Article
Environmental Sciences
Lone S. Jevne, Maria Guttu, Anna S. Batnes, Yngvar Olsen, Kjell I. Reitan
Summary: This study demonstrates the significant impact of temperature on the density of planktonic sea lice, the effectiveness of lice skirts in reducing adult sea lice on salmon and planktonic sea lice, and the successful reduction of planktonic sea lice density during the fallowing period.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Veterinary Sciences
Ingunn Fride Tvete, Magne Aldrin, Britt Bang Jensen
Summary: Mortality in farmed salmon production is a significant challenge to sustainability. A model was developed to predict daily mortality based on various environmental and production factors. Factors such as sea temperature, lice treatments, and presence of pancreas disease were considered. The model revealed a high mortality rate after stocking, gradually decreasing for the first three months and then increasing. Avoiding lice treatments and pancreas disease could significantly reduce total mortality.
PREVENTIVE VETERINARY MEDICINE
(2023)
Article
Fisheries
M. Aldrin, R. B. Huseby, L. C. Stige, K. O. Helgesen
Summary: This study estimates the effectiveness of different salmon lice treatments used in the salmonid industry by analyzing data from 90 production cycles. The most commonly used treatments are thermal, mechanical, freshwater, and feed treatments with emamectin benzoate. These treatments have variable effectiveness, with an average lice kill rate of 70-80%. Hydrogen peroxide and pyrethroids bath treatments are estimated to kill around 74% and 50% of the lice, respectively, on average. The study provides valuable information for fish farmers and authorities to make informed decisions regarding lice control and treatment selection.
Article
Multidisciplinary Sciences
Victor H. S. Oliveira, Katharine R. Dean, Lars Qviller, Carsten Kirkeby, Britt Bang Jensen
Summary: This study found that baseline mortality of Atlantic salmon in Norway is influenced by factors such as sea lice treatments, stocking month, weight, sea surface temperature, and salinity. Understanding these factors can help reduce mortality in aquaculture.
SCIENTIFIC REPORTS
(2021)
Article
Fisheries
Anne D. Sandvik, Sussie Dalvin, Rasmus Skern-Mauritzen, Morten D. Skogen
Summary: Climate change poses a threat to sustainable growth in the aquaculture industry, with salmon lice-induced mortality in wild salmonid populations identified as a major risk factor. Higher temperatures lead to increased production and infectivity of salmon lice, contributing to a significant rise in infection pressure from farmed to wild salmonids.
ICES JOURNAL OF MARINE SCIENCE
(2021)
Article
Biodiversity Conservation
Thomas Bohn, Rune Nilsen, Karl Oystein Gjelland, Martin Biuw, Anne Dagrun Sandvik, Raul Primicerio, Orjan Karlsen, Rosa Maria Serra-Llinares
Summary: The study found that sea trout in areas with high salmon farm densities on the West coast of Norway had lice infestation rates exceeding 50%, and even in areas with salinities below louse tolerance levels, there were still high lice infestation rates, indicating possible infections elsewhere. This suggests that sea trout are at a higher risk of lice infestations from industrial salmon farming, raising concerns about the environmental sustainability of current aquaculture practices in intensive farming areas.
JOURNAL OF APPLIED ECOLOGY
(2022)
Article
Fisheries
Solveig Engebretsen, Magne Aldrin, Lars Qviller, Leif Christian Stige, Trond Rafoss, Ole Roald Danielsen, Andreas Lindhom, Peder A. Jansen
Summary: This paper analyzed the stomach contents of over 20,000 lumpfish from 80 different Norwegian farms to investigate the salmon lice grazing efficacy. Factors such as lumpfish weight, weight of salmonids, salmon lice abundance in the cage, cloud cover, and sea temperature were considered. The results showed that 3.1% of the lumpfish had salmon lice in their stomach contents, with most having few lice and a few having many lice. The study found that lumpfish weight, salmon lice abundance, salmonid weight, and weather conditions influenced salmon lice grazing, while sea temperature did not. The findings contribute to understanding the factors affecting salmon lice grazing by lumpfish and can guide the best practices for using lumpfish as a control measure.
Article
Geosciences, Multidisciplinary
Simon Hird, Christopher Stokes, Gerd Masselink
Summary: Coastal dune erosion is a critical issue in the face of rising sea levels and increased storminess. This study focuses on the severe erosion of the climbing dune system at Crantock beach in north Cornwall, UK, which has shown acceleration despite reduced severe storm events since 2013/14. The shifting channel of the River Gannel and ongoing river avulsion have played a significant role in the decoupled nature and emergent response of the dune system at Crantock.
Article
Genetics & Heredity
Lene Sveen, Aleksei Krasnov, Gerrit Timmerhaus, Andre Sture Bogevik
Summary: The study showed that the transcriptional response in the skin of Atlantic salmon fed a mineral diet and infected with lice changed, indicating enhanced immune and stress responses, with genes affected also related to the feed. The mineral diet also influenced the ratio of blue and purple mucous cells in the skin.
Article
Mathematics, Applied
Yicai Zhang, Min Zhao, Dihua Sun, Shi Hui Wang, Shuai Huang, Dong Chen
Summary: This study investigates the mixed traffic lattice hydrodynamic model to analyze the mixed traffic situation with connected and non-connected vehicles, and obtains the stability conditions of the traffic system and the modified Korteweg-de Vries equation through linear and nonlinear analysis. The numerical simulation results confirm the theoretical findings, showing that increasing the communication range and permeability of connected vehicles will enhance the stability of the traffic system.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2021)
Article
Multidisciplinary Sciences
Peter. D. D. Harrington, Danielle. L. L. Cantrell, Michael G. G. Foreman, Ming Guo, Mark. A. A. Lewis
Summary: This study develops a simple analytical model to investigate the dispersal of sea lice between two salmon farms. The arrival time distribution and cross-infection level of sea lice are calculated from the model. The study also finds that there is an intermediate interfarm spacing that maximizes the level of cross-infection, and increased temperatures lead to increased levels of cross-infection.
ROYAL SOCIETY OPEN SCIENCE
(2023)
Article
Fisheries
Bjorn Hersoug, Marit Schei Olsen, Asle Arthun Gauteplass, Tonje C. Osmundsen, Frank Asche
Summary: Aquaculture governance faces challenges due to diverse stakeholders with different objectives. Licenses play a key role in ensuring orderly development but may also restrict certain activities. The Norwegian aquaculture industry has introduced special purpose licenses to promote specific activities, raising questions about their effectiveness and impact on the regulatory system.
Article
Multidisciplinary Sciences
Asa Johannesen, Oystein Patursson, Johannus Kristmundsson, Signar Paetursonur Dam, Mats Mulelid, Pascal Klebert
Summary: This study examines the effects of strong currents and waves on the behavior of salmon and their use of available space. The results show that salmon prefer to use the entire water column but narrow their range in response to certain conditions. Salmon exhibit a strong horizontal preference in the cage, predominantly occupying the areas exposed to currents. Waves cause salmon to disperse from the exposed side to the more sheltered side.
Article
Fisheries
J. Mcilvenny, A. Youngson, B. J. Williamson, N. R. Gauld, L. Goddijn-Murphy, D. Del Villar-Guerra
Summary: The migration of Atlantic salmon smolts from fresh water to the marine environment is a crucial transitional stage in their development. This study used acoustic tracking, instrument data, and hydrodynamic modelling to examine the behavior of juvenile salmon during this transition, finding that migration timing is linked to low-light conditions and tidal currents play a significant role in their movement patterns.
ICES JOURNAL OF MARINE SCIENCE
(2021)
Article
Multidisciplinary Sciences
Wei Cheng, Ye-xiao Chen
Summary: This paper describes the phenomenon of platoon dispersion in the mixed traffic environment and provides a theoretical basis for signal timing optimization. A platoon dispersion model is developed considering the influence of the percentage of non-motor vehicles, and the model is validated using data from a specific road. The results show that the proposed model outperforms the classical Robertson model in predicting the dispersion behavior of mixed traffic under different percentages of non-motorized vehicles.
SCIENTIFIC REPORTS
(2023)
Article
Fisheries
Alessandro Cresci, Anne D. Sandvik, Pal N. Saevik, Bjorn Adlandsvik, Maria Josefina Olascoaga, Philippe Miron, Caroline M. F. Durif, Anne Berit Skiftesvik, Howard Browman, Frode Vikebo
Summary: The study reveals that lunar-driven orientation and swimming behavior observed in glass eels significantly increase their recruitment to North Sea coasts. While lunar cues enhance recruitment to certain areas like Southwestern Norway and Scotland, orientation behavior decreases recruitment to northern regions like Iceland, the Faroe Islands, and Northern Norway. The behavior of glass eels also affects the timing and location of recruitment to different regions, leading to variations in recruitment abundance.
FISHERIES OCEANOGRAPHY
(2021)
Article
Fisheries
Ingrid A. Johnsen, Alison Harvey, Pal Naeverlid Saevik, Anne D. Sandvik, Ola Ugedal, Bjorn Adlandsvik, Vidar Wennevik, Kevin A. Glover, Orjan Karlsen
Summary: This study focused on the environmental challenges of salmonid aquaculture, estimating the impact of salmon lice on wild salmon mortality in Norwegian waters using models and data analysis. Results showed that aquaculture-produced salmon lice led to varying mortality rates of wild salmon post-smolts in different rivers.
ICES JOURNAL OF MARINE SCIENCE
(2021)
Article
Evolutionary Biology
Andrew Coates, Ingrid A. Johnsen, Tim Dempster, Ben L. Phillips
Summary: The study in Atlantic salmon aquaculture showed that different behavioral traits in copepodids affect the dispersion of lice and the infestation pressure on barriers, suggesting strong directional selection on copepodid swimming behavior by barriers. The findings emphasize the potential for barriers to slow louse adaptation by limiting access during periods of strong selection, with variations in seasonal and geographic strength of selection.
EVOLUTIONARY APPLICATIONS
(2021)
Article
Fisheries
Anne D. Sandvik, Samantha Bui, Mats Huserbraten, Orjan Karlsen, Mari S. Myksvoll, Bjorn Adlandsvik, Ingrid A. Johnsen
Summary: In Norway, the government uses salmon lice-induced mortality in wild salmonid populations as a measure of environmental sustainability in aquaculture. By developing an index based on evidence-based proxies, including infestation pressure from a bio-hydrodynamic model, they aim to assess the sustainability of aquaculture. The study highlights the importance of reducing lice levels in farms to achieve environmental sustainability in the Norwegian aquaculture industry.
ICES JOURNAL OF MARINE SCIENCE
(2021)
Article
Fisheries
Anne D. Sandvik, Sussie Dalvin, Rasmus Skern-Mauritzen, Morten D. Skogen
Summary: Climate change poses a threat to sustainable growth in the aquaculture industry, with salmon lice-induced mortality in wild salmonid populations identified as a major risk factor. Higher temperatures lead to increased production and infectivity of salmon lice, contributing to a significant rise in infection pressure from farmed to wild salmonids.
ICES JOURNAL OF MARINE SCIENCE
(2021)
Article
Environmental Sciences
Aoife E. Parsons, Ole B. Samuelsen, Ingrid Askeland Johnsen, Rita Hannisdal, Tore Tjensvoll, Vivian Husa
Summary: In order to achieve a sustainable salmonid aquaculture industry, the environmental impacts of chemicals used to treat sea lice infestations need to be considered. Diflubenzuron and teflubenzuron, chitin synthesis inhibiting insecticides frequently used in Norwegian salmon farms, were found in marine sediments and benthic macrofauna near aquaculture sites. The concentrations of these compounds exceeded Norwegian environmental quality standards, indicating a potential risk to benthic marine species. Further studies are needed to fully understand the ecological impacts of these compounds in the marine environment.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Fisheries
M. B. O. Huserbraten, I. A. Johnsen, Carrie Byron
Summary: The high infestation of salmon louse raises concerns about the sustainability of the Norwegian Atlantic salmon aquaculture industry. The connectivity of infective pelagic lice stages among farms plays a vital role in louse population dynamics, but the processes regulating this connectivity are not well understood. A biophysical dispersal model using ocean currents was employed to study the connectivity network among salmon farms in western Norway, showing that the complex geography of the fjords governs the long-term topology of the network, but there is also a strong seasonal component to network fragmentation.
ICES JOURNAL OF MARINE SCIENCE
(2022)
Editorial Material
Fisheries
Ingrid A. Johnsen, Alison Harvey, Pal Naeverlid Saevik, Anne D. Sandvik, Ola Ugedal, Bjorn Adlandsvik, Vidar Wennevik, Kevin A. Glover, Orjan Karlsen
Summary: A model system was developed to estimate salmon lice-induced mortality, calibrated against empirical observations. Critics claim the model overestimates mortality, but their analysis may have shortcomings. Discrepancy between modelled and observed data does not necessarily indicate flaws, but can provide valuable supplementary information.
ICES JOURNAL OF MARINE SCIENCE
(2021)
Article
Biodiversity Conservation
Thomas Bohn, Rune Nilsen, Karl Oystein Gjelland, Martin Biuw, Anne Dagrun Sandvik, Raul Primicerio, Orjan Karlsen, Rosa Maria Serra-Llinares
Summary: The study found that sea trout in areas with high salmon farm densities on the West coast of Norway had lice infestation rates exceeding 50%, and even in areas with salinities below louse tolerance levels, there were still high lice infestation rates, indicating possible infections elsewhere. This suggests that sea trout are at a higher risk of lice infestations from industrial salmon farming, raising concerns about the environmental sustainability of current aquaculture practices in intensive farming areas.
JOURNAL OF APPLIED ECOLOGY
(2022)
Article
Fisheries
Romaric Jac, Hannes Hoffle, Jon Albretsen, Klara Jakobsdottir, Arved Staby, Guldborg Sovik, Claudia Junge
Summary: This study used research survey data and modeling techniques to determine the crucial environmental factors affecting the distribution and abundance of four benthopelagic chondrichthyans in Norwegian and Icelandic waters. The temperature and depth were found to be key drivers of the species' spatial preferences and ecological habitats. The findings have important implications for the sustainable management of these species and their ecosystems.
JOURNAL OF FISH BIOLOGY
(2022)
Article
Ecology
Alison Harvey, Oystein Skaala, Reidar Borgstrom, Per Tommy Fjeldheim, Kaja Christine Andersen, Kjell Rong Utne, Ingrid Askeland Johnsen, Peder Fiske, Synne Winterthun, Sofie Knutar, Harald Saegrov, Kurt Urdal, Kevin Alan Glover
Summary: The decline in wild Atlantic salmon populations is attributed to various factors, including natural and anthropogenic influences. This study analyzed age and growth data, spawning run sampling, and environmental factors to understand the mechanisms behind population changes. The results show a decline in marine growth, a shift in population composition, and an increase in repeat spawners, especially in females. The study also found associations between marine growth and sea surface temperature, zooplankton biomass, and salmon lice infestation intensity.
ECOLOGY AND EVOLUTION
(2022)
Article
Fisheries
Andrew Coates, Nick Robinson, Tim Dempster, Francisca Samsing, Ingrid Johnsen, Ben L. Phillips
Summary: In this study, a numerical metapopulation model was constructed to simulate the evolutionary dynamics of salmon lice in an interconnected farm network and predict the development of pesticide resistance. It was found that highly connected farms were hotspots for louse adaptation, and excluding these farms significantly reduced infestation rates and evolution. This model can be a valuable tool for coordinating pest management at a regional scale, in a way that slows or prevents the spread of resistance.
ICES JOURNAL OF MARINE SCIENCE
(2022)
Article
Fisheries
Tina Kutti, Erwann Legrand, Vivian Husa, Siri Aaserud Olsen, Oystein Gjelsvik, Marcos Carvajalino-Fernandez, Ingrid Askeland Johnsen
Summary: Cold-water corals in Norway are facing increasing pressure from open net pen aquaculture. A study found that the particulate organic waste released from fish farms negatively impacted the ecophysiology of Lophelia pertusa corals, reducing their metabolic rates, growth, and energy reserves. The study suggests that predicting the short-term effects of aquaculture effluents on coral reefs may be possible in the future, improving management decisions regarding the establishment of new farms near cold-water corals.
AQUACULTURE ENVIRONMENT INTERACTIONS
(2022)