Browsing by Author "Schwarz, Michael H."

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    Artemia Culture for Intensive Finfish and Crustacean Larviculture
    Delbos, Brendan C.; Schwarz, Michael H. (Virginia Cooperative Extension, 2009-09-25)
    Provides the background, rationale, and detailed production protocols for all stages of high quality Artemia culture for use as a live feed in finfish and shrimp aquaculture.
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    Artemia Culture for Intensive Finfish and Crustacean Larviculture
    Delbos, Brendan C.; Schwarz, Michael H.; Ovissipour, Mahmoudreza (Virginia Cooperative Extension, 2019-08-21)
    Provides the background, rationale, and detailed production protocols for all stages of high quality Artemia culture for use as a live feed in finfish and shrimp aquaculture.
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    Assessing Economic Contributions of the Virginia Seafood Industry: An Estimation Framework Utilizing Primary Data
    Gonçalves, Fernando H.; van Senten, Jonathan; Schwarz, Michael H.; Hegde, Shraddha (MDPI, 2024-05-26)
    With a focus on seafood industries, this study provides a framework for economic contribution assessments, outlines Virginia’s seafood supply chain components, and evaluates the direct, indirect, and induced economic impacts of Virginia’s seafood industry in 2019. Utilizing an analysis-by-parts method in IMPLAN, primary expenditure data from watermen, aquaculture farmers, processors, and distributors were collected through surveys. The efficacy of obtaining primary data through stakeholder surveys heavily relies on the investigator’s interpersonal skills to establish trust and elucidate the study’s benefits, particularly its potential to inform policy decisions. In 2019, the Virginia seafood industry’s estimated total economic contributions amounted to USD 1.1 billion, supporting 7187 individuals. This impact encompasses 6050 direct jobs, 523 indirect jobs, and 614 induced jobs, primarily benefiting watermen and coastal communities. Furthermore, the industry’s influence extends beyond its immediate economic sphere, supporting diverse sectors such as polystyrene foam manufacturing, boat building, sporting and athletic goods, and commercial and industrial machinery. Wages and salaries disbursed throughout the seafood supply chain ripple to Virginia’s economy, benefiting nondepository credit intermediation, owner-occupied dwellings, and real estate sectors. Future research focusing on seafood sales in restaurants and retail outlets will complete the understanding of the seafood industry’s broader economic impact on the state.
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    Assessment of Water Quality, Growth of Penaeus vannamei, and Partial Budget in Super-Intensive BFT and RAS: A Comparison Between Sustainable Aquaculture Systems
    Ramiro, Bianca de Oliveira; Wasielesky, Wilson; Pimentel, Otávio Augusto Lacerda Ferreira; Sun, Taozhu; McAlhaney, Ethan; Urick, Stephen; Gonçalves, Fernando H.; van Senten, Jonathan; Schwarz, Michael H.; Krummenauer, Dariano (MDPI, 2024-12-15)
    This study evaluated water quality, growth, and partial budget analysis (PBA) for Penaeus vannamei, comparing super-intensive Biofloc Technology (BFT) and Recirculating Aquaculture Systems (RAS). The 69-day trial used 100 L units with two treatments (RAS and BFT), each with three replicates. Shrimp were initially reared in a 30-day nursery to a weight of 0.10 ± 0.04 g and then stocked at 500 shrimp m−3. Biofloc growth in BFT was promoted by maintaining a C:N ratio of 15:1, adding dextrose when total ammonia nitrogen (TAN) reached 1 mg L−1. Probiotics (3 g m−3) were administered daily to both groups. TAN levels in BFT initially spiked but stabilized after 36 days. Vibrio abundance was initially higher in RAS, but by the end of the trial, it was higher in BFT. Final weight, weekly growth ratio, and yield were greater in BFT, whereas feed conversion ratio (FCR) and water use were higher in RAS. Survival rates were 83.33% in BFT and 88% in RAS. BFT achieved a superior net benefit/cost compared to RAS. Although RAS more effectively controlled nitrogenous compounds, BFT exhibited better growth performance, with higher final weights, lower FCR, and better Vibrio management. The partial budget analysis indicated an economic advantage for BFT, with a net positive benefit of $2270.09 when shifting from RAS to BFT due to lower operating costs and higher shrimp yield. Among these two sustainable production systems, BFT was more productive while utilizing less natural resources.
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    Book Review - Species and System Selection for Sustainable Aquaculture
    Schwarz, Michael H. (Commercial Fish and Shellfish Technologies Program, Virginia Tech, 2010-06-01)
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    Characterization of supply of marine finfish species with potential for commercial growth in the United States
    Engle, Carole R.; van Senten, Jonathan; Schwarz, Michael H. (Wiley, 2022-10-12)
    Global production of marine finfish has grown in total volume of production and the number of species farmed commercially, but there has been little production in the United States of marine finfish other than salmon and red drum. For most species considered to be ready for commercialization, there are few or no farms from which to evaluate the size of the market or to estimate revenues and costs necessary to assess economic feasibility. This present study takes a first step to fill this gap with an analysis of the existing supply of 20 marine finfish species identified as candidates for commercialization in the United States, as a proxy for effective demand (the volume of a product sold at the market equilibrium price). Secondary data from 1950 (where available) through 2019 were compiled on each species, including (1) global aquaculture production, (2) US aquaculture production, (3) US commercial landings, (4) US recreational landings, and (5) imports. Current effective market demand (measured as the sum of commercial landings, farmed production, and imports) was low, totaling 36.6 million kg across the 20 species, which is equivalent to less than 23% of the annual volume sold of US farmed catfish. Commercial landings for 17 of the 20 species exhibited declines, potentially offering opportunities for farmed product to capture market share by filling the increasing gaps in supply. The variability in commercial landings provides opportunities for farms to capitalize on their advantage in supplying product with a high degree of consistency of volume, size, delivery frequency, and quality. Several unknown factors suggest the need for follow-up studies on consumer preferences, degree of substitutability among finfish species, and effects of recreational landings on demand. An important limitation to prospective producers is the lack of species-specific import data for the generic categories of “flounder,” “bass,” and “snapper.” This supply analysis provides a foundational analysis for prospective producers, investors, and researchers interested in commercialization of these marine species.
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    Commercial Fish & Shellfish Technology Fact Sheet: Dealing with Trichodina and Trichodina-like Species
    Smith, Stephen A.; Schwarz, Michael H. (Virginia Cooperative Extension, 2009-05-01)
    Provides information on what Trichodina and Trichodina-like species are, why they are a problem in aquaculture, and how they can be controlled.
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    Dealing with Trichodina and Trichodina-like species
    Smith, Stephen A.; Schwarz, Michael H. (Virginia Cooperative Extension, 2019-02-22)
    Discusses several species of protozoan parasites of fish, their life cycles, how they affect fish, and methods of treatment.
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    Enhancing Seafood Quality and Safety by Reducing Reliance on Antibiotics: Applying a Novel Antibody in Tilapia
    Garry, Jordan Nicole (Virginia Tech, 2018-06-14)
    Disease outbreaks have overwhelmed the aquaculture industry as a whole and have been catastrophic for many single operations. To minimize disease outbreaks, efforts are underway to enhance animal health and disease resistance to pathogens without the use of antibiotics. The overall purpose of this study was to explore a potential prophylactic, a novel antibody diet, for the bacterial pathogen, Aeromonas hydrophila, in tilapia. The tilapia were on an anti-interleukin-10 antibody diet as a neutralization of interleukin-10 (IL-10), an anti-inflammatory cytokine. The anti-inflammatory function of IL-10 has been shown to allow persistence of gastrointestinal pathogens. Tilapia were fed the novel diet and were challenged via bath immersion or oral gavage with A. hydrophila. Four trials of challenge studies were conducted. Clinical signs of the disease and survival were monitored post-challenge of the bacteria. Out of the 4 trials, one bath immersion trial showed significantly lower survival in the group fed the novel antibody diet (p=0.044) compared to the control fed group, after challenged with A. hydrophila. The other trials tested showed no significant differences in survival between diets. Among the survival percentages collected as a whole, it cannot be determined from in vivo results whether this anti-IL-10 diet is effective in preventing mortality from A. hydrophila in tilapia. Therefore, an in vitro study using an enzyme-linked immunosorbent assay (ELISA) was used to determine the neutralization capability of anti-IL-10 on IL-10 using tilapia splenocytes. Interferon-γ, a pro-inflammatory cytokine, was quantified in order to find a trend in expression of IL-10 in vitro in various tilapia cell treatments. The protocol for the ELISA study is under development being that the use of this antibody is novel and has never before been done in fish.
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    Enhancing Seed Quality and Application of Soybean through High Test Weigh and Low Trypsin Inhibitors
    Shea, Zachary (Virginia Tech, 2023-02-09)
    Soybean is an integral oilseed crop that is used all over the world. Despite this, soybean has been experiencing a decrease in seed quality seen by the decreasing trend in test weight, and is limited in its uses due to the antinutritional factor, trypsin inhibitor (TI). This project first worked to identify single nucleotide polymorphisms (SNPs) associated with high test weight through a genome-wide association study (GWAS) as well as determine the relationship between important seed composition traits and test weight. Additionally, it focused on identifying and knocking out KTI genes specifically expressed in soybean seed tissue through CRISPR/Cas9. Lastly, this project investigated further use of soybean in aquaculture by evaluating the performance of Rainbow trout fed diets with low-TI, 'VT Barrack' soy meal. Nine SNPs on chromosome 15 were found to be significantly associated with high test weight as and eight potential gene candidates were identified. Test weight was found to be significantly, and negatively related to seed oil content and had inconsistent correlations with protein and sugar content. The KTI genes KTI1, Glyma01g095000, and KTI3, Glyma08g341500, were found to be only expressed in seed tissues and multiple KTI knock-out soybean plants with decreased seed TI content and activity were developed. Lastly, we found that our low-TI soymeal could replace 30% of fish meal in aquafeeds with no negative effects on trout growth and health.
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    Farm-Level Cost Drivers of Salmonid Fish Health Inspections
    Engle, Carole; van Senten, Jonathan; Schwarz, Michael H.; Hartman, Kathleen; Gustafson, Lori; Johnson, Kamina; Creekmore, Lynn (2021-10-22)
    Regulatory costs on aquaculture farms have been shown to be of a magnitude that warrants additional analysis. The drivers of farm-level costs of fish health inspections were identified in this study from national survey data on U.S. salmonid farms. The greatest costs identified were related primarily to state fish health requirements for inspection and testing to certify that fish are free of specific pathogens prior to approval of necessary permits to sell and/or transport animals. Fish health inspection costs included laboratory testing, farm personnel time, veterinary fees, and shipping samples to laboratories, with laboratory testing and the value of farm personnel time being the most expensive components. Principal cost drivers were the number of tests and whether required sampling was farmwide or for each lot as identified by the collector. Farmers who primarily sold into recreational markets had greater fish health costs than farmers who primarily sold food fish because of the greater numbers of species and size-/age-classes of salmonids on their farms. Regulatory requirements to test all species and size-/age-classes on farms increased inspection costs by increasing the total number of tests, the total value of fish sacrificed, and shipping costs. Consequently, for farms with more than one species or more than one size-/age-class, annual farm-level testing was less costly than annual lot-based testing. Increased numbers of tests in a given year, although reported by only a few respondents, can increase costs dramatically and turn profitable farms unprofitable, even food fish farms. Smaller salmonid farms experienced disproportionately greater inspection cost burdens than did larger farms. The fish health inspection scenario of only one annual inspection of only the most susceptible species and size-/age-class showed a cost burden that did not generate economic distress, even on smaller salmonid farms. Other scenarios modeled (based on survey data) that included lot-based surveys of multiple species and size-/age-classes resulted in substantially greater fish health inspection costs that led to unprofitability for various farm sizes and business types. Study results suggest that implementing Comprehensive Aquaculture Health Program Standards might allow for risk- and pathogen-based reductions in the total number of inspections and fish sampled while maintaining equivalent or greater health status compared to current methods. American Fisheries Society-Fish Health Section Blue Book inspection methods are interpreted and applied inconsistently across states and generally yield lot- rather than farm-level health attestations because the history of testing results, risk assessment, and biosecurity practices are not typically taken into account. The cost effects of alternative fish health sampling and testing requirements should be considered in decisions and policy on fish health regulation.
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    Getting Acquainted with Amyloodinium ocellatum
    Schwarz, Michael H.; Smith, Stephen A. (Virginia Cooperative Extension, 2009-05-01)
    Provides basic information on Amyloodinium ocellatum and explains why it is a problem to aquaculture and the best methods to control it.
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    Getting Acquainted with Amyloodinium Ocellatum
    Smith, Stephen A.; Schwarz, Michael H. (Virginia Cooperative Extension, 2019-02-22)
    Provides basic information on Amyloodinium ocellatum and explains why it is a problem in aquaculture, and discusses best methods to control it.
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    Impacts of COVID-19 on U.S. aquaculture allied business: Quarter 1 Results March 23, 2020 to April 10, 2020
    Engle, Carole R.; van Senten, Jonathan; Smith, Matthew A.; Clark, Charles; Fluharty, Shannon; Schwarz, Michael H. (Virginia Cooperative Extension, 2021-01-12)
    In response to the coronavirus disease (COVID-19), Virginia Tech and the Ohio State University collected information about how aquaculture/aquaponics farms and allied businesses have been affected by the COVID-19 pandemic. A survey was conducted at the conclusion of the first quarter of 2020 to capture and quantify these impacts and effects. The survey will be distributed once per quarter throughout 2020, to capture the evolving effects of coronavirus disease (COVID-19) on your farm or business. This publication summarizes the first set of results for the 1st quarter of 2020.
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    Impacts of COVID-19 on U.S. aquaculture, aquaponics, and allied businesses located in the USDA North Central Aquaculture Region: Quarter 1 Results March 23, 2020 to April 10, 2020
    Engle, Carole R.; van Senten, Jonathan; Smith, Matthew A.; Clark, Charles; Fluharty, Shannon; Schwarz, Michael H. (Virginia Cooperative Extension, 2021-01-13)
    In response to the coronavirus disease (COVID-19), Virginia Tech and the Ohio State University collected information about how aquaculture/aquaponics farms and allied businesses have been affected by the COVID-19 pandemic. A survey was conducted at the conclusion of the first quarter of 2020 to capture and quantify these impacts and effects. The survey will be distributed once per quarter throughout 2020, to capture the evolving effects of coronavirus disease (COVID-19) on your farm or business. This publication summarizes the first set of results for the 1st quarter of 2020.
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    Impacts of COVID-19 on U.S. aquaculture, aquaponics, and allied businesses located in the USDA Tropical and Subtropical Aquaculture Region: Quarter 1 Results March 23, 2020 to April 10, 2020
    Engle, Carole R.; van Senten, Jonathan; Smith, Matthew A.; Clark, Charles; Fluharty, Shannon; Schwarz, Michael H. (Virginia Cooperative Extension, 2021-01-14)
    In response to the coronavirus disease (COVID-19), Virginia Tech and the Ohio State University collected information about how aquaculture/aquaponics farms and allied businesses have been affected by the COVID-19 pandemic. A survey was conducted at the conclusion of the first quarter of 2020 to capture and quantify these impacts and effects. The survey will be distributed once per quarter throughout 2020, to capture the evolving effects of coronavirus disease (COVID-19) on your farm or business. This publication summarizes the first set of results for the 1st quarter of 2020.
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    Impacts of COVID-19 on U.S. aquaculture, aquaponics, and allied businesses located in the USDA Western Aquaculture Region: Quarter 1 Results March 23, 2020 to April 10, 2020
    Engle, Carole R.; van Senten, Jonathan; Smith, Matthew A.; Clark, Charles; Fluharty, Shannon; Schwarz, Michael H. (Virginia Cooperative Extension, 2021-01-18)
    In response to the coronavirus disease (COVID-19), Virginia Tech and the Ohio State University collected information about how aquaculture/aquaponics farms and allied businesses have been affected by the COVID-19 pandemic. A survey was conducted at the conclusion of the first quarter of 2020 to capture and quantify these impacts and effects. The survey will be distributed once per quarter throughout 2020, to capture the evolving effects of coronavirus disease (COVID-19) on your farm or business. This publication summarizes the first set of results for the 1st quarter of 2020.
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    Impacts of COVID-19 on U.S. aquaculture, aquaponics, and allied businesses: Quarter 1 - March 23, 2020 to April 10, 2020
    Engle, Carole R.; van Senten, Jonathan; Smith, Matthew A.; Clark, Charles; Fluharty, Shannon; Schwarz, Michael H. (Virginia Cooperative Extension, 2021-01-13)
    In response to the coronavirus disease (COVID-19), Virginia Tech and the Ohio State University collected information about how aquaculture/aquaponics farms and allied businesses have been affected by the COVID-19 pandemic. A survey was conducted at the conclusion of the first quarter of 2020 to capture and quantify these impacts and effects. The survey will be distributed once per quarter throughout 2020, to capture the evolving effects of coronavirus disease (COVID-19) on your farm or business. This publication summarizes the first set of results for the 1st quarter of 2020.
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    Impacts of COVID-19 on U.S. aquaculture, aquaponics, and allied businesses: Quarter 2 Results
    van Senten, Jonathan; Smith, Matthew A.; Engle, Carole R.; Clark, Charles A.; Schwarz, Michael H. (Virginia Cooperative Extension, 2020-08-05)
    In response to the coronavirus (COVID-19) disease pandemic, a collaborative initiative was launched byThe Ohio State University, Virginia Tech, and Engle-Stone Aquatic$, LLC to assess the impacts ofthe pandemic on U.S. aquaculture, aquaponics, and allied industry. Results from the first quarter survey(AAEC-218NP) demonstrated that the U.S. aquaculture industry has been impacted by the coronavirus (COVID-19) disease pandemic; with 90% of respondents reporting that their farm or business had been affected by the pandemic in some way. Marketing channels, challenges with labor, and challenges with production. Over the course of the first quarter of 2020, the U.S. government developed and implemented several emergency relief measures, in an effort to assist small businesses and individuals. The Q2 survey asked specifically about these relief and assistance programs, as well as questions on adaptations and changes being implemented by farms and businesses in response to the ongoing challenges. This fact sheet summarizes the Q2 results of this study, covering the period from April 10th to June 29th, 2020
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    Impacts of COVID-19 on U.S. crustacean farms: Quarter 1 Results March 23, 2020 to April 10, 2020
    Engle, Carole R.; van Senten, Jonathan; Smith, Matthew A.; Clark, Charles; Fluharty, Shannon; Schwarz, Michael H. (Virginia Cooperative Extension, 2021-01-14)
    In response to the coronavirus disease (COVID-19), Virginia Tech and the Ohio State University collected information about how aquaculture/aquaponics farms and allied businesses have been affected by the COVID-19 pandemic. A survey was conducted at the conclusion of the first quarter of 2020 to capture and quantify these impacts and effects. The survey will be distributed once per quarter throughout 2020, to capture the evolving effects of coronavirus disease (COVID-19) on your farm or business. This publication summarizes the first set of results for the 1st quarter of 2020.