5 results on '"Hinke, Jefferson"'
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2. Observing change in pelagic animals as sampling methods shift: the case of Antarctic krill
- Author
-
Hill, Simeon L, Atkinson, Angus, Arata, Javier, Belcher, Anna, Bengtson-Nash, Susan, Bernard, Kim S., Cleary, Alison, Conroy, John, Driscoll, Ryan, Fielding, Sophie, Flores, Hauke, Forcada, Jaume, Halfter, Svenja, Hinke, Jefferson, Hückstädt, Luis, Johnston, Nadine M., Kane, Mary, Kawaguchi, So, Krafft, Bjørn A., Krüger, Lucas, La, Hyoung Sul, Liszka, Cecilia, Meyer, Bettina, Murphy, Eugene, Pakhomov, Evgeny, Perry, Frances, Piñones, Andrea, Polito, Michael J., Reid, Keith, Reiss, Christian, Rombola, Emilce, Saunders, Ryan A., Schmidt, Katrin, Sylvester, Zephryr, Takahashi, Akinori, Tarling, Geraint A., Trathan, Philip N., Veytia, Devi, Watters, George, Xavier, José C., Yang, Guang, Hill, Simeon L, Atkinson, Angus, Arata, Javier, Belcher, Anna, Bengtson-Nash, Susan, Bernard, Kim S., Cleary, Alison, Conroy, John, Driscoll, Ryan, Fielding, Sophie, Flores, Hauke, Forcada, Jaume, Halfter, Svenja, Hinke, Jefferson, Hückstädt, Luis, Johnston, Nadine M., Kane, Mary, Kawaguchi, So, Krafft, Bjørn A., Krüger, Lucas, La, Hyoung Sul, Liszka, Cecilia, Meyer, Bettina, Murphy, Eugene, Pakhomov, Evgeny, Perry, Frances, Piñones, Andrea, Polito, Michael J., Reid, Keith, Reiss, Christian, Rombola, Emilce, Saunders, Ryan A., Schmidt, Katrin, Sylvester, Zephryr, Takahashi, Akinori, Tarling, Geraint A., Trathan, Philip N., Veytia, Devi, Watters, George, Xavier, José C., and Yang, Guang
- Abstract
Understanding and managing the response of marine ecosystems to human pressures including climate change requires reliable large-scale and multi-decadal information on the state of key populations. These populations include the pelagic animals that support ecosystem services including carbon export and fisheries. The use of research vessels to collect information using scientific nets and acoustics is being replaced with technologies such as autonomous moorings, gliders, and meta-genetics. Paradoxically, these newer methods sample pelagic populations at ever-smaller spatial scales, and ecological change might go undetected in the time needed to build up large-scale, long time series. These global-scale issues are epitomised by Antarctic krill (Euphausia superba), which is concentrated in rapidly warming areas, exports substantial quantities of carbon and supports an expanding fishery, but opinion is divided on how resilient their stocks are to climatic change. Based on a workshop of 137 krill experts we identify the challenges of observing climate change impacts with shifting sampling methods and suggest three tractable solutions. These are to: improve overlap and calibration of new with traditional methods; improve communication to harmonise, link and scale up the capacity of new but localised sampling programs; and expand opportunities from other research platforms and data sources, including the fishing industry. Contrasting evidence for both change and stability in krill stocks illustrates how the risks of false negative and false positive diagnoses of change are related to the temporal and spatial scale of sampling. Given the uncertainty about how krill are responding to rapid warming we recommend a shift towards a fishery management approach that prioritises monitoring of stock status and can adapt to variability and change.
- Published
- 2024
3. Observing change in pelagic animals as sampling methods shift: the case of Antarctic krill
- Author
-
World Wildlife Fund, Natural Environment Research Council (UK), National Science Foundation (US), European Commission, Instituto Antártico Chileno, Instituto Milenio de Oceanografía (Chile), Korea Polar Research Institute, Ministry of Oceans and Fisheries (South Korea), Helmholtz Association, Natural Sciences and Engineering Research Council of Canada, Agencia Nacional de Investigación y Desarrollo (Chile), Fondo Nacional de Desarrollo Científico y Tecnológico (Chile), Japan Society for the Promotion of Science, University of Tasmania, Fundação para a Ciência e a Tecnologia (Portugal), Hill, Simeon L., Atkinson, Angus, Arata, Javier A., Belcher, Anna, Bengtson Nash, Susan, Bernard, Kim S., Cleary, Alison, Conroy, John A., Driscoll, Ryan, Fielding, Sophie, Flores, Hauke, Forcada, Jaume, Halfter, Svenja, Hinke, Jefferson T., Hückstädt, Luis, Johnston, Nadine M., Kane, Mary, Kawaguchi, So, Krafft, Bjørn A., Krüger, Lucas, La, Hyoung Sul, Liszka, Cecilia M., Meyer, Bettina, Murphy, Eugene J., Pakhomov, Evgeny A., Perry, Frances, Piñones, Andrea, Polito, Michael J., Reid, Keith, Reiss, Christian, Rombola, Emilce, Saunders, Ryan A., Schmidt, Katrin, Sylvester, Zephyr T., Takahashi, Akinori, Tarling, Geraint A., Trathan, Phil N., Veytia, Devi, Watters, George M., Xavier, José C., Yang, Guang, World Wildlife Fund, Natural Environment Research Council (UK), National Science Foundation (US), European Commission, Instituto Antártico Chileno, Instituto Milenio de Oceanografía (Chile), Korea Polar Research Institute, Ministry of Oceans and Fisheries (South Korea), Helmholtz Association, Natural Sciences and Engineering Research Council of Canada, Agencia Nacional de Investigación y Desarrollo (Chile), Fondo Nacional de Desarrollo Científico y Tecnológico (Chile), Japan Society for the Promotion of Science, University of Tasmania, Fundação para a Ciência e a Tecnologia (Portugal), Hill, Simeon L., Atkinson, Angus, Arata, Javier A., Belcher, Anna, Bengtson Nash, Susan, Bernard, Kim S., Cleary, Alison, Conroy, John A., Driscoll, Ryan, Fielding, Sophie, Flores, Hauke, Forcada, Jaume, Halfter, Svenja, Hinke, Jefferson T., Hückstädt, Luis, Johnston, Nadine M., Kane, Mary, Kawaguchi, So, Krafft, Bjørn A., Krüger, Lucas, La, Hyoung Sul, Liszka, Cecilia M., Meyer, Bettina, Murphy, Eugene J., Pakhomov, Evgeny A., Perry, Frances, Piñones, Andrea, Polito, Michael J., Reid, Keith, Reiss, Christian, Rombola, Emilce, Saunders, Ryan A., Schmidt, Katrin, Sylvester, Zephyr T., Takahashi, Akinori, Tarling, Geraint A., Trathan, Phil N., Veytia, Devi, Watters, George M., Xavier, José C., and Yang, Guang
- Abstract
Understanding and managing the response of marine ecosystems to human pressures including climate change requires reliable large-scale and multi-decadal information on the state of key populations. These populations include the pelagic animals that support ecosystem services including carbon export and fisheries. The use of research vessels to collect information using scientific nets and acoustics is being replaced with technologies such as autonomous moorings, gliders, and meta-genetics. Paradoxically, these newer methods sample pelagic populations at ever-smaller spatial scales, and ecological change might go undetected in the time needed to build up large-scale, long time series. These global-scale issues are epitomised by Antarctic krill (Euphausia superba), which is concentrated in rapidly warming areas, exports substantial quantities of carbon and supports an expanding fishery, but opinion is divided on how resilient their stocks are to climatic change. Based on a workshop of 137 krill experts we identify the challenges of observing climate change impacts with shifting sampling methods and suggest three tractable solutions. These are to: improve overlap and calibration of new with traditional methods; improve communication to harmonise, link and scale up the capacity of new but localised sampling programs; and expand opportunities from other research platforms and data sources, including the fishing industry. Contrasting evidence for both change and stability in krill stocks illustrates how the risks of false negative and false positive diagnoses of change are related to the temporal and spatial scale of sampling. Given the uncertainty about how krill are responding to rapid warming we recommend a shift towards a fishery management approach that prioritises monitoring of stock status and can adapt to variability and change.
- Published
- 2024
4. A method to estimate prey density from single-camera images: A case study with chinstrap penguins and Antarctic krill.
- Author
-
Hermanson, Victoria R., Cutter, George R., Hinke, Jefferson T., Dawkins, Matthew, and Watters, George M.
- Subjects
EUPHAUSIA superba ,ARTIFICIAL neural networks ,PREDATORY aquatic animals ,PREDATION ,KRILL - Abstract
Estimating the densities of marine prey observed in animal-borne video loggers when encountered by foraging predators represents an important challenge for understanding predator-prey interactions in the marine environment. We used video images collected during the foraging trip of one chinstrap penguin (Pygoscelis antarcticus) from Cape Shirreff, Livingston Island, Antarctica to develop a novel approach for estimating the density of Antarctic krill (Euphausia superba) encountered during foraging activities. Using the open-source Video and Image Analytics for a Marine Environment (VIAME), we trained a neural network model to identify video frames containing krill. Our image classifier has an overall accuracy of 73%, with a positive predictive value of 83% for prediction of frames containing krill. We then developed a method to estimate the volume of water imaged, thus the density (N·m
-3 ) of krill, in the 2-dimensional images. The method is based on the maximum range from the camera where krill remain visibly resolvable and assumes that mean krill length is known, and that the distribution of orientation angles of krill is uniform. From 1,932 images identified as containing krill, we manually identified a subset of 124 images from across the video record that contained resolvable and unresolvable krill necessary to estimate the resolvable range and imaged volume for the video sensor. Krill swarm density encountered by the penguins ranged from 2 to 307 krill·m-3 and mean density of krill was 48 krill·m-3 (sd = 61 krill·m-3 ). Mean krill biomass density was 25 g·m-3 . Our frame-level image classifier model and krill density estimation method provide a new approach to efficiently process video-logger data and estimate krill density from 2D imagery, providing key information on prey aggregations that may affect predator foraging performance. The approach should be directly applicable to other marine predators feeding on aggregations of prey. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
5. Observing change in pelagic animals as sampling methods shift: the case of Antarctic krill.
- Author
-
Hill, Simeon L., Atkinson, Angus, Arata, Javier A., Belcher, Anna, Nash, Susan Bengtson, Bernard, Kim S., Cleary, Alison, Conroy, John A., Driscoll, Ryan, Fielding, Sophie, Flores, Hauke, Forcada, Jaume, Halfter, Svenja, Hinke, Jefferson T., Hückstädt, Luis, Johnston, Nadine M., Kane, Mary, Kawaguchi, So, Krafft, Bjørn A., and Krüger, Lucas
- Subjects
EUPHAUSIA superba ,SAMPLING methods ,RESEARCH vessels ,KRILL ,FISHERIES ,FISHERY management ,MARINE ecosystem management - Abstract
Understanding and managing the response of marine ecosystems to human pressures including climate change requires reliable large-scale and multidecadal information on the state of key populations. These populations include the pelagic animals that support ecosystem services including carbon export and fisheries. The use of research vessels to collect information using scientific nets and acoustics is being replaced with technologies such as autonomous moorings, gliders, and meta-genetics. Paradoxically, these newer methods sample pelagic populations at ever-smaller spatial scales, and ecological change might go undetected in the time needed to build up large-scale, long time series. These global-scale issues are epitomised by Antarctic krill (Euphausia superba), which is concentrated in rapidly warming areas, exports substantial quantities of carbon and supports an expanding fishery, but opinion is divided on how resilient their stocks are to climatic change. Based on a workshop of 137 krill experts we identify the challenges of observing climate change impacts with shifting sampling methods and suggest three tractable solutions. These are to: improve overlap and calibration of new with traditional methods; improve communication to harmonise, link and scale up the capacity of new but localised sampling programs; and expand opportunities from other research platforms and data sources, including the fishing industry. Contrasting evidence for both change and stability in krill stocks illustrates how the risks of false negative and false positive diagnoses of change are related to the temporal and spatial scale of sampling. Given the uncertainty about how krill are responding to rapid warming we recommend a shift towards a fishery management approach that prioritises monitoring of stock status and can adapt to variability and change. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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