Integrated study of benthic foraging resources for Atlantic walrus (Odobenus rosmarus rosmarus) in the Pechora Sea,south-eastern Barents Sea

1. The Atlantic walrus, Odobenus rosmarus rosmarus, forms a herd of nearly 4,000 heads in the Pechora Sea (south-eastern Barents Sea). The Near Threatened status of O. rosmarus rosmarus and the relative isolation of the Pechora Sea population, as well as the potential impacts of human activities in the area, make it important to characterize key habitats, including feeding grounds, in order to protect the species.
2. The aim of the present study was to integrate multiple sources of environmental and biological data collected by satellite telemetry, remotely operated vehicle (ROV), and benthic grab sampling to examine the distribution and diversity of benthic foraging resources used by walrus in the Pechora Sea.
3. Analysis of satellite telemetry data from seven males tagged on Vaigach Island helped to identify areas of high use by walruses near haulout sites on Matveev and Vaigach islands, and in between. Field data were collected from those feeding grounds in July 2016 using ROV video recordings and bottom grab sampling. Analysis of 19 grab stations revealed a heterogeneous macrobenthic community of 133 taxa with a mean biomass of 147.11 ± 7.35 g/m². Bivalve molluscs, particularly Astarte borealis, Astarte montagui, and Ciliatocardium ciliatum, dominated the overall macrobenthic biomass, making up two-thirds of the total.
4. Analysis of 16 ROV video transects showed high occurrences of mobile benthic decapods (3.03 ± 2.74 ind./min) and provided the first direct evidence that areas actively used by walrus in the Pechora Sea overlap with the distribution of the non-native omnivorous snow crab, Chionoecetes opilio.
5. Integrating multiple data sources provides an early foundation for the kinds of ecosystem-based approaches needed to improve Pechora Sea resource management and to underpin Russia’s nascent marine spatial planning initiatives. Factors that need to be considered in marine spatial planning include impacts on benthic feeding grounds from offshore oil and gas development and the spread of the snow crab.

     

Cold‐water coral Madrepora oculata in the eastern Ligurian Sea (NW Mediterranean): Historical and recent findings

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Benthic habitat modelling and mapping as a conservation tool for marine protected areas: A seamount in the western Mediterranean

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A brachiopod biotope associated with rocky bottoms at the shelf break in the central Mediterranean Sea: Geobiological traits and conservation aspects

1. In the Recent, brachiopods only seldom occur in benthic communities. A biotope dominated by Megerlia truncata was identified in 2013 by exploration of the south‐easternmost Adriatic margin by Remotely Operated Vehicle (ROV).
2. Emerging rocky substrates next to the shelf break at approximately 120 m appear intensively exploited by this eurybathic rhynchonelliformean brachiopod, attaining a population of more than 300 individuals per m².
3. Calcareous red algae are almost ubiquitous at this site and preferentially encrust sectors of the substrate where brachiopods are minimal.
4. This Megerlia biotope is a novel finding for this part of the Mediterranean Sea, similar to a situation previously observed in the Western Basin, off the Mediterranean French coast.
5. It is proposed that this remarkable brachiopod biotope and the adjacent rhodolith bed are considered important for conservation management.

     

Leiopathes glaberrima millennial forest from SW Sardinia as nursery ground for the small spotted catshark Scyliorhinus canicula

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Illegal ingegno fishery and conservation of deep red coral banks in the Sicily Channel (Mediterranean Sea)

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The high biodiversity and vulnerability of two Mediterranean bathyal seamounts support the need for creating offshore protected areas

1. Seamounts host some of the most important deep-sea ecosystems. The unique environmental characteristics of seamounts sustain rich biological hot spots, which, in recent times, have suffered the effects of intense fishing pressure.
2. Biodiversity and vulnerability data are extremely scarce for Mediterranean seamounts, and this, in addition to the complex socio-economic and juridical status of offshore sites, results in difficulty in identifying the best management strategies.
3. An extensive remotely operated vehicle (ROV) survey was used to characterize the megabenthic assemblages of the summits of two upper bathyal seamounts, Ulisse and Penelope (Ligurian Sea, north-west Mediterranean Sea). The biogeographic implications of these findings and the possible environmental factors favouring the occurrence of these communities are discussed.
4. High densities of abandoned, lost, or otherwise discarded fishing gear (mainly longlines) and a reduction in the average size of the fragile and slow-growing habitat-forming gorgonian Callogorgia verticillata indicate the occurrence of high levels of anthropogenic impacts on the summit regions, which are fishing grounds for artisanal and recreational fishers.
5. The recovery of fishing data describing the first catches in the 1970s proved to be useful in inferring the short- and long-term effects of fishing practices in these previously unexploited offshore areas. In particular, the local extinction of demersal top predators, subjected to exceptional catches nearly 50 years ago, highlights the slow recovery rate of such species.
6. Criteria defining vulnerability are discussed for the two study areas, and specific conservation actions, including the creation of regulated protected areas, are proposed.

     

Development of human-powered fish feeding machine for freshwater aquaculture farms of developing countries

Feeding the fishes rightly has been a problem for the fish farmers and developing suitable feeding devices is one of the most challenging problems faced by aquaculture engineers. Fish farmers of developing nations find manual feeding economical rather than opting for expensive mechanized feeding. In this study, a simple human-powered fish feeding machine which can economically solve the feeding issue in freshwater aquaculture, has been developed. The major parts of the feeder are cylindrical feed drums mounted on a pedal powered shaft, a catamaran barge, propeller and steering arrangements. When the operator pedals, the feed shaft rotates and the feed in the feed drums is metered through the metering holes provided in the feed drums. Human muscle power is used to power feeding operation as well as to propel the feeder. Since the device has been designed to utilize optimum human power for its entire operation, it is energy-efficient, environmental friendly and most importantly affordable. The developed device has been tested in laboratory and has been observed to be successfully operating in field condition while achieving the desired feed rate.     

关于淞江鲈学名和模式产地以及地理分布之探讨

淞江鲈学名Trachidermus fasciatusHeckel,1840,我国鱼类学文献沿用至今,属名有误,因其阴性Trachiderma早已为其它动物先据而失效。订正后的属名Trachiderm is是有效名称,淞江鲈的学名应写作Trachiderm is fasciatusHeckel,1840。模式产地菲律宾记录有问题,自1840年迄今,菲律宾未见再有该鱼之报道,淞江鲈个体发育水温不宜超过14℃,否则导致胚体畸形和死亡,菲律宾地处热带,气温年平均26.6℃左右,淞江鲈不可能得以繁衍。该鱼为西北太平洋所特有,仅分布于中国、朝鲜半岛和日本南部,我国分布于黄渤海和东海沿岸以及沿岸诸河下游及河口。     

Analysis and optimisation of dynamic facility ventilation in recirculation aquacultural systems

Facility ventilation is one of the main energy consumers in a recirculation aquacultural system (RAS).In this work, operating points have been optimised in order to maintain an acceptable facility climate on the one hand but an energy input as low as possible on the other hand. The energy savings have been quantified by evaluation of energy input into the ventilation stream at various flow rates. Moreover, additional measurements have been undertaken in order to understand the correlation between air humidity in the facility, ventilation rate, humidity production of the RAS and ambient climate.The main findings are that dynamic facility ventilation offers a significant potential for energy savings up to 85% compared to a static operation at design flow rates according to DIN EN 13779. Air humidity–as a major constraint–is predominantly affected by ambient climate conditions. Based on the main findings, a first approach for a dynamic ventilation strategy (i.e. for automation) has been made.     

Recent advances in the high-density rotifer culture in Japan

The success of rapidly growing aquaculture industry depends on the steady supply of fish seeds. Appropriate food for initial larval stages is critical for mass scale fish seed production. Live food found better over artificial food for fish larvae culture. Rotifers have been found to be the best live food for feeding fish larvae in early life stage. Attempts have been made to develop viable techniques for the production of rotifer through batch, continuous, and semi-continuous culture methods. In order to feed increased number of fish larvae, rotifer need to be cultured under high-density method. Various efforts have been made for increasing culture density of rotifer. In Japan, stable high-density culture of rotifer has been developed in commercial scale at a rate of 20,000–30,000 ind. ml^?1. Later on, ultra-high-density rotifer culture (160,000 ind. ml^?1) was found successful, which can fulfill the increased demand for rotifer as fish larval food. Furthermore, a scope of alternative use of rotifer can be explored. The development of the high-density rotifer culture method in Japan has been reviewed. The considerations of the associated nutritional requirements, microbial aspects, and prospects of high-density culture have been discussed.     

Hydrodynamic modeling and management alternatives in a Mediterranean, fishery exploited, coastal lagoon

Model development is described, related to the restoration efforts of Vassova Lagoon, a small and shallow, fishery exploited coastal lagoon, located in the region of eastern Macedonia, N. Greece. This lagoon has been configured and is used for fisheries, by having dredged through tidal channels and installed fish entrapment devices. Decreases in fish production have been related to poor seawater circulation, limited water renewal and related water quality problems. The aim of this study is to evaluate the current situation of the lagoon and propose alternative management scenarios for improvement of water flow and lagoon ecosystem. The SWMM-EXTRAN mathematical model has been adapted, calibrated, verified, and applied to describe the current situation of the lagoon, and evaluate alternative scenarios for increasing tidal flushing and water residence time. Data necessary for model validation have been collected in the field. Among the tested restoration alternatives were the following: widening and/or deepening the lagoon inlet; constructing a second inlet; widening and/or deepening the tidal channels inside the lagoon. The combined influence of opening the existing communication channel of Vassova Lagoon with the adjacent Eratino Lagoon was also considered for each scenario. The implications of the various scenarios on lagoon's fisheries management are discussed. The alternative of constructing a second tidal inlet channel, 5 m wide, and keeping the Eratino Lagoon channel open provided most tidal flushing and increased internal and inlet flow that favors recruitment of juvenile fish. This alternative was proposed for implementation.     

利斯特氏病原菌在水产品中的传播

近年,欧洲和北美已多次发生由利斯特氏菌引起爆发性传染病,该菌现已列为食品检查标准中的一种重要病原菌,它多由环境污染引起,具有抗热性和耐冷性,煮沸,冷藏仍能存活,介绍了它的生态环境,传播规律,鉴别方法和预防措施,认为煮沸－冷冻－融化过程为利斯特氏菌的致死过程。     

高铁酸盐复合剂在水质净化和鱼病防治上的应用

高铁酸盐是近年来国际上流行的环保型消毒杀菌剂，己被广泛应用于工业工程水处理，饮用水，农牧渔业上杀菌、除藻、防腐、保鲜等方面。作者将高铁酸锶复合剂应用于虾、蟹、鳗、鳜、鲈等饲养，在大面积推广中取得了良好的效果。本文着重介绍该合剂的作用原理，以期在渔业上得到更好的应用。     

浓缩鱼蛋白的食用安全性

对浓缩鱼蛋白（FPC）进行动物致突变试验、急性毒性试验、以及卫生指标鉴定，分析评价了其食用的安全性。结果表明，浓缩鱼蛋白是一种无毒、无致突变性、安全卫生的健康食品。     

Hydraulic‐habitat modelling for setting environmental river flow needs for salmonids

Abstract There is an increasing demand for tools to assist in the management of environmental flows in rivers. Changes in river discharge act on biota through a hydraulic template, which is mediated by channel morphology. Hence, environmental flow assessments also need to consider channel morphology, especially if morphology has been altered by human activities. Computer models describing the preferences of fish for hydraulic microhabitats have been applied to environmental flow problems since the mid‐1970s. Salmonids have been a particular focus for these methods. Other reviews have provided comprehensive coverage of the basic features and principles of such models. These are briefly discussed focusing on the developments that have occurred in the last 15 years and whose application has so far been infrequent. These include improvements to the representation of hydraulics at reach‐scale and of longer river sections, and improved representation of interacting physical variables that describe habitat. The central theme is the spatial coverage and fundamental granularity of such models. Despite a broad literature, there is a lack of documented examples of the application of hydraulic‐habitat models through all stages in the environmental flow decision‐making process. The review concludes with four short examples that illustrate the use of model output.     

An improved prioritization framework for selecting new finfish mariculture candidates for research and development in Indonesia

Aquaculture, particularly marine‐based production, is one of the fastest growing industries in Indonesia. Indonesia's competitiveness in the trade of aquaculture products is constrained by a lack of research and development (R&D) of new aquaculture species candidates. Mariculture has the greatest potential due to Indonesia's vast marine resources and archipelagic geography. Although there are over 3,000 species of marine fish in Indonesia, only 14 species have been widely cultured, largely finfish. Production is dominated by shrimp, groupers and milkfish. Traditionally, candidate species for mariculture in Indonesia and elsewhere have often been selected on their market value before their biological suitability for culture has been established leading to partially successful R&D efforts or even failure. The present study developed a framework for selecting marine fish species to support mariculture R&D in Indonesia based on an improved analytic hierarchy process (AHP). The approach combined various quantitative and qualitative data and involved different R&D stakeholder groups in the selection process. Ten species that had not been previously researched for their aquaculture potential were identified. The modified approach addressed the interaction complexity of criteria and different preferences across the stakeholders. The involvement of different stakeholders in the selection process not only ensured acceptance of the selected species for further research, but also tested the validity and consistency of the method used in this study. The methodology has relevance for mariculture globally given that efficient candidate selection can help focus efforts and investment in mariculture R&D.     

Two systems for collection of zooplankton for the culture of larval and juvenile fish

Two systems for enrichment and collection of natural Zooplankton in cooling water recipients were developed for rearing fish fry. One system filters-off plankton from the cooling water with rotating dip-nets (diam. 60 cm). The rotation is powered by the kinetic energy of the water and the nets are continuously flushed clean by high-pressure sprays. The water from the nets, being enriched with plankton, is pumped continuously to a grading station where undesirable size fractions are removed, after which the water is distributed to the rearing pens. The system has been tested at a nuclear power station in the south-western part of the Bothnian Sea and found to be promising, with a collection of, on average, 280 g day^–1. The other system is based on attraction using underwater lamps and pumping of organisms into floating rearing pens. The system is automatic and powered by electricity from the grid. The technical performance has been good. The plankton has been size-graded by attaching net baskets around the lamps. At a nuclear power station on the western coast of the central Baltic Sea, the amount collected has, on average, been 45–570 g Zooplankton lamp^–1 night^–1. The collection system is considered to be of use in productive areas with moderate turnover of water. Both systems are in early stages of development and have not reached their full potential. Improvements are proposed and discussed.     

Electric stunning: a humane slaughter method for trout

The most common commercial slaughter method for portion-sized rainbow trout is asphyxiation in ice slurry. This method is however widely believed to expose the fish to unnecessary pain and suffering. The industry is consequently seeking an alternative method, which offers improved welfare of the fish at slaughter. Electric stunning of fish in water is identified as a suitable method. Parameters of an electric field that stuns trout beyond the point of recovery without causing carcass damage have been identified. A 60-s exposure to a 1000-Hz sinusoidal electric field of 250 V/m r.m.s. is recommended. Several practical options for implementing this method on commercial trout farms are identified and equipment for one of these approaches has been built and tested. The UK trout industry appears to be moving towards electric stunning as its preferred slaughter method.     

Developing native fish species for aquaculture: the interacting demands of biodiversity, sustainable aquaculture and livelihoods

Aquaculture continues to be the fastest growing animal production industry and this rate of expansion must continue if aquaculture is to satisfy global demand for fish products in the face of dwindling capture fisheries. The relationship between aquaculture and biodiversity is complex, with examples of positive and negative impacts having been reported. To enable this expansion while avoiding negative impacts from introductions of exotic species, the investigation of indigenous species becomes important and worthwhile.This paper establishes the background to development of new species for culture and describes the example of the Mexican silverside Menidia estor, which has for centuries been the principal species in an artesanal fishery in Lake Pátzcuaro, Mexico. The species is geographically isolated and is unique but is now endangered because of a range of factors including overfishing, environmental degradation and introduction of exotic species. Considerable advances have been made recently in developing a closed reproductive cycle, understanding feeding and small‐scale on‐growing technology for the species. Based on this, a Darwin Initiative programme was developed focused on technology transfer to implement small‐scale pilot on‐growing thus helping to conserve the species and to improve livelihoods. This has allowed successful pilot scale development of aquaculture for the species while at the same time addressing the objectives of the international Convention on Biodiversity.