Profile of the Marine Aquarium Fish Trade in Hong Kong

A market survey and review of government statistics were carried out to establish imports and exports of marine ornamental fishes into and out of Hong Kong, and to examine the local trade in terms of volume, value and species composition. Official government import figures for marine aquarium fishes were available from 1984 to 1991 and from 1997 and 1998. When compared with net imports, export and re-export volumes over the 15-year period were small, indicating that most imports entered the local market, or were exported unrecorded. The market survey of marine aquarium shops in Hong Kong was carried out between August 1996 and January 1997. From this survey, an annual estimate of 957,563 coral reef fish was calculated for the local trade, valued at HK$57,453,780, with a mean retail price of HK$60 per fish. These figures account for an estimated 2–3% of the global value and volume of marine aquarium fish trade, according to 1992 figures and, compared with government figures, indicate that official declarations of imports are underreported by at least 2–3 fold. A total of 342 marine aquarium fish species, from 49 families, were recorded with about 60% belonging to the families Labridae, Chaetodontidae, Pomacanthidae and Pomacentridae. It was estimated that a large proportion of the trade was in juvenile fishes and almost all fish were less than 10cm in standard length. It was common to see fishes in poor condition, species hard to maintain in captivity, or those listed for conservation concern, on sale. There are no regulations for local traders of live marine fishes other than those relating to either protected species or animal welfare. Licensing of traders in marine fishes could be introduced under existing Hong Kong legislation if fishes were to be re-classified as animals. This is strongly recommended as a step towards regulating and managing the trade in Hong Kong.     

Characterising reef fish populations and habitats within and outside the US Virgin Islands Coral Reef National Monument: a lesson in marine protected area design

Abstract  Marine protected areas are an important tool for management of marine ecosystems. Despite their utility, ecological design criteria are often not considered or feasible to implement when establishing protected areas. In 2001, the Virgin Islands Coral Reef National Monument (VICRNM) in St John, US Virgin Islands was established by Executive Order. The VICRNM prohibits almost all extractive uses. Surveys of habitat and fishes inside and outside of the VICRNM were conducted in 2002–2004. Areas outside the VICRNM had significantly more hard corals, greater habitat complexity, and greater richness, abundance and biomass of reef fishes than areas within the VICRNM. The administrative process used to delineate the boundaries of the VICRNM did not include a robust ecological characterisation of the area. Because of reduced habitat complexity within the VICRNM, the enhancement of the marine ecosystem may not be fully realised or increases in economically important reef fishes may take longer to detect.     

Lessons from the past: the collapse of Jamaican coral reefs

Since Pre-Columbian times, humans have exploited Jamaican marine ecosystems with significant consequences for flora and fauna. This study focuses on the history of reef fish exploitation in Jamaica, from first human occupation to the present day, to determine how past fishing activities contributed to subsequent declines in the coral reef ecosystem. The pattern of declining reef fish populations was nonlinear. Reef fish first declined in prehistoric times but then potentially recovered, following genocide of the native human population. Reduced fishing pressure lasted until the mid-19th century. At that time, depletion of reef fish populations again occurred with a precipitous decline from the 1850s to the 1940s. The final shift from relatively abundant to overfished marine fauna corresponded to subtle changes in fish trap design as well as development of recreational fishing. Government subsidies throughout the second half of the 20th century exacerbated the declines. This analysis shows that local artisanal fisheries with relatively low levels of effort and seemingly subtle shifts in technology can significantly impact the coral reef ecosystem and that declines occurred decades to centuries before modern ecological studies began. This research shows how historical analysis can be a powerful tool to minimize shifted baselines and establish realistic targets for recovery and sustainable management of marine ecosystems.     

徐闻珊瑚礁保护区鱼类种类组成初步研究

对徐闻珊瑚礁保护区栖息的鱼类进行4个季节的调查分析.结果表明,徐闻珊瑚礁保护区有鱼类2纲13目55科91属135种,其中软骨鱼纲有1目3科3属6种,硬骨鱼纲有12目52科88属129种.在硬骨鱼纲中鲈形目种类最多,有26科45属73种,约占总渔获物种类数的54.1%.在渔获的鱼类中底层鱼类有69种,中下层鱼类有34种,中上层鱼类有32种,分别占鱼类总种数的51.1%、25.2%和23.7%.在春季渔获的鱼类种数最多,有74种,夏季、秋季和冬季渔获鱼类种数变化较小,分别有38种、46种和52种,而在4个季节均有出现的鱼类仅有8种.     

人工鱼礁生态诱集技术的机理及研究进展

人工鱼礁是用于营造海洋牧场、调控和优化海洋生态环境、增殖渔业资源的人工设施。人工鱼礁所形成的环境可以作为鱼类良好的栖息、庇护和产卵场所,有利于鱼类的生存和繁殖,因此对鱼类具有良好的诱集效应。本文从多个角度论述了人工鱼礁生态诱集技术的机理以及鱼类行为和生态诱集技术的研究进展,探讨了目前人工鱼礁生态诱集技术研究所面临的问题和主要发展方向,旨在为我国沿海人工鱼礁建设提供一定的理论基础。     

基于环境DNA metabarcoding的舟山及其邻近海域鱼类空间分布格局的初步研究

为了解舟山及其邻近海域主要鱼类群落的种类组成,监测和保护其多样性,本研究于2019年5月在舟山及其邻近海域9个站位共采集了 27个水样,采用环境DNA(environ-mental DNA,eDNA)metabarcoding技术确定了各站位鱼类群落组成和生物多样性.结果显示,舟山及其邻近海域共检出52种鱼类,隶属于18目37科49属,有4种鱼类仅注释到属级分类阶元.其中,鲈形目和鲭形目占比最高,分别为28.85％和15.38％,不同海域优势种存在较大差异.多样性(Shannon指数、Simpson指数和Pielou指数)表现趋势基本相同,均表现为舟山近海海域＞长江河口海域＞舟山外海海域.各鱼种eDNA在不同水层变化趋势大致可以分为3种,且多数鱼种序列丰度在水层间的变化趋势与其栖息水层偏好高度吻合.此外,通过与其他学者的研究结果进行比较分析,发现同一时间相同海域的eDNA metabarcoding研究结果差异较大,表明目前eDNA技术仍不能完全替代传统调查方法.未来可以将eDNA metabarcoding技术作为一种辅助手段应用于渔业资源监测,提高检测效率并减少对生态系统的干扰.本研究可为岛礁海域的鱼类群落调研提供新的思路和方法.     

长江中下游干流环境DNA样本鱼类物种检测的初步研究

为了解舟山及其邻近海域主要鱼类群落的种类组成,监测和保护其多样性,本研究于2019年5月在舟山及其邻近海域9个站位共采集了27个水样,采用环境DNA (environmental DNA,eDNA) metabarcoding技术确定了各站位鱼类群落组成和生物多样性。结果显示,舟山及其邻近海域共检出52种鱼类,隶属于18目37科49属,有4种鱼类仅注释到属级分类阶元。其中,鲈形目和鲭形目占比最高,分别为28.85%和15.38%,不同海域优势种存在较大差异。多样性(Shannon指数、Simpson指数和Pielou指数)表现趋势基本相同,均表现为舟山近海海域>长江河口海域>舟山外海海域。各鱼种eDNA在不同水层变化趋势大致可以分为3种,且多数鱼种序列丰度在水层间的变化趋势与其栖息水层偏好高度吻合。此外,通过与其他学者的研究结果进行比较分析,发现同一时间相同海域的eDNA metabarcoding研究结果差异较大,表明目前eDNA技术仍不能完全替代传统调查方法。未来可以将eDNA metabarcoding技术作为一种辅助手段应用于渔业资源监测,提高检测效率并减少对生态系统的干扰。本研究可为岛礁海域的鱼类群落调研提供新的思路和方法。

     

Trouble on the reef: the imperative for managing vulnerable and valuable fisheries

Reef fishes are significant socially, nutritionally and economically, yet biologically they are vulnerable to both over‐exploitation and degradation of their habitat. Their importance in the tropics for living conditions, human health, food security and economic development is enormous, with millions of people and hundreds of thousands of communities directly dependent, and many more indirectly so. Reef fish fisheries are also critical safety valves in times of economic or social hardship or disturbance, and are more efficient, less wasteful and support far more livelihoods per tonne produced than industrial scale fisheries. Yet, relative to other fisheries globally, those associated with coral reefs are under‐managed, under‐funded, under‐monitored, and as a consequence, poorly understood or little regarded by national governments. Even among non‐governmental organizations, which are increasingly active in tropical marine issues, there is typically little focus on reef‐associated resources, the interest being more on biodiversity per se or protection of coral reef habitat. This essay explores the background and history to this situation, examines fishery trends over the last 30 years, and charts a possible way forward given the current realities of funding, capacity, development patterns and scientific understanding of coral reef ecosystems. The luxury live reef food‐fish trade is used throughout as a case study because it exemplifies many of the problems and challenges of attaining sustainable use of coral reef‐associated resources. The thesis developed is that sustaining reef fish fisheries and conserving biodiversity can be complementary, rather than contradictory, in terms of yield from reef systems. I identify changes in perspectives needed to move forward, suggest that we must be cautious of ‘fashionable’ solutions or apparent ‘quick fixes’, and argue that fundamental decisions must be made concerning the short and long‐term values of coral reef‐associated resources, particularly fish, for food and cash and regarding alternative sources of protein. Not to address the problems will inevitably lead to growing poverty, hardship and social unrest in many areas.     

西沙群岛重要珊瑚礁海域鱼类区系

根据1998年5月、1999年5月和2003年5月在西沙群岛北礁、永兴岛、琛航岛、华光礁、浪花礁、金银岛、东岛和玉琢礁等8个岛礁的调查资料,研究了西沙群岛岛礁水域的鱼类区系。在8个岛礁共捕获鱼类48科261种,其中礁栖性鱼类占78.93%,在8个岛礁广泛分布的鱼类只有33种,各礁区之间种类的相似度不超过41%,因此,种类多样性高和相似度低是该区域鱼类区系的2个主要特征。与南沙岛礁(1998～1999)延绳钓、刺网和手钓以及南沙群岛西南陆架区(1991)、南海北部海域等底拖网鱼类相比较,物种相似度分别为34.0%、5.1%和6.8%。