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We assessed genetic variation at mitochondrial DNA (mtDNA) and nuclear DNA microsatellites for progeny (i.e., juveniles produced at a hatchery) of five endangered Epioblasma species reared at three hatcheries in the eastern United States.The progeny of Epioblasma aureola, Epioblasma brevidens, Epioblasma obliquata and Epioblasma triquetra showed no loss of mtDNA haplotype diversity relative to broodstock (i.e., wild collected gravid females used to produce juveniles) and wildstock (i.e., individuals sampled in the wild to assess baseline genetic diversity), while progeny of Epioblasma capsaeformis showed no loss relative to broodstock but an ~50% loss relative to wildstock.At DNA microsatellites, mean expected heterozygosities (He) were maintained in wildstock, broodstock and progeny, with the lowest values observed in E. aureola and E. triquetra. Among progeny, values of He and allelic richness (A) at times exceeded those observed in the wildstock and broodstock. Hence, no loss of genetic variation at DNA microsatellites was observed in progeny among species.We documented multiple paternity in progeny of E. aureola, E. capsaeformis and E. obliquata and in part attribute their high He and A to fertilization of broodstock females by multiple males in the wild.We observed significant divergence in FST and D values between progeny to wildstock and progeny to broodstock. Most pairwise comparisons for E. brevidens and E. capsaeformis were significantly diverged, and for E. obliquata, divergence was low but also significantly different, and only for E. aureola was it low and nonsignificant.Our results showed that population genetic structure can develop quickly between progeny and their progenitors in the first generation (F1) of offspring produced from a set of parents and that genetic diversity at mtDNA and nuclear DNA microsatellites was generally maintained in progeny of endangered Epioblasma species reared at three mussel hatcheries utilizing current propagation practices. [ABSTRACT FROM AUTHOR]

Large dam removal is being used to restore river systems, but questions remain regarding their outcomes. We examine how the removal of two large dams in the Elwha River, coupled with hatchery production and fishing closures, affected population attributes of Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss). Initial responses by returning adult Chinook salmon and steelhead was an increase in the number and spatial extent of natural and hatchery origin fish. Although few naturally produced juvenile Chinook salmon and steelhead outmigrants were observed prior to and during dam removal, abundances increased three years after adult fish passage was restored, suggesting that impacts due to downstream sedimentation after dam removal were reduced. The Chinook salmon population demographics remain dominated by hatchery production, while increases in winter steelhead abundance included both hatchery and natural-origin spawners. The spatial expansion of winter steelhead upstream of former dam sites was predominantly by natural-origin spawners. We also observed a natural "reawakening" of summer steelhead that were in part derived from an up-river resident population that returned to the Upper Elwha. Our results showed that a combination of habitat, hatchery, and harvest actions can result in positive responses for salmonid populations. [ABSTRACT FROM AUTHOR]

Hatcheries and stocking programs serve a variety of objectives, including the conservation of salmon populations. Much attention has been given to the importance of genetic integrity and adaptive capacity of salmon stocks, particularly as they interact with hatchery‐origin fish. Literature on hatchery and stocking programs has increasingly focused on genetic indicators of quality and success, with genetically 'wild' salmon valued over hatchery‐influenced salmon. However, conservation in the Anthropocene is challenging paradigms of wildness and definitions of conservation success. For salmon populations that exist on the ragged edge of climate change where threats are unlikely to be remediated to the status of ecologies past, definitions of 'wild' and the role of conservation hatcheries and stocking becomes convoluted. If definitions of 'wild' or 'natural' salmon depend on salmon archetypes situated in historic ecologies, then what do salmon futures look like? In that context, we argue to expand from primarily genetic criteria for conservation stocking to additional criteria cognizant of hybrid ecosystems and future human‐salmon relationships. We draw on the concept of adaptive epistemologies within the context of conservation‐oriented hatchery and stocking programs to critically reflect on knowledge paradigms and values that underlie salmon conservation stocking efforts and the changing ecosystems in which they are situated. We critique 'wild' discourses rooted in western thought and make suggestions toward a reimagining of salmon conservation‐via‐hatchery in the Anthropocene that allows for expansive human‐salmon futures. Critically, we conclude with warnings against using the arguments in this paper as social permission to use hatcheries as a conservation panacea. [ABSTRACT FROM AUTHOR]

Local environmental stewardship supports resilience of social-ecological systems through a wide range of actions that benefit both environmental and human wellbeing. Stewardship actions of harvesters have been recognized as an important component in building adaptive capacity of coastal fisheries undergoing change. In Southeast Alaska, where commercial fishing plays a key role in cultures and economies, concerns for local fisheries have arisen from declines in salmon returns, high price variability, and barriers to participation, among other issues. Here, we aimed to understand existing and potential pathways for stewardship actions of small-boat commercial fishers in Juneau, Alaska. We conducted semi-structured interviews with 22 commercial fishers, agency staff, and leaders of seafood associations to document fisher-led stewardship actions and ways that small-boat commercial fishers engage formally and informally with local management, explore the role of fishery management agencies in facilitating collaboration and communication with fishers in the Juneau area, and understand local perspectives on how the stewardship capacities of the fishery system can be better supported. We found that multiple pathways for stewardship exist in commercial salmon and shellfish fisheries, including formal and informal interactions with state fishery management staff and decision-makers, participation in fishing associations and advocacy organizations, knowledge sharing among fishers, and taking personal conservation actions to care for fisheries. We identified areas of relatively low social, financial, and institutional capital that may limit the effectiveness of these stewardship actions. Our findings highlight diverse perspectives of fishery participants on how these stewardship actions might be better supported through policy, advocacy, and collaboration. [ABSTRACT FROM AUTHOR]

Thermal conditions in the nest affect the development of sea turtle clutches, with high temperatures potentially reducing reproductive success and the quality of hatchlings. In a warming climate, increasing temperatures could become a threat to sea turtles in many locations. This has prompted the implementation or recommendation of climate mitigation strategies in nests that incubate in hatchery conditions. Here, olive ridley turtle (Lepidochelys olivacea) clutches relocated to a beach hatchery in Playa Grande, Costa Rica (10° 20 N, 85° 51 W) were used to study the effect of temperature on hatching success and hatchling size. Data from 5 nesting seasons (2017/18 to 2022/23, excluding 2020/21) were tested to determine the effect of mean incubation temperature by thirds of development, as well as over the whole incubation period. Hatching success was lower at low and high temperatures and higher at intermediate ones during the second and last thirds of development. Optimal mean temperature ranges were 29–32 °C and 32–35 °C across the second and last thirds of development respectively, and 30–32.5 °C during the whole incubation period. There was no statistically significant effect of temperature on hatching success during the first third of development. High temperature resulted in shorter carapace width but did not statistically affect mass or carapace length. The temperature effect on carapace width occurred in all thirds of development. Studying temperature effects on target species nests at the local level, throughout incubation, and over multiple years is important for applying climate mitigation strategies properly. [ABSTRACT FROM AUTHOR]

Large dam removal is being used to restore river systems, but questions remain regarding their outcomes. We examine how the removal of two large dams in the Elwha River, coupled with hatchery production and fishing closures, affected population attributes of Chinook salmon (Oncorhynchus tshawytscha) and steelhead (O. mykiss). Initial responses by returning adult Chinook salmon and steelhead was an increase in the number and spatial extent of natural and hatchery origin fish. Although few naturally produced juvenile Chinook salmon and steelhead outmigrants were observed prior to and during dam removal, abundances increased three years after adult fish passage was restored, suggesting that impacts due to downstream sedimentation after dam removal were reduced. The Chinook salmon population demographics remain dominated by hatchery production, while increases in winter steelhead abundance included both hatchery and natural-origin spawners. The spatial expansion of winter steelhead upstream of former dam sites was predominantly by natural-origin spawners. We also observed a natural “reawakening” of summer steelhead that were in part derived from an up-river resident population that returned to the Upper Elwha. Our results showed that a combination of habitat, hatchery, and harvest actions can result in positive responses for salmonid populations.

Salmonellosis represents a critical problem not only to the poultry producers owing to it is economic impact, but also for poultry consumers due to it is zoonotic health problems. In the present study avian Salmonellae were isolated from local hatcheries in 2 Egyptian governorates, Beni Suef and El Fayoum, during the period from May, 2018 until November, 2019. Samples were collected from 16 local chicken hatcheries in Beni Suef (N=12) and El Fayoum (N=4) governorates. Specimens were collected from liver of dead in shell embryos. Salmonella isolation was successful in 31.25% of the samples. Serotyping revealed detection of S. kentucky, S. sinchew, S. infantis S. larochelle, and S. colindale. Salmonellae examination for antimicrobial susceptibility by disc diffusion method showed resistance to several antimicrobial drugs including [penicillin, amoxicillin, cefradine and streptomycine (no sensitivity at all) followed by apramycin and tetracyclines (25% sensitivity for each)]. On the other hand, Salmonellae were sensitive to enrofloxacin (100%) fosfomycin (75%) and sulphamethoxazole-trimethoprime (75%). Molecular screening of both virulence and drug resistance genes revealed the harboring of invA, stn, avrA virulence genes by all isolates. Phenotypic and genotypic variation in drug resistance was observed for different serovars and different classes of antimicrobial agents; S. infantis and S. larochelle were positive for PCR targeting qnrA gene although phenotypically they were sensitive to enrofloxacin. All of the tested serovars (except S. colindale) showed sensitivity to sulphamethoxazole-trimethoprime although they harbored sul1 gene. At the same time S. colindale harbored tetA gene and it was sensitive to oxytetracycline by disc diffusion. Similar discrepancy was observed for florfenicol and some aminoglycosides. [ABSTRACT FROM AUTHOR]

Fred Utter died in his sleep during the night of 5 March 2023 at the age of 91. In this paper, 3 friends and colleagues of Fred describe the important role that his genetics research has played in the management and conservation of fish populations. [ABSTRACT FROM AUTHOR]

The main discovery of the 20th century in the field of sturgeon breeding is “method of pituitary injections”. In earlier experiments, fish breeders needed to catch spawning sturgeons in nature because final stages of maturation in these fishes were blocked at hatcheries. The Leningrad ichthyologist N.L. Gerbilsky. Proposed methods of mass extraction of sturgeon pituitaries, their dehydration by acetone for later storage and use, testing of pituitary gonadotropic activity on different objects. The effective doses of dried pituitaries for sturgeons were determined in milligrams and loach units or frog units. This method of hormonal stimulation of final stages of maturation was used for functioning of sturgeon breeding facilities at Volga, Don, Kuban and Kura and other rivers. For guaranteed answer fish, breeders used hyperdoses of dry pituitary powder because its gonadotropic activity varied in dependence on stage of maturity of fish-“donors”. The followers of N.L. Gerbilsky led by Prof. I.A. Barannikova developed the technique of production of special glycerol hypophyseal extract (GHE) with determined gonadotropic activity. The main role in formulation of the recipe of GHE belongs to A.A. Boyev. The use of GHE has removed the problem of hyperdosing leading to worsening quality of mature germinal cells of sturgeons. Later A.A. Boyev on the basis of this recipe with replacement of glycerol to propylene glycol created stabilizing solution of analogue of mammal LH-RH (“surphagon”) of long-term storage with concentration of active substance from 20 to 500 micrograms/ml. [ABSTRACT FROM AUTHOR]

Abstract Background Aeromonas hydrophila is an opportunistic pathogen. Thus, it has received significant attention mainly in the fish sectors with high production scales. Nile tilapia broodstock confined in the environment of fish hatcheries can be stressed. Hence, they are vulnerable to A. hydrophila. Results Sequencing of the gyr B gene revealed the presence of 18 different A. hydrophila strains (kdy 10,620–10,637), which were deposited in the NCBI under accession numbers ON745861–ON745878. The median lethal doses of the isolates ranged from 2.62 × 104 to 3.02 × 106 CFU/mL. Antibiotic resistant genes, sulfonamide (sul1) and tetracycline (tetA) were found in the eighteen isolates. Approximately 83.3% of A. hydrophila strains were sensitive to ciprofloxacin and florfenicol. Further, eight A. hydrophila strains had high MDR indices at 0.27–0.45. All isolates presented with hemolysin activity. However, only 72.22% of them had proteolytic activity, and only 61.11% could form biofilms. Bacterial isolates harbored different pattern virulence genes, the heat-stable cytotonic enterotoxin (ast), cytotoxic enterotoxin (act), and hemolysin (hly) genes were the most prevalent. Also, a trial to inhibit bacterial growth was conducted using titanium dioxide nanoparticles (TiO2 NPs) with three sizes (13, 32, and 123 nm). If A. hydrophila strains with a high MDR index were tested against TiO2 NPs (20 µg/mL) for 1, 12, and 24 h, those with a small size had a greater bactericidal action than large ones. Bacterial strains were inhibited at different percentages in response to TiO2 NP treatment. Conclusions Nile tilapia broodstock, mortality is associated with different A. hydrophila strains, which harbored virulent and MDR genes. Furthermore, TiO2 NPs had bactericidal activity, thereby resulting in a considerable reduction in bacterial load.

Piscine orthoreovirus genotype 1 (PRV-1) is a common virus in farmed and wild salmon in the northeastern Pacific Ocean. Its regional occurrence in freshwater is far less clear. From 2019 to 2021, tissues of 5619 juvenile anadromous salmon (primarily Atlantic, Chinook, and coho) sampled from 12 commercial and 27 enhancement British Columbia hatcheries during 83 sampling events were screened for PRV-1 prior to seawater entry. More than 2200 (∼40%) were also screened using a Pan-PRV assay targeting all known PRV genotypes. PRV-1 was detected in four coho salmon at two freshwater enhancement facilities and in one Chinook salmon at a commercial facility. Partial (S1 segment) genome sequencing identified detections to be of the PRV-1 subgenotype endemic to the northeastern Pacific. PRV-1 was not detected (5611 individuals; 99.9%) or test results were inconclusive (3 individuals; 0.05%) for all remaining samples screened for PRV-1. PRV-2 and PRV-3 were not detected using the Pan-PRV assay. It is concluded that commercial and enhancement freshwater hatcheries of British Columbia contribute minimally to the prevalence and persistence of PRV-1 in anadromous salmon of the northeastern Pacific, and these hatcheries appear not to have contracted or participated in the distribution of nonendemic forms of PRV in recent years.

Many aspects of natural and hatchery origin salmonid genetics, physiology, behaviour, anatomy and life histories have been compared due to the concerns about what effects domestication and hatchery rearing conditions have on fitness. Genetic and environmental stressors associated with hatchery rearing could cause greater developmental instability (DI), and therefore a higher degree of fluctuating asymmetry (FA) in various bilaterally paired characters, such as otoliths. Nonetheless, to appropriately infer the effects of DI on otolith asymmetry, otolith mineralogy must be accounted for. Vateritic otoliths differ substantially from aragonitic otoliths in terms of mass and shape and can artificially inflate any measurement of FA if not properly accounted for. In this study, measurements of otolith asymmetry between hatchery and natural origin Coho salmon Oncorhynchus kisutch from three different river systems were compared to assess the overall differences in asymmetry when the calcium carbonate polymorph accounted for 59.3% of otoliths from hatchery origin O. kisutch was vateritic compared to 11.7% of otoliths from natural origin O. kisutch. Otolith mineralogy, rather than origin, was the most significant factor influencing the differences in asymmetry for each shape metric. When only aragonitic otoliths were compared, there was no difference in absolute asymmetry between hatchery and natural origin O. kisutch. The authors recommend other researchers to assess otolith mineralogy when conducting studies regarding otolith morphometrics and otolith FA. [ABSTRACT FROM AUTHOR]

Background: Exposure to microbes early in life has long-lasting effects on microbial community structure and function of the microbiome. However, in commercial poultry settings chicks are reared as a single-age cohort with no exposure to adult birds which can have profound effects on microbiota development and subsequent pathogen challenge. Microbiota manipulation is a proven and promising strategy to help reduce pathogen load and transmission within broiler flocks. However, administration of microbiota transplant products in a hatchery setting may prove challenging. Effective administration strategies are dependent on key factors, such as; the age of chicks receiving interventions and mode of delivery. This study aimed to assess these two aspects to provide supporting evidence towards microbiome manipulation strategies for use in commercial hatcheries. Results: Manipulation of the microbiota between 4 and 72 h of hatch markedly reduced faecal shedding and colonisation with the foodborne pathogen Salmonella enterica serovar Typhimurium (ST4/74). Administration of transplant material via spray or gel drop delivery systems had minimal effect on the protection conferred with fewer birds in transplant groups shown to shed ST4/74 in the faeces compared to PBS-gavaged control birds. Analysis of the microbiome following transplantation demonstrated that all transplant groups had higher diversity and species richness than non-transplant groups during the first week of life and the early stages of infection with ST47/4.The relative abundance of the bacterium Faecalibacterium prausnitzii was significantly higher in CMT groups compared to PBS controls. The presence of F. prausnitzii was also shown to increase in PBS-challenged birds compared to unchallenged birds potentially indicating a role of this bacterium in limiting Salmonella infections. Conclusions: This study demonstrated that administration of microbiome transplants, using methods that would align with hatchery practices, effectively reduced colonisation and shedding of Salmonella in chickens. Age of chicks at microbiome administration had limited effect on the diversity and composition of the microbiome and conferred protection against Salmonella infections. Traditional hatchery delivery systems, such as spray or gel-drop, are sufficient to transfer donor material, alter the microbiome and confer protection against Salmonella. This study helps highlight the opportunity for use of microbiome modification methods within the hatchery. [ABSTRACT FROM AUTHOR]

Simple Summary: The artificial reproduction of endangered Sturgeon in the transboundary Caspian basin has been performed by five states (Russia, Iran, Kazakhstan, Azerbaijan, Turkmenistan). The Russian Federation is the Sturgeon breeding leader with the largest number of Sturgeon Hatcheries—eight, which produce and release up to 61 million Sturgeon juveniles into the natural habitat. This technology was systematized and published in the Caspian states national and international scientific press and FAO. However, this guide does not sufficiently reflect the presence of Sturgeon anomalies in early ontogenesis, identified in the second half of the 20th century. The change in Sturgeon breeding paradigm from wild producers to brood stock spawners provides the incentive and basis for detailed study of Sturgeon anomalies. All previously known Sturgeon anomalies are divided into nine classes. Assessment of Sturgeon anomalies as predictors of their survival in the natural habitat will allow the evaluation of the Sturgeon stock status in the Caspian Sea. Purpose: Review the experience, principles and parameters of the sturgeon assessment quality by anomalies in early ontogeny. Results: Maintaining the number of sturgeon fish in the transboundary Caspian Sea is provided by five states (Russia, Iran, Azerbaijan, Turkmenistan, Kazakhstan) at 16 Sturgeon hatcheries, where their artificial reproduction is carried out. FAO recognizes Russia's leadership in creating the basic technology for the sturgeon artificial reproduction, but the other four Caspian states also make a significant contribution to its modern optimizations. There is almost a century of tradition behind the technological development of artificial reproduction in sturgeons. During the artificial reproduction of sturgeons, anomalies in the structure and functions may occur, such as deformities, defects in organs and tissues, edema, hematomas, etc. The sturgeon anomalies classification is based on structural and functional principles. Identification of anomalies is carried out on the basis of a previously created classification, divided into nine large classes. Identification of sturgeon anomalies during the period of their artificial reproduction makes it possible to clarify the real value of replenishment of their stock. Methods: Analysis of professional scientific literature and practical guides. Conclusions: The presence and number of Sturgeon anomalies make it possible to determine their death percentage to calculate the real number of replenishment of the Caspian Sturgeon stock. [ABSTRACT FROM AUTHOR]

The gut microbiome may represent a relatively untapped resource in the effort to manage and conserve threatened or endangered fish populations, including wild and hatchery-reared Pacific salmonids. To clarify this potential, we defined how steelhead trout gut microbiome composition varies across watersheds and as a function of ancestry. First, we measured this variation across watersheds using wild steelhead trout sampled from nine locations spanning three river basins. While gut microbial composition differs across basins, there exist bacterial clades that are ubiquitous across all populations. Correlating the phylogenetic composition of clades with geographic distance reveals 395 clades of bacteria whose ecological distribution implicates their co-diversification with steelheads. Second, we quantified how microbiome composition varies between first generation hatchery-reared steelhead and traditional hatchery-reared steelhead. Despite being subject to the same hatchery management strategies, fish bred from wild parents carry distinct microbiomes from those bred from hatchery broodstock, implicating the role of genotype on microbiome composition. Finally, we integrated all data from both studies to reveal two distinct, yet robust clusters of community composition. Collectively, our study documents for the first time how the steelhead gut microbiome varies by geography or broodstock and uncovers microbial taxa that may indicate the watershed or hatchery from which an individual was sourced. [ABSTRACT FROM AUTHOR]

Pacific salmon (Oncorhynchus spp.) are exposed to increased environmental change and multiple human stressors. To anticipate future impacts of global change and to improve sustainable resource management, it is critical to understand how wild salmon populations respond to stressors associated with human‐caused changes such as climate warming and ocean acidification, as well as competition in the ocean, which is intensified by the large‐scale production and release of hatchery reared salmon. Pink salmon (O. gorbuscha) are a keystone species in the North Pacific Ocean and support highly valuable commercial fisheries. We investigated the joint effects of changes in ocean conditions and salmon abundances on the productivity of wild pink salmon. Our analysis focused on Prince William Sound in Alaska, because the region accounts for ~50% of the global production of hatchery pink salmon with local hatcheries releasing 600–700 million pink salmon fry annually. Using 60 years of data on wild pink salmon abundances, hatchery releases, and ecological conditions in the ocean, we find evidence that hatchery pink salmon releases negatively affect wild pink salmon productivity, likely through competition between wild and hatchery juveniles in nearshore marine habitats. We find no evidence for effects of ocean acidification on pink salmon productivity. However, a change in the leading mode of North Pacific climate in 1988–1989 weakened the temperature–productivity relationship and altered the strength of intraspecific density dependence. Therefore, our results suggest non‐stationary (i.e., time varying) and interactive effects of ocean climate and competition on pink salmon productivity. Our findings further highlight the need for salmon management to consider potential adverse effects of large‐scale hatchery production within the context of ocean change. [ABSTRACT FROM AUTHOR]

This cross-sectional study was conducted to determine the occurrence, risk factors, and characteristics of Salmonella isolates recovered from imported fertile broiler hatching eggs, hatcheries, and broiler farms in Trinidad and Tobago. Standard methods were used to isolate and characterize Salmonella isolates from two broiler hatcheries and 27 broiler farms in the country. The frequency of isolation of Salmonella was 0.0% for imported fertile hatching eggs (0 of 45 pools of 10 eggs each, i.e., 450 eggs), 7.6% for hatcheries (12 of 158 samples), and 2.8% for broiler farms (24 of 866 samples) (P = 0.006). Stillborn chicks at hatcheries had the highest prevalence of Salmonella (7 of 28 samples, 28.0%), whereas on broiler farms the cloacal swabs had the highest prevalence of Salmonella (15 of 675 samples, 2.2%). None of the 15 farm management and production practices investigated were significantly associated (P > 0.05) with the isolation of Salmonella. The predominant Salmonella serotypes were Kentucky (83.3%) and Infantis (62.5%) among hatchery and farm isolates, respectively. The disk diffusion method revealed frequencies of antimicrobial resistance (i.e., resistance to one or more agents) of 44.0% (11 of 25 isolates) and 87.5% (35 of 40 isolates) at hatcheries and broiler farms, respectively (P = 0.0002). Antimicrobial resistance among hatchery isolates was highest (28.0%) to doxycycline and kanamycin and was very high (>65%) among farm isolates to sulfamethoxazole-trimethoprim, gentamicin, ceftriaxone, kanamycin, and doxycycline. Multidrug resistance (MDR; i.e., resistance to antimicrobial agents from three or more classes) was exhibited by 4.0 and 85.7% of Salmonella isolates recovered from several environmental and animal sources at the hatcheries and farms, respectively (P < 0.0001). The high level of antimicrobial resistance and the presence of MDR among Salmonella isolates from broiler farms highlight the therapeutic implications and the potential for MDR strains to enter the food chain. [ABSTRACT FROM AUTHOR]

In this study, we aimed to set up and test two models of annular-column photobioreactors (AC-PBR 1 and AC-PBR 2) in order to produce microalgae for fish hatcheries. Both models with a different design were characterized by a short light-path and central LED light source providing homogenous illumination of thin culture layer, sufficient mixing, and continuous temperature control guaranteed a stable cultivation regime and high biomass productivity. The AC-PBR 1 is characterized by a culture thickness of 5.5 cm and the maximum irradiance of 1200 µmol photons m−2 s−1 while in AC-PBR 2, the culture layer was decreased to 4.6 cm and the maximum irradiance intensity could reach 1600 µmol photons m−2 s−1. AC-PBR 1 and AC-PBR 2 were compared using the selected microalgae strain Vischeria helvetica (class Eustigmatophyceae) which is a suitable feed source for rotifers further used as a live food for fish larvae. The photosynthetic performance, biomass productivity, pigment content, and fatty acid profile were evaluated. The volumetric productivity under continuous illumination at optimal growth temperature reached 0.16 and 0.33 g DW L−1 day−1, corresponding to an areal productivity of 12.4 and 18.9 g DW m−2 day−1 for AC-PBR 1 and AC-BR2, respectively. [ABSTRACT FROM AUTHOR]

This study was conducted to determine antibiotic susceptibility of Flavobacterium psychrophilum isolated in diseased rainbow trout (Oncorhynchus mykiss) from two hatcheries in the Mediterranean region of Turkey. The samples were taken from the kidney and spleen for bacteriology from rainbow trout juveniles (weight 0.7-1 g) in April and isolates obtained on tryptone yeast extract salts (TYES) agar medium at 15°C for 72 hours. Fourteen isolates were identified as F. psychrophilum using biochemical, physiological, and morphological characteristics and API ZYM test. Antibiotic sensitivities of the isolates were determined by the disc diffusion method on TYES agar, and the results were evaluated according to CLSI standards. Only one isolate from each hatchery was used for the antibiogram test. Both isolates were sensitive to amoxicillin/clavulanic acid 2:1, penicillin, nitrofurantoin, florfenicol, amoxicillin, clindamycin, chloramphenicol, ampicillin, doxycycline, streptomycin, and erythromycin; resistant to sulfadiazine, sulfamethoxazole/trimethoprim, oxolinic acid, vancomycin, trimethoprim/sulfadiazine, gentamicin, kanamycin, nalidixic acid, oxacillin, enrofloxacin, flumequine, tobramycin. The results show that isolating F. psychrophilum and performing the antimicrobial susceptibility testing is important issue in disease control. [ABSTRACT FROM AUTHOR]

Abstract Stakeholders with shared interests in fish conservation often disagree about which specific conservation measures are appropriate, leading to conflicts with sometimes long‐lasting and disruptive social and political effects. Managers are challenged to balance opposing stakeholder preferences with their own mandates in a charged environment. Using the 2014 termination of Atlantic salmon (Salmo salar) stocking in Wales as a case, we conducted a critical discourse analysis of interview data, online print media, social media and policy documents to examine conflict and its mechanisms over time. The data sources represented four discourse planes: the social, media, social media and policy planes. We report five key findings: The conflict around salmon stocking took place in three stages, beginning with a negotiated, manifest conflict that escalated during the 2014 policy process that terminated stocking, creating a persistent spin‐off conflict. The stocking debate was shaped by two discourse coalitions promoting either pro‐ or anti‐hatchery arguments, and an emerging third coalition advocating for compromise. The coalitions disagreed on the effectiveness of stocking, the status of the salmon stock and had different management goals, revealing that the pro‐ or anti‐stocking debate was caused by complex, intertwined and partly opposing beliefs and values. Different elements of the discourses emerged on different planes and arguments were mobile across the planes over time, explaining how selected key arguments were able to persist, gain dominance, re‐appear over time, thus dynamically fuelling and (re)shaping the conflict. The policy change decision to terminate stocking in Wales institutionalized anti‐stocking discourses. It forced all stakeholder groups to acquiesce to one perspective of stocking, creating a win‐lose situation for some stakeholders. The handling and result of the policy change led to the alienation of some stakeholder groups. Ecological management goals were achieved in the short term, but the acrimonious and yet‐unsettled social side effects affected the long‐term relationships and may negatively impact future conservation issues in the area. We conclude that transdisciplinary active management designed for joint learning about stocking trade‐offs may be a suitable alternative to the ‘either‐or' outcomes observed in Wales that fostered sustained stakeholder conflicts instead of joint production of knowledge and understanding. A free Plain Language Summary can be found within the Supporting Information of this article. An abridged and annotated audio version of this article can be found here.

Incubation temperatures, sex ratio and hatching success of leatherback turtles have received little attention in conservation programs in Mexico. This study was carried out from October 2014 to May 2017 in two enclosed hatchery sites. To determine temperature parameters in the nest chamber environment and their variation during the incubation period, we placed data loggers in the centre of the egg mass in relocated nests. We then buried other data loggers in the sand near the relocated nests, inside and outside the hatchery. A total of 46 nests were examined over three nesting seasons. Mean nest temperature showed no statistical difference between nests in either the San Juan Chacahua hatchery or in the Palmarito hatchery nests. The mean sex ratio based on average temperature during the middle third of incubation duration was 96.3 % skewed to female production. Hatching success in both San Juan Chacahua and Palmarito was high. Our findings support the common pattern of a female–dominated leatherback turtle sex ratio. Furthermore, hatching success rates in the shade–cloth hatchery were higher than those in the natural nests observed in other population.

Purpose: Review the experience, principles and parameters of the sturgeon assessment quality by anomalies in early ontogeny. Results: Maintaining the number of sturgeon fish in the transboundary Caspian Sea is provided by five states (Russia, Iran, Azerbaijan, Turkmenistan, Kazakhstan) at 16 Sturgeon hatcheries, where their artificial reproduction is carried out. FAO recognizes Russia’s leadership in creating the basic technology for the sturgeon artificial reproduction, but the other four Caspian states also make a significant contribution to its modern optimizations. There is almost a century of tradition behind the technological development of artificial reproduction in sturgeons. During the artificial reproduction of sturgeons, anomalies in the structure and functions may occur, such as deformities, defects in organs and tissues, edema, hematomas, etc. The sturgeon anomalies classification is based on structural and functional principles. Identification of anomalies is carried out on the basis of a previously created classification, divided into nine large classes. Identification of sturgeon anomalies during the period of their artificial reproduction makes it possible to clarify the real value of replenishment of their stock. Methods: Analysis of professional scientific literature and practical guides. Conclusions: The presence and number of Sturgeon anomalies make it possible to determine their death percentage to calculate the real number of replenishment of the Caspian Sturgeon stock.

Determination of the chick embryonic developmental period at which embryonic mortalities occur could help in establishing the cause of such mortalities. The late stage of embryonic development has particular importance due to its dramatic effect on life after hatching. This study was conducted to investigate the occurrence, frequency and bacterial isolates from dead-in-shell chick embryos in Northern Jordan. A total of 1,000 unhatched eggs were collected at hatching day from 10 hatcheries located in Northern Jordan. Out of 1,000 eggs, 357 (35.7%) were fertile, of which 210 (58.8%) were dead-in-shell embryos. Approximately 50.5% of the dead embryos displayed abnormalities, including neck muscles with subcutaneous petechial haemorrhages (44.3%), beak abnormalities (3.8%), eye deformities (1.9%) and anencephaly (0.5%). Sixty-six bacterial isolates were identified from 82 samples from the dead-in-shell embryos. The isolates were 22 (33.3%) Escherichia coli, 18 (27.3%) Klebsiella pneumoniae, 14 (21.2%) Staphylococcus aureus, 5 (7.6%) Pseudomonas aeruginosa, 4 (6.1%) Salmonella enteritidis, 2 (3%) Bacillus cereus and 1 (1.5%) Proteus vulgaris. Mixed growth was also recorded in 16 (19.5%) samples. There was a significant (P < 0.05) association between Escherichia coli as a bacterial isolate and the occurrence of neck and beak abnormalities. In this study, infection of check embryos with several bacterial species, particularly Escherichia coli, was identified as an important cause of multiple congenital abnormalities involving the neck and beak of unhatched chicks.

The gut microbiome may represent a relatively untapped resource in the effort to manage and conserve threatened or endangered fish populations, including wild and hatchery-reared Pacific salmonids. To clarify this potential, we defined how steelhead trout gut microbiome composition varies across watersheds and as a function of ancestry. First, we measured this variation across watersheds using wild steelhead trout sampled from nine locations spanning three river basins. While gut microbial composition differs across basins, there exist bacterial clades that are ubiquitous across all populations. Correlating the phylogenetic composition of clades with geographic distance reveals 395 clades of bacteria whose ecological distribution implicates their co-diversification with steelheads. Second, we quantified how microbiome composition varies between first generation hatchery-reared steelhead and traditional hatchery-reared steelhead. Despite being subject to the same hatchery management strategies, fish bred from wild parents carry distinct microbiomes from those bred from hatchery broodstock, implicating the role of genotype on microbiome composition. Finally, we integrated all data from both studies to reveal two distinct, yet robust clusters of community composition. Collectively, our study documents for the first time how the steelhead gut microbiome varies by geography or broodstock and uncovers microbial taxa that may indicate the watershed or hatchery from which an individual was sourced.

Artificial propagation strategies often incur selection in captivity that leads to traits that are maladaptive in the wild. For propagation programs focused on production rather than demographic contribution to wild populations, effects on wild populations can occur through unintentional escapement or the need to release individuals into natural environments for part of their life cycle. In this case, 2 alternative management strategies might reduce unintended fitness consequences on natural populations: (1) reduce selection in captivity as much as possible to reduce fitness load (keep them similar), or (2) breed a separate population to reduce captive-wild interactions as much as possible (make them different). We quantitatively evaluate these 2 strategies with a coupled demographic-genetic model based on Pacific salmon hatcheries that incorporates a variety of relevant processes and dynamics: selection in the hatchery relative to the wild, assortative mating based on the trait under selection, and different life cycle arrangements in terms of hatchery release, density dependence, natural selection, and reproduction. Model results indicate that, if natural selection only occurs between reproduction and captive release, the similar strategy performs better. However, if natural selection occurs between captive release and reproduction, the different and similar strategies present viable alternatives to reducing unintended fitness consequences because of the greater opportunity to purge maladaptive individuals. In this case, the appropriate approach depends on the feasibility of each strategy and the demographic goal (e.g., increasing natural abundance, or ensuring that a high proportion of natural spawners are naturally produced). In addition, the fitness effects of hatchery release are much greater if hatchery release occurs before (vs. after) density-dependent interactions. Given the logistical challenges to achieving both the similar and different strategies, evaluation of not just the preferred strategy but also the consequences of failing to achieve the desired target is critical.

This study was conducted to test the effect of different micro-algal food on the development and the survival of the early stages of sea cucumber (Holothuria scabra) in the Red Sea at the Kingdom of Saudi Arabia. Four types of microalgae, Chaetoceros gracilis, Isochrysis galbana and Tetraselmis chuii and Spirulina powder were tested individually and in a mixture. Good positive results were observed with Chaetoceros gracilis, Isochrysis galbana and Tetraselmis chuii, whether singly used or in a mixture. Full larval metamorphosis, from late-auricularia to dololaria, was recorded with the mixture of micro-algae at 96 hours, while Chaetoceros gracilis, Isochrysis galbana and Tetraselmis chuii recorded 90%, 92% and 82%, respectively. After 72 hrs, a full larval settlement was recorded with Tetraselmis chuii and the mixture of micro-algae. Whereas, a percentage of 97 and 91 of larval settlement was shown with Isochrysis galbana and Chaetoceros gracilis, respectively. The survival rate of larvae, from the first day of hatching to the juveniles, was 7% with the mixture of microalgae followed by 4% with Isochrysis galbana and 2% for both Tetraselmis chuii and Chaetoceros gracilis. The current study proved that feeding the larvae of sea cucumber on different types of live micro-algae was beneficial to increase the survival rate, and improve the larval metamorphosis and settlement. However, considering the current data, future investigations are required to enrich the existing data with proper information to develop sea cucumber hatcheries. [ABSTRACT FROM AUTHOR]

Hatcheries release >4.5 billion juvenile Pacific salmon (Oncorhynchus spp.) into the North Pacific Ocean annually, raising concerns about competition with wild salmon populations. We used retrospective scale analysis to investigate how the growth of chum salmon (O. keta) from western Alaska is affected by the abundance of chum salmon from Japanese hatcheries and wild pink salmon (O. gorbuscha) from the Russian Far East. Over nearly five decades, the growth of Kuskokwim River chum salmon was negatively correlated with the abundance of Japanese hatchery chum salmon after accounting for the effects of sex and spring/summer sea‐surface temperature in the Bering Sea. An effect of wild eastern Kamchatka pink salmon abundance on the growth of Kuskokwim River salmon was detectable but modest compared to the intraspecific competitive effect. A decrease in Japanese hatchery chum salmon releases in 2011–2013 was not associated with increased growth of Bering Sea chum salmon. However, the abundance of wild chum salmon from the Russian Far East increased during that time, possibly obscuring reduced competition with hatchery chum salmon. Our results support previous evidence that chum salmon are affected by intraspecific competition, and to a lesser extent interspecific competition, in the North Pacific, underscoring that the effects of salmon hatchery production transcend national boundaries. [ABSTRACT FROM AUTHOR]

This paper is concerned with fishing in tile kingdom of Valencia during the Middle Ages based, niainly, on documentary evidence. Due to features of the sources, il focuses on coastal fishing although it also explores the inland fishing and the existence of fisheries and hatcheries. Although fishing was practised by people from different economic contexts, this paper focused on those that made fishing not their unique but their main professional activity. Through examination of notarial records, local regulations and registries of the court of justice, it analyses fishermen both from a social and an economic perspective. Besides. it deals with the cost of the means of production, trying to stablish how much a boat and the nets costed. Fishing techniques are also studied. An attempt of examining production is made using fish tithe evidence. Consumption is also analysed considering differences among the different social sections but also in accordance with the different religions. Finally, it tackles the trading, the supply and the consumption of fish thanks to urban regulations and tithe, manorial and local custom accounts. [ABSTRACT FROM AUTHOR]

Abstract Understanding how protected species influence the population dynamics of each other is an essential part of ecosystem‐based management. Chinook salmon (Oncorhynchus tshawytscha) are critical prey for endangered southern resident killer whales (SRKWs; Orcinus orca), and increasing releases of hatchery Chinook salmon has been proposed to aid SRKW recovery. We analyzed 30 yr of data and found that density‐dependent survival of hatchery Chinook salmon released into the central and southern parts of the Salish Sea (Washington, USA; and British Columbia, Canada) may be associated with the presence of naturally produced pink salmon (O. gorbuscha), which are highly abundant as juveniles only in even‐numbered years. We first modeled hatchery Chinook salmon marine survival as a function of the numbers of juvenile Chinook released and the presence of emigrating juvenile pink salmon between 1983 and 2012. Then, we related reconstructed numbers of hatchery Chinook salmon returning to Puget Sound to the abundance of juvenile Chinook released in even (pink emigration) and odd (non‐pink emigration) years from 1980 to 2010. We found that in some regions of the Salish Sea, both hatchery Chinook salmon marine survival and adult Chinook returns varied depending on the number of hatchery Chinook released and the presence of juvenile pink salmon. Specifically, in some regions survival of hatchery Chinook salmon decreased when greater numbers of juveniles were released into the Salish Sea in even years, when large numbers of pink salmon were present, but increased or remained stable when pink salmon were not present in large numbers (in odd years). This suggests lower, density‐dependent survival of juvenile Salish Sea Chinook salmon during even outmigration years. Our analyses suggest that scientists and managers should further investigate potential mechanisms for density‐dependent survival of hatchery Chinook salmon from Salish Sea hatcheries when designing strategies to maximize adult returns.

Infections associated with Escherichia coli are responsible for immense losses in poultry production; moreover, poultry products may serve as a source of pathogenic and/or resistant strains for humans. As early as during the first hours of life, commercially hatched chickens are colonized with potentially pathogenic E. coli from the environment of hatcheries. The source of contamination has not been quite elucidated and the possibility of vertical spread of several avian pathogenic E. coli (APEC) lineages has been suggested, making the hatcheries an important node where cross-contamination of chicken of different origin can take place. The recent technological progress makes the method of whole-genome sequencing (WGS) widely accessible, allowing high-throughput analysis of a large amount of isolates. Whole-genome sequencing offers an opportunity to trace APEC and extended-spectrum/plasmid-encoded AmpC beta-lactamasesproducing E. coli (ESBL/pAmpC-E.coli) along the poultry processing chain and to recognize the potential pathways of “epidemicˮ sequence types. Data from WGS may be used in monitoring antimicrobial resistance, comparative pathogenomic studies describing new virulence traits and their role in pathogenesis and, above all, epidemiologic monitoring of clonal outbreaks and description of different transmission routes and their significance. This review attempts to outline the complexity of poultry-associated E. coli issues and the possibility to employ WGS in elucidating them. [ABSTRACT FROM AUTHOR]

Aquaculture farms, such as the ones that produce mollusks, marine fish, and shrimp, require a constant supply of microalgae biomass as feed. Microalgae cultures are subject to failures in continuity; therefore, concentrated inocula could be used during episodes of crashes to reestablish the production of microalgae biomass. For this reason, the present work evaluated a concentrated inocula of the microalgae Nannochloropsis oculata harvested by flocculation and stored in a refrigerator with additives (vitamin C or citric acid) and without additives. Sensorial analysis (color and odor), protein content, cell integrity rate, cell resuspension rate, and culture growth parameters (maximum cell density and growth rate) were estimated for 15 weeks. The concentrates with citric acid presented an alteration in the color aspect at the 11th week of storage. No differences were seen in the protein content and cell integrity rates either between storage methods or storage weeks. In sum, the use of additives did not significantly influence the growth performance of any of the treatments, since their cells continued to reproduce throughout the entire trial period. In addition, the additives enhanced the cell resuspension rate of the concentrates. For that reason, the concentrated inoculum with vitamin C was selected as the best treatment. [ABSTRACT FROM AUTHOR]

Operational characteristics as influenced by management systems are crucial to the sustainability of fish seed production industry. However, there is a dearth of technical information on the characteristics and financial performance of most fish hatcheries in Nigeria. There is, therefore, a need to provide this information to properly guide existing operators and the will-be investors on operational features that will ensure sustainability of fish seed production in Nigeria. The study was, therefore, carried out to compare and understand the performance of different fish seed production management systems in Ibadan, Nigeria. A survey of 51 registered and operational hatcheries employing flow-through (FL), recirculating cum flow-through (RCFL) and recirculating systems (RC), in the eleven Local government areas of Ibadan metropolis was carried out between April and May, 2017. Technical information was sourced using structured questionnaire. Data was analysed using descriptive statistics and oneway ANOVA with means separated using Duncan Multiple Range Test. The study showed that the average African Catfish hatchery production was 4.90 million seed per year as computed from the mean from the three systems (2.29 million, 2.63 million and 9.79 million for RC, RCFL and FL systems, respectively). On average, 64.6% of hatchery production was sold as fingerlings (5cm), while 35.4% of seed production was sold as juveniles (8 -15cm). Total costs and total revenues in FL hatcheries (N21.38 million and N86.09 million, respectively) were highest and least values (N5.62 million and N22.72 million, respectively) were recorded in RC hatcheries. Net profits were significantly higher in FL systems (79.6% of sales) and RC systems (79.2% of sales), than RCFL (67.7% of sales) and. A 50% reduction in seed price and 75% increase in operating costs resulted in losses only in RCFL system. Main challenges of hatchery operation were price fluctuation, a high cost of power and availability of high-quality broodstock, among other factors. Flow-through culture system is mostly adopted in Ibadan, South-western Nigeria and gave the highest net profit as a percentage of sales, but profit was marginally higher than the result from the recirculating system. [ABSTRACT FROM AUTHOR]

Understanding how protected species influence the population dynamics of each other is an essential part of ecosystem-based management. Chinook salmon (Oncorhynchus tshawytscha) are critical prey for endangered southern resident killer whales (SRKWs; Orcinus orca), and increasing releases of hatchery Chinook salmon has been proposed to aid SRKW recovery. We analyzed 30 yr of data and found that density-dependent survival of hatchery Chinook salmon released into the central and southern parts of the Salish Sea (Washington, USA; and British Columbia, Canada) may be associated with the presence of naturally produced pink salmon (O. gorbuscha), which are highly abundant as juveniles only in evennumbered years. We first modeled hatchery Chinook salmon marine survival as a function of the numbers of juvenile Chinook released and the presence of emigrating juvenile pink salmon between 1983 and 2012. Then, we related reconstructed numbers of hatchery Chinook salmon returning to Puget Sound to the abundance of juvenile Chinook released in even (pink emigration) and odd (non-pink emigration) years from 1980 to 2010. We found that in some regions of the Salish Sea, both hatchery Chinook salmon marine survival and adult Chinook returns varied depending on the number of hatchery Chinook released and the presence of juvenile pink salmon. Specifically, in some regions survival of hatchery Chinook salmon decreased when greater numbers of juveniles were released into the Salish Sea in even years, when large numbers of pink salmon were present, but increased or remained stable when pink salmon were not present in large numbers (in odd years). This suggests lower, density-dependent survival of juvenile Salish Sea Chinook salmon during even outmigration years. Our analyses suggest that scientists and managers should further investigate potential mechanisms for density-dependent survival of hatchery Chinook salmon from Salish Sea hatcheries when designing strategies to maximize adult returns. [ABSTRACT FROM AUTHOR]

Abstract For over a century, hatchery programs have been used to subsidize natural salmon populations in order to increase fisheries opportunities and, more recently, to conserve declining natural populations. While an extensive literature has described the impacts of large‐scale hatchery operations on freshwater ecosystems, less attention has been given to ecosystem interactions within the marine environment. We analyzed records of hatchery‐released Chinook salmon in the Salish Sea to assess temporal and spatial changes in hatchery practices since 1950, with the goal of identifying potential implications for ecosystem dynamics and conservation efforts in the region. Over the past 65 yr, we found significant changes in the size and time at which juvenile salmon are released, resulting in decreased diversity of these traits. Research suggests that predation on juvenile salmon by other fish, avian, and marine mammal species could be size‐dependent, and our results indicate that current hatchery practices are releasing Chinook salmon in the size range preferred by these predators. With current marine survival rates at chronically low levels, and increasing demand for hatchery subsidies, it is important to consider how modifying existing hatchery programs intended to reduce homogenization may promote more natural marine food web dynamics, with potential benefits to both hatchery and natural Chinook populations.

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For over a century, hatchery programs have been used to subsidize natural salmon populations in order to increase fisheries opportunities and, more recently, to conserve declining natural populations. While an extensive literature has described the impacts of large-scale hatchery operations on freshwater ecosystems, less attention has been given to ecosystem interactions within the marine environment. We analyzed records of hatchery-released Chinook salmon in the Salish Sea to assess temporal and spatial changes in hatchery practices since 1950, with the goal of identifying potential implications for ecosystem dynamics and conservation efforts in the region. Over the past 65 yr, we found significant changes in the size and time at which juvenile salmon are released, resulting in decreased diversity of these traits. Research suggests that predation on juvenile salmon by other fish, avian, and marine mammal species could be size-dependent, and our results indicate that current hatchery practices are releasing Chinook salmon in the size range preferred by these predators. With current marine survival rates at chronically low levels, and increasing demand for hatchery subsidies, it is important to consider how modifying existing hatchery programs intended to reduce homogenization may promote more natural marine food web dynamics, with potential benefits to both hatchery and natural Chinook populations. [ABSTRACT FROM AUTHOR]

The Anthropocene, simply put, is characterized by the recognition that natural processes are inextricably entwined with human influence. Against this backdrop, managing natural resources needs to be fundamentally rethought as balancing human-nature entanglements continues to challenges policymakers and conservation managers obligated toward politically and scientifically feasible measures. A closer look at wild Atlantic salmon management in Europe reveals dynamic shifts over the past two centuries, particularly with regard to how hatcheries are used as conservation tools. We use case studies on Norwegian and Welsh wild salmon cultivation practices to trace these shifts in conservation and management practices. We frame our analysis through a lens of shifting conceptualizations of naturalness and human-salmon relationships. Starting at the multinational level and then moving to groundlevel cases, we show how naturalness is conceptualized by managers and hatchery stakeholders, and how those perceptions play into definitions of desired outcomes for wild salmon conservation as well as the strategies and technologies implemented to achieve these conservation goals. We highlight two paradoxes that are illuminated by the disputes and shifting perceptions surrounding salmon hatcheries. First, we show that hatcheries are no longer perceived as appropriate tools to increase wild salmon populations. Rather, hatchery technologies are being withdrawn, limited, or transformed, often resulting in local-level controversy. Paradoxically, these changes are, in themselves highly technical processes involving genomic testing and big data inventories. Second, despite the recognition of ever more complex human-nature entanglements, the practical outcomes for salmon conservation are oriented toward standardized testability and manageability and limiting certain human-salmon interactions, and although some technologies are instrumental, others are disregarded. As a result, those techno-social communities organized around hatchery technologies are at risk of being removed or otherwise excluded from their preferred conservation activities. [ABSTRACT FROM AUTHOR]

Regular flusher-disinfection in hatcheries is an important measure to prevent epidemic diseases. However, traditional chemical disinfectants used in hatcheries can cause toxic residue, low disinfection effect and bacterial resistance. In practical production of hatchery, the traditional clean-in-place including three parts: 1) surface of the inside wall of the hatcher, 2) surface of the floor, 3) surface of the hatching basket. The flusher-disinfection durations were set 4 min for the surface of the inside wall of the hatcher and the floor and 40 s for the surface of the hatching basket with traditional chemical disinfectants (povidone-iodine solution or benzalkonium bromide solution) to reduce the number of bacterial microorganisms and maintain good hygiene condition. Slightly acidic electrolyzed water (SAEW, pH=5.0-6.5) is proved to be a broad-spectrum, high-efficiency, low corrosive, residue-free, and environment-friendly disinfectant, which could be a potential alternative disinfection of the traditional chemical disinfectants. Aiming at finding an optimal of using SAEW in cleaning hatcher and reducing cleaning costs, an experiment with three components: bacterial distribution on the surface of the hatching equipment, germicidal efficacy of various disinfectants, and the effect of disinfection time on the sterilizing rate were conducted. Surface swabbing was used to sample the total bacteria, Escherichia coli, and Staphylococcus aureus on the surface of the inside wall, floor, and hatching basket of the hatching equipment. SAEW with the concentrations of 60, 80, and 100 mg/L, as alternative disinfections of flusher disinfection, were chosen to compare with two traditional chemical disinfectants (povidone-iodine solution and benzalkonium bromide solution) by single-factor test. In the study of the effect of disinfection time on the sterilizing rate, disinfection durations were set as 1, 2, 3, 4, 5 min for the surface of inside wall and floor, and 10, 20, 30, 40 s for the surface of hatching basket, respectively. high-pressure water jet with nozzle orifice diameter of 2.2 mm operated at 3.5 MPa was used in the whole cleaning process. The results showed that flusher-disinfection using 60-100 mg/L (available chlorine concentration, ACC) slightly acidic electrolytic water could effectively reduce the total bacteria (total aerobic bacteria), Escherichia coli and Staphylococcus aureus on the surface of the inside wall and floor in hatcheries, and the surface of hatching basket. The bactericidal effect increased with the increase of ACC and treatment time. The total bacteria sterilization rates were 93.9% and 85.6% by flusher-disinfection using 100 mg/L SAEW at the duration of 3 min for the surface of the inside walls and floor of hatchers, respectively, which was significantly higher than using 50 mg/L povidone-iodine solution or 50 mg/L benzalkonium bromide solution (P<0.05). Flusher-disinfection using 100 mg/L SAEW for 40 s on the hatching basket surfaces could reach a sterilization rate of 79.6%. The bactericidal effect of flusher-disinfection in hatches could be improved by using SAEW which is also a broad-spectrum and non-residual disinfectant, and flusher-disinfection using SAEW can be an alternative to traditional chemical disinfectants used for disinfection in hatcheries. [ABSTRACT FROM AUTHOR]

Abstract The distribution of twenty-four metals and elements in the tissues and organs of brood stock European seabass (Dicentrarchus labrax) was investigated. Muscle, liver, kidney, gills, bone, scales, gonads, otoliths and stomach were dissected from seabass brood stock from hatcheries in different sites in Greece, Eastern Mediterranean. The tissues and organs were clearly different depending on their metal and element content, except for bone and scales. The concentrations of most metals and elements were higher in the liver, kidney, bone and scales compared to the other body tissues and organs. Liver and kidney are the main detoxifying tissues of fish. Bone and scales accumulate the essential elements for the physiological function of the organisms. Muscle and otoliths accumulated the lowest concentrations of most metals and elements compared to the other tissues due to their low metabolic activity. However, the content of a few metals and elements was higher in gills, scales and stomach. Thus, it seems that the accumulation of metals and elements is tissue/ organ-specific and depends mainly on the biological role and activity of each tissue and the exposure pathway as well as on the chemistry of each element. Highlights • This is the first work investigating the simultaneous distribution of 24 elements in 9 tissues of brood stock seabass. • The tissues and organs were clearly different depending on their element content, except for bone and scales. • The elemental content was higher in the liver, kidney, bone and scales and lower in the muscle and otoliths. • The metal accumulation is tissue-specific and depends on the biological role and activity of each tissue. [ABSTRACT FROM AUTHOR]

Abstract This study evaluated reproductive performance of non-ablated Litopenaeus vannamei and the quality of their offspring under commercial conditions. Five tanks were stocked with non-ablated female and other five with ablated individuals as control. Two different larval rearing trials (Larviculture I and II) have been conducted. Six larviculture tanks (n = 3) were used on the first trial (LI) and ten for the second one (LII) (n = 3). Postlarvae from LII were used for nursery and grow-out. Spawning event and hatching rate per day were similar between both treatments. Mating success, mortality of female and number of eggs and nauplii per tank per day of non-ablated group were significantly lower than ablated female. Non-ablated female fecundity (number of eggs and nauplii per spawned female per day) was significantly higher than control. There was no significant difference between daily larval stage index of larvae in LI and LII. The response to the salinity stress test, and final survival and weight in LI was similar. However in LII, postlarvae derived from non-ablated had significantly higher survival to salinity stress test. Identical survival, final weight, weekly growth, feed conversion rate and yield were observed in nursery. The same was observed in grow-out, including weight gain and specific growth rate. Overall this study demonstrates that non-ablated females can have comparable level of productivity to ablated females in intensive commercial hatchery conditions. Their offspring perform comparably in all culture stages with evidence of enhanced resistance to stress in larvae derived from non-ablated female broodstock. Highlights • Non-ablated females have higher fecundity and survival in hatchery than conventionally ablated broodstock. • Non-ablated female offspring perform similarly to those from ablated group from early development stage to consumed size. • A comparable level of productivity can be realised by a hatchery using non-ablated broodstock. [ABSTRACT FROM AUTHOR]

Introduced species often colonize regions that have vastly different ecological and environmental conditions than those found in their native range. As such, species introductions can provide a deeper understanding into the process of adaptive evolution. In the 1880s, steelhead trout (Oncorhynchus mykiss) from California were introduced into Lake Michigan (Laurentian Great Lakes, North America) where they established naturally reproducing populations. In their native range, steelhead hatch in rivers, migrate to the ocean and return to freshwater to spawn. Steelhead in Lake Michigan continue to swim up rivers to spawn, but now treat the freshwater environment of the Great Lakes as a surrogate ocean. To examine the effects of this introduction, we sequenced the genomes of 264 fish. By comparing steelhead from Lake Michigan to steelhead from their ancestral range, we determined that the introduction led to consistent reductions in genetic diversity across all 29 chromosomes. Despite this reduction in genetic diversity, three chromosomal regions were associated with rapid genetic adaptation to the novel environment. The first region contained functional changes to ceramide kinase, which likely altered metabolic and wound‐healing rates in Lake Michigan steelhead. The second and third regions encoded carbonic anhydrases and a solute carrier protein, both of which are critical for osmoregulation, and demonstrate how steelhead physiologically adapted to freshwater. Furthermore, the contemporary release of diverse hatchery strains into the lake increased genetic diversity but reduced the signature of genetic adaptation. This study illustrates that species can rapidly adapt to novel environments despite genome‐wide reductions in genetic diversity. see also the Perspective by Seeb et al. [ABSTRACT FROM AUTHOR]

Voluntary hatcheries, or hatcheries operated privately by local anglers and fishery owners, are a historical part of salmonid conservation and enhancement efforts in Europe. However, these types of hatcheries have faced increasing scrutiny over the last several decades because of the potential negative ecological impacts created by stocking salmon into wild (albeit declining) populations. We hypothesized that hatchery programs provide value to communities well beyond the possible conservation contribution to local salmon. Utilizing a qualitative ethnographic approach, we identified and classified a range of benefits produced by voluntary salmon hatcheries within three case studies in Norway, Wales, and Germany. Across all cases, voluntary hatcheries facilitated or provided diverse social, psychological, and conservation benefits to individuals and groups of cultivators, as well as to the river environment. Voluntary hatcheries can be considered as a visible means of environmental stewardship and are perceived by many operators as an important means for mitigating human obstacles to wild salmon conservation. Based on the multiple benefits that voluntary hatcheries create for the people engaged in hatchery activities, we lay out alternative views that add to the traditionally black-and-white, pro or anti-hatchery perspectives. Improved incorporation of multiple social-psychological hatchery benefits into future fisheries management decisions, outreach, and communication will provide a more holistic approach to sustainable hatchery management, reduce stakeholder conflict, foster civil engagement in salmon conservation, and enhance environmental stewardship. [ABSTRACT FROM AUTHOR]

The number of outbreaks of Salmonella infections linked to live poultry contact increased from 1990 to 2016. In 2016, the number of human illnesses linked to live poultry was the highest reported, with more than 900 cases, including 209 hospitalizations and three deaths. Live poultry harboring Salmonella typically appear healthy but can intermittently shed bacteria in their droppings, contaminating their feathers, beaks, and the areas where they live and roam. Thus, both direct contact with poultry and indirect contact with anything in areas where animals live and roam can result in human Salmonella infection. To prevent Salmonella infections linked to live poultry, a One Health approach for control and prevention is required. This approach unifies animal and human health needs and takes into account the environments at the hatcheries where poultry are produced, the agricultural retail stores where poultry are sold, and the customers who own and raise poultry. Agricultural retail stores are the main point of sale for backyard poultry in the U.S. Therefore, stores can play a vital role in preventing infections by sourcing poultry from hatcheries that take steps to reduce Salmonella in the environment, by displaying poultry in areas that can be easily cleaned, and by using barriers that allow customers to view, but not touch, poultry from a distance. Retail store employees also have a role in preventing illnesses and contamination after the sale by educating customers about appropriate housing for live poultry in outdoor coops, barns, or other designated areas. [ABSTRACT FROM AUTHOR]