Offshore aquaculture: Spatial planning principles for sustainable development

Marine aquaculture is expanding into deeper offshore environments in response to growing consumer demand for seafood, improved technology, and limited potential to increase wild fisheries catches. Sustainable development of aquaculture will require quantification and minimization of its impacts on other ocean‐based activities and the environment through scientifically informed spatial planning. However, the scientific literature currently provides limited direct guidance for such planning. Here, we employ an ecological lens and synthesize a broad multidisciplinary literature to provide insight into the interactions between offshore aquaculture and the surrounding environment across a spectrum of spatial scales. While important information gaps remain, we find that there is sufficient research for informed decisions about the effects of aquaculture siting to achieve a sustainable offshore aquaculture industry that complements other uses of the marine environment.     

The genetic structure of fish: differences in the intraspecific distribution of biochemical genetic variation between marine, anadromous, and freshwater species

Biochemical genetic markers have been increasingly used for inferences on the population genetic structure of various fish, but little attention has been paid to relative differences in the distribution of variability within species in different groups of fish. Nested gene diversity analyses of multiple locus electrophoretic data from the literature for 19 species (6 marine species, 4 anadromous salmonids, and 9 freshwater species (5 salmonids)), mainly from Scandinavia and North America, show that (i) average heterozygosity is higher in marine species than in freshwater species, (ii) the average fraction of the total gene diversity allocated between localities increases in the order marine (1.6%), anadromous (3.7%), and freshwater species (29.4%), and (iii) the fraction of the total gene diversity associated with differences between geographic clusters of localities is generally smaller than that between localities within clusters. This finding is consistent with that the differentiation observed in most species is of postglacial origin, and that the timespan available since deglaciation has been too short to result in the accumulation of substantial differences between clusters.     

Present status of fisheries in Turkey

Turkey’s natural and ecological situations are very suitable for aquaculture. Turkey also has a wide variety of freshwater and marine species comprising trout, carp, sea bass, sea bream, turbot, mussel, crayfish, etc. The total production of fish and shellfish was 646,310 tons in 2008. The contribution of freshwater catch to total fishery production is relatively small. Capture fisheries production amounted to 494,124 tons whilst aquaculture production was 152,186 tons in the same year. In Turkey, Engraulis encrasicholus (anchovy) is the main caught sea fish species. Fisheries in the Black Sea are the most important fishery by far and show the greatest variations in total catch. Alburnus tarichii (a local species belonging to Cyprinidae) and Cyprinus carpio (the common carp) are the most important species caught from freshwaters. Aquaculture is going to play an increasingly important role in the Turkish economy, as fishery products are the only products of animal origin that can be exported to the EU. There has been a fast increase in the aquaculture production in Turkey with the implementation of scientific and technological modernization. For example, total aquaculture production for 1986 and 2008 was 3,075 and 152,186 tons, respectively. The percentage of aquaculture in total fish production has been rising every year. The ratio of cultured fish production to total fish production was 1.5% in 1990 s, 13.57% in 2000 and more than 20% in 2005. It was 23.55% in 2008. Trouts are the main cultured freshwater fish species. Raceways and floating cages are employed in culture of trout. Carps are also important cultured freshwater fish species. Sea bass and gilthead sea bream are grown marine fish species. Floating cages, off-shore and earthen ponds are used for marine fish species culture. There has been an increase in fishery exports and imports in recent years. It was more than US500 million in 2008, but that of 2004 was just over US 500 million in 2008, but that of 2004 was just over US 233 million. However, aquaculture production is still far away from the production targets and fisheries sector is not an important part of the economy at present.     

海产贝类尼氏单抱子虫病害的研究进展

目前,我国形成规模养殖的经济贝类有近20种,贝类增养殖已经成为沿海海水养殖业的支柱产业。资料显示,2004年全国海水贝类产量为1024万吨,占海水养殖总产量的77．82％。但是目前,由于气候变化、海洋环境污染、外来生物入侵等因素导致我国海产贝类病害越来越重,寄生虫就是主要病原之一,其中尼氏单孢子虫就是其中的一种原生动物寄生虫,寄生于很多种海产贝类体内。这种病害在很多地区都有暴发,国外对其研究较多,国内梁玉波等时这一病害进行了研究。因此,系统阐述国外贝类尼氏单孢子虫病害的研究现状与进展,对我国海产贝类病害的研究具有现实意义。本文时尼氏单孢子虫的分类、病害的流行情况、尼氏单孢子虫的形态学,病害的主要症状。尼氏单孢子虫的检测方法,尼氏单孢子虫与寄主之间的交互作用,环境因素时病害流行的影响等方面进行了论述,为我国贝类病害的研究和防治提供参考。     

Current status and future perspectives of Italian finfish aquaculture

Currently available data show that shellfish and finfish production in Italy, derived both from fisheries and aquaculture activities, is on the order of 474,000 tons, each activity representing 50 % of the total amount. In this context, the finfish aquaculture industry contributes on average 31 % to the national aquaculture production and on average 59 % of its value, giving a total amount of 72,000 tons and a value of around 351 million € (2010). According to FEAP statistics, Italy is the fourth largest finfish producer in EU27, after the UK, Greece, and Spain, while it is also one of the six largest finfish producers among the non-EU and EU member countries, together with Norway, UK, Greece, Turkey, and Spain. Presently, fish culture activities are mainly focused on rainbow trout (Oncorhynchus mykiss, 55.5 %), followed by European sea bass (Dicentrarchus labrax, 13.6 %), gilthead sea bream (Sparus aurata, 12.2 %), gray mullet (Mugil cephalus, 5.3 %), sturgeon (Acipenser spp., 2 %), and European eel (Anguilla anguilla, 1.7 %). Over the last 20 years, freshwater fish production and aquaculture (trout, carp, and eel) have decreased in Italy, with the exception of sturgeon. In contrast, marine fish production has significantly increased during the same period, and the two leading species, European sea bass and gilthead sea bream, presently contribute 25.8 % of the finfish production. From 1,900 tons in 1990, production reached 19,000 tons in 2010, with a 900 % increase, at an average percentage of 4.5 %. In addition, new marine fish species were successfully cultured over the same period. This review outlines the past and present situation of finfish culture in Italy and discusses future developments and priorities, with particular emphasis on new, emerging aquaculture species.     

Parasitic diseases of cultured marine finfishes and their surveillance in China

More than 40 species of marine fishes are cultured in China and a wide variety of parasites are reported as lethal pathogens of these fishes in culture conditions. In the case of net cages, the culture facilities provides a good substrate for monogenean eggs to become entangled and the intensive aggregation of fishes facilitates the transmission of parasites between hosts. Relatively thorough studies on parasitic pathogens of marine fishes in China predominately concern the ciliate Cryptocaryon irritans and capsalid monogeneans (mainly Benedenia sp. and Neobenedenia sp.). Although nearly all such reports are related to treatment procedures, no single method has proved to be adequate for the effective control of these parasitic pathogens in marine cultured fishes. The National Fisheries Technology Extension Center (NFTEC) has established surveillance systems to monitor the diseases of aquaculture, including the parasitic diseases of maricultured fishes. The national monitoring stations for diseases of cultured marine fishes are distributed in the coastal counties or cities and provide remote in situ diagnoses of diseased fishes. International cooperation and effort are required for the control of parasitic diseases of marine finfish because of both the increasing international trade of eggs (seed) and larvae and commercial products in terms of live marine finfishes, which can readily result in the transmission of pathogens.     

Native marine bacteriophages

Abstract Isolation and cultivation of marine bacteriophages have shown that they are ubiquitous in seawater, and direct counting has shown that the total numbers of viruses frequently exceed the bacterial concentration by a factor of 10. About 150 different isolates of phages from marine environments have been characterized in the literature reviewed in the present report. Knoblike projections on phage heads seem to be a morphological property more common in marine phages than among phages from other sources. The cultured phages were generally much larger than the majority of viruses observed by direct transmission electron microscopy of seawater samples, indicating that culturing methods are not providing unbiased samples of environmental viruses. Cultured marine viruses frequently are more sensitive to organic solvents than the more intensively studied phages from other sources. Burst sizes from recent in situ studies are 50% lower than the average from culture studies. Phages in the marine environment may have half lives lasting less than a day, with consequent high turnover. Host ranges varies, and cross species host ranges have not been demonstrated. More information and further development of methods are needed, both from culture and from in situ studies.     

A Scoping Analysis of Peer-Reviewed Literature About Linkages Between Aquaculture and Determinants of Human Health

For many of the world’s poor, aquatic products are critical for food security and health. Because the global population is increasing as wild aquatic stocks are declining, aquaculture is an increasingly important source of aquatic products. We undertook a scoping review of the English-language peer-reviewed literature to evaluate how the research community has examined the impacts of aquaculture on four key determinants of human health: poverty, food security, food production sustainability, and gender equality. The review returned 156 primary research articles. Most research (75%) was focused in Asia, with limited research from Africa (10%) and South America (2%). Most research (80%) focused on freshwater finfish and shrimp production. We used qualitative content analysis of records which revealed 11 themes: famer income; the common environment; shared resources; integrated farming/ polyculture; employment; extensive vs. intensive production; local vs. distant ownership; food security; income equity; gender equality; and input costs. We used quantitative content analysis of records and full-text publications about freshwater finfish and shrimp aquaculture to record the frequency with which themes were represented and the positive or negative impacts of aquaculture associated with each theme. Scatter plots showed that no theme was identified in more than half of all articles and publications for both production types. Farmer income was a theme that was identified commonly and was positively impacted by both shrimp and fresh water finfish aquaculture. Polyculture, employment, and local ownership were identified less often as themes, but were also associated with positive impacts. The common environment and shared resources were more common themes in shrimp aquaculture than freshwater finfish aquaculture research, while polyculture and local ownership were more common themes in freshwater finfish aquaculture than shrimp aquaculture. Gender equality, employment, and food security were themes found in a lower percentage of records than full-text publications for both production types.     

Marine finfish hatchery technology in the USA – status and future

In 1993, about 52% of the 433 698 tons of thetotal US aquaculture production came from theproduction of freshwater catfish. Excludingsalmonid culture, the percentage of marine finfishculture in total aquaculture production in the UShas been negligible. Commercial scale production ofmarine finfish in hatcheries is very limited in theUS.Studies on eggs and larvae of marine finfishspecies in the US have stemmed from theconsideration of fisheries management rather thanaquaculture. Most of the marine finfish larvaeproduced in the laboratory has been for the purposeof providing materials for other academic relatedstudies. Results of these studies can be applied inthe development of marine finfish hatcherytechnology. Hatchery technology for several marinefinfish species has been developed for stockenhancement, technology transfer and aquaculture. This paper reviews the current hatchery technologyof striped mullet (Mugil cephalus), dolphinfish (Coryphaena hippurus), red drum (Sciaenops ocellatus), and other potentialaquaculture species.     

Domestication, comparative biology and interactions of wild and cultured fish: convenor's synthesis

Aquaculture is expanding rapidly and many fish species are brought into cultivation, entering a process of domestication with consequences for their morphology, physiology, ecology and evolution. In some species the abundance of cultured populations matches or exceeds that of wild stocks, and interactions between cultured and wild fish can pose significant conservation challenges. At the same time, captive breeding and re‐introduction play an important role in the conservation of some of the world's most endangered fishes. Drawing on contributions from the FSBI Symposium and the wider literature, we synthesize current knowledge of the process and extend of fish domestication, interactions between cultured and wild fish, and the use of cultured fish in fisheries enhancement and restoration. We provide a perspective on the role of biological issues within the wider context of aquaculture development and aquatic conservation biology, and conclude with a discussion of promising avenues for further research.     

Bacterial biota of shrimp intestine is significantly modified by the use of a probiotic mixture: a high throughput sequencing approach

The use of probiotics is a common practice of current shrimp aquaculture. Despite the immunophysiological responses that have been measured in shrimp exposed to probiotics, no information is currently available on the effect of this practice on the intestinal microbiota. The objective of this work was to evaluate the effect of a probiotic mixture on the intestinal microbiota of shrimp cultured under farm conditions. A culture-independent method based on high-throughput-sequencing (16S rRNA) was used to examine intestinal bacterial communities. A traditional system (without probiotics) was used as the reference. Targeted metagenomics analysis revealed that the probiotic mixture was based on bacteria in the phyla Proteobacteria and Firmicutes. A total of 23 species of bacteria were detected in the probiotic mixture; of these, 11 were detected in the intestine of shrimp reared in both systems, and 12 were novel for the system. Eight of the novel species were detected in shrimp cultured with the probiotic mixture; however, none of these novel species were related to marine or inclusively aquacultural environments, and only one (Bacillus subtilis) was recognized as probiotic for shrimp. The use of the probiotic mixture modified the bacterial profile of the shrimp intestine; however, most of the bacteria incorporated into the intestine were nonindigenous to the marine environment with no previous evidence of probiotic effects on any marine organism. The use of this probiotic mixture may represent a risk of causing environmental imbalances, particularly because farms using these types of probiotic mixtures discharge their effluents directly into the ocean without prior treatment.     

Catalogue of the ants (Hymenoptera, Formicidae) of Bulgaria

The present catalogue of the ants (Hymenoptera, Formicidae) of Bulgaria is made on a base of critical reconsideration of literature (covering the period from 1892 till 2009 and part of 2010) as well as on examination of the authors' and several museum's collections. A lot of data were omitted in the previous Bulgarian monograph on ants, lots of new data were recently added and many important additions and alterations were made due to taxonomic revisions of Eurasian Formicidae during the last three decades. Two new species are reported for the country [Temnothorax graecus (Forel, 1911) and Temnothorax cf. korbi (Emery, 1924)].This catalogue contains a list of 163 ant species belonging to 40 genera of 6 subfamilies now known from Bulgaria. Synonyms and information on the previously reported names in relevant publications are given. Known localities of the species are grouped by geographic regions. Maps with concrete localities or regions for each species were prepared. The conservation status of 13 ant species is given as they are included in IUCN Red List of Threatened Species and Bulgarian Biodiversity Act. In comparison with adjacent Balkan regions the ant fauna of Bulgaria is quite rich and its core is composed of South European elements.     

Freshwater salmon aquaculture in Chile and transferable antimicrobial resistance

Large amounts of antimicrobials are used in salmonid aquaculture in Chile. Most are used in marine aquaculture, but appreciable amounts are also employed in freshwater aquaculture. Much research and many publications have examined transferable antimicrobial resistance in bacteria isolated from marine salmon farms, but much less attention has been paid to this area in freshwater salmon farming. A recent paper by Domínguez et al. (2019) has as least in part remedied this situation. We now comment on some of its interpretations and have attempted to point out its areas of strength and weakness in light of the published scientific literature. Seen in this setting, the important results presented by Domínguez et al. (2019) underline the need for increased awareness of the challenge to animal and human health posed by excessive use of antimicrobials in aquaculture.     

我国主要海域海水养殖碳汇能力评估及其影响效应——基于我国9个沿海省份面板数据

随着海水养殖业的碳汇功能逐渐被认识和肯定,海水养殖不再单是一项经济活动,而是对环境具有正向影响的碳汇生态活动。以我国沿海9个省份为例,选取海水养殖业碳汇主要贡献的贝类和藻类海产品,并按照各自的碳汇方式对我国沿海地区2008—2015年海水养殖碳汇能力测算,进一步将9个沿海省份按照主要海域划分为渤海、黄海、东海、南海,利用LMDI模型从海水养殖的结构效应和规模效应角度分析碳汇能力的区域差异和主要影响因素。研究结果显示,黄海沿岸海水养殖碳汇能力最强,南海沿岸海水养殖的碳汇转化比例最高,规模效应与我国沿海地区海水养殖碳汇能力始终呈正相关,结构效应的作用显著但不稳定。基于上述结论,我国沿海地区碳汇养殖业应首先提升碳汇养殖技术、稳定海水养殖产量,其次注重优化养殖结构,对碳汇潜力巨大的贝类多加关注。     

Aquaculture of three phyla of marine invertebrates to yield bioactive metabolites: process developments and economics

Large-scale, renewable supplies of chemical constituents derived from marine invertebrates have limited development of potential new natural product drugs. This paper describes the development of two in-sea aquaculture systems designed and engineered for production of large quantities of biomass for two species of marine invertebrates desired for their natural product chemical constituents. The two invertebrates and their products were: (1) the cosmopolitan, arborescent bryozoan Bugula neritina (Phylum Bryozoa) for its anticancer chemical constituent bryostatin 1; and (2) Ecteinascidia turbinate (Phylum Tunicata) the source of anticancer ecteinascidin 743. For the third invertebrate Phylum Porifera, and its representative sponge Acanthella cavernosa (desired for its anti-parasitic and anti-infective kalihinols) in-sea systems were not developed in favor of controlled environment tank aquaculture systems. For the bryozoan and tunicate, projected economics for commercial-scale in-sea production proved cost effective. This was in contrast to the controlled environment sponge culture tank system, which did not prove to be economical due to inherent slow growth and low natural product yields of the sponge in culture. A non-destructive method for "milking" natural product chemicals from sponges was tested and is described.     

Regional effects as important determinants of local diversity in both marine and terrestrial systems

Community ecologists have struggled to create unified theories across diverse ecosystems, but it has been difficult to acertain whether marine and terrestrial communities differ in the mechanisms responsible for structure and dynamics. One apparent difference between marine and terrestrial ecology is that the influence of regional processes on local populations and communities is better established in the marine literature. We examine three potential explanations: 1) influential early studies emphasized local interactions in terrestrial communities and regional dispersal in marine communities. 2) regional‐scale processes are actually more important in marine than in terrestrial communities. 3) recruitment from a regional species pool is easier to study in marine than terrestrial communities. We conclude that these are interrelated, but that the second and especially the third explanations are more important than the first. We also conclude that in both marine and terrestrial systems, there are ways to improve our understanding of regional influences on local community diversity. In particular, we advocate examining local vs regional diversity relationships at localities within environmentally similar regions that differ in their diversity either because of their sizes or their varying degrees of isolation from a species source.     

GB Non-native Species Information Portal: documenting the arrival of non-native species in Britain

Information on non-native species (NNS) is often scattered among a multitude of sources, such as regional and national databases, peer-reviewed and grey literature, unpublished research projects, institutional datasets and with taxonomic experts. Here we report on the development of a database designed for the collation of information in Britain. The project involved working with volunteer experts to populate a database of NNS (hereafter called “the species register”). Each species occupies a row within the database with information on aspects of the species’ biology such as environment (marine, freshwater, terrestrial etc.), functional type (predator, parasite etc.), habitats occupied in the invaded range (using EUNIS classification), invasion pathways, establishment status in Britain and impacts. The information is delivered through the Great Britain Non-Native Species Information Portal hosted by the Non-Native Species Secretariat. By the end of 2011 there were 1958 established NNS in Britain. There has been a dramatic increase over time in the rate of NNS arriving in Britain and those becoming established. The majority of established NNS are higher plants (1,376 species). Insects are the next most numerous group (344 species) followed by non-insect invertebrates (158 species), vertebrates (50 species), algae (24 species) and lower plants (6 species). Inventories of NNS are seen as an essential tool in the management of biological invasions. The use of such lists is diverse and far-reaching. However, the increasing number of new arrivals highlights both the dynamic nature of invasions and the importance of updating NNS inventories.     

Physiology and immunology of Lepeophtheirus salmonis infections of salmonids

'Sea lice' is a common name for a large number of species of marine ectoparasitic copepods, many of which are widespread and important disease-causing agents that infect both cultured and wild fish. Of these copepods, the salmon louse Lepeophtheirus salmonis is the most extensively studied because of its economic impact on the salmonid aquaculture industry and its possible impacts on wild salmonid populations. Different levels of infection by this parasite can affect the long-term survival and viability of its hosts. In this article, we review the nature of the interactions between L. salmonis and it hosts to identify crucial areas that warrant further research to aid understanding of the impact of infection with L. salmonis.     

Cultured fish: integrative biology and management of domestication and interactions with wild fish

Fish aquaculture for commodity production, fisheries enhancement and conservation is expanding rapidly, with many cultured species undergoing inadvertent or controlled domestication. Cultured fish are frequently released, accidentally and deliberately, into natural environments where they may survive well and impact on wild fish populations through ecological, genetic, and technical interactions. Impacts of fish released accidentally or for fisheries enhancement tend to be negative for the wild populations involved, particularly where wild populations are small, and/or highly adapted to local conditions, and/or declining. Captive breeding and supplementation can play a positive role in restoring threatened populations, but the biology of threatened populations and the potential of culture approaches for conserving them remain poorly understood. Approaches to the management of domestication and cultured‐wild fish interactions are often ad hoc, fragmented and poorly informed by current science. We develop an integrative biological framework for understanding and managing domestication and cultured‐wild fish interactions. The framework sets out how management practices in culture and for cultured fish in natural environments affect domestication processes, interactions between cultured and wild fish, and outcomes in terms of commodity production, fisheries yield, and conservation. We also develop a typology of management systems (specific combinations of management practices in culture and in natural environments) that are likely to provide positive outcomes for particular management objectives and situations. We close by setting out avenues for further research that will simultaneously improve fish domestication and management of cultured‐wild fish interactions and provide key insights into fundamental biology.