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- DNA barcoding (6)
- Species identification (6)
- Machine learning (3)
- Real-time PCR (3)
- BIOTECHNOLOGY (2)
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- COST (2)
- EXTERNALITIES (2)
- FISHERIES (2)
- FISHERY economics (2)
- Finfish Farming and Fish Hatcheries (2)
- Fish (2)
- GEAR selectivity (2)
- MARINE resources (2)
- Mislabeling (2)
- Multi-mode spectroscopy (2)
- PRODUCTION (2)
- RENEWABLE natural resources (2)
- Seafood fraud (2)
- Shark cartilage (2)
- Species substitution (2)
- Acceptable market name (1)
- Age (1)
- Aplysia californica (1)
- Artificial intelligence (1)
- Atlantic salmon (1)
- Attack behavior (1)
- Bottom-up effects (1)
- Cadmium (1)
- Canned tuna (1)
- Catfish (1)
- Publication Year
Articles 1 - 25 of 25
Full-Text Articles in Life Sciences
A Novel Machine-Learning Framework Based On A Hierarchy Of Dispute Models For The Identification Of Fish Species Using Multi-Mode Spectroscopy, Mitchell Sueker, Amirreza Daghighi, Alireza Akhbardeh, Nicholas Mackinnon, Gregory Bearman, Insuck Baek, Chansong Hwang, Jianwei Qin, Amanda M. Tabb, Jiahleen Roungchun, Rosalee S. Hellberg, Fartash Vasefi, Moon Kim, Kouhyar Tavakolian, Hossein Kashini Zadeh
A Novel Machine-Learning Framework Based On A Hierarchy Of Dispute Models For The Identification Of Fish Species Using Multi-Mode Spectroscopy, Mitchell Sueker, Amirreza Daghighi, Alireza Akhbardeh, Nicholas Mackinnon, Gregory Bearman, Insuck Baek, Chansong Hwang, Jianwei Qin, Amanda M. Tabb, Jiahleen Roungchun, Rosalee S. Hellberg, Fartash Vasefi, Moon Kim, Kouhyar Tavakolian, Hossein Kashini Zadeh
Food Science Faculty Articles and Research
Seafood mislabeling rates of approximately 20% have been reported globally. Traditional methods for fish species identification, such as DNA analysis and polymerase chain reaction (PCR), are expensive and time-consuming, and require skilled technicians and specialized equipment. The combination of spectroscopy and machine learning presents a promising approach to overcome these challenges. In our study, we took a comprehensive approach by considering a total of 43 different fish species and employing three modes of spectroscopy: fluorescence (Fluor), and reflectance in the visible near-infrared (VNIR) and short-wave near-infrared (SWIR). To achieve higher accuracies, we developed a novel machine-learning framework, where groups of …
Comparison Of Dna Extraction Methods For The Detection Of Canned Tuna Species With Dna Mini-Barcoding, Aubrey J. Emmi, Biola Fatusin, Rosalee S. Hellberg
Comparison Of Dna Extraction Methods For The Detection Of Canned Tuna Species With Dna Mini-Barcoding, Aubrey J. Emmi, Biola Fatusin, Rosalee S. Hellberg
Food Science Faculty Articles and Research
Tuna is susceptible to species mislabeling due to its high demand, quick rate of production, and wide range of price points. DNA barcoding, a sequencing-based technique, allows for the detection of species mislabeling by targeting a standardized region of DNA. A mitochondrial control region (CR) DNA barcode has been found to be capable of species discrimination for tuna, but it is challenging to recover the entire DNA fragment from canned tuna. While a short fragment of CR, referred to as a “mini-barcode,” has shown some success with canned tuna species identification, more research is needed to improve identification rates. The …
Microbiological Safety And Quality Of Ceviche, Poke, And Sushi Dishes Sold At Retail Outlets In Orange County, Ca, Grace E. Marquis, Samantha M. Covaia, Amanda M. Tabb, Courtney J. Kitch, Rosalee S. Hellberg
Microbiological Safety And Quality Of Ceviche, Poke, And Sushi Dishes Sold At Retail Outlets In Orange County, Ca, Grace E. Marquis, Samantha M. Covaia, Amanda M. Tabb, Courtney J. Kitch, Rosalee S. Hellberg
Food Science Faculty Articles and Research
Raw, ready-to-eat (RTE) seafood products, such as ceviche, poke, and sushi, have experienced growing demand globally; however, these products have the potential to be contaminated with foodborne pathogens. The objective of this study was to determine the prevalence of Escherichiacoli/coliforms, Salmonella, and Listeria in ceviche, poke, and sushi dishes sold at the retail level in Orange County, CA, USA. Additional organisms detected during testing were also considered in the results. A total of 105 raw, RTE samples of ceviche, poke, and sushi were collected from restaurants and grocery stores in Orange County, CA. Samples were tested for Salmonella …
Rapid Assessment Of Fish Freshness For Multiple Supply-Chain Nodes Using Multi-Mode Spectroscopy And Fusion-Based Artificial Intelligence, Hossein Kashani Zadeh, Mike Hardy, Mitchell Sueker, Yicong Li, Angela Tzouchas, Nicholas Mackinnon, Gregory Bearman, Simon A. Haughey, Alireza Akhbardeh, Insuck Baek, Chansong Hwang, Jianwei Qin, Amanda M. Tabb, Rosalee S. Hellberg, Shereen Ismail, Hassan Reza, Fartash Vasefi, Moon Kim, Kouhyar Tavakolian, Christopher T. Elliott
Rapid Assessment Of Fish Freshness For Multiple Supply-Chain Nodes Using Multi-Mode Spectroscopy And Fusion-Based Artificial Intelligence, Hossein Kashani Zadeh, Mike Hardy, Mitchell Sueker, Yicong Li, Angela Tzouchas, Nicholas Mackinnon, Gregory Bearman, Simon A. Haughey, Alireza Akhbardeh, Insuck Baek, Chansong Hwang, Jianwei Qin, Amanda M. Tabb, Rosalee S. Hellberg, Shereen Ismail, Hassan Reza, Fartash Vasefi, Moon Kim, Kouhyar Tavakolian, Christopher T. Elliott
Food Science Faculty Articles and Research
This study is directed towards developing a fast, non-destructive, and easy-to-use handheld multimode spectroscopic system for fish quality assessment. We apply data fusion of visible near infra-red (VIS-NIR) and short wave infra-red (SWIR) reflectance and fluorescence (FL) spectroscopy data features to classify fish from fresh to spoiled condition. Farmed Atlantic and wild coho and chinook salmon and sablefish fillets were measured. Three hundred measurement points on each of four fillets were taken every two days over 14 days for a total of 8400 measurements for each spectral mode. Multiple machine learning techniques including principal component analysis, self-organized maps, linear and …
An Investigation Into Country Of Origin Labeling, Species Authentication And Short Weighting Of Commercially Sold Frozen Fish Fillets, April M. Peterson, Gabrielle E. Mcbride, Seeret K. Jhita, Rosalee S. Hellberg
An Investigation Into Country Of Origin Labeling, Species Authentication And Short Weighting Of Commercially Sold Frozen Fish Fillets, April M. Peterson, Gabrielle E. Mcbride, Seeret K. Jhita, Rosalee S. Hellberg
Food Science Faculty Articles and Research
Proper labeling of seafood is important to prevent economic deception and protect public health. The goal of this research was to investigate prepackaged frozen fish for Country of Origin Labeling (COOL) compliance, species labeling, net weights/short weighting, and percent glaze. A total of 111 frozen prepackaged fish fillets were purchased from grocery stores in Southern California (USA). Samples were designated as COOL compliant if they displayed both procurement method and country of origin in accordance with COOL requirements. Species labeling was examined by comparing the species identified with DNA barcoding to the acceptable market names provided in the FDA Seafood …
Authentication Of Red Snapper (Lutjanus Campechanus) Fillets Using A Combination Of Real-Time Pcr And Dna Barcoding, Rachel B. Isaacs, Rosalee S. Hellberg
Authentication Of Red Snapper (Lutjanus Campechanus) Fillets Using A Combination Of Real-Time Pcr And Dna Barcoding, Rachel B. Isaacs, Rosalee S. Hellberg
Food Science Faculty Articles and Research
Red snapper (Lutjanus campechanus) is a historically overfished and highly valued species that is commonly substituted with other fish, such as tilapia, rockfish, and other snapper species. The objective of this study was to assess the ability of real-time PCR to be used as a screening tool to rapidly test commercial fillets for the presence of red snapper, followed by species identification of negative samples with DNA barcoding. A total of 24 frozen, fresh, or thawed (previously frozen) fillets labeled as “red snapper” were tested with real-time PCR, along with 54 fillets from fish that are common substitutes …
Inspecting Species And Freshness Of Fish Fillets Using Multimode Hyperspectral Imaging Techniques, Jianwei Qin, Fartash Vasefi, Rosalee S. Hellberg, Alireza Akhbardeh, Rachel B. Isaacs, Ayse Gamze Yilmaz, Chansong Hwang, Insuck Baek, Walter F. Schmidt, Moon S. Kim
Inspecting Species And Freshness Of Fish Fillets Using Multimode Hyperspectral Imaging Techniques, Jianwei Qin, Fartash Vasefi, Rosalee S. Hellberg, Alireza Akhbardeh, Rachel B. Isaacs, Ayse Gamze Yilmaz, Chansong Hwang, Insuck Baek, Walter F. Schmidt, Moon S. Kim
Food Science Faculty Articles and Research
This study developed multimode hyperspectral imaging techniques to detect substitution and mislabeling of fish fillets. Line-scan hyperspectral images were collected from fish fillets in four modes, including reflectance in visible and nearinfrared (VNIR) region, fluorescence by 365 nm UV excitation, reflectance in short-wave infrared (SWIR) region, and Raman by 785 nm laser excitation. Fish fillets of six species (i.e., red snapper, vermilion snapper, Malabar snapper, summer flounder, white bass, and tilapia) were used for species differentiation and frozen-thawed red snapper fillets were used for freshness evaluation. A total of 24 machine learning classifiers were used for fish species and freshness …
Detection Of Fish Fillet Substitution And Mislabeling Using Multimode Hyperspectral Imaging Techniques, Jianwei Qin, Fartash Vasefi, Rosalee S. Hellberg, Alireza Akhbardeh, Rachel B. Isaacs, Ayse Gamze Yilmaz, Chansong Hwang, Insuck Baek, Walter F. Schmidt, Moon S. Kim
Detection Of Fish Fillet Substitution And Mislabeling Using Multimode Hyperspectral Imaging Techniques, Jianwei Qin, Fartash Vasefi, Rosalee S. Hellberg, Alireza Akhbardeh, Rachel B. Isaacs, Ayse Gamze Yilmaz, Chansong Hwang, Insuck Baek, Walter F. Schmidt, Moon S. Kim
Food Science Faculty Articles and Research
Substitution of high-priced fish species with inexpensive alternatives and mislabeling frozen-thawed fish fillets as fresh are two important fraudulent practices of concern in the seafood industry. This study aimed to develop multimode hyperspectral imaging techniques to detect substitution and mislabeling of fish fillets. Line-scan hyperspectral images were acquired from fish fillets in four modes, including reflectance in visible and near-infrared (VNIR) region, fluorescence by 365 nm UV excitation, reflectance in short-wave infrared (SWIR) region, and Raman by 785 nm laser excitation. Fish fillets of six species (i.e., red snapper, vermilion snapper, Malabar snapper, summer flounder, white bass, and tilapia) were …
Microplate Immunocapture Coupled With The 3m Molecular Detection System And Selective Plating For The Rapid Detection Of Salmonella Infantis In Dry Dog Food And Treats, Danielle K. Rosen, Miguel Gallardo, Mcclain Vail, Rosalee S. Hellberg
Microplate Immunocapture Coupled With The 3m Molecular Detection System And Selective Plating For The Rapid Detection Of Salmonella Infantis In Dry Dog Food And Treats, Danielle K. Rosen, Miguel Gallardo, Mcclain Vail, Rosalee S. Hellberg
Food Science Faculty Articles and Research
The objective of this study was to use microplate immunocapture (IC) to reduce the enrichment time required for detection of Salmonella in pet food with the 3 M Molecular Detection System (MDS) or selective plating on XLD. Dog food and pig ear treats were inoculated with Salmonella Infantis at concentrations of 100–104 CFU/25 g, followed by a 3-h enrichment, then microplate IC and 3 M MDS or microplate IC and selective plating on XLD. Another set of samples underwent a traditional 24-h enrichment followed by 3 M MDS or selective plating. Based on the results of three …
Pcr Cloning Combined With Dna Barcoding Enables Partial Identification Of Fish Species In A Mixed-Species Product, Anthony J. Silva, Michael D. Kawalek, Donna M. Williams-Hill, Rosalee S. Hellberg
Pcr Cloning Combined With Dna Barcoding Enables Partial Identification Of Fish Species In A Mixed-Species Product, Anthony J. Silva, Michael D. Kawalek, Donna M. Williams-Hill, Rosalee S. Hellberg
Food Science Faculty Articles and Research
DNA barcoding is a valuable tool for regulatory identification of fish species; however, it does not perform well when multiple species are present within the same food product. Therefore, the objective of this study was to examine the use of PCR cloning to identify fish in a mixed-species product that cannot be identified with standard DNA barcoding. A total of 15 fish ball mixtures were prepared with known amounts of Nile tilapia (Oreochromis niloticus), Pacific cod (Gadus macrocephalus), and walleye pollock (Gadus chalcogrammus). Three subsamples from each fish ball underwent DNA extraction, full DNA barcoding (655 bp), and mini-barcoding (226 …
Labeling Compliance And Species Authentication Of Fish Fillets Sold At Grocery Stores In Southern California, Priscila Liou, Angela Banda, Rachel B. Isaacs, Rosalee S. Hellberg
Labeling Compliance And Species Authentication Of Fish Fillets Sold At Grocery Stores In Southern California, Priscila Liou, Angela Banda, Rachel B. Isaacs, Rosalee S. Hellberg
Food Science Faculty Articles and Research
Seafood mislabeling has numerous consequences, including economic deception and food safety risks. The focus of this study was to investigate fish species labeling, use of acceptable market names, and Country of Origin Labeling (COOL) compliance for fresh fish fillets sold at grocery store seafood counters in Southern California. A total of 120 fillets representing 16 different categories of fish were collected from 30 Perishable Agricultural Commodities Act (PACA)-listed grocery stores. Each sample underwent DNA barcoding to identify the species. Acceptable market names were confirmed using the FDA Seafood List. Samples were determined to be compliant with COOL if both …
Development Of A Dna Mini-Barcoding Protocol Targeting Coi For The Identification Of Elasmobranch Species In Shark Cartilage Pills, Rowena J. Zahn, Anthony J. Silva, Rosalee S. Hellberg
Development Of A Dna Mini-Barcoding Protocol Targeting Coi For The Identification Of Elasmobranch Species In Shark Cartilage Pills, Rowena J. Zahn, Anthony J. Silva, Rosalee S. Hellberg
Food Science Faculty Articles and Research
Many elasmobranch (shark and ray) species are considered threatened and their identification in processed products is important for conservation and authentication purposes. However, identification of elasmobranch species in shark cartilage pills has proven difficult using existing methodologies. The objective of this study was to develop a DNA mini-barcoding protocol using a ~130 bp region of the cytochrome c oxidase subunit I (COI) gene for species identification in shark cartilage pills. A total of 22 shark cartilage products underwent DNA extraction in duplicate using the DNeasy Blood and Tissue Kit (Qiagen). The effectiveness of a clean-up step following DNA extraction was …
Multi-Instrument Evaluation Of A Real-Time Pcr Assay For Identification Of Atlantic Salmon: A Case Study On The Use Of A Pre-Packaged Kit For Rapid Seafood Species Identification, Amanda A. Naaum, Rosalee S. Hellberg, Tara A. Okuma, Robert H. Hanner
Multi-Instrument Evaluation Of A Real-Time Pcr Assay For Identification Of Atlantic Salmon: A Case Study On The Use Of A Pre-Packaged Kit For Rapid Seafood Species Identification, Amanda A. Naaum, Rosalee S. Hellberg, Tara A. Okuma, Robert H. Hanner
Food Science Faculty Articles and Research
Protecting the seafood supply chain from species substitution is critical for economic, health, and conservation reasons. DNA-based methods represent an effective means to detect species substitution, but current methods can be time consuming or costly, and require specialized instruments and operators. Real-time PCR provides an alternative that can be performed quickly, and in some cases even on-site. The use of commercial kits reduces the expertise required by the operator and therefore increases accessibility to testing. This potentially increases the likelihood of adoption into the supply chain, but only if the kits are robust across multiple operators, instruments, and samples. In …
Identification Of Shark Species In Commercial Products Using Dna Barcoding, Rosalee S. Hellberg, Rachel B. Isaacs, Eduardo L. Hernandez
Identification Of Shark Species In Commercial Products Using Dna Barcoding, Rosalee S. Hellberg, Rachel B. Isaacs, Eduardo L. Hernandez
Food Science Faculty Articles and Research
Sharks are harvested globally and sold in a variety of commercial products. However, they are particularly vulnerable to overfishing and many species are considered protected or endangered. The objective of this study was to identify species in various commercial shark products and to assess the effectiveness of three different DNA barcoding primer sets. Thirty-five products were collected for this study, including fillets, jerky, soup, and cartilage pills. DNA barcoding of these products was undertaken using two full-length primer sets and one mini-barcode primer set within the cytochrome c oxidase subunit (COI) gene. Successfully sequenced samples were then analyzed and identified …
Cellular Mechanisms Of Slime Gland Refilling In Pacific Hagfish (Eptatretus Stoutii), Sarah Schorno, Todd E. Gillis, Douglas S. Fudge
Cellular Mechanisms Of Slime Gland Refilling In Pacific Hagfish (Eptatretus Stoutii), Sarah Schorno, Todd E. Gillis, Douglas S. Fudge
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Hagfishes use their defensive slime to ward off gill-breathing predators. Slime gland refilling is a surprisingly slow process, and previous research has shown that the composition of the slime exudate changes significantly during refilling, which likely has consequences for the functionality of the slime. This study set out to expand our understanding of slime gland refilling by examining the cellular processes involved in refilling of the glands, as well as determining where in the gland the main slime cells – the gland thread cells and gland mucous cells – arise. Slime glands were electro-stimulated to exhaust their slime stores, left …
Species Substitution And Country Of Origin Mislabeling Of Catfish Products On The U.S. Commercial Market, Shayna A. Bosko, Denise M. Foley, Rosalee S. Hellberg
Species Substitution And Country Of Origin Mislabeling Of Catfish Products On The U.S. Commercial Market, Shayna A. Bosko, Denise M. Foley, Rosalee S. Hellberg
Food Science Faculty Articles and Research
Catfish belong to the order Siluriformes and include both the Ictaluridae and Pangasiidae families. However, U.S. labeling laws require only species of the family Ictaluridae to be marketed as catfish. The lower production price of Pangasiidae, combined with changes in regulations over time, have resulted in high potential for species substitution and country of origin mislabeling among catfish products. The objective of this study was to conduct a market survey of catfish products sold at the U.S. retail level to examine species mislabeling and compliance with Country of Origin Labeling (COOL) regulations. A total of 80 catfish samples were collected …
Emptying And Refilling Of Slime Glands In Atlantic (Myxine Glutinosa) And Pacific (Eptatretus Stoutii) Hagfishes, Sarah Schorno, Todd E. Gillis, Douglas S. Fudge
Emptying And Refilling Of Slime Glands In Atlantic (Myxine Glutinosa) And Pacific (Eptatretus Stoutii) Hagfishes, Sarah Schorno, Todd E. Gillis, Douglas S. Fudge
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Hagfishes are known for their unique defensive slime, which they use toward off gill-breathing predators. Although much is known about the slime cells (gland thread cells and gland mucous cells), little is known about how long slime gland refilling takes, or how slime composition changes with refilling or repeated stimulation of the same gland. Slime glands can be individually electrostimulated to release slime, and this technique was used to measure slime gland refilling times for Atlantic and Pacific hagfish. The amount of exudate produced, the composition of the exudate and the morphometrics of slime cells were analyzed during refilling, and …
Evaluation Of Dna Barcoding Methodologies For The Identification Of Fish Species In Cooked Products, Sophia J. Pollack, Michael D. Kawalek, Donna M. Williams-Hill, Rosalee S. Hellberg
Evaluation Of Dna Barcoding Methodologies For The Identification Of Fish Species In Cooked Products, Sophia J. Pollack, Michael D. Kawalek, Donna M. Williams-Hill, Rosalee S. Hellberg
Food Science Faculty Articles and Research
DNA barcoding is a powerful sequencing-based tool for the detection of fish species substitution. However, various cooking methods have the potential to reduce the quality and success of DNA sequencing. The objective of this study was to determine the effects of common cooking methods on DNA sequencing results with both full-length (655 bp) and mini-barcodes (208–226 bp), and to determine the optimal methodology to use for species identification of various fish products. Six types of fish (salmon, tuna, scad, pollock, swai and tilapia) were prepared in triplicate using the following methods: uncooked, baked, fried, broiled, acid-cooked, smoked and canned. DNA …
Use Of The Mitochondrial Control Region As A Potential Dna Mini-Barcoding Target For The Identification Of Canned Tuna Species, Jacquelyn K. Mitchell, Rosalee S. Hellberg
Use Of The Mitochondrial Control Region As A Potential Dna Mini-Barcoding Target For The Identification Of Canned Tuna Species, Jacquelyn K. Mitchell, Rosalee S. Hellberg
Food Science Faculty Articles and Research
In this study, a DNA mini-barcoding methodology was developed for the differentiation of species commonly found in canned tuna. Primers were designed to target a 236-base pair (bp) fragment of the mitochondrial control region (CR) and a 179-bp fragment of the first internal transcribed spacer region (ITS1). Phylogenetic analysis revealed the ability to differentiate 13 tuna species on the basis of the CR mini-barcode, except in a few cases of species introgression. Supplementary use of ITS1 allowed for differentiation of introgressed Atlantic bluefin tuna (Thunnus thynnus) and albacore tuna (Thunnus alalunga), while differentiation of introgressed Atlantic …
Shifts In Attack Behavior Of An Important Kelp Forest Predator Within Marine Reserves, J. S. Berriman, M. C. Kay, D. C. Reed, A. Rassweiler, D. A. Goldstein, William G. Wright
Shifts In Attack Behavior Of An Important Kelp Forest Predator Within Marine Reserves, J. S. Berriman, M. C. Kay, D. C. Reed, A. Rassweiler, D. A. Goldstein, William G. Wright
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Marine reserves have become increasingly valuable tools with which to manage ecosystems. These reserves consistently restore populations of top predators, often reducing availability of their favored prey. We hypothesized that such prey reduction in reserves causes protected predators to alter their attack behavior to include less palatable prey, potentially amplifying top-down effects on community structure. To test this hypothesis, we presented the relatively unpalatable sea hare Aplysia californica to freely foraging spiny lobsters Panulirus interruptus in 4 marine no-take reserves, each paired with an adjacent fished area. We found that lobsters only attacked sea hares inside reserves, where lobster density …
Connecting Model Species To Nature: Predator-Induced Long-Term Sensitization In Aplysia Californica, Maria J. Mason, Amanda J. Watkins, Jordann Wakabayashi, Jennifer Buechler, Christine Pepino, Michelle Brown, William G. Wright
Connecting Model Species To Nature: Predator-Induced Long-Term Sensitization In Aplysia Californica, Maria J. Mason, Amanda J. Watkins, Jordann Wakabayashi, Jennifer Buechler, Christine Pepino, Michelle Brown, William G. Wright
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
Previous research on sensitization in Aplysia was based entirely on unnatural noxious stimuli, usually electric shock, until our laboratory found that a natural noxious stimulus, a single sublethal lobster attack, causes short-term sensitization. We here extend that finding by demonstrating that multiple lobster attacks induce long-term sensitization (>= 24 h) as well as similar, although not identical, neuronal correlates as observed after electric shock. Together these findings establish long-and short-term sensitization caused by sublethal predator attack as a natural equivalent to sensitization caused by artificial stimuli.
Effects Of Variable Oceanographic Conditions On Forage Fish Lipid Content And Fatty Acid Composition In The Northern California Current, Marisa N. C. Litz, Richard D. Brodeur, Robert L. Emmett, Selina S. Heppell, Rosalee S. Hellberg, Linda O'Higgins, Matthew S. Morris
Effects Of Variable Oceanographic Conditions On Forage Fish Lipid Content And Fatty Acid Composition In The Northern California Current, Marisa N. C. Litz, Richard D. Brodeur, Robert L. Emmett, Selina S. Heppell, Rosalee S. Hellberg, Linda O'Higgins, Matthew S. Morris
Food Science Faculty Articles and Research
Lipids and fatty acids (FA) were investigated in 4 species of forage fish: northern anchovy Engraulis mordax, Pacific sardine Sardinops sagax, Pacific herring Clupea pallasi, and whitebait smelt Allosmerus elongatus, for their ability to serve as biological indicators of ocean conditions in the California Current large marine ecosystem (CCLME). Samples were collected during the oceanographically contrasting years of 2005 and 2006. Upwelling was severely curtailed in the spring and early summer of 2005, leading to delayed biological productivity, whereas upwelling was relatively normal in spring 2006. Principal components analysis described 78% of the variance within the …
Effect Of Age And Tissue Weight On The Cadmium Concentration In Pacific Oysters (Crassostrea Gigas), Rosalee S. Hellberg, Michael T. Morrissey, Dan Cheney
Effect Of Age And Tissue Weight On The Cadmium Concentration In Pacific Oysters (Crassostrea Gigas), Rosalee S. Hellberg, Michael T. Morrissey, Dan Cheney
Food Science Faculty Articles and Research
This study investigated the influence of age and tissue weight on cadmium (Cd) levels in Pacific oysters (Crassostrea gigas). Oysters from 4 different age groups (1, 2, 3, and 4 y) were collected at an oyster farm in Willapa Bay, Washington. To examine the effects of age, 60 oysters from each group were sorted into 3 composites of 20, and Cd analysis was carried out on all composite samples. To study the effects of tissue weights, 25 oysters from each of the 4 age groups were collected and analyzed individually for Cd. All oyster Cd concentrations were below …
On Models Of Commercial Fishing: The Traditional Literature Needs No Defenders, Vernon L. Smith
On Models Of Commercial Fishing: The Traditional Literature Needs No Defenders, Vernon L. Smith
Economics Faculty Articles and Research
Examines the models of commercial fishing. Representation of the variable K as a measure of crowding externality in the cost function; Change of the degree of fishing pressure without changing the variable K; Modification of the output of firms by varying the inputs.
On Models Of Commercial Fishing, Vernon L. Smith
On Models Of Commercial Fishing, Vernon L. Smith
Economics Faculty Articles and Research
Commercial fishing is characterized by three key economic and technological features that are relevant to the formulation of an economic theory of fish production. 1. A fishery resource, although conceivably exhaustible, is replenishable; that is, it is subject to laws of natural growth which define an environmental biotechnological constraint on the activities of the fishing industry. 2. The resource and the activity of production from it form a stock-flow relationship. The new growth in the population fish mass depends upon the harvest rate relative to natural recruitment to the stock. If the harvest rate exceeds the recruitment rate, the stock …