Article
Food Science & Technology
Jesse Brinkhof, Bent Herrmann, Manu Sistiaga, Roger B. Larsen, Nadine Jacques, Svein Helge Gjosund
Summary: The study assesses the damage levels of cod captured with a new gear design in the Barents Sea bottom trawl fishery, and investigates the impact of the compulsory sorting grid and diamond mesh codend configuration on cod damage during capture. Results show that substituting the gear configuration can increase the probability of cod having no catch damage by 6.00% and significantly reduce the severity of all catch damage categories.
Article
Oceanography
Jesse Brinkhof, Roger B. Larsen, Bent Herrmann
Summary: This study compared the size selectivity and catch efficiency of two diamond-meshed codends turned 90 degrees (T90) with two different mesh sizes (135 and 145 mm) with those of a sorting grid followed by a diamond-mesh codend. The results showed that using a diamond-mesh codend is a more advantageous alternative to the sorting grid method in terms of catch efficiency and selectivity.
OCEAN & COASTAL MANAGEMENT
(2022)
Article
Ecology
Manu Sistiaga, Bent Herrmann, Jesse Brinkhof, Roger B. Larsen
Summary: Sorting grids are used in trawl fisheries to improve size selectivity. This study compares the size selective properties of a steel grid mounted in three different netting section configurations: 2-panel section, 4-panel section, and 4-panel section with a modified lifting panel. The results demonstrate that the 2-panel configuration performs better than the two 4-panel configurations tested.
REGIONAL STUDIES IN MARINE SCIENCE
(2023)
Article
Environmental Sciences
Matt K. Broadhurst, Ian A. Knuckey, Russell B. Millar
Summary: Investigated the use of larger and more T90 meshes in an Australian fish-trawl codend to improve size selection and reduce discards of deepwater flathead. Larger-meshed codends caught fewer immature flathead but lost some larger fish. The discard percentage in this fishery is likely to remain high (>75%), and efforts to improve selection should consider other modifications besides codend changes.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Fisheries
Matt K. Broadhurst, Russell B. Millar
Summary: This experiment evaluated the effects of a narrower-than-recommended hooped cover on the conventional trawl codend, as well as the impact of inserting a large panel of smaller square-shaped mesh on the size selection of eastern school whiting. The results suggest that modifying the mesh size in the codend can marginally improve size selection for the targeted fish species.
FISHERIES RESEARCH
(2022)
Article
Fisheries
Jesse Brinkhof, Manu Sistiaga, Bent Herrmann, Eduardo Grimaldo, Roger B. Larsen
Summary: The use of compulsory selectivity gear configuration in the bottom trawl fishery in the Northeast Atlantic has shown problems with performance and efficiency. A recent study compared different gear configurations and found that an alternative codend with shortened lastridge ropes and a thinner twine improved size selectivity. The study also suggested that the abundance of cod below minimum legal size in the fishing area was low, and spatial and seasonal closures combined with flexible selection devices and modern monitoring tools could be an alternative to rigid enforcement of selective fishing gear.
ICES JOURNAL OF MARINE SCIENCE
(2022)
Article
Environmental Sciences
Matt K. Broadhurst, Ian A. Knuckey, Russell B. Millar
Summary: Turning conventional diamond-shaped meshes 90 degrees ('T90') in trawl extensions or codends is a simple modification that has improved size selection in European fisheries. However, in the Great Australian Bight, using the T90 mesh in the anterior codend did not significantly affect catches or sizes of discarded or retained species, except for a slightly improved quality of deepwater flathead attributed to the release of abrasive debris from the codend.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Fisheries
Manu Sistiaga, Bent Herrmann, Jesse Brinkhof, Roger B. Larsen, Juan Santos, Daniel Stepputtis, Ilmar Brinkhof, Nadine Jacques, Kristine Cerbule, Andrea Petetta, Elsa Cuende, Liz Kvalvik
Summary: Shortening codend lastridge ropes can improve size selection in diamond mesh codends, but the optimal length is uncertain. Shortened ropes can cause folding of the net, potentially affecting size selectivity.
FISHERIES RESEARCH
(2023)
Article
Engineering, Marine
Lei Yan, Bingzhong Yang, Peng Zhang, Jie Li, Teng Wang
Summary: This study conducted experiments to assess the selectivity of diamond mesh codends in capturing largehead hairtail in the Beibu Gulf. Different mesh sizes were used, and models were fitted to the catch data to determine the best fit curve. It was found that the present minimum mesh size did not match the landing size and suggestions for the optimal configuration and mesh size were made.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Engineering, Marine
Eduardo Grimaldo, Bent Herrmann, Jure Brcic, Kristine Cerbule, Jesse Brinkhof, Leif Grimsmo, Nadine Jacques
Summary: The increasing interest in harvesting mesopelagic fish species has raised the demand for optimizing trawl designs for efficient catch. This study investigates the potential net panel selectivity and provides design parameters for trawls targeting mesopelagic species. The simulation model demonstrates that using small-mesh liners in specific parts of the trawl reduces panel selectivity and increases catch efficiency.
Article
Environmental Sciences
Michael S. Bank, Sylvia Frantzen, Arne Duinker, David Amouroux, Emmanuel Tessier, Kjell Nedreaas, Amund Maage, Bente M. Nilsen
Summary: Mercury pollution in the ocean, particularly in marine apex predators like Greenland halibut, has been a global concern. A study on Greenland halibut showed a decrease in Hg bioaccumulation in fillet tissue over a ten-year period, with methylmercury being the predominant form. The decrease in Hg concentrations was attributed to factors such as declines in Hg air emissions, estimated trophic position, and trophic shifts in the food web dynamics.
ENVIRONMENTAL POLLUTION
(2021)
Article
Fisheries
Tonje K. Jensen, Jesse Brinkhof, Stein-Kato Lindberg, Torbjorn Tobiassen, Karsten Heia, Stein Harris Olsen, Roger B. Larsen, Margrethe Esaiassen
Summary: This study aimed to compare the catch quality of Northeast Atlantic cod caught using the conventional configuration and T90 turned mesh codend. The results showed that there was no significant difference in catch damage or residual blood levels between the two gears.
FISHERIES RESEARCH
(2022)
Article
Engineering, Marine
Bingzhong Yang, Bent Herrmann, Rong Wan
Summary: We tested and compared the selective properties of four experimental codends in order to optimize the size selectivity of demersal trawl targeting Banded Scad in the South China Sea (SCS). The results showed that the T0_30 codend presented the best size selectivity and is a potential choice for harvesting Banded Scad in the studied area. Although using the T0_35 or T90_30 codend might improve the size selectivity slightly, it could result in the loss of marketable-size individuals. Based on our study and previous research, we recommend mandating the use of T0_30 codend in the fisheries management regulation of trawl fisheries targeting Banded Scad in the SCS.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Engineering, Marine
Xinxing You, Fuxiang Hu, Yuki Takahashi, Daisuke Shiode, Shuchuang Dong
Summary: The study conducted hydrodynamic experiments and CFD analysis on trawl plane nettings in a flume tank at various flow speeds and solidity ratios, aiming to refine the understanding of the relationship between resistance performance and flow behavior. Results showed that the drag coefficient of the plane nettings varied with the solidity ratio and angle of attack, indicating a dual effect of the solidity ratio on the drag coefficient relative to the inclination angle. Additionally, a transition of flow behavior from flowing above to passing through the netting was observed, with changing local flow velocity consistent with resistance performance relative to the solidity ratio for the tested nettings.
Article
Environmental Sciences
Michele Luca Geraci, Giacomo Sardo, Danilo Scannella, Fabio Falsone, Federico Di Maio, Vita Gancitano, Fabio Fiorentino, Pierangela Chirco, Daniela Massi, Sergio Vitale
Summary: The study compared the effectiveness of different by-catch reduction devices (BRDs) in the central Mediterranean Sea. The results showed that the T45 40 mm sorting grid was more effective in catching Parapenaeus longirostris, while the T90 50 mm codend was more selective for Merluccius merluccius.
FRONTIERS IN MARINE SCIENCE
(2023)
Article
Fisheries
Esther Savina, Bent Herrmann, Rikke P. Frandsen, Ludvig A. Krag
Summary: This paper presents a new method for estimating the length-dependent fish capture modes in gillnets. The study focused on cod in commercial monofilament nylon gillnets and found that the capture modes were dependent on fish size. The findings have implications for improving gear selectivity and efficiency.
ICES JOURNAL OF MARINE SCIENCE
(2022)
Article
Oceanography
Jesse Brinkhof, Roger B. Larsen, Bent Herrmann
Summary: This study compared the size selectivity and catch efficiency of two diamond-meshed codends turned 90 degrees (T90) with two different mesh sizes (135 and 145 mm) with those of a sorting grid followed by a diamond-mesh codend. The results showed that using a diamond-mesh codend is a more advantageous alternative to the sorting grid method in terms of catch efficiency and selectivity.
OCEAN & COASTAL MANAGEMENT
(2022)
Article
Multidisciplinary Sciences
Elsa Cuende, Manu Sistiaga, Bent Herrmann, Luis Arregi
Summary: This study examines the size selectivity and catch patterns of different gear combinations in the Basque bottom trawl fishery. The results demonstrate the significant impact of design changes in square mesh panels and codends on the size selectivity and catch patterns of hake and blue whiting. The study suggests prioritizing research on codend size selectivity and the addition of selection devices once good selective properties are achieved.
Article
Oceanography
Y. E. Fakioglu, H. Ozbilgin, G. Gokce, B. Herrmann
Summary: The study aimed to modify bottom trawl fishing gears to reduce the bycatch of slow-growing marine species such as rays and skates. Sea trials showed that the modified gear significantly reduced the capture probability of guitarfish and stingrays compared to the standard gear. The results for spiny butterfly ray were inconclusive. For most target species, there was no significant reduction in catch efficiency when using the modified gear, except for common sole. The technical measure of modifying bottom trawl gears has the potential to be an efficient and cost-effective way to reduce unwanted bycatch.
OCEAN & COASTAL MANAGEMENT
(2022)
Article
Oceanography
Juan Santos, Daniel Stepputtis, Daniel Oesterwind, Bent Herrmann, Uwe Lichtenstein, Constanze Hammerl, Uwe Krumme
Summary: This study developed and tested a simple roofless design concept to reduce cod bycatch in flatfish-directed trawl fisheries. The baseline roofless design consistently reduced cod bycatch by about 75%, with minimal impact on the catch of the target species flounder and plaice. The use of the baseline roofless concept could significantly increase fishing possibilities for flatfish.
OCEAN & COASTAL MANAGEMENT
(2022)
Article
Environmental Sciences
Andrea Petetta, Bent Herrmann, Massimo Virgili, Daniel Li Veli, Jesse Brinkhof, Alessandro Lucchetti
Summary: The study found that design changes that work for the codend of bottom trawls do not necessarily work for other parts of the trawl, and may even have negative effects.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Ecology
Bent Herrmann, Kristine Cerbule, Jure Brcic, Eduardo Grimaldo, Maxime Geoffroy, Malin Daase, Jorgen Berge
Summary: Measures of biodiversity are crucial for monitoring ecosystems. Marine faunal biodiversity is often quantified using samples collected through trawling. To track changes in biodiversity, samples are collected from multiple stations. Estimation of biodiversity indices must account for spatial-temporal variation and uncertainty in sample size. The nested bootstrapping method presented here addresses these uncertainties and allows for inference of biodiversity changes.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2022)
Article
Fisheries
Zita Bak-Jensen, Bent Herrmann, Juan Santos, Nadine Jacques, Valentina Melli, Jordan P. Feekings
Summary: This study found that the commonly used diamond-mesh codends in demersal trawls tend to have varying mesh geometry during fishing, resulting in an unclear size selection process. By comparing experimental tests, it was discovered that rigid codends with constant mesh geometry have better stability in size selection for Atlantic cod. These findings can guide the design of more suitable codends in future research.
CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES
(2022)
Article
Fisheries
Jesse Brinkhof, Manu Sistiaga, Bent Herrmann, Eduardo Grimaldo, Roger B. Larsen
Summary: The use of compulsory selectivity gear configuration in the bottom trawl fishery in the Northeast Atlantic has shown problems with performance and efficiency. A recent study compared different gear configurations and found that an alternative codend with shortened lastridge ropes and a thinner twine improved size selectivity. The study also suggested that the abundance of cod below minimum legal size in the fishing area was low, and spatial and seasonal closures combined with flexible selection devices and modern monitoring tools could be an alternative to rigid enforcement of selective fishing gear.
ICES JOURNAL OF MARINE SCIENCE
(2022)
Article
Oceanography
Jesse Brinkhof, Eduardo Grimaldo, Bent Herrmann, Hermann Pettersen
Summary: This study compared the effectiveness of two different sizes of sorting grids in Norway pout fishery, finding that increasing grid area can reduce unwanted by-catch species without affecting the catch efficiency of target species.
OCEAN & COASTAL MANAGEMENT
(2022)
Article
Engineering, Marine
Eduardo Grimaldo, Bent Herrmann, Jure Brcic, Kristine Cerbule, Jesse Brinkhof, Leif Grimsmo, Nadine Jacques
Summary: The increasing interest in harvesting mesopelagic fish species has raised the demand for optimizing trawl designs for efficient catch. This study investigates the potential net panel selectivity and provides design parameters for trawls targeting mesopelagic species. The simulation model demonstrates that using small-mesh liners in specific parts of the trawl reduces panel selectivity and increases catch efficiency.
Article
Marine & Freshwater Biology
Eduardo Grimaldo, Jesse Brinkhof, Bent Herrmann, Kristine Cerbule, Leif Grimsmo, Hermann Pettersen
Summary: In this study, the effectiveness of a trawl with a standard rigid sorting grid was compared to a trawl with a newly developed flexible system called the Excluder in reducing bycatch. Fishing trials were conducted in the Norwegian pout small-meshed trawl fishery in the North Sea. The Excluder significantly reduced the bycatch of multiple species, while only slightly decreasing the catch efficiency of Norwegian pout. This research highlights the potential of the Excluder in reducing bycatch, but also raises concerns about its impact on fishery profitability.
ESTUARINE COASTAL AND SHELF SCIENCE
(2023)
Article
Multidisciplinary Sciences
Kristine Cerbule, Leif Grimsmo, Bent Herrmann, Eduardo Grimaldo
Summary: The use of food grade wild-captured species as bait for other fisheries raises concerns about the sustainability of food production. In the snow crab fishery, large amounts of bait from wild-capture fisheries are used, leading to economic and environmental sustainability issues. Alternative bait sources, such as processed by-products from commercial fisheries, need to be considered.
Article
Engineering, Marine
Eduardo Grimaldo, Bent Herrmann, Enis N. Kostak, Jesse Brinkhof
Summary: A major challenge for the aquaculture sector is finding sustainable and cost-effective raw materials for feed. This study aimed to develop a more energy-efficient and efficient trawl for harvesting zooplankton. The results showed that the filtration efficiency of the net increased with increasing flow velocity and decreasing solidity and taper angle.
Article
Fisheries
Miguel Petrere Jr, Davi Butturi-Gomes
Summary: This short communication aims to raise awareness about the misuse of confidence intervals in Ecology and Fisheries statistical models that ignore the lack of independence.
FISHERIES RESEARCH
(2024)
Article
Fisheries
Peter-John F. Hulson, Benjamin C. Williams
Summary: This study evaluates the impact of considering ageing error and growth variability on the determination of input sample size (ISS) in statistical catch-at-age assessment models. The results show that including these sources of uncertainty decreases the ISS determined through bootstrap methods. This indicates that there is more variability in age composition and conditional age-at-length data than previously accounted for. Including these sources of uncertainty improves the estimation of ISS and subsequently improves the quality of stock assessment models.
FISHERIES RESEARCH
(2024)
Article
Fisheries
Jason M. Cope
Summary: Fishery resource assessment is a complex and challenging task, but with the use of different analysis methods and tools, effective management guidance can be provided even with limited data and resources.
FISHERIES RESEARCH
(2024)
Article
Fisheries
Regina L. Cunha, Joana I. Robalo, Sara M. Francisco, Ines Farias, Rita Castilho, Ivone Figueiredo
Summary: Recent advances in genomics have greatly contributed to the assessment of fish stocks by providing precise identification of genetic boundaries. This study used a genotyping-by-sequencing approach to reveal the existence of an additional genetic cluster of blackspot seabream in the northeast Atlantic, which was not previously identified. Factors such as ocean circulation patterns and local upwelling may play a role in the genetic differentiation observed in this study.
FISHERIES RESEARCH
(2024)
Article
Fisheries
Huihua Lee, Mark N. Maunder, Kevin R. Piner
Summary: Estimating growth is important for fish population assessment. Integrated assessment models and the influence of misfitting size composition data have renewed interest in how growth is modeled. The available data types control how the length-at-age relationship is estimated. Estimating length-at-age is complex due to multiple sources of biological variability and difficulties in obtaining representative samples.
FISHERIES RESEARCH
(2024)
Article
Fisheries
A. Ladino, I. Perez-Arjona, V. Espinosa, M. Chillaron, V. Vidal, L. M. Godinho, G. Moreno, G. Boyra
Summary: This study examines the acoustic properties of skipjack tuna and Atlantic mackerel, both bladderless pelagic fish species, and explains the significant differences observed. The research shows that the differences in material properties of their tissues predict a more than 10 dB greater reduced target strength in skipjack compared to mackerel at certain frequencies.
FISHERIES RESEARCH
(2024)
Article
Fisheries
Nelly Pena-Cutimbo, Cristel Cordero-Maldonado, Clara Ortiz-Alvarez, Joanna Alfaro-Shigueto, Jeffrey C. Mangel
Summary: Bycatch is a global problem for marine megafauna. This study assessed the bycatch interactions of the Peruvian artisanal purse-seine fishery in 2019 and found that all taxa groups were affected by bycatch. Dusky dolphins, guanay cormorants, and eagle rays were the most frequently reported bycatch species.
FISHERIES RESEARCH
(2024)
Article
Fisheries
Jen-Ming Liu, Po-Yuk So
Summary: The set-net fishery is an environmentally friendly fishery posing little risk to the marine ecosystem. This study identified ocean temperature, sea surface factors, and climatic factors as the main factors affecting the installation of set-nets.
FISHERIES RESEARCH
(2024)
Article
Fisheries
Josie L. Palmer, Carina Armstrong, Hasan D. Akbora, Damla Beton, Cigdem Caglar, Brendan J. Godley, Kristian Metcalfe, Meryem Ozkan, Robin T. E. Snape, Annette C. Broderick
Summary: Small-scale fisheries are vital for global food security and cultural heritage, but the lack of information hampers effective management and mitigation of ecological impacts. This study provides the first comprehensive overview of the small-scale fishery fleet in Northern Cyprus. The fleet operates mainly over the continental shelf, using static and demersal gear types, and catches a diverse range of species, some of which are threatened. The findings can be used to improve fisheries management and conservation measures.
FISHERIES RESEARCH
(2024)
