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Auswahl der wissenschaftlichen Literatur zum Thema „Breeding and sale of live fish“
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Zeitschriftenartikel zum Thema "Breeding and sale of live fish"
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McManus, C., und R. Thompson. „Breeding objectives for red deer“. Animal Science 57, Nr. 1 (August 1993): 161–67. http://dx.doi.org/10.1017/s0003356100006735.
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AbstractThe definition of breeding objectives for farmed red deer in the United Kingdom (UK) was investigated. Options studied include the effects of discounting gene flow and the effect of altering variable costs/income (such as price of food or price received for sale animals). Three different herd structures were investigated. As the discount rate increased the importance of traits measured on the offspring also increased. Traits included in the economic breeding objective included number of calves weaned, carcass weights of stag calves and surplus hinds, hind calf live weight and food consumption for hinds and calves. The breeding objective derived does not include a measure of antler size, as antlers have little/no economic value in the UK market. Suggestions are made for further research.
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Hossain, Q. Z., M. A. Hossain und S. Psrween. „Breeding Biology, Captive Breeding and Fry Nursing of Himped Featherback (Notopterus chilata, Hamilton-Buchanan, 1822)“. Ecoprint: An International Journal of Ecology 13 (04.06.2009): 41–47. http://dx.doi.org/10.3126/eco.v13i0.1628.
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A study was conducted to observe the captive breeding performance with maturing sages and fry nursing of the threatened indigenous fish species Notopterus chitala at Arabpur fish farm (Longitude 89°12'15" E, Latitude 23°10'30" N), Jessore, Bangladesh during 1998 to 2001. The peak period of ovulation for N. chitala was found from July to August and the fish attained its first maturity at third year of age. Captive breeding is the most effective and basis process in case of N. chitala when cemented tank was used for collection of fertilized eggs, percentage of fertilization and hatching in stead of bamboo pole, plastic barrel, cemented tank and barrel made of tin. In the nursery practices live benthos, hatching of Thai punti and silver carp were used as feed of the spawn but the highest growth and survivability of the fish fry obtained by using Barbodes gonionotus (thai punti) spawn and live Tubifex sp. (benthos).Key Words: Fertilization; hatching; growth; survivabilitydoi: 10.3126/eco.v13i0.1628Ecoprint (An International Journal of Ecology) Vol. 13, No. 1, 2006 Page : 41-47
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Juwarno, Reno. „An Enquiry on Fish Selling Culture at South Sumatera: Investigation from Islamic Perspective“. Journal of Islamic Economic Laws 1, Nr. 1 (31.07.2018): 53–77. http://dx.doi.org/10.23917/jisel.v1i1.6205.
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The diversity in Indonesia makes each region having their model of live, behavior and the mode of transactions. South Sumatera is one of those regions that have been practicing a way of fish sale which is different from others. Fish is sold directly from a pit underneath water flow called lebung through an auction model. This different model of regular sale and auction evokes curiosity as to whether it conforms to shariah requirements or not. The purpose of this research is to investigate the habitual transaction of fish sale in this region. This paper will focus on the practice of people at Seri Kembang I village about the sale by carrying out qualitative approach in a field research involving observation, interview and documentation as the means for collecting data. All data collected will be analyzed through evaluation process by comparing the practice over the actual standard. We conclude that such practice is deemed to be non-permissible since it does not pass some of the standards, especially the garar element. We also provide some suggestion as the alternative of this habitual practice.
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Patel, Sunil Das, Rupak Karn, Sagar Bhusal, Sujita Balami, Prabin Adhikari und Raju Kharel. „Production and Marketing of Carp Species in Rupandehi, Nepal“. Malaysian Journal of Halal Research 3, Nr. 1 (01.06.2020): 1–5. http://dx.doi.org/10.2478/mjhr-2020-0001.
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AbstractThe research was conducted from January 2019 to June 2019 to study the fish production and marketing system in fish zone, Rupandehi. Altogether 95 respondents including 27 small farmers, 35 medium farmers and 33 large farmers were selected for household survey using simple random sampling for the study. Statistical tools, Ms- excel and SPSS of version 23 were used for data analysis. From the study, it was evident that, six species of carps of fingerlings size were stocked with high average number of common carps (3885.5/ha.) followed by silver carp (3880.5/ha). The average production of fish species was 6.06ton/ha which is slightly higher than the national average. The observed data revealed that, marketing of major quantity of fish was from on farm sale i.e. 55.78% followed by local market sale (18.94%), live fish sale in retailers (5.26%). Similarly, percentage of farmers selling fish to wholesaler, consumers, retailers and neighbours were 63.3%, 30.5%, 26.5% and 26.3% respectively. Cost and returns analysis showed average B/C ratio of 2.13. Problem ranking using 5 point scale value showed high cost of feed as the most serious problem with index value of 0.94 in the study area.
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Tsuneizumi, Kazuhide, Mieko Yamada, Hee-Jin Kim, Hiroyuki Ichida, Katsunori Ichinose, Yoshitaka Sakakura, Koushirou Suga et al. „Application of heavy-ion-beam irradiation to breeding large rotifer“. Bioscience, Biotechnology, and Biochemistry 85, Nr. 3 (14.01.2021): 703–13. http://dx.doi.org/10.1093/bbb/zbaa094.
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ABSTRACT In larviculture facilities, rotifers are generally used as an initial food source, while a proper size of live feeds to connect rotifer and Artemia associated with fish larval growth is needed. The improper management of feed size and density induces mass mortality and abnormal development of fish larvae. To improve the survival and growth of target larvae, this study applied carbon and argon heavy-ion-beam irradiation in mutation breeding to select rotifer mutants with larger lorica sizes. The optimal irradiation conditions of heavy-ion beam were determined with lethality, reproductivity, mutant frequency, and morphometric characteristics. Among 56 large mutants, TYC78, TYC176, and TYA41 also showed active population growth. In conclusion, (1) heavy-ion-beam irradiation was defined as an efficient tool for mutagenesis of rotifers and (2) the aforementioned 3 lines that have larger lorica length and active population growth may be used as a countermeasure of live feed size gap during fish larviculcure.
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Cehla, Béla. „Presentation of sales price reserves for live lamb“. Acta Agraria Debreceniensis, Nr. 34 (02.09.2009): 37–45. http://dx.doi.org/10.34101/actaagrar/34/2819.
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Although sheep breeding in Hungary is grounded in strong traditions, its activities only comprise 1% of the total production value generated from agriculture, and 2% of that for animal-based products. The most significant portion of incomes earned in the Hungarian sheep sector has, for years now, stemmed from the sale of live animals. The sector is decidedly export-oriented, as the domestic demand for its main product, i.e. lamb meat, and is minimal, equaling some 20-30dkg per person per year. Part of the sold animals is sold to market as dairy sheep, while the greaterpart is sold in the category of lamb carcasses. For this reason, the average weight of slaughter sheep has lied between 19-22 kg for years now. The target markets for live lamb sales are predominately Italy and Greece. In Greece, movement on this market has shown an upward tendency in recent years; noteworthy are also sales to Austria, Holland, Bosnia-Herzegovina and Poland. In 2003, we exported sheep meat in the form of carcasses to Italy, as well as to Germany, and of these exports, 94% went to Italy, while the remaining 6% went to Germany.Among sheep products, only the trade balance for live animal sales is positive. But even for such producers, only those who are specialized in intensive breeding and those sheep farms “targeting” meat production can obtain earnings. Specialized literature on the sector argues that the quality of Hungarian lamb has diminished dramatically and is beginning to lose its market position. If Hungarian lamb does not meet market expectations, then it will only be bought from producers at lower prices.My research focuses on those factors which influence price. I separately discuss the question of quality, as one of the most important decisive factors on price. Within this discussion, I describe the market expectations which actually have an effect on the acceptance of live animals for sale on commission. In practice, after the problems of quality, the next most important question is that of when sale is made. In the course of my research, I studied the development of averages for sales on commission of live lambs using statistical methods. The most important problem of this sector is the hierarchical system used in sales: this is the topic hich neither the producer, nor the buyer, wish to discuss, not even with each other. On the basis of the information at my disposal, I outlined the levels of traders and individual levels used to arrive at commission prices. Finally, I examined the components of the production value of live lamb sales. The results I obtained quantified the key role of the prices and the yield, as well as the factors influencing income.
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Reddon, Adam R., Mathew R. Voisin, Constance M. O’Connor und Sigal Balshine. „Isotocin and sociality in the cooperatively breeding cichlid fish, Neolamprologus pulcher“. Behaviour 151, Nr. 10 (2014): 1389–411. http://dx.doi.org/10.1163/1568539x-00003190.
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The ultimate functions of sociality, or the tendency to associate with conspecifics and to live within a social group, are increasingly well understood. However, the proximate mechanisms that mediate this behaviour have received less attention. The oxytocin family of nonapeptide hormones (including isotocin in teleost fish) is thought to play an important role in regulating social behaviour across a wide range of taxa and social contexts. In the current study, we investigated the influence of exogenous administration of isotocin and an oxytocin receptor antagonist on sociality in a cooperatively breeding fish, Neolamprologus pulcher. In our first experiment, we found that a high (and a low) dose of peripherally administered exogenous isotocin decreased the time spent associating with conspecifics in N. pulcher, while an intermediate dose had no effect relative to control. In our second experiment, we found that a peripheral administration of an oxytocin receptor antagonist increased grouping preference in male N. pulcher. The results of both experiments suggest that IT may inhibit grouping behaviour in this species. These results contribute to a growing body of literature suggesting that the broad generalization that the oxytocin family of nonapeptides facilitate grouping behaviour is overly simplistic, and that specific behavioural effects depend the study species and testing conditions.
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Petrov, R., S. Nazarenko, F. Muravyov, O. Kutah und O. Podlubny. „Assessment of commodities fishing in the trade network of the city of Sumy“. Bulletin of Sumy National Agrarian University. The series: Veterinary Medicine, Nr. 3 (46) (01.10.2019): 35–40. http://dx.doi.org/10.32845/bsnau.vet.2019.3.5.
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Introduction. To date, one of the priority tasks of the agro-industrial complex of Ukraine is to provide the population with benign and safe environmental and veterinary-sanitary products of animal products. Aquaculture is one of the fastest growing industries in the rapidly developing agro-industrial complex. The mentioned industry is able to provide the population with high quality nutritious and dietary fishery products in a relatively short period. Fish products replenish the human diet with essential amino acids, polyunsaturated fatty acids, trace elements and other nutrients to meet the needs of the body. But important indicators are the quality and safety of fish and fish products. The use of hazardous fish products by humans can lead to human diseases. Therefore, research on determining the safety and quality of fish remains an important link.
The goal of the work. The purpose of our research was to investigate commercial fish sold in the Sumy trade network and to carry out its veterinary and sanitary evaluation.
Materials and methods of research. These studies were conducted under the conditions of the Department of Veterinary Expertise, Microbiology, Zohygiene and Safety and Quality of Livestock Products of Sumy National Agrarian University and in Sumy Regional State Laboratory of the State Consumer Service.
Conducted research on commercial fish, which came to the sale in the trade network of the city of Sumy, namely in supermarkets, specialized stores and agri-food markets. Fresh, dried and frozen fish were studied..
Results of research and discussion. As a result of the study of the selected samples was found in live fish, namely the fathead, characteristic signs of postodiplastomosis. This disease manifested itself as small black spots on the body of a fish. It was also revealed in the study of carp in two specimens that the chronic course of aeromonosis was manifested by the presence of fissured ulcers on the body of the fish. Since the detection of the disease did not spoil the product indicators of fish, then all living fish are allowed to sell.
When examining dried fish, no deviations from the requirements for dried fish were found in the submitted samples. All fish are identified as benign and admitted for sale.
Studies of fresh frozen fish (hake) revealed the presence in the muscle tissue of the nematode Contracoecum squalii
Affected fish are characterized by an increased content of microorganisms in the deep and superficial muscle layers, a doubtful or negative reaction to peroxidase, a doubtful or substandard reaction with a Nesler reagent, a doubtful or substandard reaction with sulfuric acid, acidification.
Conclusions and prospects for further research: 1. In a study of 323 samples of live, dried, frozen fish, which entered the trade network in Sumy, it was found that 8 (2.47%) samples did not correspond to good-quality fish.2. Signs of diseases characteristic of aeromonosis (2 specimens), postodiplastomosis (1 specimen) and contracenosis (5 specimens) were established in the selected fish samples.3. A batch of hake (170 kg) in which the pathogen Contracoecum squalii was detected is not allowed for sale and is intended for technical disposal.
In the future, it is planned to develop and implement a permanent monitoring system for the quality and safety of fish and fishery products that are commercially available.
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Verbuch, I. V., und H. V. Bratkovska. „METHODS OF EVALUATION OF BREEDING VALUE OF LARGE WHITE BREED PIGS OF THE BREEDING PLANT OF SE “PASICHNA” DEPARTMENT OF KHMELNYTSK REGION“. Animal Breeding and Genetics 60 (23.11.2020): 5–11. http://dx.doi.org/10.31073/abg.60.01.
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Goal. To accelerate the selection process and create populations of pigs with high level of productivity to assess the most effective modern methods breeding value of large white pigs in the SE "DG" Pasichna "Institute of Feed and Agriculture Podillya NAAS" Starosinyavsky district of Khmelnytsky region on the basis of a combined assessment of repair young for their own productivity and assessment meat qualities by MD Berezovsky and B. Tyler and the most promising method BLUP. Methods. Comparison, zootechnical and biometric analyzes. Results. The breeding value of pigs of large white breed of the breeding farm of SE "Pasichna" ICSGP NAAS "Starosinyavsky district of Khmelnytsky region by modern effective methods, namely: BLUP. According to the average indicators of the combined assessment of own productivity of animals at control fattening, taking into account their live weight on the date of birth and weaning, average daily gain, live weight and age of 100 kg, body length and fat thickness, boars significantly outweighed pigs. Compared with pigs, their live weight at the date of birth and weaning (at the age of 30 days) was higher by 0.1 and 0.81 kg. The age of reaching a live weight of 100 kg exceeded by 5.43 days, the average daily gain of 0.016 kg. Live weight and body length of pigs on the date of fat thickness measurement was greater by 4.04 kg and 1.03 cm. Lifetime fat thickness at three measurement points at the level of 6–7 thoracic vertebrae, on the buttocks and in the midpoint of the back between withers and buttocks was thinner by 0.92; 0.94 and 1.06 mm. Evaluation indices of fattening and meat qualities by growth energy and fat thickness (Ia) and average daily gain and fat thickness (Iv) in boars indicate their higher level by 2.07 and 7.67 points compared to pigs and are equal to, respectively, 95.12 ± 1.95 and 152.96 ± 2.38 points. The coefficient of variability (Cv, %) of indicators of own productivity and estimated indices of fattening and meat qualities of repair boars ranged from 1.92% (body length on the date of fat thickness measurement, cm) to 15.12% (age of live weight 100 kg, days), repair pigs – from 4.63% (body length on the date of fat thickness measurement, cm) to 28.19% (index of assessment for growth energy and fat thickness, (Ia), points). The best average values of indicators of breeding value of animals are found on the basis of modern, most promising method BLUP, because it is considered in terms of mathematics, statistics and selection is the most accurate, well-founded, has the best theoretical basis and the lowest error variance. The average value of the BLUP index (parent lines) for boars of large white breed is 101.71 ± 1.681, pigs – 96.94 ± 0.724 points. At the same time, boars outweighed pigs by 4.77 points. The most positive correlation between live weight of piglets at weaning with their body length (r = 0.16), average daily gain (r = 0.19) and fat thickness (r = 0.24), the average correlation between the indices of fattening and meat qualities according to MD Berezovsky and B. Tyler (r = 0.56) P > 0.99 and the weak correlation between live weight of piglets at weaning and the BLUR index (r = 0,21) P > 0.99. It should be noted that there are almost no correlations between the fattening and meat quality indices of pigs and the BLUP index. Conclusions. In the conditions of breeding and specialized farms for the production of commercial pork in the region, to determine the breeding value of animals for further reproduction of their own herd and sale to other breeding farms of Ukraine, to systematically assess repair young animals for their own productivity and clear qualities of pigs and the most perfect BLUP index.
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Iskandar, Andri, Riza Septyanigar Islamay und Yudi Kasmono. „Optimalisasi Pembenihan Ikan Nila Merah Nilasa Oreochromis sp. Di Ukbat Cangkringan, Yogyakarta“. Samakia : Jurnal Ilmu Perikanan 12, Nr. 1 (12.04.2021): 29–37. http://dx.doi.org/10.35316/jsapi.v12i1.887.
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Abstract
The aim of this study was to evaluate the optimization of Nilasa red tilapia fish Oreochromis niloticus breeding process at Work Unit Freshwater Aquaculture (WUFA) Cangkringan, Technology Development Center of Fisheries (TDCOF) Yogyakarta. Nilasa red tilapia fish is one of the commodity that has advantages, including respond to artificial feed, grow fast, can live with high density and resistance to disease. WUFA Cangkringan was one of the government fisheries center which develop nilasa red tilapia fish. The hatchery activities is including maintenance of the parentstock, spawning, larval rearing, harvesting and post harvest. Nilasa red tilapia fish was a test fish that used at the WUFA Cangkringan from red tilapia study and released under the name Nilasa in 2012, start from 1st generation (F-0) to the 5th generation (F-4) in the program selection. The survival rate resulting from the hatchery activities with seed 2-3 cm was 80% and the seed was sold at Rp50 fish-1. The profit obtained Rp150 699 688 year-1, R/C ratio 1,34 and payback period 9 month.
Key word: nilasa red tilapia fish, breeding process, survival rate
Dissertationen zum Thema "Breeding and sale of live fish"
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Kuklica, Roman. „Podnikatelský plán společnosti zabývající se chovem a prodejem živých ryb na Slovensku“. Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2021. http://www.nusl.cz/ntk/nusl-442907.
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The diploma thesis is focused on the creation of an economically feasible business plan for the establishment of a company dealing with the breeding and sale of live fish in Slovakia. The theoretical part contains a definition of the issues related to the main idea of the plan and its validation in the form of selected analytical and evaluation tools, the structure and content of individual parts of the business plan. The analytical part is devoted to the validation of the business model and analysis of the market and general environment, including the analysis of own resources and capabilities to identify key factors and evaluate them with subsequent decision-making on the appropriate market strategy. The design part describes the selected strategy of the company and the business model, which is elaborated into partial parts of the business plan.
Buchteile zum Thema "Breeding and sale of live fish"
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„Fish Habitat: Essential Fish Habitat and Rehabilitation“. In Fish Habitat: Essential Fish Habitat and Rehabilitation, herausgegeben von Thomas J. Minello. American Fisheries Society, 1999. http://dx.doi.org/10.47886/9781888569124.ch7.
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<em>Abstract.</em> —The Magnuson-Stevens Fishery Conservation and Management Act (Magnuson-Stevens Act) of 1996 requires the identification of essential fish habitat (EFH) for fishery species under federal fishery management plans (FMPs). As defined in the Magnuson-Stevens Act, EFH includes waters and substrate necessary for spawning, breeding, feeding, or growth to maturity. Without EFH, fishery species will be unable to maintain the productivity needed to support a sustainable fishery or contribute ecologically to aquatic ecosystems. The highly productive estuaries in the northern Gulf of Mexico contain many habitat types that are potentially essential for species under FMPs such as brown shrimp <em>Penaeus aztecus, </em> white shrimp <em>P. setiferus</em> , pink shrimp <em>P. duorarum, </em> gulf stone crab <em>Menippe adina, </em> red drum <em>Sciaenops ocellatus</em> , gray snapper <em>Lutjanus griseus</em> , and bluefish <em>Pomatomus saltatrix</em> ; these species spend their juvenile life stages in estuarine nurseries. Estuarine habitats also may be important for prey required as forage by managed species and for other fishery species not under FMPs. My objective in this paper was to summarize information on densities of juvenile fishery species and other animals (all generally <100 mm total length) in shallow-water estuarine areas of Texas and Louisiana. I attempted to identify where these species live (delineate their habitat) and to analyze density patterns within habitats that would be useful in distinguishing EFH. My analysis was restricted to data collected with enclosure sampling techniques because these techniques have been shown to provide comparable density estimates among highly diverse shallow-water areas. Habitat types evaluated included <em>Spartina alterniflora </em> marsh edge (SAME), mixed-vegetation marsh edge, inner marsh (>5 m from open water), submerged aquatic vegetation (SAV), oyster reefs, and shallow nonvegetated bottom (SNB). Data also were categorized by season, salinity regime, estuarine system, and year of collection. Mean densities among habitat types frequently varied in relation to salinity regime, but overall, SAME was used most by brown shrimp, white shrimp, blue crab <em>Callinectes sapidus</em> , spotted seatrout <em>Cynoscion nebulosus</em> , and southern flounder <em>Paralichthys lethostigma</em> . Highest densities of pink shrimp, red drum, and sand seatrout <em>Cynoscion arenarius </em> were found in SAV. Stone crabs had highest mean densities on oyster reefs and gulf menhaden <em>Brevoortia patronus </em> on SNB. Each of the six habitat types examined ranked first or second in use by at least one of these fishery species. Thus, all of these habitat types are likely essential for some fishery species. The analysis highlighted many of the challenges confronted in determining habitat-use patterns and emphasized the need for additional systematic sampling to examine geographic variability in habitat use and to examine distribution patterns within habitats. However, in addition to analyses of intrahabitat densities, the identification of EFH requires information on functional relationships between fishery species and habitat characteristics.
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„Fish Habitat: Essential Fish Habitat and Rehabilitation“. In Fish Habitat: Essential Fish Habitat and Rehabilitation, herausgegeben von Thomas J. Minello. American Fisheries Society, 1999. http://dx.doi.org/10.47886/9781888569124.ch7.
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<em>Abstract.</em> —The Magnuson-Stevens Fishery Conservation and Management Act (Magnuson-Stevens Act) of 1996 requires the identification of essential fish habitat (EFH) for fishery species under federal fishery management plans (FMPs). As defined in the Magnuson-Stevens Act, EFH includes waters and substrate necessary for spawning, breeding, feeding, or growth to maturity. Without EFH, fishery species will be unable to maintain the productivity needed to support a sustainable fishery or contribute ecologically to aquatic ecosystems. The highly productive estuaries in the northern Gulf of Mexico contain many habitat types that are potentially essential for species under FMPs such as brown shrimp <em>Penaeus aztecus, </em> white shrimp <em>P. setiferus</em> , pink shrimp <em>P. duorarum, </em> gulf stone crab <em>Menippe adina, </em> red drum <em>Sciaenops ocellatus</em> , gray snapper <em>Lutjanus griseus</em> , and bluefish <em>Pomatomus saltatrix</em> ; these species spend their juvenile life stages in estuarine nurseries. Estuarine habitats also may be important for prey required as forage by managed species and for other fishery species not under FMPs. My objective in this paper was to summarize information on densities of juvenile fishery species and other animals (all generally <100 mm total length) in shallow-water estuarine areas of Texas and Louisiana. I attempted to identify where these species live (delineate their habitat) and to analyze density patterns within habitats that would be useful in distinguishing EFH. My analysis was restricted to data collected with enclosure sampling techniques because these techniques have been shown to provide comparable density estimates among highly diverse shallow-water areas. Habitat types evaluated included <em>Spartina alterniflora </em> marsh edge (SAME), mixed-vegetation marsh edge, inner marsh (>5 m from open water), submerged aquatic vegetation (SAV), oyster reefs, and shallow nonvegetated bottom (SNB). Data also were categorized by season, salinity regime, estuarine system, and year of collection. Mean densities among habitat types frequently varied in relation to salinity regime, but overall, SAME was used most by brown shrimp, white shrimp, blue crab <em>Callinectes sapidus</em> , spotted seatrout <em>Cynoscion nebulosus</em> , and southern flounder <em>Paralichthys lethostigma</em> . Highest densities of pink shrimp, red drum, and sand seatrout <em>Cynoscion arenarius </em> were found in SAV. Stone crabs had highest mean densities on oyster reefs and gulf menhaden <em>Brevoortia patronus </em> on SNB. Each of the six habitat types examined ranked first or second in use by at least one of these fishery species. Thus, all of these habitat types are likely essential for some fishery species. The analysis highlighted many of the challenges confronted in determining habitat-use patterns and emphasized the need for additional systematic sampling to examine geographic variability in habitat use and to examine distribution patterns within habitats. However, in addition to analyses of intrahabitat densities, the identification of EFH requires information on functional relationships between fishery species and habitat characteristics.
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van Eeten, Michel J. G., und Emery Roe. „The Paradox of the Rising Demand for Both a Better Environment and More Reliable Services“. In Ecology, Engineering, and Management. Oxford University Press, 2002. http://dx.doi.org/10.1093/oso/9780195139686.003.0004.
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The examples go on and on: loading fish in trucks and on barges to enable them to swim downstream; opening a water gate and drowning endangered birds in one area, or closing the gate and risk burning out habitat of the same species someplace else; spending more than $400 million a year to protect a handful of endangered species in just one region of a country; hatching endangered fish that end up too fat or stick out like neon in the water once released; releasing salmon trained to come to the surface for hatchery food when what is actually dropping from the sky are the ducks ready to eat them; keeping water in a reservoir to save the fish there, thus sacrificing other fish downstream; building a 250-foot-wide, 300-foot-high, $80 million device to better regulate the water temperature for salmon eggs in just one reservoir; controlled burning for fuel load management in the forests that harms not only air quality but also chronically bleeds pollution into adjacent aquatic ecosystems; breeding the wild properties out of endangered fish and releasing them, thereby polluting the gene pool of river fish; fighting urbanization to protect a green and open area, thereby condemning that area to monotonous, industrial agriculture and worse; closing a gate or releasing reservoir water in reaction to a sample of fish coming downstream and triggering electrical blackouts or the most severe urban water quality crisis in decades; restoring natural floodplains, erasing some of the oldest, best preserved, and greenest cultural landscapes in a country; putting in place even more massive infrastructure to keep ecosystems natural, thereby imprisoning them in intensive care units for life; and more. For some readers, these examples may appear a mix of the ridiculous and the desperate. Yet they are prime examples of a hard paradox at work: how do you reconcile the public’s demand for a better environment which requires ecosystem improvements with their concurrent demand for reliable services from that environment, including clean air, water, and power?
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„Proceedings of the First International Snakehead Symposium“. In Proceedings of the First International Snakehead Symposium, herausgegeben von Jimmy Barnett. American Fisheries Society, 2019. http://dx.doi.org/10.47886/9781934874585.ch3.
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<em>Abstract.</em>—Northern Snakeheads <em>Channa argus </em>were imported by fish farmers in Arkansas for use and sale in live food markets before being banned by the state in July 2002. Farmers were advised to destroy their stock in 2002 when importation and interstate trade were federally banned under the Lacey Act (18 U.S.C § 42(a) (1)). These farmers reportedly attempted this action, but on April 14, 2008; a wild Northern Snakehead, confirmed by the Arkansas Game and Fish Commission, was captured by a local row crop farmer. An eradication plan was formulated for Fall 2008 involving several government agencies and universities. Arkansas experienced several late summer storms resulting in flood conditions during that time. The eradication effort, named Operation Mongoose, was rescheduled for March, 2009. Operation Mongoose involved the application of the fish toxicant rotenone using helicopters, Marsh Masters, boats, and ground teams to cover approximately 700 km of creeks, ditches, and backwater areas within the 20,250 ha Piney Creek watershed. The effort reduced the Northern Snakehead population in the drainage but did not eradicate them. Because this area is prone to annual flooding, range expansion of Northern Snakehead occurred. The Arkansas Game and Fish Commission tracks Northern Snakehead dispersal through reporting from the angling public. During 2017, the first confirmed range expansion outside of Arkansas occurred in Mississippi.
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„Burbot: Ecology, Management, and Culture“. In Burbot: Ecology, Management, and Culture, herausgegeben von Inne Vught, Alireza Shiri Harzevilli, Johan Auwerx und Daniel De Charleroy. American Fisheries Society, 2008. http://dx.doi.org/10.47886/9781888569988.ch10.
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<em>Abstract.</em>—The freshwater gadoid, burbot <em>Lota lota</em>, was the subject of a captive breeding program to produce larvae for reintroduction into natural waters of Flanders, Belgium. Burbot broodfish were collected in 2002 from a river in France and maintained in earthen ponds at the Fish Research Center of the Research Institute for Nature and Forest in Linkebeek, Belgium. Each winter, they underwent gonadal maturation. In October, the mature fish were transferred to stocking ponds and fed with live fish. From the middle of December, they were exposed in indoor tanks to a continuous coldwater temperature of 4°C and a simulated natural light regime. This way, natural spawning could be induced without hormonal treatment. Between 582,766 and 984,963 eggs/kg bodyweight were collected from individual fish. Eggs averaged 1.00 mm in diameter. After fertilization, hatching started around day 32–33 when incubated at about 4°C (i.e., between 128 and 132 degree-days). Seventeen days later, at about 4°C, the larvae filled their swim bladder. A few days later (on day 21–24 posthatching when kept on 4°C), the larvae started exogenous feeding. The freshwater rotifer <em>Brachionus calyciflorus</em> proved to be an adequate starter food for growing burbot larvae but had to be replaced by larger food organisms like <em>Artemia </em>after 7–8 d. Burbot larvae were grown to one-summer-old juveniles (average survival 4%, average length 10 cm) in rearing ponds. The survival rate of the juvenile burbot in the ponds after 9 months was higher when the larvae were prefed with rotifers and <em>Artemia</em> prior to stocking in the ponds (survival up to 28% when fed for 18 d prior to the stocking).
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Emsley, John. „Mercury poisons us all“. In The Elements of Murder. Oxford University Press, 2005. http://dx.doi.org/10.1093/oso/9780192805997.003.0006.
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Mercury is everywhere and we cannot avoid it. The average adult contains around 6 mg of mercury – assuming they have no mercury amalgam fillings in their teeth – and this is something we have to live with because we can do almost nothing to reduce it. Our average intake of mercury is about 3 mg/day for adults, and about 1 μg for babies and young children. At these levels the amount we consume in a lifetime is less than a tenth of a gram, although in previous centuries people would consume more than this in a day in the form of medication, generally for embarrassing diseases, such as the unspeakable syphilis or, even worse, the unmentionable constipation. We shed mercury from our body through our urine, faeces, and even our hair. We could excrete mercury via our saliva glands, which are greatly stimulated by mercury, but the mercury in saliva tends to return to the stomach. So where does it all come from? The answer is mainly from the food we eat, although a little comes from the air we breathe and the water we drink, and some may even come from our own body if we have mercury amalgam fillings in our teeth. Agricultural soils may hold as much as 0.2 ppm of mercury and this finds its way into plants and food crops. Grass contains relatively little mercury, around 0.004 ppm, which explains why grazing animals are not really contaminated, and meat and dairy products have low levels. Seawater contains even less mercury than the cleanest soil and has only 0.00004 ppm, yet some fish absorb mercury to the extent of concentrating it in excess of 1 ppm. Are we harmed by this amount of mercury? Probably not. In December 1997, the US Environmental Protection Agency (EPA) published a seven-volume report on mercury and announced a safe daily dose of 0.1 μg/kg body weight, which for an ordinary adult would be 7 μg. Were this limit to be acted upon then it would outlaw the sale of all swordfish, shark, and most tuna, whereas the Food and Drugs Administration (FDA), which has a more pragmatic view of mercury, bans their sale only if their mercury content exceeds 1 ppm.
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Semmens, Kenneth J. „Paddlefish: Ecological, Aquacultural, and Regulatory Challenges of Managing a Global Resource“. In Paddlefish: Ecological, Aquacultural, and Regulatory Challenges of Managing a Global Resource, herausgegeben von William L. Shelton, Steven D. Mims und Rafael Cuevas-Uribe. American Fisheries Society, 2019. http://dx.doi.org/10.47886/9781934874530.ch9.
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<i>Abstract</i>.—Detailed knowledge of the life history of Paddlefish <i>Polyodon spathula</i> is a relatively recent scientific chapter. The foundation was initially established in Missouri, where there was a significant sport fishery for Paddlefish; initial observations on natural spawning and subsequent techniques for artificial propagation were developed there. Building on this impetus, a different trajectory was initiated in the late 1970s by our research group, one focusing on aquaculture with a goal of developing a breeding program to produce all-female progeny; our collaboration continued over the next three and one-half decades. Managed reproduction through artificial propagation, nursing of juveniles and grow-out for commercial production were components of this program, but more detailed techniques such as ploidy manipulation, sperm physiology, and cryopreservation were also developed. Our present objective is to highlight the improvements in artificial propagation that have been incorporated into hatchery programs. Initially, ovulation was induced with pituitary glands, but today Luteinizing Hormone Releasing Hormone analog (LHRHa) is used; ovulated eggs were collected by laboriously stripping, then a caesarian-section technique used in sturgeon was adopted, and subsequently the Minimally Invasive Surgical Technique (MIST) was introduced. Today, a Modified MIST technique offers a more efficient means of collecting eggs. Nursing of juveniles continues to evolve; primary nursing is now commonly done in tanks where fish may be offered live food during training to a prepared diet instead of starting culture in enriched ponds managed for zooplankton. The development of Paddlefish artificial propagation has benefitted from techniques which were initially developed and used in sturgeon culture. These operational hatchery techniques are common to both culture for restoration stocking and food fish production.
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„Anadromous Sturgeons: Habitats, Threats, and Management“. In Anadromous Sturgeons: Habitats, Threats, and Management, herausgegeben von Jörn Gessner, Gerd-Michael Arndt, Arne Ludwig und Frank Kirschbaum. American Fisheries Society, 2007. http://dx.doi.org/10.47886/9781888569919.ch17.
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<em>Abstract</em>.—A century ago, sea sturgeon (Atlantic sturgeon <em>Acipenser oxyrinchus</em> and European sturgeon <em>A. sturio</em>) were prevalent in the fish communities of all major German rivers, both in the North and the Baltic Sea drainages. Since then, population sizes have decreased rapidly due to overfishing, pollution, and hydropower construction. The last catches in the Baltic drainage occurred in the late 1960s. Only individual captures of sturgeon have been reported in the last 30 years, the most recent being in Lake Ladoga (Russia) in 1984 and off the coast of Estonia in 1996, approximately 25 years after the disappearance of the species from the fishery. Today, sturgeon are considered extinct in German waters. In 1996, the Federal Agency for Nature Conservation, in cooperation with the Society to Save the Sturgeon, started the pilot phase of a remediation program involving assessment of the prerequisites for remediation. The first juvenile European sturgeon were transferred to the Leibniz-Institute of Freshwater Ecology and Inland Fisheries under a scientific cooperation agreement with the Centre d’Étude du Machinisme Agricole, du Rural, des Eaux et Forêts in May 1996. With these specimens, an ex situ measure was initiated. In addition, phylogenetic and population genetic analyses of the species were carried out using mitochondrial DNA and microsatellites. These genetic analyses of recent and historical material have proven the existence of two different species in what was previously considered the Baltic or common sturgeon. The Atlantic sturgeon has been identified as endemic in the Baltic Sea and the European sturgeon in the North Sea. According to morphological evidence based on archaeological samples, the Atlantic sturgeon invaded the Baltic Sea approximately 2,000 years ago and has been the only sturgeon species there for the last few centuries. These results led to the separation of the remediation activities in North Sea and Baltic Sea tributaries. Broodstock development using the northernmost populations of the Atlantic sturgeon is currently being carried out. Subsequent reproduction for restocking requires a sufficiently large broodstock and a genetic breeding plan based on pedigree analysis. As a further prerequisite, an evaluation of the status of critical habitat for the early life stages of Atlantic sturgeon in the Oder River has been performed in collaboration with the Institute for Inland Fisheries of Poland. Alternative fisheries techniques, based on data for the bycatch of exotic sturgeon, are being developed to reduce the fishing pressure on juvenile sturgeon upon release.
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„Invasive Asian Carps in North America“. In Invasive Asian Carps in North America, herausgegeben von Leo G. Nico und Howard L. Jelks. American Fisheries Society, 2011. http://dx.doi.org/10.47886/9781934874233.ch7.
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<em>Abstract</em>.—Our book <em>The Black Carp: Biological Synopsis and Risk Assessment of an Introduced Fish </em>was published in 2005. The present chapter provides a brief overview of new events and re-examines pieces of earlier information on this molluskeating species. Effective November 19, 2007, black carp <em>Mylopharyngodon piceus </em>was placed on the Lacey Act list of injurious wildlife. Listing pertains to all forms of live black carp, including diploids (reproductively fertile), triploids (thought to be sterile), hybrids, and gametes and viable eggs, prohibiting their import into the United States and banning interstate transport. States retain rights to regulate black carp already within their jurisdiction. Although many states now ban black carp, a few states in the lower Mississippi basin still permit breeding programs and allow use of black carp for snail control in ponds. In North America, black carp are present in open waters of the lower Mississippi River basin. Likely the result of escape from aquaculture, some captures reportedly date to the early 1990s. Most (10 of 11) wild captures tested have been found to be diploids. During the mid-1990s, an estimated 400,000 black carp were in aquaculture. The number fluctuates and present total is uncertain but includes diploids. Currently, it is not possible to adequately assess the risk of additional escape because the numbers and distribution of diploid and triploid black carp held in aquaculture and the frequency and intensity of farm-pond flooding are not fully documented. Much also remains unknown about wild black carp populations in the Mississippi basin, especially with regard to their distribution, abundance, reproduction status, and types of mollusk prey consumed. The paucity of data is largely attributed to the difficulty of capturing wild black carp and the near absence of field research targeting this species.
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„Invasive Asian Carps in North America“. In Invasive Asian Carps in North America, herausgegeben von Leo G. Nico und Howard L. Jelks. American Fisheries Society, 2011. http://dx.doi.org/10.47886/9781934874233.ch7.
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<em>Abstract</em>.—Our book <em>The Black Carp: Biological Synopsis and Risk Assessment of an Introduced Fish </em>was published in 2005. The present chapter provides a brief overview of new events and re-examines pieces of earlier information on this molluskeating species. Effective November 19, 2007, black carp <em>Mylopharyngodon piceus </em>was placed on the Lacey Act list of injurious wildlife. Listing pertains to all forms of live black carp, including diploids (reproductively fertile), triploids (thought to be sterile), hybrids, and gametes and viable eggs, prohibiting their import into the United States and banning interstate transport. States retain rights to regulate black carp already within their jurisdiction. Although many states now ban black carp, a few states in the lower Mississippi basin still permit breeding programs and allow use of black carp for snail control in ponds. In North America, black carp are present in open waters of the lower Mississippi River basin. Likely the result of escape from aquaculture, some captures reportedly date to the early 1990s. Most (10 of 11) wild captures tested have been found to be diploids. During the mid-1990s, an estimated 400,000 black carp were in aquaculture. The number fluctuates and present total is uncertain but includes diploids. Currently, it is not possible to adequately assess the risk of additional escape because the numbers and distribution of diploid and triploid black carp held in aquaculture and the frequency and intensity of farm-pond flooding are not fully documented. Much also remains unknown about wild black carp populations in the Mississippi basin, especially with regard to their distribution, abundance, reproduction status, and types of mollusk prey consumed. The paucity of data is largely attributed to the difficulty of capturing wild black carp and the near absence of field research targeting this species.