In times of rapid environmental changes, baseline biodiversity data are crucial for management. In freshwaters, fish inventories are commonly based on the capture and morphological identification of specimens. The sampling of environmental DNA (eDNA) provides an alternative to assess diversity across large catchments. Here, we used extensive historic data of fish communities collected across 89 river sites in all major catchments of Switzerland and compared their diversity and community composition to a single campaign of eDNA and electrofishing, respectively. Locally, we found that eDNA provided diversity estimates similar to the integrated historic richness, while the electrofishing campaign captured a significantly lower local richness. Fish species locally recorded by electrofishing were nested (Jaccard’s dissimilarity index) within the respective eDNA community for most sites. Finally, eDNA sequence reads positively correlated with the overall electrofishing biomass. Despite the congruences, the eDNA data did not correlate well with the electrofishing water quality index. Overall, eDNA was more accurately assessing overall diversity than a simultaneous electrofishing campaign, but yet cannot be directly used to calculate fish-based water quality indices.
{"title":"Contrasting strengths of eDNA and electrofishing compared to historic records for assessing fish community diversity and composition","authors":"Jeanine Brantschen, Florian Altermatt","doi":"10.1139/cjfas-2023-0053","DOIUrl":"https://doi.org/10.1139/cjfas-2023-0053","url":null,"abstract":"In times of rapid environmental changes, baseline biodiversity data are crucial for management. In freshwaters, fish inventories are commonly based on the capture and morphological identification of specimens. The sampling of environmental DNA (eDNA) provides an alternative to assess diversity across large catchments. Here, we used extensive historic data of fish communities collected across 89 river sites in all major catchments of Switzerland and compared their diversity and community composition to a single campaign of eDNA and electrofishing, respectively. Locally, we found that eDNA provided diversity estimates similar to the integrated historic richness, while the electrofishing campaign captured a significantly lower local richness. Fish species locally recorded by electrofishing were nested (Jaccard’s dissimilarity index) within the respective eDNA community for most sites. Finally, eDNA sequence reads positively correlated with the overall electrofishing biomass. Despite the congruences, the eDNA data did not correlate well with the electrofishing water quality index. Overall, eDNA was more accurately assessing overall diversity than a simultaneous electrofishing campaign, but yet cannot be directly used to calculate fish-based water quality indices.","PeriodicalId":9515,"journal":{"name":"Canadian Journal of Fisheries and Aquatic Sciences","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136104459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joe R. Sánchez Schacht, Paul W. MacKeigan, Zofia E. Taranu, Yannick Huot, Irene Gregory-Eaves
{"title":"Correction: agricultural land use and morphometry explain substantial variation in nutrient and ion concentrations in lakes across Canada","authors":"Joe R. Sánchez Schacht, Paul W. MacKeigan, Zofia E. Taranu, Yannick Huot, Irene Gregory-Eaves","doi":"10.1139/cjfas-2023-0271","DOIUrl":"https://doi.org/10.1139/cjfas-2023-0271","url":null,"abstract":"","PeriodicalId":9515,"journal":{"name":"Canadian Journal of Fisheries and Aquatic Sciences","volume":"2010 24","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135365745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michaelis Vasiliadis, Jennifer J. Freer, Martin A. Collins, Alison Clare Cleary
Lanternfishes (Myctophidae) are key components of mesopelagic fish communities globally. In the Southern Ocean, incomplete information on myctophid diets limits our understanding of their energetics, interactions and wider ecosystem impact. Traditional microscopic methods of diet analysis have relatively coarse prey resolution and possible taxonomic and observer biases. DNA metabarcode sequencing promises higher taxonomic and temporal resolution, but uncertainty remains in comparing this is with microscopy-based analyses. Here, we applied 18S DNA metabarcode sequencing to stomach contents from twenty Electrona antarctica individuals which had previously been examined via microscopic analysis. Across all fish, crustacean and gastropod taxa dominated the prey identified via both methods, with broad agreement between methods on the relative abundance of different prey items. DNA metabarcode sequencing recovered greater taxonomic diversity and resolution, particularly for soft-bodied prey items and small crustaceans. DNA sequencing results also more clearly differentiated diet between individuals collected from different environments. Overall, our findings illustrate how DNA based methods are complementary to, and consistent with, traditional methods and can provide additional, high-resolution data on a range of trophic interactions.
{"title":"Assessing the trophic ecology of Southern Ocean Myctophidae: the added value of DNA metabarcoding","authors":"Michaelis Vasiliadis, Jennifer J. Freer, Martin A. Collins, Alison Clare Cleary","doi":"10.1139/cjfas-2023-0079","DOIUrl":"https://doi.org/10.1139/cjfas-2023-0079","url":null,"abstract":"Lanternfishes (Myctophidae) are key components of mesopelagic fish communities globally. In the Southern Ocean, incomplete information on myctophid diets limits our understanding of their energetics, interactions and wider ecosystem impact. Traditional microscopic methods of diet analysis have relatively coarse prey resolution and possible taxonomic and observer biases. DNA metabarcode sequencing promises higher taxonomic and temporal resolution, but uncertainty remains in comparing this is with microscopy-based analyses. Here, we applied 18S DNA metabarcode sequencing to stomach contents from twenty Electrona antarctica individuals which had previously been examined via microscopic analysis. Across all fish, crustacean and gastropod taxa dominated the prey identified via both methods, with broad agreement between methods on the relative abundance of different prey items. DNA metabarcode sequencing recovered greater taxonomic diversity and resolution, particularly for soft-bodied prey items and small crustaceans. DNA sequencing results also more clearly differentiated diet between individuals collected from different environments. Overall, our findings illustrate how DNA based methods are complementary to, and consistent with, traditional methods and can provide additional, high-resolution data on a range of trophic interactions.","PeriodicalId":9515,"journal":{"name":"Canadian Journal of Fisheries and Aquatic Sciences","volume":"15 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135366496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michael J. Malick, Mary Hunsicker, Melissa A. Haltuch, Sandy L. Parker-Stetter, Kristin N. Marshall, John Pohl, Aaron M Berger, Samantha Siedlecki, Stéphane Gauthier, Al Hermann
In the California Current Ecosystem, the California Undercurrent (CU) is the predominate subsurface current that transports nutrient rich water from southern California poleward. In this study, we used a large data set of spatially explicit in situ observations of Pacific hake and the CU (36.5–48.3°N) to estimate relationships between northward undercurrent velocity and hake distribution and determine if these relationships vary across space or life-history stage. We found that both hake occurrence and density had strong spatially complex relationships with the CU. In areas north of 44°N (central Oregon), the CU effect was spatially consistent and opposite for occurrence (negative) and density (positive), indicating that hake may aggregate in areas of high northward velocity in this region. In areas south of 44°N, the CU effect showed a cross-shelf gradient for both occurrence and density, indicating a more nearshore hake distribution when northward velocity is higher in this region. Together, our results suggest that future changes in the CU due to climate change are likely to impact hake differently in northern and southern areas.
{"title":"Spatially-varying effects of the California Undercurrent on Pacific hake distribution","authors":"Michael J. Malick, Mary Hunsicker, Melissa A. Haltuch, Sandy L. Parker-Stetter, Kristin N. Marshall, John Pohl, Aaron M Berger, Samantha Siedlecki, Stéphane Gauthier, Al Hermann","doi":"10.1139/cjfas-2023-0202","DOIUrl":"https://doi.org/10.1139/cjfas-2023-0202","url":null,"abstract":"In the California Current Ecosystem, the California Undercurrent (CU) is the predominate subsurface current that transports nutrient rich water from southern California poleward. In this study, we used a large data set of spatially explicit in situ observations of Pacific hake and the CU (36.5–48.3°N) to estimate relationships between northward undercurrent velocity and hake distribution and determine if these relationships vary across space or life-history stage. We found that both hake occurrence and density had strong spatially complex relationships with the CU. In areas north of 44°N (central Oregon), the CU effect was spatially consistent and opposite for occurrence (negative) and density (positive), indicating that hake may aggregate in areas of high northward velocity in this region. In areas south of 44°N, the CU effect showed a cross-shelf gradient for both occurrence and density, indicating a more nearshore hake distribution when northward velocity is higher in this region. Together, our results suggest that future changes in the CU due to climate change are likely to impact hake differently in northern and southern areas.","PeriodicalId":9515,"journal":{"name":"Canadian Journal of Fisheries and Aquatic Sciences","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135824608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anna M DeSellas, Andrew M. Paterson, Kathleen M Rühland, John P Smol
There is a scarcity of long-term, chemical monitoring data for lakes in Algonquin Provincial Park (APP), with minimal understanding of the impacts of cottage-leases (e.g., cottage lots, campgrounds, and commercial leases) on lakewater chemistry. We examine spatial patterns in water chemistry and landscape features of 32 reference and 22 cottage-lease lakes in APP. Multivariate techniques were used to examine differences in water chemistry, and to identify the subset of landscape features that best explain this variability. Breakpoint analysis was used to examine the relationship between gradients of water chemistry and specific landscape features. Lakes were separated along a primary gradient of ions and pH and a secondary gradient of nutrients and colour. These gradients were best explained by a combination of six landscape features (wetlands, elevation, lake depth, road length, coniferous trees). Except for chloride, there was no statistically significant difference in water chemistry between cottage-lease and reference lakes. A roughly west-to-east gradient in catchment vegetation and lake chemistry was related to the location of the Algonquin Dome, a natural geological feature in APP, and the park’s glacial history. These results emphasize the importance of the park’s topography in influencing regional water chemistry.
{"title":"Lakewater chemistry and its relationship to shoreline residential development and natural landscape features in Algonquin Provincial Park, Ontario, Canada","authors":"Anna M DeSellas, Andrew M. Paterson, Kathleen M Rühland, John P Smol","doi":"10.1139/cjfas-2023-0103","DOIUrl":"https://doi.org/10.1139/cjfas-2023-0103","url":null,"abstract":"There is a scarcity of long-term, chemical monitoring data for lakes in Algonquin Provincial Park (APP), with minimal understanding of the impacts of cottage-leases (e.g., cottage lots, campgrounds, and commercial leases) on lakewater chemistry. We examine spatial patterns in water chemistry and landscape features of 32 reference and 22 cottage-lease lakes in APP. Multivariate techniques were used to examine differences in water chemistry, and to identify the subset of landscape features that best explain this variability. Breakpoint analysis was used to examine the relationship between gradients of water chemistry and specific landscape features. Lakes were separated along a primary gradient of ions and pH and a secondary gradient of nutrients and colour. These gradients were best explained by a combination of six landscape features (wetlands, elevation, lake depth, road length, coniferous trees). Except for chloride, there was no statistically significant difference in water chemistry between cottage-lease and reference lakes. A roughly west-to-east gradient in catchment vegetation and lake chemistry was related to the location of the Algonquin Dome, a natural geological feature in APP, and the park’s glacial history. These results emphasize the importance of the park’s topography in influencing regional water chemistry. 
","PeriodicalId":9515,"journal":{"name":"Canadian Journal of Fisheries and Aquatic Sciences","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135993773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jorrit Lucas, Albert Ros, Juergen Geist, Alexander Brinker
This study investigated how northern pike with two behavioral strategies in the context of predation interact with natural and artificial baits in simulated angling experiments. Predator types were assessed in three behavioral trials over 15 days by measuring foraging latency under altered conditions (abruptly increased light intensity). Latency revealed fast and slow predator responses showing high individual repeatability, interpreted as proactive and reactive predator types, with reactive individuals adapting their response over time. Both types displayed similar hunting performances in predation trials with live prey under habituated conditions. In angling trials, proactive pike expressed significantly more predation than reactive pike, independent of bait type. During angling trials, predator type did not affect bait handling, while both predator types developed strong sequential bait avoidance, indicating a learning effect. Angling trials did not affect hunting for live prey. The results suggest that pike exhibit individual differences in responses to environmental changes linked to their predatory behavior. Angling selection may play a role in pike populations, with the proactive predator type more likely to be hooked than the reactive type.
{"title":"Effects of behavioral strategies on catchability, bait selectivity, and hunting behavior in northern pike (<i>Esox lucius</i>)","authors":"Jorrit Lucas, Albert Ros, Juergen Geist, Alexander Brinker","doi":"10.1139/cjfas-2023-0004","DOIUrl":"https://doi.org/10.1139/cjfas-2023-0004","url":null,"abstract":"This study investigated how northern pike with two behavioral strategies in the context of predation interact with natural and artificial baits in simulated angling experiments. Predator types were assessed in three behavioral trials over 15 days by measuring foraging latency under altered conditions (abruptly increased light intensity). Latency revealed fast and slow predator responses showing high individual repeatability, interpreted as proactive and reactive predator types, with reactive individuals adapting their response over time. Both types displayed similar hunting performances in predation trials with live prey under habituated conditions. In angling trials, proactive pike expressed significantly more predation than reactive pike, independent of bait type. During angling trials, predator type did not affect bait handling, while both predator types developed strong sequential bait avoidance, indicating a learning effect. Angling trials did not affect hunting for live prey. The results suggest that pike exhibit individual differences in responses to environmental changes linked to their predatory behavior. Angling selection may play a role in pike populations, with the proactive predator type more likely to be hooked than the reactive type.","PeriodicalId":9515,"journal":{"name":"Canadian Journal of Fisheries and Aquatic Sciences","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135993539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Brandon Gerig, Shawn P Sitar, Will F. Otte, Daniel L Yule, Heidi K Swanson, Charles R. Bronte, Dray Carl, Joshua Blankenheim
We investigated the spatial overlap, diet, isotopic niche, and growth of juvenile lean and siscowet lake charr (Salvelinus namaycush) in Lake Superior to address concerns of potential competition with implications to the study of resource polymorphism. Catch data revealed the greatest levels of sympatry in waters from 40-60 m. Juvenile lean and siscowet diet changed ontogenetically with Mysis dominant prey item for the smallest lake charr but differentiating with onset of piscivory. As ecotypes increased in size, lean diets became dominated by pelagic prey whereas siscowets had equal proportions of benthic and pelagic prey. Isotopic niche overlap declined between ecotypes coincident with siscowet lake charr shifting to deeper habitats around 400 mm. Lean and siscowet exhibited different growth trajectories. However, length at age-4 declined in parallel for both ecotypes with no trend in condition suggesting that lake charr growth is sensitive to prey biomass and unlikely related to competition. Our findings indicate minimal evidence of competition and support the concept that multiple sympatric ecotypes of lake charr in Lake Superior are maintained by resource polymorphism.
{"title":"TROPHIC ECOLOGY OF JUVENILE LEAN AND SISCOWET LAKE CHARR (Salvelinus namaycush) IN LAKE SUPERIOR: ASSESSING FOR POTENTIAL COMPETITION","authors":"Brandon Gerig, Shawn P Sitar, Will F. Otte, Daniel L Yule, Heidi K Swanson, Charles R. Bronte, Dray Carl, Joshua Blankenheim","doi":"10.1139/cjfas-2023-0102","DOIUrl":"https://doi.org/10.1139/cjfas-2023-0102","url":null,"abstract":"We investigated the spatial overlap, diet, isotopic niche, and growth of juvenile lean and siscowet lake charr (Salvelinus namaycush) in Lake Superior to address concerns of potential competition with implications to the study of resource polymorphism. Catch data revealed the greatest levels of sympatry in waters from 40-60 m. Juvenile lean and siscowet diet changed ontogenetically with Mysis dominant prey item for the smallest lake charr but differentiating with onset of piscivory. As ecotypes increased in size, lean diets became dominated by pelagic prey whereas siscowets had equal proportions of benthic and pelagic prey. Isotopic niche overlap declined between ecotypes coincident with siscowet lake charr shifting to deeper habitats around 400 mm. Lean and siscowet exhibited different growth trajectories. However, length at age-4 declined in parallel for both ecotypes with no trend in condition suggesting that lake charr growth is sensitive to prey biomass and unlikely related to competition. Our findings indicate minimal evidence of competition and support the concept that multiple sympatric ecotypes of lake charr in Lake Superior are maintained by resource polymorphism.","PeriodicalId":9515,"journal":{"name":"Canadian Journal of Fisheries and Aquatic Sciences","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136079093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Felipe Javier Quezada, Desiree Tommasi, Timothy Frawley, Barbara Muhling, Isaac Kaplan, Stephen Stohs
Fishers often target multiple species. More diverse harvest portfolios may reduce income risk, increasing resilience to climate-driven changes in target species’ spatial distributions and availability. Moreover, different effects can be observed across vessels in response to the same shocks and stressors, as fishers are heterogeneous. Evaluation of climate risk within a particular fishery requires consideration of heterogeneous climate impacts on the availability of multiple target species and how such changes may impact substitution behavior. Here we analyze how historical climate-driven changes in forage species distribution and the closure of the Pacific sardine fishery affected landings per vessel of three coastal pelagic species (CPS): Pacific sardine (Sardinops sagax), market squid (Doryteuthis opalescens), and northern anchovy (Engraulis mordax) targeted by the U.S. West Coast CPS fleet from 2000-2020. Using cluster analysis, we grouped vessels into different fleet segments and estimated heterogeneous responses by fleet segment and port area. Our results show that considering heterogeneity is essential in the development of equitable and effective adaptation policies designed to mitigate the impact of change in these fisheries.
{"title":"Catch as catch can: Markets, availability, and fishery closures drive distinct responses among the U.S. West Coast Coastal Pelagic Species fleet segments","authors":"Felipe Javier Quezada, Desiree Tommasi, Timothy Frawley, Barbara Muhling, Isaac Kaplan, Stephen Stohs","doi":"10.1139/cjfas-2023-0094","DOIUrl":"https://doi.org/10.1139/cjfas-2023-0094","url":null,"abstract":"Fishers often target multiple species. More diverse harvest portfolios may reduce income risk, increasing resilience to climate-driven changes in target species’ spatial distributions and availability. Moreover, different effects can be observed across vessels in response to the same shocks and stressors, as fishers are heterogeneous. Evaluation of climate risk within a particular fishery requires consideration of heterogeneous climate impacts on the availability of multiple target species and how such changes may impact substitution behavior. Here we analyze how historical climate-driven changes in forage species distribution and the closure of the Pacific sardine fishery affected landings per vessel of three coastal pelagic species (CPS): Pacific sardine (Sardinops sagax), market squid (Doryteuthis opalescens), and northern anchovy (Engraulis mordax) targeted by the U.S. West Coast CPS fleet from 2000-2020. Using cluster analysis, we grouped vessels into different fleet segments and estimated heterogeneous responses by fleet segment and port area. Our results show that considering heterogeneity is essential in the development of equitable and effective adaptation policies designed to mitigate the impact of change in these fisheries.","PeriodicalId":9515,"journal":{"name":"Canadian Journal of Fisheries and Aquatic Sciences","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135854219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alyssa D. Murdoch, Brendan M. Connors, Nicolas W.R. Lapointe, Joanna Mills Flemming, Steven J. Cooke, Chrystal Mantyka-Pringle
Recent declines of Yukon River Chinook salmon (Oncorhynchus tshawytscha) populations have severely impacted people residing in the Yukon and Alaska. Evidence-based conservation strategies focused on stock recovery and adaptation are urgently needed but are limited by our understanding of what is driving declines, particularly in Canadian portions of the Yukon River basin. We examined how multiple environmental drivers may be influencing Canadian-origin Yukon River Chinook salmon productivity for eight populations over a 28-year period. We found that productivity was related to various environmental and ecosystem processes acting cumulatively over multiple life stages and across broad geographic scales. Productivity decreased in association with warmer upriver migration temperatures, wetter freshwater juvenile rearing habitats, and increasing abundances of potential marine competitors. In contrast, productivity increased in years with warmer and snowier winters and earlier spring onset. We found that different populations had similar relationships with environmental drivers, with potentially negative implications for regional fisheries stability. Our findings provide insight into how Chinook salmon are responding to rapid environmental change and can help inform salmon conservation initiatives and sustainable harvest strategies.
{"title":"Multiple environmental drivers across life-stages influence Yukon River Chinook salmon productivity","authors":"Alyssa D. Murdoch, Brendan M. Connors, Nicolas W.R. Lapointe, Joanna Mills Flemming, Steven J. Cooke, Chrystal Mantyka-Pringle","doi":"10.1139/cjfas-2022-0254","DOIUrl":"https://doi.org/10.1139/cjfas-2022-0254","url":null,"abstract":"Recent declines of Yukon River Chinook salmon (Oncorhynchus tshawytscha) populations have severely impacted people residing in the Yukon and Alaska. Evidence-based conservation strategies focused on stock recovery and adaptation are urgently needed but are limited by our understanding of what is driving declines, particularly in Canadian portions of the Yukon River basin. We examined how multiple environmental drivers may be influencing Canadian-origin Yukon River Chinook salmon productivity for eight populations over a 28-year period. We found that productivity was related to various environmental and ecosystem processes acting cumulatively over multiple life stages and across broad geographic scales. Productivity decreased in association with warmer upriver migration temperatures, wetter freshwater juvenile rearing habitats, and increasing abundances of potential marine competitors. In contrast, productivity increased in years with warmer and snowier winters and earlier spring onset. We found that different populations had similar relationships with environmental drivers, with potentially negative implications for regional fisheries stability. Our findings provide insight into how Chinook salmon are responding to rapid environmental change and can help inform salmon conservation initiatives and sustainable harvest strategies.","PeriodicalId":9515,"journal":{"name":"Canadian Journal of Fisheries and Aquatic Sciences","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136293499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Renee Mina van Dorst, Anna Gårdmark, Kimmo Kahilainen, Leena Nurminen, Satu Estlander, Hannu Huuskonen, Mikko Olin, Martti Rask, Magnus Huss
Size-specific body growth responses to warming are common among animal taxa, but sex-specific responses are poorly known. Here we ask if body growth responses to warming are sex-dependent, and if such sex-specific responses vary with size and age. This was tested with sex-specific data of back-calculated individual growth trajectories, in European perch (Perca fluviatilis) from a long-term whole-ecosystem warming experiment (6.3°C above the surrounding sea). Warming led to both size- and sex-specific differences in growth responses. Warming had a consistent positive effect on body growth of females, but negative effects on male growth at size >10 cm and age >2 years. These sex-specific growth responses translate to an increased degree of female-biased sexual size dimorphism (in length-at-age) with warming. Although the exact temperature-mediated effects underlying differential growth responses could not be resolved, results imply global warming may have highly different effects during ontogeny of male and female perch. Such effects should be considered in climate warming scenarios concerning fish growth, population size-structure and dynamics of aquatic food webs that include fish exhibiting sexual size dimorphism.
{"title":"Ecosystem heating experiment reveals sex-specific growth responses in fish","authors":"Renee Mina van Dorst, Anna Gårdmark, Kimmo Kahilainen, Leena Nurminen, Satu Estlander, Hannu Huuskonen, Mikko Olin, Martti Rask, Magnus Huss","doi":"10.1139/cjfas-2023-0034","DOIUrl":"https://doi.org/10.1139/cjfas-2023-0034","url":null,"abstract":"Size-specific body growth responses to warming are common among animal taxa, but sex-specific responses are poorly known. Here we ask if body growth responses to warming are sex-dependent, and if such sex-specific responses vary with size and age. This was tested with sex-specific data of back-calculated individual growth trajectories, in European perch (Perca fluviatilis) from a long-term whole-ecosystem warming experiment (6.3°C above the surrounding sea). Warming led to both size- and sex-specific differences in growth responses. Warming had a consistent positive effect on body growth of females, but negative effects on male growth at size >10 cm and age >2 years. These sex-specific growth responses translate to an increased degree of female-biased sexual size dimorphism (in length-at-age) with warming. Although the exact temperature-mediated effects underlying differential growth responses could not be resolved, results imply global warming may have highly different effects during ontogeny of male and female perch. Such effects should be considered in climate warming scenarios concerning fish growth, population size-structure and dynamics of aquatic food webs that include fish exhibiting sexual size dimorphism.","PeriodicalId":9515,"journal":{"name":"Canadian Journal of Fisheries and Aquatic Sciences","volume":"224 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135345975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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