Article
Fisheries
Isabella Maria Friederike Kratzer, Daniel Stepputtis, Juan Santos, Frauke Luetkefedder, Arne Stoltenberg, Lea Hartkens, Matthias Schaber, Lotte Kindt-Larsen, Finn Larsen
Summary: This study investigates the use of small acrylic glass spheres attached to gillnets to increase their acoustic reflectivity and reduce incidental capture of small cetaceans. The results show that gillnets equipped with these spheres have higher acoustic backscattering strength, with the best performance observed when the sphere-sphere distance is 20 cm. The findings suggest that modifying gillnets with reflective spheres can be an effective way to reduce bycatch of small cetaceans.
FISHERIES RESEARCH
(2022)
Article
Fisheries
Giovanni Bearzi, Randall R. Reeves
Summary: Some marine mammals have modified their behavior to take advantage of the opportunities provided by fishing, leading to interactions that involve removing or damaging marketable organisms and bait. The use of the term "depredation" when referring to this behavior could reinforce misunderstandings and the belief that marine resources belong solely to humans. Alternative wording would prevent ambiguity and acknowledge the ecological roles of large marine predators.
ICES JOURNAL OF MARINE SCIENCE
(2022)
Article
Environmental Sciences
Simon D. Goldsworthy, Brad Page, Derek J. Hamer, Andrew D. Lowther, Peter D. Shaughnessy, Mark A. Hindell, Paul Burch, Daniel P. Costa, Shannon L. Fowler, Kristian Peters, Rebecca R. McIntosh, Frederic Bailleul, Alice I. Mackay, Roger Kirkwood, Dirk Holman, Simon Bryars
Summary: The bycatch of the endangered Australian sea lion in gillnet fisheries off South Australia has been a major threat to its populations. A comprehensive assessment combined with management measures, including spatial closures, observer programs, and incentives for alternate fishing methods, resulted in a significant reduction in sea lion bycatch mortality and a transition to longline fishing. The successful implementation of these measures showcases how effective management can mitigate bycatch mortality of marine mammals.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Biology
Lotte Kindt-Larsen, Gildas Glemarec, Casper W. Berg, Sara Konigson, Anne-Mette Kroner, Mathias Sogaard, David Lusseau
Summary: Incidental captures (bycatch) of harbour porpoise in European Union fisheries remain a significant threat to cetaceans. A long-term monitoring program in Denmark using electronic monitoring has provided detailed data on porpoise bycatch and gillnet fishing effort. The study highlights the importance of considering fishing characteristics in estimating bycatch rates and emphasizes the need for effective monitoring methods and mitigation techniques.
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2023)
Article
Multidisciplinary Sciences
Yann Rouxel, Rory Crawford, Ian R. Cleasby, Pete Kibel, Ellie Owen, Veljo Volke, Alexandra K. Schnell, Steffen Oppel
Summary: The study showed that a device called the 'Looming eyes buoy' (LEB) could effectively reduce the number of long-tailed ducks around gillnets, indicating the potential for above-water visual devices to contribute to reducing seabird bycatch. However, some habituation to the LEB was detected during the project duration.
ROYAL SOCIETY OPEN SCIENCE
(2021)
Article
Multidisciplinary Sciences
Yann Rouxel, Holmfriour Arnardottir, Steffen Oppel
Summary: Bycatch of seabirds in gillnets is a significant conservation issue in the north Atlantic. This study tested the effectiveness of a floating device called 'looming-eyes buoy' (LEB) in reducing seabird bycatch in the Icelandic lumpfish fishery. The study found no direct effect of LEBs on target lumpfish catch and bycatch, but indicated that fishing depth-based restrictions could effectively eliminate seabird bycatch. The study estimated that limiting fishing to waters deeper than 50 meters could save between 5000 and 9300 seabirds annually, without significant impact on fish catch.
ROYAL SOCIETY OPEN SCIENCE
(2023)
Article
Multidisciplinary Sciences
Soren Post, Flemming Merkel, Zita Bak-Jensen, Christoffer Koch, Rasmus Berg Hedeholm
Summary: Bycatch in gillnets is a global issue, particularly in the North Atlantic lumpfish fisheries where there are no permanent initiatives to reduce it. Researchers in West Greenland experimented with modified gillnets that included a small-meshed net panel at the bottom, resulting in a 71% reduction in common eider bycatch and a 25% reduction in female lumpfish catch rate. It is recommended to further study the net modification's effect and explore the option of postponing the fishing season to reduce bycatch.
ROYAL SOCIETY OPEN SCIENCE
(2023)
Article
Environmental Sciences
Dwi Ariyoga Gautama, Hendro Susanto, Mochammad Riyanto, Ronny I. Wahju, Michael Osmond, John H. Wang
Summary: Small-scale fisheries play an important role in the economic and cultural aspects of coastal areas worldwide. However, these fisheries often have high rates of unintentional catching of protected marine species. Recent studies have suggested that net illumination could be an effective method to reduce sea turtle bycatch in these fisheries. A controlled experiment conducted in a coastal gillnet fishery in Indonesia showed that net illumination significantly reduced sea turtle bycatch, particularly for green sea turtles, without affecting the overall catch and target species. Additionally, the study found that the market value of the catch increased when net illumination was used. These results suggest that net illumination could be a viable conservation tool for small-scale gillnet fisheries in Indonesia and Southeast Asia.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Fisheries
Catherine E. O'Keefe, Steven X. Cadrin, Gildas Glemarec, Yann Rouxel
Summary: Despite the global problem of gillnet bycatch on seabirds, no effective universal measures have been found. Strategies to reduce seabird bycatch in gillnet fisheries were evaluated, focusing on time-area fishing restrictions and gear-switching. Consideration of species behavior and fine-scale spatial and temporal measures can help reduce bycatch. Combining measures may be feasible in some regions if detailed information about seabird-gillnet gear overlap is available.
REVIEWS IN FISHERIES SCIENCE & AQUACULTURE
(2023)
Article
Fisheries
Isabella Maria Friederike Kratzer, Mollie Elizabeth Brooks, Sabri Bilgin, Suleyman Ozdemir, Lotte Kindt-Larsen, Finn Larsen, Daniel Stepputtis
Summary: This study demonstrates the feasibility of using a modified gillnet with small acrylic glass spheres to reduce bycatch of harbor porpoises in a commercial fishery. The focus of pilot experiments was on gear handling and identifying requirements for a full-scale trial, with promising results shown for reducing bycatch of endangered echolocating marine mammals and no negative impact on catch efficiency of vulnerable bottom-dwelling species.
FISHERIES RESEARCH
(2021)
Article
Environmental Studies
Sarah J. Dolman, Charlotte N. Breen, Philippa Brakes, Andy Butterworth, Simon J. Allen
Summary: The prevalence of small cetacean bycatch in fisheries worldwide remains a conservation and welfare challenge. Despite the implementation of mitigation methods such as BRDs and ADDs, individuals interacting with these devices still experience negative welfare impacts.
Article
Environmental Studies
Molly Scott, Edward Cardona, Kaylee Scidmore-Rossing, Mark Royer, Jennifer Stahl, Melanie Hutchinson
Summary: Changes to fishing gear configurations have the potential to decrease injury and mortality for non-target species in commercial fisheries. This two-part study found that switching from wire to monofilament leaders can reduce shark catch rates while maintaining catch rates of target species, and that monofilament leaders are more durable than wire leaders after soaking.
Article
Ornithology
Kjell Larsson
Summary: The West Siberian/North European population of Long-tailed Duck has experienced a rapid decline since the 1990s. Research on wintering ducks in the Baltic Sea revealed fluctuations in female age ratios and a biased proportion of males. Population modeling showed that the low female age ratios have constrained population growth during the study period.
Article
Construction & Building Technology
Xiang Chen, Haiming Chen, Weibo Tan
Summary: The addition of glass fiber and glass powder can significantly improve the mechanical properties and durability of cement mortar, reduce cement consumption and carbon dioxide emissions, and play an important role in environmental protection.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2022)
Article
Ecology
Kimberly T. Murray, Joshua M. Hatchl, Robert A. DiGiovanni, Elizabeth Josephson
Summary: This study used satellite telemetry on gray seal pups to measure the risk of encounter with gillnet fishing gear in the Gulf of Maine and southern New England. The highest risk of seals encountering fishing gear was found off southeastern Massachusetts in spring, in line with expectations that high levels of habitat use and fishing effort correspond to increased encounter risk. The approach can help identify times and areas of high encounter risk for altered fishing practices or targeted observer monitoring to characterize and quantify bycatch.
MARINE ECOLOGY PROGRESS SERIES
(2021)
Article
Fisheries
Jerome Chladek, Daniel Stepputtis, Andreas Hermann, Peter Ljungberg, Paco Rodriguez-Tress, Juan Santos, Jon Christian Svendsen
Summary: Fish pots have lower catch efficiency than gillnets and trawls, but using transparent acrylic triggers can significantly improve catch efficiency, especially for Atlantic cod. Transparent acrylic fingers have higher entry-to-exit ratios compared to conventional Neptune fingers, and combining them with funnels further enhances catch efficiency.
ICES JOURNAL OF MARINE SCIENCE
(2021)
Article
Fisheries
Jerome Chladek, Daniel Stepputtis, Andreas Hermann, Isabella M. F. Kratzer, Peter Ljungberg, Paco Rodriguez-Tress, Juan Santos, Jon C. Svendsen
Summary: The study found that design parameters such as funnel color, presence, and length significantly impact the efficiency of fish pots for Atlantic cod. Transparent funnels had the highest entrance passage rates, and funnel presence increased entrance encounter rates. Additionally, the use of an infrared camera revealed a diurnal pattern in cod-pot interactions, emphasizing the importance of vision in guiding these interactions.
FISHERIES RESEARCH
(2021)
Article
Fisheries
Isabella Maria Friederike Kratzer, Mollie Elizabeth Brooks, Sabri Bilgin, Suleyman Ozdemir, Lotte Kindt-Larsen, Finn Larsen, Daniel Stepputtis
Summary: This study demonstrates the feasibility of using a modified gillnet with small acrylic glass spheres to reduce bycatch of harbor porpoises in a commercial fishery. The focus of pilot experiments was on gear handling and identifying requirements for a full-scale trial, with promising results shown for reducing bycatch of endangered echolocating marine mammals and no negative impact on catch efficiency of vulnerable bottom-dwelling species.
FISHERIES RESEARCH
(2021)
Article
Biodiversity Conservation
Andrea A. Cabrera, Elena Schall, Martine Berube, Pia Anderwald, Lutz Bachmann, Simon Berrow, Peter B. Best, Phillip J. Clapham, Haydee A. Cunha, Luciano Dalla Rosa, Carolina Dias, Kenneth P. Findlay, Tore Haug, Mads Peter Heide-Jorgensen, A. Rus Hoelzel, Kit M. Kovacs, Scott Landry, Finn Larsen, Xenia M. Lopes, Christian Lydersen, David K. Mattila, Tom Oosting, Richard M. Pace, Chiara Papetti, Angeliki Paspati, Luis A. Pastene, Rui Prieto, Christian Ramp, Jooke Robbins, Richard Sears, Eduardo R. Secchi, Monica A. Silva, Malene Simon, Gisli Vikingsson, Oystein Wiig, Nils Oien, Per J. Palsboll
Summary: Global warming has significant effects on population dynamics and trophic interactions, particularly for baleen whales and their prey. The study reveals that the post-LGM global warming led to expansions in baleen whale populations in both Southern and North Atlantic Ocean, with pronounced increases in abundance and inter-ocean connectivity. It also highlights the persistent and long-lasting impacts of global warming on marine fauna even after global temperatures stabilized.
GLOBAL CHANGE BIOLOGY
(2022)
Article
Fisheries
Isabella Maria Friederike Kratzer, Daniel Stepputtis, Juan Santos, Frauke Luetkefedder, Arne Stoltenberg, Lea Hartkens, Matthias Schaber, Lotte Kindt-Larsen, Finn Larsen
Summary: This study investigates the use of small acrylic glass spheres attached to gillnets to increase their acoustic reflectivity and reduce incidental capture of small cetaceans. The results show that gillnets equipped with these spheres have higher acoustic backscattering strength, with the best performance observed when the sphere-sphere distance is 20 cm. The findings suggest that modifying gillnets with reflective spheres can be an effective way to reduce bycatch of small cetaceans.
FISHERIES RESEARCH
(2022)
Article
Oceanography
Steffi Meyer, Uwe Krumme, Daniel Stepputtis, Christopher Zimmermann
Summary: There is a lack of data on the use of mobile devices in commercial small-scale fisheries, but this study used a smartphone application to collect data on fishing activities in German Baltic small-scale fishery. The data review showed that not all data could be used directly due to errors, but editing during data evaluation improved the usability of the data. The study provided new insights into the activities of small-scale fishing vessels, particularly those smaller than 8 meters. Potential improvements include training fishermen, using independent GPS sensors, remote control, and tailored tools for data analysis.
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
Fisheries
Dennis Brennecke, Ursula Siebert, Lotte Kindt-Larsen, Henrik Skov Midtiby, Henrik Dyrberg Egemose, Sara Torres Ortiz, Katrin Knickmeier, Magnus Wahlberg
Summary: This study demonstrates that harbor porpoises exhibit strong avoidance behavior and reduced surfacing frequency in response to pinger sounds, indicating the effectiveness of pingers in reducing bycatch. However, there is also a diversity in behavioral responses, with some porpoises not reacting to pinger sounds at all. This suggests that pinger use should be carefully considered and alternative mitigation measures may need to be explored.
FISHERIES RESEARCH
(2022)
Article
Environmental Sciences
David Lusseau, Lotte Kindt-Larsen, Floris M. van Beest
Summary: Human activities at sea are becoming more complex, requiring adaptable management interventions to mitigate their cumulative effects on biodiversity conservation. Coastal cetaceans, particularly harbour porpoises, are threatened by bycatch and the indirect effects of repeated exposure to disturbances such as acoustic disturbances. The prevalence of pingers, used to mitigate bycatch, can affect both bycatch rate and the population consequences of noise disturbance. Understanding the physiological effects on reproductive decisions and behavioural responses to noise is crucial for evaluating the cumulative impacts of bycatch and its mitigations.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Fisheries
Lotte Kindt-Larsen, Casper Willestofte Berg, Maria Hedgarde, Sara Konigson
Summary: This study investigates the catch rates of various cod pot designs for Baltic Sea with the aim of reducing the negative impact of seal populations on gillnet fisheries. The findings show that volume and soak time are positively correlated with catch rates, and round bottom-standing pots with a fish holding chamber, funnels, and 5 entrances have the highest catch rates. These findings are important for the development of cod pots that can be used in high seal density areas, reducing carbon emissions and minimizing bycatch of marine mammals and sea birds.
FISHERIES RESEARCH
(2023)
Article
Biology
Lotte Kindt-Larsen, Gildas Glemarec, Casper W. Berg, Sara Konigson, Anne-Mette Kroner, Mathias Sogaard, David Lusseau
Summary: Incidental captures (bycatch) of harbour porpoise in European Union fisheries remain a significant threat to cetaceans. A long-term monitoring program in Denmark using electronic monitoring has provided detailed data on porpoise bycatch and gillnet fishing effort. The study highlights the importance of considering fishing characteristics in estimating bycatch rates and emphasizes the need for effective monitoring methods and mitigation techniques.
PROCEEDINGS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
(2023)
Article
Multidisciplinary Sciences
Marcos Suarez-Menendez, Martine Berube, Fabricio Furni, Vania E. Rivera-Leon, Mads-Peter Heide-Jorgensen, Finn Larsen, Richard Sears, Christian Ramp, Britas Klemens Eriksson, Rampal S. Etienne, Jooke Robbins, Per J. Palsboll
Summary: Direct estimation of germline mutation rate in baleen whales using pedigrees shows higher values than phylogeny-based estimates, similar to estimates for primates and toothed whales. Our results reduce previous genetic-based estimates of preexploitation whale abundance and challenge the explanation of low cancer rates in large mammals.
