Oregon Sea Grant

ABSTRACT Medium‐grade Alaska pollock surimi was used to investigate the effects of functional protein additives on texture and colors. Torsion failure and differential scanning calorimetry tests were applied to measure gel strength, gel deformability, and calorimetric properties. CIE Lab color values were also measured. Shear stress values of gels and peak temperature of DSC thermograms were all increased. Shear strain, a good indicator of protein‐protein interaction, was increased only by addition of egg white and beef plasma protein. Yellowness (b*) values were affected by all additives except frozen egg white. Whiteness index (L*‐3b*) was a more effective indicator to differentiate additives.

ABSTRACT Beef plasma protein (BPP), egg white and potato extract were tested for their ability to inhibit proteolysis in fish mince and surimi made from Pacific whiting ( Merluccius productus ). Strong inhibition resulted from all three compounds in fish mince when measured by autolysis. However, when tested in surimi significant differences occurred among the compounds. BPP showed strongest inhibition of proteolytic effect followed by egg white and potato extract when measured by autolysis, gel electrophoresis and torsion. BPP was an effective inhibitor in surimi at a concentration as low as 1%.

ABSTRACT Cathepsin B was the most active cysteine protease in Pacific whiting fish fillets; cathepsin L was predominant in surimi. Cathepsin L showed highest activity at 55°C in both fish fillets and surimi, indicating its function in myosin degradation during conventional heating of fillets and surimi, gels. Washing during surimi processing removed cathepsin B and H but not cathepsin L. Myosin heavy chain was the primary substrate during autolysis of surimi paste and actin and myosin light chain showed limited hydrolysis during 2 hr incubation. Purified Pacific whiting cathepsin L hydrolyzed myofibrils, myosin and native and heat‐denatured collagen. The degradation pattern of myofibrils by the protease was the same as the autolytic pattern of surimi.

The amphibian fungal pathogen Batrachochytrium dendrobatidis (Bd) has received considerable attention due to its role in amphibian population declines worldwide. Although many amphibian species appear to be affected by Bd, there is little information on species-specific differences in susceptibility to this pathogen. We used a comparative experimental approach to examine Bd susceptibility in 6 amphibian species from the United States. We exposed postmetamorphic animals to Bd for 30 days and monitored mortality, feeding rates, and infection levels. In all species tested, Bd-exposed animals had higher rates of mortality than unexposed (control) animals. However, we found differences in mortality rates among species even though the amount of Bd detected on the different species' bodies did not differ. Of the species tested, southern toads (Anaxyrus terrestris) and wood frogs (Lithobates sylvaticus) had the highest rates of Bd-related mortality. Within species, we detected lower levels of Bd on individuals that survived longer and found that the relationship between body size and infection levels differed among species. Our results indicate that, even under identical conditions, amphibian species differ in susceptibility to Bd. This study represents a step toward identifying and understanding species variation in disease susceptibility, which can be used to optimize conservation strategies.

ABSTRACT Capacitive (Radio Frequency) dielectric heating has great potential for achieving rapid and uniform heating patterns in foods, providing safe, high quality food products. This review describes and discusses the major technology behind capacitive (RF) dielectric heating in food processing and preservation, the current applications of the technology in the industry, the potential use of mathematical modeling for heating system design, and the major challenges facing the use of this technology in food processing. A vast amount of work is still necessary to further understand the dielectric properties of both food and packaging materials in order to refine system design and maximize performance of this technology in the field of packaged food products. Various economic studies will also play an important role in understanding the overall cost and viability of commercial application of this technology in food processing.

Abstract This study conducts the first systematic literature review of climate change adaptation in aquaculture. We address three specific questions: (i) What is aquaculture adapting to? (ii) How is aquaculture adapting? and (iii) What research gaps need to be addressed? We identify, characterise and examine case studies published between 1990 and 2018 that lie at the intersection of the domains of climate change, adaptation and aquaculture. The main areas of documented climate change impacts relate to extreme events and the general impacts of climate change on the aquaculture sector. Three categories of adaptation to climate change are identified: coping mechanisms at the local level (e.g. water quality management techniques), multilevel adaptive strategies (e.g. changing culture practices) and management approaches (e.g. adaptation planning, community‐based adaptation). We identify four potential areas for future research: research on inland aquaculture adaptation; studies at the household level; whether different groups of aquaculture farmers (e.g. indigenous people) face and adapt differently to climate change; and the use of GIS and remote sensing as cost‐effective tools for developing adaptation strategies and responses. The study brings essential practical and theoretical insights to the aquaculture industry as well as to climate change adaptation research across the globe.

Abstract Considerable time and effort have been invested in understanding the motivations of museum visitors. Many investigators have sought to describe why people visit museums, resulting in a range of descriptive categorizations. Recently, investigators have begun to document the connections between visitors' entering motivations and their exiting learning. Doering and Pekarik have proposed starting with the idea that visitors are likely to enter a museum with an “entry narrative” (1996; see also Pekarik, Doering and Karns 1999). Doering and Pekarik argue that these entry narratives are likely to be self‐reinforcing, directing both learning and behavior, since visitors' perceptions of satisfaction will be directly related to experiences that resonate with their entering narrative. Falk took these ideas one step further and proposed that—although people have diverse reasons for choosing to visit museums—these diverse reasons tended to cluster around a relatively small number of motivational categories (2006). These categories appeared to be related to visitors' desires to use the museum for fulfilling identity‐related needs. Each of us assumes many identities over the course of our life. Some of our identities are enduring and long‐lasting; others are more ephemeral and situation‐specific; all help us navigate through the complexities of life.

Koi herpesvirus (KHV) has recently been classified as a member of the family of Alloherpesviridae within the order of Herpesvirales. One of the unique features of Herpesviridae is latent infection following a primary infection. However, KHV latency has not been recognized. To determine if latency occurs in clinically normal fish from facilities with a history of KHV infection or exposure, the presence of the KHV genome was investigated in healthy koi by PCR and Southern blotting. KHV DNA, but not infectious virus or mRNAs from lytic infection, was detected in white blood cells from investigated koi. Virus shedding was examined via tissue culture and reverse transcription-PCR (RT-PCR) testing of gill mucus and feces from six koi every other day for 1 month. No infectious virus or KHV DNA was detected in fecal secretion or gill swabs, suggesting that neither acute nor persistent infection was present. To determine if KHV latent infections can be reactivated, six koi were subjected to a temperature stress regime. KHV DNA and infectious virus were detected in both gill and fecal swabs by day 8 following temperature stress. KHV DNA was also detectable in brain, spleen, gills, heart, eye, intestine, kidney, liver, and pancreas in euthanized koi 1 month post-temperature stress. Our study suggests that KHV may become latent in leukocytes and other tissues, that it can be reactivated from latency by temperature stress, and that it may be more widespread in the koi population than previously suspected.

ABSTRACT Colors (CIE L*, a*, and b*) of Alaska pollock ( 7′heragra chalcogramma ) and Pacific whiting ( Mecs productus ) surimi gels were evaluated and related to compositional and physical conditions during preparation and measurements. Ten samples were used in each treatment. Water addition, sample size, species, cooking and test temperatures, and freeze/thaw affected lightness (L*) and yellowness (b*) values, while outside light conditions at measurement did not affect colors. Greenness (‐a*) values were less affected by all conditions.

FisheriesVolume 25, Issue 3 p. 22-30 Article Management of Pacific Rockfish S. J. Parker, S. J. Parker NMFS Long Marine Laboratory in Santa Cruz, California, USASearch for more papers by this authorS. A. Berkeley, S. A. Berkeley Oregon Department of Fish and Wildlife (ODFW) Marine Resources Program in Newport, USASearch for more papers by this authorJ. T. Golden, J. T. Golden Hatfield Marine Science Center in Newport, Oregon. AFS Marine Fisheries Section, USASearch for more papers by this authorD. R. Gunderson, D. R. Gunderson ODFW Marine Resources Program in Newport, USASearch for more papers by this authorJ. Heifetz, J. Heifetz School of Fisheries at the University of Washington in Seattle, USASearch for more papers by this authorM. A. Hixon, M. A. Hixon National Marine Fisheries Service (NMFS) Auke Bay, Alaska, laboratory, USASearch for more papers by this authorR. Larson, R. Larson Department of Zoology at Oregon State University in Corvallis, USASearch for more papers by this authorB. M. Leaman, B. M. Leaman Department of Biology at San Francisco State University in California, USASearch for more papers by this authorM. S. Love, M. S. Love International Pacific Halibut Commission in Seattle, Washington, USASearch for more papers by this authorJ. A. Musick, J. A. Musick Marine Science Institute at the University of California in Santa Barbara, USASearch for more papers by this authorV. M. O'Connell, V. M. O'Connell Vertebrate Ecology and Systematics programs at the Virginia Institute of Marine Science in Gloucester Point, USASearch for more papers by this authorS. Ralston, S. Ralston Alaska Department of Fish and Game in Sitka, USASearch for more papers by this authorH. J. Weeks, H. J. Weeks NMFS Tiburon, California, laboratory, USASearch for more papers by this authorM. M. Yoklavich, M. M. Yoklavich Oregon State University Sea Grant Extension in Newport, USASearch for more papers by this author S. J. Parker, S. J. Parker NMFS Long Marine Laboratory in Santa Cruz, California, USASearch for more papers by this authorS. A. Berkeley, S. A. Berkeley Oregon Department of Fish and Wildlife (ODFW) Marine Resources Program in Newport, USASearch for more papers by this authorJ. T. Golden, J. T. Golden Hatfield Marine Science Center in Newport, Oregon. AFS Marine Fisheries Section, USASearch for more papers by this authorD. R. Gunderson, D. R. Gunderson ODFW Marine Resources Program in Newport, USASearch for more papers by this authorJ. Heifetz, J. Heifetz School of Fisheries at the University of Washington in Seattle, USASearch for more papers by this authorM. A. Hixon, M. A. Hixon National Marine Fisheries Service (NMFS) Auke Bay, Alaska, laboratory, USASearch for more papers by this authorR. Larson, R. Larson Department of Zoology at Oregon State University in Corvallis, USASearch for more papers by this authorB. M. Leaman, B. M. Leaman Department of Biology at San Francisco State University in California, USASearch for more papers by this authorM. S. Love, M. S. Love International Pacific Halibut Commission in Seattle, Washington, USASearch for more papers by this authorJ. A. Musick, J. A. Musick Marine Science Institute at the University of California in Santa Barbara, USASearch for more papers by this authorV. M. O'Connell, V. M. O'Connell Vertebrate Ecology and Systematics programs at the Virginia Institute of Marine Science in Gloucester Point, USASearch for more papers by this authorS. Ralston, S. Ralston Alaska Department of Fish and Game in Sitka, USASearch for more papers by this authorH. J. Weeks, H. J. Weeks NMFS Tiburon, California, laboratory, USASearch for more papers by this authorM. M. Yoklavich, M. M. Yoklavich Oregon State University Sea Grant Extension in Newport, USASearch for more papers by this author First published: 09 January 2011 https://doi.org/10.1577/1548-8446(2000)025<0022:MOPR>2.0.CO;2Citations: 67AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume25, Issue3March 2000Pages 22-30 RelatedInformation

Dosidicus gigas (jumbo or Humboldt squid) is a semelparous, major predator of the eastern Pacific that is ecologically and commercially important. In the Gulf of California, these animals mature at large size (>55 cm mantle length) in 1-1.5 years and have supported a major commercial fishery in the Guaymas Basin during the last 20 years. An El Niño event in 2009-2010, was accompanied by a collapse of this fishery, and squid in the region showed major changes in the distribution and life-history strategy. Large squid abandoned seasonal coastal-shelf habitats in 2010 and instead were found in the Salsipuedes Basin to the north, an area buffered from the effects of El Niño by tidal upwelling and a well-mixed water column. The commercial fishery also relocated to this region. Although large squid were not found in the Guaymas Basin from 2010 to 2012, small squid were abundant and matured at an unusually small mantle-length (<30 cm) and young age (approximately 6 months). Juvenile squid thus appeared to respond to El Niño with an alternative life-history trajectory in which gigantism and high fecundity in normally productive coastal-shelf habitats were traded for accelerated reproduction at small size in an offshore environment. Both small and large mature squid, were present in the Salsipuedes Basin during 2011, indicating that both life- history strategies can coexist. Hydro-acoustic data, reveal that squid biomass in this study area nearly doubled between 2010 and 2011, primarily due to a large increase in small squid that were not susceptible to the fishery. Such a climate-driven switch in size-at-maturity may allow D. gigas to rapidly adapt to and cope with El Niño. This ability is likely to be an important factor in conjunction with longerterm climate-change and the potential ecological impacts of this invasive predator on marine ecosystems.

ABSTRACT Commonly used protease assays and substrates were compared for sensitivity and simplicity in analyzing proteolytic activity in Pacific whiting causing gel weakening of surimi during heat‐setting. Assay based on detection of trichloroacetic acid (TCA)‐soluble products, using azocasein as substrate, showed highest sensitivity. By that assay, optimal pH of the protease was 5.5, and optimal temperature, 55°. The validity of the assay for measuring activity was confirmed by pH profiles of residual proteolytic and autolytic activities of uncooked surimi. These analyses showed pH profiles similar to those of fish juice with a pH optimum of 5.5.

With the aim to establish a novel nanocarrier system with higher payload and higher photo-protection for deltamethrin (active ingredient) compared to solid lipid nanoparticles (SLN), nanostructured lipid carriers (NLC) were prepared by combining hot homogenization and sonication with different ratios of corn oil (liquid lipid) and beeswax (solid lipid). Compared to SLN, the incorporation of corn oil gave a higher payload, slower release rate and higher photo-protection for deltamethrin. Particularly, compared to beeswax solid lipid nanoparticles (BSLN), NLC gave a higher payload (approximately 1.79 times) with a high encapsulation efficiency (83.6%), higher photo-protection in direct photolysis (1.8 times) after 12 h exposure of ultraviolet light (UV) and in indirect photolysis (1.37 times) after 2 h exposure of UV in 2% (v/v) acetone solution used as a photosensitizer. This study demonstrated that novel nanocarrier possesses a wide range of applicability in protecting photo-labile compounds for the crop, food and pharmaceutical industries.

ABSTRACT Effects of salt concentrations and washing cycles on the extraction of proteins were evaluated. Sarcoplasmic proteins were readily soluble in water (0% NaCl) and removed in the initial washing steps. Myofibrillar proteins became relatively soluble and were lost during extensive washing. Control of water/meat ratio, washing time, and washing cycles was critical in reducing the loss of myofibrillar proteins. Washing with 0.25%, 0.5%, and 1.0% NaCl solutions reduced the loss of myofibrillar proteins. However, these solutions were not very effective in removing sarcoplasmic proteins even with increased washing cycles. High salt (2.0% NaCl) washing resulted in low removal of sarcoplasmic proteins and severe loss of myofibrillar proteins.

ABSTRACT: The fermentation condition for producing Pacific whiting fish sauce was static atmospheric fermentation with 25% salt at 50 °C. The effective enzymes in fermentation were heat stable and salt tolerant. Fermentation at 50 °C gave higher yields than at 35 °C. Total nitrogen content of whole fish fermented at 50 °C reached the equivalent level of commercial fish sauce before 15 d, supporting the strong degradation effects of Pacific whiting enzymes at earlier stages. Soluble solid and relative gravity also reached commercial level at 60 d. However, color value of unripened fish sauce was far from commercial fish sauce, indicating that ripening may be necessary to develop proper color. Staphylococcus, Bacillus , and Micrococcus were found as predominant microorganisms during fermentation.

Ontogenetic variation in the diet of Engraulis encrasicolus (L.) was examined in the northern Adriatic Sea, off the River Po delta, by stomach contents analysis. Anchovy (10 to 130 mm total length) were collected during a 1 wk cruise in October 2002. Feeding activity was mainly diurnal in all the length classes: stomach fullness, calculated for each 10 mm size class, was always higher during the day than at night, with maximal values measured for the 40 to 49 and 50 to 59 mm size classes. All analysed life stages of E. encrasicolus had a strictly zooplanktivorous diet based on a few species of copepods. The principal prey of E. encrasicolus were small-sized copepods, measuring about 0.2 to 0.3 or 0.5 to 0.6 mm in prosoma length. The copepods Euterpina acutifrons and Oncaea spp. dominated anchovy diet during the day, both in terms of frequency, number and biomass, in all anchovy size classes. During the night, bivalve larvae were also important dietary items, with Oncaea spp. and E. acutifrons making up > 69% of total prey number for all anchovy size classes. Within the considered size range, the dimensions of particles does not seem to be a limiting factor in food selection, and no relationship was found between anchovy length and the maximal dimension of ingested prey. Ivlev's electivity index confirmed that European anchovy was able to select specific food items and preferred small copepods such as E. acutifrons and Oncaea spp., and bivalve and decapod larvae.

Abstract We conducted a global systematic literature review of climate change adaptation in fisheries. We addressed three specific questions: (i) What are fisheries adapting to? (ii) How are fisheries adapting? and (iii) What research gaps need to be addressed? We identified, characterized and examined case studies published between 1990 and 2019 that lie at the intersection of the domains of climate change, adaptation and fisheries. We characterized the documented climate change effects in fisheries that are being adapted to multiple stressors, general climate impacts, extreme events, ocean conditions, marine system shifts, climate variability, fishery dynamics, species distribution and atmospheric warming. Three categories of adaptive responses came to light: coping mechanisms (e.g. changing fishing location, use of traditional knowledge); adaptive strategies (e.g. livelihood diversification, incorporation of technology); and management responses (e.g. adaptive management, adaptation planning). We identified key potential areas for future research, including studies on the limits and barriers for adaptation, studies using specific conceptual and methodological approaches, and studies focussing on the top‐producing countries such as China, Indonesia, Peru and Russia. This analysis gives broader insights to the fisheries industry and to climate change adaptation research to proceed in the face of new global challenges.

ABSTRACT: Three different solid byproducts (skin, frame, and refiner discharge) from Pacific whiting surimi manufacturing are a good resource for collagen extraction according to their total protein concentrations and other biochemical properties. Denaturation temperature of acid‐soluble collagens was 23.3°C for refiner discharge, 21.7 °C for skin, and 20.6°C for frame. Based on the functional properties, acid‐soluble collagen from refiner discharge was the best and showed potential as an ingredient in processed food manufacturing.

Two behavior patterns of fishermen, specialist and generalist, are evaluated as ways of coping with market and natural variability. Changes in these behaviors predicted by an analytical model are evaluated against data from several fisheries. The predictions and the data suggest that a mix of specialist and generalist fishing behavior is a way of coping with unpredictability. Management usually regards fishing behavior as homogeneous; as a result, many management rules discriminate against one type of behavior or the other.

Abstract Both natural scientists and economists commonly use quantitative data to create models of the systems that interest them and then use these models to inform fisheries management. Other social scientists rely on lengthier, descriptive texts based primarily on qualitative data to assess the human dimensions. To their dismay, fisheries social scientists find that much of their rich narrative with keen insights ends up filling pages that are neither read nor meaningfully integrated into decision-making in fisheries management. Nevertheless, what all scientists, practitioners, and managers want and need is information that will lead to a better understanding of the ecosystem (comprised of interdependent ecological and human systems) and therefore to fisheries management that benefits the whole system. Based on the belief that only a combination of high-quality quantitative and qualitative data will provide both the numbers and the context needed for success in ecosystem-based management, we discuss efforts to present social and cultural information in forms that are more familiar to those who rely on models for a representation of reality in the fisheries context. We point out how the designers of these models (or how we) think the models might be applied to fisheries management, noting how each model attempts to incorporate qualitative data to depict context essential for grounding the more commonly used biological and economic models. We also assess the benefits and limitations of these models, including the constraints on their development and use.