部水域（YS-3）,桡足类幼体丰度最大值出现在美济礁潟湖北部水域（MJ-2）。聚类分析结果显示,3个岛礁潟湖中部区域的微型浮游动物群落相似度较高,溶解氧是影响群落结构的最重要因素,特别是对MJ-3站位影响最为突出。摄食实验结果显示,3个岛礁潟湖水域浮游植物生长率为0.22～1.36 d^-1;微型浮游动物摄食率范围为0.22～0.60 d^-1,微型浮游动物每天约摄食浮游植物现存量的...     

Natural and artificially-induced habitat complexity and freshwater fish species composition

Abstract  The effects of habitat complexity, induced by construction of artificial reefs, on the fish assemblages in the Barra Bonita reservoir, Brazil, and in the lotic zone immediately below the dam were studied. Four artificial reefs were constructed in each habitat at variable distances from the shore. Multiple correspondence analysis showed that the factors distance from the shore and type of habitat were determinants for the group formation, and artificial reefs had a lesser effect. Fish species composition was about the same at locations with and without reefs.     

Artificial Reefs, the Attraction-production Issue, and Density Dependence in Marine Ornamental Fishes

Artificial reefs may provide a useful tool to enhance production of marine ornamentals and to divert detrimental harvesting activities from sensitive natural habitat. The efficacy of this strategy depends, in part, on the extent to which artificial reefs contribute to new production (vs. attract fishes from natural habitat) and therefore benefit harvested populations on a local and regional basis. Here the attraction and production hypotheses and their application to marine ornamentals are presented. Specifically, it is discussed how the strength and timing of density dependence can affect the response of fish population dynamics to artificial reefs. In addition to this discussion, examples of density dependence in marine ornamentals and related reef fishes are provided. Based on this information, a simple conceptual model is presented to clarify the role of density dependence, and this is followed by a discussion on the use of artificial reefs in the management and production of marine ornamentals. Finally, unresolved scientific issues that remain to be addressed are provided.     

Applying forest restoration principles to coral reef rehabilitation

• 1. Forest restoration through silviculture (gardening) programs revives productivity, biodiversity, and stability. As in silviculture approaches, the coral ‘gardening’ strategy is based on a two‐step protocol.
• 2. The first step deals with the establishment of in situ and/or ex situ coral nurseries in which corals are farmed (originating from two types of source material: asexual [ramets, nubbins], and sexual [planula larvae, spat] recruits).
• 3. The second is the reef rehabilitation step, where maricultured colonies are transplanted into degraded sites.
• 4. We compare here the rationale of forest restoration to coral reef ecosystem restoration by evaluating major key criteria. As in silviculture programs, a sustainable mariculture operation that focuses on the prime structural component of the reef (‘gardening’ with corals) may promote the persistence of threatened coral populations, as well as that of other reef taxa, thus maintaining genetic diversity. In chronically degrading reef sites this may facilitate a halt in biodiversity depletion.
• 5. Within the current theoretical framework of ecosystem restoration, the recovery of biodiversity indices is considered a core element since a rich species diversity provides higher ecosystem resilience to disturbances.
• 6. The gardening measure may also be implemented worldwide, eliminating the need to extract existing colonies for transplantation operations. At degraded reef sites, the coral gardening strategy can assist in managing human and non‐human stakeholders' requirements as is done in forest management.

Copyright © 2003 John Wiley & Sons, Ltd.     

A new large‐scale and cost‐effective restoration method for cold‐water coral gardens

1. Gorgonians dwelling on the Mediterranean continental shelf are among the most frequent fishing bycatch taxa. These species display several traits, such as long lifespans and slow growth, which make them very vulnerable to the impacts caused by fishing activities with far‐reaching and long‐lasting effects.
2. Hence, restoration and mitigation actions are crucial to enhance and speed up the natural recovery of damaged cold‐water coral gardens. Given the growing concern to develop effective and affordable restoration actions, the present study aims to propose and technically validate a new large‐scale and cost‐effective restoration method.
3. This technique, named ‘badminton method', consists of attaching bycatch Eunicella cavolini colonies to cobble supports and returning them to the continental shelf by gently throwing the gorgonian transplants directly from a boat.
4. Two consecutive field experiments were conducted in order to find the best cobble type support and gorgonian size to be used: first, to evaluate the landing efficiency of gorgonian transplants at different depths (from 5 to 30 m) and second, to evaluate their capability to maintain a correct position over time.
5. Natural cobbles with large gorgonians attached were the best option. Field results and modelling approaches suggest that the transplants would correctly land on the continental shelf seabed in a predicted area of around 60 m². Moreover, they would successfully maintain an upright position ensuring gorgonian survival over time.
6. The success of this method highlights the feasibility of large‐scale and low‐cost restoration actions with promising results for the conservation and recovery of cold‐water coral gardens.

     

Lipid distribution in branching coral Montipora digitata

>ABSTRACT: The lipid profile was studied along the branch length, from the top, middle to base portion, of coral Montipora digitata to gain more insight into the physiological significance of lipids in the coral energy budget. The lipids of M. digitata consisted of seven major lipid classes: polar lipid, sterol, free fatty acid, unknown lipids 1 and 2, triacylglycerol (TG), and wax ester. The concentration of storage lipids, TG, and wax ester showed a top–base gradient along the length, whereas the levels of free fatty acid and unknown lipids showed a base–top gradient. The proportions of polar lipid and sterol in the top portion of the branch were slightly higher than those in the base portion. This observation appeared to be compatible with the view that the increased energy expenditure for proliferation enhanced the mobilization of the storage fuel lipids of wax ester and TG rather than the structure lipids of polar lipids and sterols at the top portion of the branch. Compositions of fatty acid also showed a length-wise diversity. The top portion had a lower proportion of palmitic acid (16   :   0) in all lipid classes of fatty acid ester, suggesting that this fatty acid was preferentially mobilized at the top portion, probably for the growth of coral cells.     

Tracking the Trade in Ornamental Coral Reef Organisms: The Importance of CITES and its Limitations

The extraction of coral reef organisms for the aquarium and curio trade is reported to be contributing to coral reef degradation. The total international trade and associated impacts are unknown, because data are collected only for organisms listed on Appendix II of CITES, which include stony corals, antipatharians and giant clams. CITES data indicate that trade in live stony coral and reef substrate (live rock) increased by 15–30% each year during the 1990s, with most exports since 1992 from Indonesia and Fiji. Overall, 19% of all stony coral traded (by item) from 1985 to 1997 was live; 71kern-1pt% of this was traded between 1993 and 1997 (52% of total trade). Although tracking trade using information from the CITES Trade Database provides limited information (e.g., coral is reported to genus, and volume is reported by item or weight), the CITES mechanism promotes the development of strategies to protect resources. In response to CITES requirements, Indonesia developed a management plan for sustainable harvest of corals, but not for non-CITES listed species such as soft corals and fishes. Trade in hard and soft coral provides revenue for developing countries; however, in order to be of lasting value the industry must be developed with a conservation ethic. This requires support for international programs such as CITES, management plans for sustainable harvest, and improved enforcement.     

Coral Farming: Past, Present and Future Trends

There Have Been Significant Technical Advances in Marine Aquarium Maintenance in The Last 20 Years. It is Now Possible to Maintain, Grow and Reproduce in Aquaria Many of the Coral Species Found on Coral Reefs. Due to the increased Demand For Live Corals and Other Reef Invertebrates, The Commercial Production of these Organisms for the Home Aquarium Market Has Become Feasible. This Paper Describes the Early Beginnings of Live Coral Propagation, Current Coral Propagation Facilities Located in Europe, North America, and the Pacific Basin Followed by a Discussion of an Example of the Possible Future for Coral Farming, Namely Propagation by Sexual Reproduction. Suggestions for Areas of Further Research in Captive Coral Propagation are Also Presented.     

南海主要珊瑚礁(鱼旨)科鱼类的组成与分布

1998年3~5月和1999年5~6月,采用手钓、延绳钓和刺网3种作业方式在西沙的浪花礁、华光礁、琛航岛、永兴岛、北礁和南沙的渚碧礁、南薰礁、东门礁、美济礁、赤瓜礁、永署礁、华阳礁等12座珊瑚礁水域进行了2个航次的鱼类资源调查,捕获科鱼类6属25种,渔获量计942尾256.4kg;其中在南沙调查区捕获6属22种,共641尾205.5kg,优势种依次为尾纹九棘鲈、蜂巢石斑鱼、六角石斑鱼、黑边石斑鱼;在西沙调查区捕获6属14种,共301尾50.9kg,优势种依次为尾纹九棘鲈、六角石斑鱼、黑边石斑鱼、蜂巢石斑鱼,同时分析了主要种类尾纹九棘鲈、六角石斑鱼和蜂巢石斑鱼的生物学特征。     

Effect of bleaching on lipid content and composition of Okinawan corals

Lipid contents and compositions of the bleached Okinawan corals were analyzed for the first time. Bleached corals collected at Sesoko Okinawa, Japan (26°38′N, 127°52′E), after the 1998 bleaching event showed decreased lipid content with a concomitant decline of wax in the lipid composition. The reductionin the lipid content of corals showed diversity depending on their colony morphology. On the whole, corals of massive morphology were relatively rich in lipid even after the bleaching event, and hence lesser reduction in the lipid content compared with the cases for those of branching morphology. Furthermore, there was a positive correlation between lipid content and zooxanthellae density in the bleached corals, suggesting again the importance of symbiont for the supply of lipid to the host cells, and hence for the survival of the bleaching event.