In resource management, the kind and extent of ecological co-occurrence between closely related species frequently requires assessment of the spatial relationship among taxa. In my study, analysis of inter-species pair-wise distances revealed no syntopic overlap between Church’s sideband (Monadenia churchi) and Trinity bristle snails (M. setosa). No pair of samples had the same geographic coordinates and no parapatric boundary in environmental covariates was evident between species. This “microsympatric” spatial relationship resembled a metapopulation structure with no high degree of overlap, as co-occurrence was rare and small in geographic scope. Fifteen forest cover-types and 82 soil-types were identified between species. The most common forest-type for M. churchi was Sierra Mixed Conifer (39.9%) and Douglas fir (28.9%). In M. setosa the most common forest-types were the same but in much different percentages (78.8% and 14.8%, respectively). Sixty-one and 39 soil-types were associated with samples of M. churchi and M. setosa, respectively. The Hohmann-Neuns family complex was the most common (22.5%) soil-type for M. churchi and the Holland Deep-Hugo family complex was the most (50.6%) dominant for M. setosa. There were significant differences between species in all environmental attributes and in values of monthly temperature and precipitation, which reflected variance in the mesoclimatic regime seasonally. Principal Components Analysis (PCA) accounted for 57.8% of the dispersion contained in environmental variables on the first 3-eigenvectors. Evapotranspiration and Summer and Winter Temperatures loaded positively while Summer and Winter Precipitation and Elevation loaded negatively along PC I (26.2%). Given significant inter-species differences in ecological occupancy, it seems plausible that microsympatry is based in part on both mesoscale habitat variance and subtle differences in mesoclimate defined by seasonal variation in temperature and precipitation. The hypothesis that M. setosa is adapted to cool habitats and M. churchi to warmer more arid environs in microsympatry was substantiated at a macroscale level.
在资源管理中，密切相关物种之间生态共存的种类和程度经常需要对分类群之间的空间关系进行评估。在我的研究中，对物种间配对距离的分析表明，丘奇侧带（Monadenia churchi）和三一鬃蜗牛（M. setosa）之间没有同域重叠。没有一对样本具有相同的地理坐标，物种之间的环境协变量也没有明显的同域边界。这种 "微交配 "的空间关系类似于没有高度重叠的元种群结构，因为共同出现的情况很少，地理范围也很小。在物种之间发现了 15 种森林植被类型和 82 种土壤类型。M.churchi最常见的森林类型是山地混合针叶林（39.9%）和花旗松（28.9%）。在 M. setosa 中，最常见的森林类型相同，但所占比例却大不相同（分别为 78.8% 和 14.8%）。与 M. churchi 和 M. setosa 样本相关的土壤类型分别为 61 种和 39 种。Hohmann-Neuns 家族复合土壤是 M. churchi 最常见的土壤类型（22.5%），而 Holland Deep-Hugo 家族复合土壤是 M. setosa 最主要的土壤类型（50.6%）。物种之间在所有环境属性以及月温度和降水量值方面都存在明显差异，这反映了季节性中层气候的差异。主成分分析（PCA）解释了前 3 个特征向量上环境变量所含离散度的 57.8%。蒸散量、夏季和冬季气温呈正相关，而夏季和冬季降水量及海拔高度在 PC I 上呈负相关（26.2%）。考虑到物种间在生态占用方面的显著差异，似乎可以认为微交配性部分是基于中尺度生境差异以及由温度和降水的季节性变化所定义的中尺度气候的微妙差异。M.setosa适应凉爽的栖息地，而M.churchi适应较温暖干旱的微生境的假说在宏观尺度上得到了证实。
{"title":"Spatial relationships and mesoscale habitat variance in co-occurring populations of Church’s sideband and Trinity bristle snail in the Greater Trinity Basin, northern California","authors":"Robert M. Sullivan","doi":"10.51492/cfwj.109.13","DOIUrl":"https://doi.org/10.51492/cfwj.109.13","url":null,"abstract":"In resource management, the kind and extent of ecological co-occurrence between closely related species frequently requires assessment of the spatial relationship among taxa. In my study, analysis of inter-species pair-wise distances revealed no syntopic overlap between Church’s sideband (Monadenia churchi) and Trinity bristle snails (M. setosa). No pair of samples had the same geographic coordinates and no parapatric boundary in environmental covariates was evident between species. This “microsympatric” spatial relationship resembled a metapopulation structure with no high degree of overlap, as co-occurrence was rare and small in geographic scope. Fifteen forest cover-types and 82 soil-types were identified between species. The most common forest-type for M. churchi was Sierra Mixed Conifer (39.9%) and Douglas fir (28.9%). In M. setosa the most common forest-types were the same but in much different percentages (78.8% and 14.8%, respectively). Sixty-one and 39 soil-types were associated with samples of M. churchi and M. setosa, respectively. The Hohmann-Neuns family complex was the most common (22.5%) soil-type for M. churchi and the Holland Deep-Hugo family complex was the most (50.6%) dominant for M. setosa. There were significant differences between species in all environmental attributes and in values of monthly temperature and precipitation, which reflected variance in the mesoclimatic regime seasonally. Principal Components Analysis (PCA) accounted for 57.8% of the dispersion contained in environmental variables on the first 3-eigenvectors. Evapotranspiration and Summer and Winter Temperatures loaded positively while Summer and Winter Precipitation and Elevation loaded negatively along PC I (26.2%). Given significant inter-species differences in ecological occupancy, it seems plausible that microsympatry is based in part on both mesoscale habitat variance and subtle differences in mesoclimate defined by seasonal variation in temperature and precipitation. The hypothesis that M. setosa is adapted to cool habitats and M. churchi to warmer more arid environs in microsympatry was substantiated at a macroscale level.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":"67 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139254376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Book Review – George Meléndez Wright: The Fight for Wildlife and Wilderness in the National Parks","authors":"V. Bleich","doi":"10.51492/cfwj.109.15","DOIUrl":"https://doi.org/10.51492/cfwj.109.15","url":null,"abstract":"","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139252741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Habitat suitability criteria (HSC) are a key information source used in designing habitat restoration projects. Many site-specific HSC have been developed in the Central Valley of California for various life stages of anadromous salmonids. Substantial differences between the HSC can be due to watershed characteristics and the methods used to develop the HSC. Spawning HSC generally have optimum depths of 0.3–1 m, optimum velocities of 0.3–1 m/s, and substrate sizes ranging from 25–100 mm. Optimum conditions for fry are generally shallow (less than 0.5 m) and slow (less than 0.1 m/s) with woody cover. Juvenile salmonids use deeper (0.5–1 m) and faster (up to 0.4 m/s) conditions than fry but are similar to fry in their preference for woody cover. HSC developed by the U.S. Fish and Wildlife Service on the Yuba River are recommended for evaluating habitat restoration projects on larger rivers, while HSC developed on Clear Creek are recommended for evaluating habitat restoration projects on smaller Central Valley streams. A key limitation of existing HSC is that they were only developed for in-channel conditions; fishery benefits of floodplain restoration projects are best quantified using total wetted area. Optimal HSC values are most useful in the initial design of habitat restoration projects, while flow-habitat relationships for existing versus proposed conditions can be useful in identifying needed design refinements, such as adding large woody debris.
{"title":"Central Valley anadromous salmonid habitat suitability criteria","authors":"Mark Gard","doi":"10.51492/cfwj.109.12","DOIUrl":"https://doi.org/10.51492/cfwj.109.12","url":null,"abstract":"Habitat suitability criteria (HSC) are a key information source used in designing habitat restoration projects. Many site-specific HSC have been developed in the Central Valley of California for various life stages of anadromous salmonids. Substantial differences between the HSC can be due to watershed characteristics and the methods used to develop the HSC. Spawning HSC generally have optimum depths of 0.3–1 m, optimum velocities of 0.3–1 m/s, and substrate sizes ranging from 25–100 mm. Optimum conditions for fry are generally shallow (less than 0.5 m) and slow (less than 0.1 m/s) with woody cover. Juvenile salmonids use deeper (0.5–1 m) and faster (up to 0.4 m/s) conditions than fry but are similar to fry in their preference for woody cover. HSC developed by the U.S. Fish and Wildlife Service on the Yuba River are recommended for evaluating habitat restoration projects on larger rivers, while HSC developed on Clear Creek are recommended for evaluating habitat restoration projects on smaller Central Valley streams. A key limitation of existing HSC is that they were only developed for in-channel conditions; fishery benefits of floodplain restoration projects are best quantified using total wetted area. Optimal HSC values are most useful in the initial design of habitat restoration projects, while flow-habitat relationships for existing versus proposed conditions can be useful in identifying needed design refinements, such as adding large woody debris.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":"31 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139252009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Community-based macroinvertebrate habitat suitability criteria are needed for two reasons: (1) community-based criteria, such as with macroinvertebrates, are a better measure of ecosystem health than single-species habitat suitability criteria (HSC); and (2) if food rather than physical habitat is the limiting factor for juvenile salmonids, it is better to evaluate habitat restoration projects based on macroinvertebrate habitat than juvenile habitat. The goal of this study was to generate habitat suitability criteria for macroinvertebrates in the Sacramento River. Habitat suitability criteria were derived for three macroinvertebrate community metrics. One of the metrics (biomass of baetids, chironomids and hydropsychids) was selected to represent food supply for juvenile salmonids, while the other two metrics (total biomass and diversity) were selected as measures of ecosystem health. Baetidae, Chironomidae and Hydropsychidae were chosen because they are the dominant taxa present in stomach contents samples of Sacramento River juvenile Chinook Salmon Oncorhynchus tschawytscha. Habitat suitability criteria were developed using data from 75 macroinvertebrate samples stratified by season, mesohabitat type, depth, velocity, and substrate. The criteria for depth, velocity and substrate were developed taking into account several potential confounding variables, and using a polynomial regression for depth and velocity, and analysis of variance for substrate (a categorical variable). The criteria showed no effect of substrate on baetid/chironomid/hydropsychid biomass or diversity. Criteria for total biomass showed a higher suitability for larger cobbles, versus other substrates, for total biomass. The optimum depths for baetid/chironomid/hydropsychid biomass, total biomass and diversity were, respectively, 0.82–0.85 m, 0.61–0.67 m and 1.16–1.19 m. The optimum velocities for baetid/chironomid/hydropsychid biomass, total biomass and diversity were, respectively, 0.73–0.79 m/sec, 0.61–0.67 m/sec, and 0.61–0.73 m/s. Suggestions for development of future macroinvertebrate HSC include: (1) stratifying sampling by depth, velocity and substrate; (2) measuring the amount of organic matter in samples for use as an additional potential confounding factor; and (3) sampling a large area (0.84 m2) with a sampler with a rubber foam lining on the bottom of the sampler.
{"title":"Development of habitat suitability criteria for macroinvertebrate community metrics for use in habitat restoration projects","authors":"Mark Gard","doi":"10.51492/cfwj.109.14","DOIUrl":"https://doi.org/10.51492/cfwj.109.14","url":null,"abstract":"Community-based macroinvertebrate habitat suitability criteria are needed for two reasons: (1) community-based criteria, such as with macroinvertebrates, are a better measure of ecosystem health than single-species habitat suitability criteria (HSC); and (2) if food rather than physical habitat is the limiting factor for juvenile salmonids, it is better to evaluate habitat restoration projects based on macroinvertebrate habitat than juvenile habitat. The goal of this study was to generate habitat suitability criteria for macroinvertebrates in the Sacramento River. Habitat suitability criteria were derived for three macroinvertebrate community metrics. One of the metrics (biomass of baetids, chironomids and hydropsychids) was selected to represent food supply for juvenile salmonids, while the other two metrics (total biomass and diversity) were selected as measures of ecosystem health. Baetidae, Chironomidae and Hydropsychidae were chosen because they are the dominant taxa present in stomach contents samples of Sacramento River juvenile Chinook Salmon Oncorhynchus tschawytscha. Habitat suitability criteria were developed using data from 75 macroinvertebrate samples stratified by season, mesohabitat type, depth, velocity, and substrate. The criteria for depth, velocity and substrate were developed taking into account several potential confounding variables, and using a polynomial regression for depth and velocity, and analysis of variance for substrate (a categorical variable). The criteria showed no effect of substrate on baetid/chironomid/hydropsychid biomass or diversity. Criteria for total biomass showed a higher suitability for larger cobbles, versus other substrates, for total biomass. The optimum depths for baetid/chironomid/hydropsychid biomass, total biomass and diversity were, respectively, 0.82–0.85 m, 0.61–0.67 m and 1.16–1.19 m. The optimum velocities for baetid/chironomid/hydropsychid biomass, total biomass and diversity were, respectively, 0.73–0.79 m/sec, 0.61–0.67 m/sec, and 0.61–0.73 m/s. Suggestions for development of future macroinvertebrate HSC include: (1) stratifying sampling by depth, velocity and substrate; (2) measuring the amount of organic matter in samples for use as an additional potential confounding factor; and (3) sampling a large area (0.84 m2) with a sampler with a rubber foam lining on the bottom of the sampler.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":"52 5","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139253641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sara Moriarty-Graves, Erin Zulliger, Tom Batter, Christine Found-Jackson
In northern California, Roosevelt (Cervus canadensis roosevelti) and Rocky Mountain (C. c. nelsoni) elk occupy a wide variety of habitats over a large extent, including the Marble Mountains Elk Management Unit (MM EMU). Dense forest canopy and steep, mountainous terrain present significant challenges for monitoring elk populations using traditional aerial and ground-based methods. These constraints have resulted in inadequate spatial and temporal research and monitoring. To address the need for comprehensive and reliable elk abundance estimates, we implemented a landscape-level camera trap study within the MM EMU. We deployed 180 cameras and applied a time-to-event model to estimate elk abundance. This method uses the movement rate, area in front of each camera, and leverages the latency time to detection for a given species. Analysis yielded an estimate of 1,415 (95% CI: 1,044–1,919) elk across the management unit. Here, we present the use of a recently developed method to non-invasively estimate the abundance of unmarked elk at the landscape-level in northern California. Implementation of this method can provide reliable information to aid management decisions for the continued recreational, ecological, and economic benefits of elk and wildlife in general.
在加利福尼亚州北部，罗斯福麋鹿（Cervus canadensis roosevelti）和落基山麋鹿（C. c. nelsoni）占据了包括大理石山麋鹿管理区（MM EMU）在内的大片栖息地。茂密的林冠和陡峭的多山地形给使用传统的空中和地面方法监测麋鹿种群带来了巨大挑战。这些制约因素导致了时空研究和监测的不足。为了满足对麋鹿数量进行全面、可靠估计的需要，我们在 MM 环境管理单元内开展了一项景观级相机陷阱研究。我们部署了 180 台照相机，并采用时间到事件模型来估算麋鹿的数量。这种方法使用移动速度、每个摄像头前的区域，并利用特定物种的检测延迟时间。分析结果表明，整个管理单元的麋鹿数量估计为 1,415 头（95% CI：1,044-1,919 头）。在此，我们介绍了使用最近开发的一种方法，在加利福尼亚州北部景观层面对无标记麋鹿的丰度进行非侵入式估计。采用这种方法可以提供可靠的信息，帮助管理决策，使麋鹿和野生动物继续带来娱乐、生态和经济效益。
{"title":"Utilizing the time-to-event framework to estimate elk abundance over a large spatial scale in the Klamath Mountains of California","authors":"Sara Moriarty-Graves, Erin Zulliger, Tom Batter, Christine Found-Jackson","doi":"10.51492/cfwj.109.10","DOIUrl":"https://doi.org/10.51492/cfwj.109.10","url":null,"abstract":"In northern California, Roosevelt (Cervus canadensis roosevelti) and Rocky Mountain (C. c. nelsoni) elk occupy a wide variety of habitats over a large extent, including the Marble Mountains Elk Management Unit (MM EMU). Dense forest canopy and steep, mountainous terrain present significant challenges for monitoring elk populations using traditional aerial and ground-based methods. These constraints have resulted in inadequate spatial and temporal research and monitoring. To address the need for comprehensive and reliable elk abundance estimates, we implemented a landscape-level camera trap study within the MM EMU. We deployed 180 cameras and applied a time-to-event model to estimate elk abundance. This method uses the movement rate, area in front of each camera, and leverages the latency time to detection for a given species. Analysis yielded an estimate of 1,415 (95% CI: 1,044–1,919) elk across the management unit. Here, we present the use of a recently developed method to non-invasively estimate the abundance of unmarked elk at the landscape-level in northern California. Implementation of this method can provide reliable information to aid management decisions for the continued recreational, ecological, and economic benefits of elk and wildlife in general.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":"204 3","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139253979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Angler demographics and behaviors have a significant impact on recreational fishery-dependent data, and recently, human dimensions have become more widely recognized as an important part of fisheries management. California’s steelhead (Oncorhynchus mykiss) report card program has served to track recreational fishing effort and catch each calendar year for management purposes through angler self-reporting. However, angler report card return rates are consistently low, and there has been no recent effort to investigate angler attributes that may be contributing to nonresponse. This study evaluated trends in angler demographics as they relate to annual steelhead report card return rates as well as online reporting rates across the 2012–2019 study period. The study also assessed whether specific demographic or behavioral characteristics may affect the likelihood of anglers returning their report cards. Older, more avid anglers were found to have a greater likelihood of reporting in general. Motivations or deterrents for response vs. nonresponse could not be identified due to data limitations and should be the subject of future research.
{"title":"Human dimensions of angler nonresponse in California’s recreational steelhead fishing report card program","authors":"Vanessa M. Gusman Costa, Colby L. Hause","doi":"10.51492/cfwj.109.11","DOIUrl":"https://doi.org/10.51492/cfwj.109.11","url":null,"abstract":"Angler demographics and behaviors have a significant impact on recreational fishery-dependent data, and recently, human dimensions have become more widely recognized as an important part of fisheries management. California’s steelhead (Oncorhynchus mykiss) report card program has served to track recreational fishing effort and catch each calendar year for management purposes through angler self-reporting. However, angler report card return rates are consistently low, and there has been no recent effort to investigate angler attributes that may be contributing to nonresponse. This study evaluated trends in angler demographics as they relate to annual steelhead report card return rates as well as online reporting rates across the 2012–2019 study period. The study also assessed whether specific demographic or behavioral characteristics may affect the likelihood of anglers returning their report cards. Older, more avid anglers were found to have a greater likelihood of reporting in general. Motivations or deterrents for response vs. nonresponse could not be identified due to data limitations and should be the subject of future research.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":"132 ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139250837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Alvarez, Maresa Scofield, Francesca Cannizzo, Kimberly Comer, Marina L. Olson, Matt Coyle, Jeffery T. Wilcox
{"title":"Post-fire survival of the threatened California red-legged frog in the Sierra Nevada following the Mosquito Fire","authors":"J. Alvarez, Maresa Scofield, Francesca Cannizzo, Kimberly Comer, Marina L. Olson, Matt Coyle, Jeffery T. Wilcox","doi":"10.51492/cfwj.109.7","DOIUrl":"https://doi.org/10.51492/cfwj.109.7","url":null,"abstract":"","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43266019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Foott, J. Kindopp, Katie Gordon, Alana Imrie, Kassie Hikey
We performed a five-year (2015–2020) survey of juvenile natural Chinook Salmon (Oncorhynchus tshawytscha), adult salmon carcasses, and river water from the lower Feather River to determine infection prevalence, distribution, and spore quantity of the myxozoan parasite Ceratonova shasta. Average prevalence of infection in juvenile salmon collected from the high flow channel ranged from 45–58% depending on assay method. Initial infection of fry and detection of actinospore stage in river water began in late January or early February. Overt disease occurred in March and was lethal. Infection of the gill was detected weeks ahead of intestinal infection. Water-borne spore measurement and fish infection demonstrate an infectious zone beginning at the outlet of the Thermalito Afterbay. This zone is expanding downriver past the confluence of the Yuba River. Adult carcasses produce billions of myxospores annually that move downriver over the winter. C. shasta infection is one of several factors (predation, limited rearing habitat, elevated water temperature, water withdrawal, etc.) limiting natural Chinook Salmon recruitment in the Feather River.
{"title":"Ceratonova shasta infection in lower Feather River Chinook juveniles and trends in water-borne spore stages","authors":"J. Foott, J. Kindopp, Katie Gordon, Alana Imrie, Kassie Hikey","doi":"10.51492/cfwj.109.9","DOIUrl":"https://doi.org/10.51492/cfwj.109.9","url":null,"abstract":"We performed a five-year (2015–2020) survey of juvenile natural Chinook Salmon (Oncorhynchus tshawytscha), adult salmon carcasses, and river water from the lower Feather River to determine infection prevalence, distribution, and spore quantity of the myxozoan parasite Ceratonova shasta. Average prevalence of infection in juvenile salmon collected from the high flow channel ranged from 45–58% depending on assay method. Initial infection of fry and detection of actinospore stage in river water began in late January or early February. Overt disease occurred in March and was lethal. Infection of the gill was detected weeks ahead of intestinal infection. Water-borne spore measurement and fish infection demonstrate an infectious zone beginning at the outlet of the Thermalito Afterbay. This zone is expanding downriver past the confluence of the Yuba River. Adult carcasses produce billions of myxospores annually that move downriver over the winter. C. shasta infection is one of several factors (predation, limited rearing habitat, elevated water temperature, water withdrawal, etc.) limiting natural Chinook Salmon recruitment in the Feather River.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":"1 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42003223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Virginia Afentoulis, Andrew Rockriver, Samreen Siddiqui, Lauren Damon
The John E. Skinner Delta Fish Protective Facility (Skinner Fish Facility) diverts entrained fish from the State Water Project’s pumping facilities in the southern Sacramento-San Joaquin Delta (the Delta) and transports them via tanker trucks away from the immediate influence of the export pumps. During this process, the fish are counted and released back into the Delta, generally known as fish salvage. Since fish are caught and released back into the Delta, this whole process involves various points that can be stressful to fish, such as the Delta Smelt (Hypomesus transpacificus), a state and federally listed species. To understand this process and improve fish facilities function, an investigation was conducted in 2005–2006, in which we evaluated sublethal stress associated with the terminal portion of the fish salvage process. This study included fish collection, handling, transportation, and release (CHTR) away from the export facilities. Physiological stress parameters for Delta Smelt were measured in the Skinner Fish Facility. We inserted wild and cultured adult Delta Smelt into the CHTR process and later sampled for plasma cortisol, glucose, and lactate, which typically respond to acute and cumulative stress in fish. To help identify the source of overall stress response, we partitioned CHTR into three test phases: collection and handling, trucking and release, and uninterrupted CHTR. Differences in the delayed stress response between the different phases of CHTR were evaluated. Delta Smelt experienced stress in all phases of the CHTR process and in experimental handling controls indicated by higher plasma cortisol concentrations compared to their pre-experiment levels. Wild Delta Smelt experienced higher levels of cortisol response and took longer to recover than did cultured Delta Smelt.
{"title":"Delta Smelt stress responses during fish salvage at the John E. Skinner Delta Fish Protective Facility, California","authors":"Virginia Afentoulis, Andrew Rockriver, Samreen Siddiqui, Lauren Damon","doi":"10.51492/cfwj.109.8","DOIUrl":"https://doi.org/10.51492/cfwj.109.8","url":null,"abstract":"The John E. Skinner Delta Fish Protective Facility (Skinner Fish Facility) diverts entrained fish from the State Water Project’s pumping facilities in the southern Sacramento-San Joaquin Delta (the Delta) and transports them via tanker trucks away from the immediate influence of the export pumps. During this process, the fish are counted and released back into the Delta, generally known as fish salvage. Since fish are caught and released back into the Delta, this whole process involves various points that can be stressful to fish, such as the Delta Smelt (Hypomesus transpacificus), a state and federally listed species. To understand this process and improve fish facilities function, an investigation was conducted in 2005–2006, in which we evaluated sublethal stress associated with the terminal portion of the fish salvage process. This study included fish collection, handling, transportation, and release (CHTR) away from the export facilities. Physiological stress parameters for Delta Smelt were measured in the Skinner Fish Facility. We inserted wild and cultured adult Delta Smelt into the CHTR process and later sampled for plasma cortisol, glucose, and lactate, which typically respond to acute and cumulative stress in fish. To help identify the source of overall stress response, we partitioned CHTR into three test phases: collection and handling, trucking and release, and uninterrupted CHTR. Differences in the delayed stress response between the different phases of CHTR were evaluated. Delta Smelt experienced stress in all phases of the CHTR process and in experimental handling controls indicated by higher plasma cortisol concentrations compared to their pre-experiment levels. Wild Delta Smelt experienced higher levels of cortisol response and took longer to recover than did cultured Delta Smelt.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43315190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Microplastics are persistent environmental contaminants that to date have been studied primarily in aquatic systems, but few studies have examined their prevalence or impact in terrestrial trophic networks. A recent study documented microplastics in the gastrointestinal (GI) tracts of terrestrial raptors in central Florida. We used protocols based on that study to develop a baseline dataset of microplastics in the GI tracts of terrestrial raptors on the central coast of California. In 2021, Pacific Wildlife Care, a wildlife rehabilitation center in Morro Bay, CA, provided 16 raptor carcasses: three red-tailed hawks (Buteo jamaicensis), four red-shouldered hawks (Buteo lineatus), two great horned owls (Bubo virginianus), and seven barn owls (Tyto alba). We found microplastics in the GI tracts of all 16 birds, with a mean (± SE) of 12.25 (± 1.89) microplastic particles per bird. Of the 196 microplastic particles we observed, microfibers were the most abundant (58%), followed by microbeads (34%), and microfragments (8%). However, microbeads were the most prevalent, found in all 16 birds, followed by microfibers (15 birds), and microfragments (6 birds). The chemical composition and source of these contaminants remains unclear, along with the physiological and ecological implications to raptor populations and their ecosystems, and the extent to which microplastics occur in other terrestrial species and regions in California.
{"title":"Documentation of microplastics in the gastrointestinal tracts of terrestrial raptors in central California, USA","authors":"Alexis Leviner, J. Perrine","doi":"10.51492/cfwj.109.6","DOIUrl":"https://doi.org/10.51492/cfwj.109.6","url":null,"abstract":"Microplastics are persistent environmental contaminants that to date have been studied primarily in aquatic systems, but few studies have examined their prevalence or impact in terrestrial trophic networks. A recent study documented microplastics in the gastrointestinal (GI) tracts of terrestrial raptors in central Florida. We used protocols based on that study to develop a baseline dataset of microplastics in the GI tracts of terrestrial raptors on the central coast of California. In 2021, Pacific Wildlife Care, a wildlife rehabilitation center in Morro Bay, CA, provided 16 raptor carcasses: three red-tailed hawks (Buteo jamaicensis), four red-shouldered hawks (Buteo lineatus), two great horned owls (Bubo virginianus), and seven barn owls (Tyto alba). We found microplastics in the GI tracts of all 16 birds, with a mean (± SE) of 12.25 (± 1.89) microplastic particles per bird. Of the 196 microplastic particles we observed, microfibers were the most abundant (58%), followed by microbeads (34%), and microfragments (8%). However, microbeads were the most prevalent, found in all 16 birds, followed by microfibers (15 birds), and microfragments (6 birds). The chemical composition and source of these contaminants remains unclear, along with the physiological and ecological implications to raptor populations and their ecosystems, and the extent to which microplastics occur in other terrestrial species and regions in California.","PeriodicalId":29697,"journal":{"name":"California Fish and Wildlife Journal","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48204123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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