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  1. Article ; Online: Climate change-informed dietary modeling in Pacific cod

    Matthew C. Rogers / Ron A. Heintz / Johanna J. Vollenweider / Ashwin Sreenivasan / Katharine B. Miller

    PLoS ONE, Vol 18, Iss

    Experimentally-derived effects of temperature and dietary quality on carbon and nitrogen stable isotope trophic discrimination factors

    2023  Volume 12

    Keywords Medicine ; R ; Science ; Q
    Language English
    Publishing date 2023-01-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Rapid and Reliable Assessment of Fish Physiological Condition for Fisheries Research and Management Using Fourier Transform Near-Infrared Spectroscopy

    Esther D. Goldstein / Thomas E. Helser / Johanna J. Vollenweider / Ashwin Sreenivasan / Fletcher F. Sewall

    Frontiers in Marine Science, Vol

    2021  Volume 8

    Abstract: Measuring fish population responses to climate change requires timely ecological information, warranting innovative approaches to data collection in fisheries research and management. Fourier transform near-infrared (FT-NIR) spectroscopy is a promising ... ...

    Abstract Measuring fish population responses to climate change requires timely ecological information, warranting innovative approaches to data collection in fisheries research and management. Fourier transform near-infrared (FT-NIR) spectroscopy is a promising tool to efficiently and cost-effectively obtain multiple types of fisheries data including fish physiological health and energetics that can provide indicators of stock status and environmental change. We tested the applicability of FT-NIR spectroscopy to determine fish physiological state and condition by developing calibration models for morphometric indices of body condition [Fulton’s K and hepatosomatic index (HSI)], biochemical measurements of tissue composition (lipid content and energy density), and a nucleic acid-based index of recent growth (RNA:DNA) of juvenile Pacific cod (Gadus macrocephalus). Calibration models had the best predictive ability for lipid content followed by HSI and energy density, whereas spectral data had weak relationships with Fulton’s K and RNA:DNA. For lipid content, energy density, and HSI, informative spectral regions were primarily associated with carbon-hydrogen bonds in lipid molecules. Additionally, FT-NIR spectroscopy calibration models better predicted lipid content than morphometric measurements that are often used as proxies for measuring energy reserves, indicating that FT-NIR spectroscopy might serve as a more informative index of body condition and energy stores than other rapid methods. Efficient sample analysis by FT-NIR spectroscopy can supplement traditional metrics of body condition and be especially useful for ensuring the availability of monitoring data in support of fisheries research and management.
    Keywords energetics ; fish body condition ; fisheries management ; Fourier transform near-infrared spectroscopy ; lipid ; Pacific cod ; Science ; Q ; General. Including nature conservation ; geographical distribution ; QH1-199.5
    Subject code 333
    Language English
    Publishing date 2021-07-01T00:00:00Z
    Publisher Frontiers Media S.A.
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  3. Article: Experimental determination of tissue turnover rates and trophic discrimination factors for stable carbon and nitrogen isotopes of Arctic Sculpin (Myoxocephalus scorpioides): A common Arctic nearshore fish

    Barton, Mark B / Brenda L. Norcross / Johanna J. Vollenweider / Kevin M. Boswell / Ron A. Heintz / Steven Y. Litvin

    Elsevier B.V. Journal of experimental marine biology and ecology. 2019 Feb., v. 511

    2019  

    Abstract: Rapid environmental changes occurring in the Arctic nearshore are expected to have significant effects on food web structures. Land-fast ice cover limits the effectiveness of monitoring methods during winter months, precluding understanding of how ... ...

    Abstract Rapid environmental changes occurring in the Arctic nearshore are expected to have significant effects on food web structures. Land-fast ice cover limits the effectiveness of monitoring methods during winter months, precluding understanding of how seasonal Arctic nearshore food webs operate. Tissue-dependent stable isotope analysis (SIA) offers an efficient and cost-effective approach to monitoring changes in food webs during ice-covered months but requires controlled laboratory experiments to determine isotopic turnover rates and trophic discrimination factors (TDFs) of different tissues. We propose that Arctic Sculpin (Myoxocephalus scorpioides) be used to investigate Arctic nearshore trophodynamics given its opportunistic feeding habits and consistent residence within nearshore Arctic habitats. We present the first tissue-dependent SIA experiment on an Arctic marine fish species and show that δ15N values of fin (or liver) and muscle of Arctic Sculpin may be used to identify shifts in low-trophic-level resource availability between 56 and 122 days before sacrifice. Furthermore, TDFs were determined for carbon isotopes (1.87‰), but results for nitrogen (1.23‰ to 3.23‰) suggest that TDFs in Arctic fish may be highly dependent on lipid content of their diet. We observed similar turnover rates between liver and fin tissues (56 and 58 days, respectively), and suggest it may not be necessary to sample both, making it possible to use Arctic Sculpin for tissue dependent analyses with potentially non-lethal sampling of fin and muscle tissues. The use of Arctic Sculpin as an indicator species can increase the understanding of food web structure and aid in monitoring changes to lower-trophic level prey availability as ecosystem dynamics are affected by climate change.
    Keywords carbon isotopes ; climate change ; cost effectiveness ; diet ; ecosystems ; food webs ; habitats ; ice ; indicator species ; laboratory experimentation ; lipid content ; liver ; marine fish ; monitoring ; muscle tissues ; muscles ; Myoxocephalus scorpioides ; nitrogen ; stable isotopes ; winter ; Arctic region
    Language English
    Dates of publication 2019-02
    Size p. 60-67.
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 410283-6
    ISSN 0022-0981
    ISSN 0022-0981
    DOI 10.1016/j.jembe.2018.11.005
    Database NAL-Catalogue (AGRICOLA)

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  4. Article ; Online: Energetic Cost of Ichthyophonus Infection in Juvenile Pacific Herring (Clupea pallasii)

    Paul K. Hershberger / Ron A. Heintz / Jake L. Gregg / Johanna J. Vollenweider

    Journal of Parasitology Research, Vol

    2011  Volume 2011

    Keywords Infectious and parasitic diseases ; RC109-216 ; Internal medicine ; RC31-1245 ; Medicine ; R ; DOAJ:Internal medicine ; DOAJ:Medicine (General) ; DOAJ:Health Sciences
    Language English
    Publishing date 2011-01-01T00:00:00Z
    Publisher Hindawi Publishing Corporation
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article: Are spatial and temporal patterns in Lynn Canal overwintering Pacific herring related to top predator activity?

    Boswell, Kevin M / David J. Csepp / Guillaume Rieucau / Jason K. Blackburn / Johanna J. Vollenweider / John R. Moran / Ron A. Heintz

    Canadian journal of fisheries and aquatic sciences. 2016 Feb. 18, v. 73, no. 9

    2016  

    Abstract: In Southeast Alaska, overwintering Pacific herring (Clupea pallasii) form large conspicuous schools that are preyed upon by an abundance of mammalian and avian predators, thus leading to the question of why herring adopt a strategy that appears ... ...

    Abstract In Southeast Alaska, overwintering Pacific herring (Clupea pallasii) form large conspicuous schools that are preyed upon by an abundance of mammalian and avian predators, thus leading to the question of why herring adopt a strategy that appears counterproductive to predator avoidance during these periods. We examined the spatial and temporal dynamics of overwintering Pacific herring and associations with predators through monthly hydroacoustic surveys during two consecutive winters. Large variation was observed through the winter season in herring distribution, school morphology, and density. Herring school characteristics and biomass estimates were negatively correlated with humpback whale (Megaptera novaeangliae) abundance patterns during both winters, and as whales departed towards the end of winter, herring distributions shifted from dispersed schools in the water column toward deep, dense schools. We postulate that the schooling patterns observed in Lynn Canal overwintering herring are likely to be mediated by predation threat rather than energetics or feeding activities. An additional consequence of humpback whales dispersing herring in the water column may be an increased threat of predation by other surface-oriented predators.
    Keywords biomass ; birds ; Clupea pallasii pallasii ; herring ; Megaptera novaeangliae ; overwintering ; predation ; predator avoidance ; predators ; surveys ; temporal variation ; whales ; winter ; Alaska
    Language English
    Dates of publication 2016-0218
    Size p. 1307-1318.
    Publishing place NRC Research Press
    Document type Article
    ZDB-ID 1473089-3
    ISSN 1205-7533 ; 0706-652X
    ISSN (online) 1205-7533
    ISSN 0706-652X
    DOI 10.1139/cjfas-2015-0192
    Database NAL-Catalogue (AGRICOLA)

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  6. Article ; Online: Effects of Environmental Temperature on the Dynamics of Ichthyophoniasis in Juvenile Pacific Herring (Clupea pallasii)

    Paul K. Hershberger / Ron A. Heintz / Courtney A. Grady / Johanna J. Vollenweider / Jake L. Gregg

    Journal of Parasitology Research, Vol

    2011  Volume 2011

    Keywords Infectious and parasitic diseases ; RC109-216 ; Internal medicine ; RC31-1245 ; Medicine ; R ; DOAJ:Internal medicine ; DOAJ:Medicine (General) ; DOAJ:Health Sciences
    Language English
    Publishing date 2011-01-01T00:00:00Z
    Publisher Hindawi Publishing Corporation
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  7. Article ; Online: Airborne Remote Sensing of a Biological Hot Spot in the Southeastern Bering Sea

    Michael F. Sigler / Nicola Hillgruber / John K. Horne / George L. Hunt / Evelyn D. Brown / Sandra Parker-Stetter / Johanna J. Vollenweider / James H. Churnside

    Remote Sensing, Vol 3, Iss 3, Pp 621-

    2011  Volume 637

    Abstract: Intense, ephemeral foraging events within localized hot spots represent important trophic transfers to top predators in marine ecosystems, though the spatial extent and temporal overlap of predators and prey are difficult to observe using traditional ... ...

    Abstract Intense, ephemeral foraging events within localized hot spots represent important trophic transfers to top predators in marine ecosystems, though the spatial extent and temporal overlap of predators and prey are difficult to observe using traditional methods. The southeastern Bering Sea has high marine productivity along the shelf break, especially near marine canyons. At a hot spot located near Bering Canyon, we observed three foraging events over a 12 day period in June 2005. These were located by aerial surveys, quantified by airborne lidar and visual counts, and characterized by ship-based acoustics and net catches. Because of the high density of seabirds, the events could be seen in images from space-based synthetic aperture radar. The events developed at the shelf slope, adjacent to passes between the Aleutian Islands, persisted for 1 to 8 days, then abruptly disappeared. Build-up and break down of the events occurred on 24 hr time scales, and diameters ranged from 10 to 20 km. These events comprised large concentrations of euphausiids, copepods, herring, other small pelagic fishes, humpback whales, Dall’s porpoise, short-tailed shearwaters, northern fulmars, and other pelagic seabirds. The lidar and acoustic remote sensing data demonstrated that prey densities inside the events were several times higher than those outside, indicating the importance of including events in forage fish surveys. This implies a need for either very intensive traditional surveys covering large expanses or for adaptive surveys guided by remote sensing. To our knowledge, this is the first time that an Alaskan hot spot was monitored with the combination of airborne and satellite remote sensing.
    Keywords ecological hot spots ; aerial surveys ; lidar ; remote sensing ; fisheries acoustics ; marine food chains ; seabirds ; marine mammals ; forage fish ; Bering Sea ; SAR ; Science ; Q
    Subject code 333
    Language English
    Publishing date 2011-03-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  8. Article: Energetic Cost of Ichthyophonus Infection in Juvenile Pacific Herring (Clupea pallasii)

    Johanna J. Vollenweider / Jake L. Gregg / Ron A. Heintz / Paul K. Hershberger
    Language English
    Document type Article
    Database AGRIS - International Information System for the Agricultural Sciences and Technology

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    Inter-library loan at ZB MED

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  9. Article: Effects of Environmental Temperature on the Dynamics of Ichthyophoniasis in Juvenile Pacific Herring (Clupea pallasii)

    Jake L. Gregg / Johanna J. Vollenweider / Courtney A. Grady / Ron A. Heintz / Paul K. Hershberger
    Language English
    Document type Article
    Database AGRIS - International Information System for the Agricultural Sciences and Technology

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    Inter-library loan at ZB MED

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  10. Article: Airborne Remote Sensing of a Biological Hot Spot in the Southeastern Bering Sea

    James H. Churnside / Evelyn D. Brown / Sandra Parker-Stetter / John K. Horne / George L. Hunt / Nicola Hillgruber / Michael F. Sigler / Johanna J. Vollenweider

    Abstract: Intense, ephemeral foraging events within localized hot spots represent important trophic transfers to top predators in marine ecosystems, though the spatial extent and temporal overlap of predators and prey are difficult to observe using traditional ... ...

    Abstract Intense, ephemeral foraging events within localized hot spots represent important trophic transfers to top predators in marine ecosystems, though the spatial extent and temporal overlap of predators and prey are difficult to observe using traditional methods. The southeastern Bering Sea has high marine productivity along the shelf break, especially near marine canyons. At a hot spot located near Bering Canyon, we observed three foraging events over a 12 day period in June 2005. These were located by aerial surveys, quantified by airborne lidar and visual counts, and characterized by ship-based acoustics and net catches. Because of the high density of seabirds, the events could be seen in images from space-based synthetic aperture radar. The events developed at the shelf slope, adjacent to passes between the Aleutian Islands, persisted for 1 to 8 days, then abruptly disappeared. Build-up and break down of the events occurred on 24 hr time scales, and diameters ranged from 10 to 20 km. These events comprised large concentrations of euphausiids, copepods, herring, other small pelagic fishes, humpback whales, Dall’s porpoise, short-tailed shearwaters, northern fulmars, and other pelagic seabirds. The lidar and acoustic remote sensing data demonstrated that prey densities inside the events were several times higher than those outside, indicating the importance of including events in forage fish surveys. This implies a need for either very intensive traditional surveys covering large expanses or for adaptive surveys guided by remote sensing. To our knowledge, this is the first time that an Alaskan hot spot was monitored with the combination of airborne and satellite remote sensing.
    Language English
    Document type Article
    Database AGRIS - International Information System for the Agricultural Sciences and Technology

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    Kategorien

    Inter-library loan at ZB MED

    Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

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