Quantifying growth in maricultured corals using photogrammetry

In coral mariculture, growth is one of the most common ways to track success. However, numerous methods of monitoring coral growth make comparative studies challenging. A literature review of 39 studies from 1982 to 2017 indicated that the most predominant non‐invasive methods used were linear and areal measurement and these were evaluated for their accuracy using nursery‐reared corals. The monthly change in linear and areal growth rates of six coral species (n = 215), Pocillopora acuta, Hydnophora rigida, Merulina ampliata, Podabacia crustacea, Echinopora lamellosa and Platygyra sinensis were measured via photogrammetry. We tested whether the planar area of coral colonies can be estimated using three geometric formulas of linear measurements. Based on the literature review, the six types of measurement methods were namely linear, volume, weight, area, count of polyps/branches and calcification, in decreasing order of application. Our results showed that the change in area calculated by geometric mean diameter (GMD) formulas provided the most accurate estimation among the three formulas and was strongly correlated with planar area (R² ≥ .60; p < .05) for all coral species, except E. lamellosa and Pl. sinensis. However, our findings suggest that it is not ideal to use geometric formulas to estimate the change in area. Instead, we posit that areal photogrammetry represents the simplest yet accurate non‐invasive method for rapid monitoring of extensive areas of corals in situ. Lastly, we discuss the recommendations and limitations for areal photogrammetry.     

大黄鱼冰鲜杂鱼饲料中细菌多样性研究

为研究大黄鱼（Larimichthys crocea）冰鲜杂鱼饲料中细菌的多样性,用细菌通用引物构建了细菌16S rRNA基因克隆文库。从文库中随机挑选125个克隆子进行限制性片段长度多态性（ RFLP）分析,得到82个不同的RFLP 带型。对部分代表性克隆子进行测序,得到23条有效序列。序列同源性分析和系统进化分析结果表明,大黄鱼冰鲜杂鱼饲料中细菌主要分为3大类群,其中γ-变形菌纲（γ-Proteobacteria）细菌占据明显地优势地位,约占所分析克隆子数的84.4％;其次是黄杆菌纲（Flavobacteria）细菌,约占10.9％;还有少量的梭杆菌纲（Fusobac-teria）细菌,约占4.7％。γ-变形菌纲细菌中以嗜冷杆菌（Psychrobacter sp.）最多,其次是发光杆菌（Photobacteri-um）。     

Dietary habits of grazers influence their suitability as biological controls of fouling macroalgae in ex situ mariculture

The dietary habits of the sea urchin Salmacis sphaeroides and the gastropod Trochus maculatus in ex situ mariculture were examined. Fouling algal assemblages on terracotta tiles were exposed to the grazers and compared. Except for Day 0, the assemblages on Days 2, 13 and 27 differed significantly across treatments. S. sphaeroides rapidly consumed most algae, leaving an assemblage dominated by turf algae and bare tile. T. maculatus primarily fed on green filamentous algae, resulting in an even distribution of other algal functional groups, while control tiles were dominated by green filamentous algae. Using three representative fouling algae species (Bryopsis corymbosa, Hypnea spinella and Lobophora variegata), the consumption rates of both grazers and dietary preferences of S. sphaeroides were examined through a single‐diet and a choice experiment respectively. The single‐diet experiment revealed differential algal consumption rates for S. sphaeroides (H. spinella = B. corymbosa > L. variegata) and T. maculatus (B. corymbosa > H. spinella = L. variegata). The choice experiment showed that S. sphaeroides preferred H. spinella over the other two species. These experiments highlighted the importance of understanding the dietary habits of grazers as this has direct implications on their effectiveness as biological controls of fouling macroalgae in mariculture.     

中国深远海养殖发展方式研究

在渔业转型发展进程中,发展深远海养殖是突破生态环境和自然资源约束性挑战,实现新时期中国海水养殖业可持续发展的战略方向。基于联合国粮食及农业组织(FAO)关于深远海养殖发展的定义,结合中国海水养殖业发展水平和海域条件,对中国深远海养殖概念进行了界定。提出养殖品种选择、养殖系统构建、养殖海域规划是关系深远海养殖产业稳步有序发展的重要因素。在养殖品种选择方面,应重点考虑经济潜力、适应水温和养殖技术;在养殖系统构建上,分析比较了不同养殖系统应用于深远海养殖的适宜性、安全性和经济性;在养殖海域规划方面,应重点考虑养殖排放、环境承载力和海域条件。     

Comanagement for aquaculture: Suggestions from a comparative study between two major production areas of milkfish in the Philippines

ABSTRACT

This study examined if, and how, comanagement is effective in controlling aquaculture industry in the municipalities of Anda and Bolinao in the province of Pangasinan, in the Philippines, the locations of two major production areas of milkfish (Chanos chanos) in the country. Institutional and community analyses conducted in these study sites revealed a unique hierarchy of resource users, as well as unique social and economic problems in aquaculture, distinct from those of capture fishery. It was also indicated that comanagement is seen as a solution for essential practices to be enforced practically and sustainably for the management of this industry. To improve aquaculture governance, it is desired that the comanagement scheme shall include not only the governments and fishers but also business operators who often have large capital and a high degree of power.     

Development of two telemetry-based systems for monitoring the feeding behaviour of Atlantic salmon (Salmo salar L.) in aquaculture sea-cages

Two novel acoustic transmitter tags intended to reflect feeding behaviours in farmed Atlantic salmon (Salmo salar L.) were developed and tested in this study. Using information from the literature and video recordings of feeding salmon, measurements of swimming depth and motion (acceleration) were identified as two promising sensing principles on which to base the tag development. Video footage and laboratory studies were used to develop corresponding algorithms that translated depth and acceleration measurements into compound parameters reflecting the different aspects that discern feeding activity from other activities. Field tests performed in a sea-farm were used to verify the functionality of the tags, and indicated that both tag types had potential in distinguishing between feeding and non-feeding behaviour. Additionally, both depth- and acceleration-based tags were seen to have applications to fish monitoring and farm management beyond that of observing feeding in salmon, in giving recordings of the vertical swimming behaviour of fish over extended periods of time as well as indications of the activity changes of fish due to external influences. These results suggest that fish telemetry using sensor-based transmitter tags could represent a useful tool in future fish farm management.     

舟山海水养殖业现状调研

舟山市拥有优越的海水养殖生产条件,较适合海水养殖业的发展,但随着该区域城市化进程的加快,海水养殖业同样面临着许多挑战。“群岛新区”的确立,工业化水平的快速发展,使水产养殖的发展陷入两难。通过对舟山市海水养殖业现状的调研,深入调查该区域目前海水养殖状况,在获得大量真实可靠的数据基础后对舟山海水养殖业现状进行剖析,认为促进新区海水养殖业发展的关键是改变当地养殖模式,将海水养殖向集约化生产模式方向发展。     

Occurrence and prevalence of infectious pancreatic necrosis virus in rainbow trout (Oncorhynchus mykiss) cultured in cages in the Black Sea

Rainbow trout (Oncorhynchus mykiss) cultured in cage systems in the South Eastern Black Sea were surveyed for the type, occurrence and prevalence of infectious pancreatic necrosis virus (IPNV). Two nearby farms (designated as Farm A and Farm B) were visited monthly in 2007 and 2008. At each farm, 385 fish were selected randomly from five cages. Another farm with infected trout from a hatchery also was monitored for IPNV from the transfer to harvest. IPNV was found to be prevalent in both farms surveyed. In Farm A, IPNV was present throughout the growing period, from January to May, and all five randomly sampled cages tested positive for IPNV in March and April of 2007. In Farm B, IPNV was present only in February and March in 2007, and in 2008, IPNV was observed in January (two cages) and February (one cages) at low levels. Interestingly, IPNV was absent 2 weeks after transfer to the sea at 17.5°C. The same strain of IPNV, genotype III that was isolated from the same stock of fish at the hatchery, reoccurred when water temperatures dropped to 12°C in December in the Black Sea. Transferring fish to the sea at high water temperatures could lessen the negative impacts of IPNV on growth of rainbow trout in brackish water.     

临高县深水网箱养殖存在问题及发展对策

深水网箱养殖是临高县从国外引进并因地制宜进行改造的一种新兴养殖方式,具有高投入、高风险、高产出的特点。1998年至今,临高县深水网箱养殖业经历了起始、徘徊、发展等三个阶段,深水网箱养殖集约化程度高、经济效益好、抗风浪能力强的优势得到明显发挥。在这个过程中,高成本、高风险、技术落后、布局不合理等问题日益凸显,急需政府引导企业进行技术创新、合理规划布局、多方融资、建立风险补贴和监督制度,完善深水网箱养殖产业链,建立深水网箱养殖示范基地和信息平台,助力我国水产品转型升级。     

福建省海水养殖业产量结构特征与发展趋势

海水养殖业合理的结构与良好的发展趋势有利于促进福建省经济的长远发展。本文基于福建省1983—2012年的海产品产量与海水养殖产量数据,研究了福建省鱼类、虾蟹类、贝类、藻类等海产品和海水养殖产品的产量结构特征,结果表明福建省海水养殖主要以贝类、藻类为主,海洋捕捞主要以鱼类、虾蟹类为主;分析了福建省海水养殖的养殖比、面积、单产等的发展趋势,得出鱼类、虾蟹类增加趋势较大,增产潜力大;针对福建省海水养殖产量结构特征和发展趋势,进行成因分析并提出对策。研究结果可以为渔业部门指导福建省海水养殖业的发展提供参考。