Stormwater management affecting an urban stream is most effective when managers design programs tailored to the physical characteristics of the stream and the political and socioeconomic characteristics of the community it serves. Likewise, restoration projects and policy implementation should be designed to address the needs of the local community. This paper documents the development and implementation of a science-based, community-driven approach to stormwater management by a United States regional stormwater utility, Sanitation District No. 1 (SD1) of Northern Kentucky, USA, that manages stormwater in 3 suburban counties in the greater metropolitan area of Cincinnati, Ohio, USA. SD1 began by establishing a hydrogeomorphic and biological monitoring program from 2006 to 2008 to gather the data needed to design a locally calibrated stormwater management program. SD1’s monitoring network has facilitated multiple cross-jurisdictional partnerships and provides validation for stormwater management rules and regulations that are tailored to Northern Kentucky. Moreover, the monitoring data has informed the activities of a watershed restoration program that prioritizes cost-effective geomorphic recovery by retrofitting existing stormwater management facilities. Furthermore, diverse stakeholders, such as local land developers, engineers, and members of the regulatory community, have embraced the data-driven approach and are currently collaborating with SD1 to incorporate hydrologic restoration via stormwater management activities into an existing program that generates stream mitigation credits. The sale of these credits, designed to mitigate the loss of stream habitat due to development, could then further fund the expansion of these restoration efforts. SD1’s approach could serve as a road map for other regional utilities hoping to tailor stormwater management to their streams and communities and find innovative funding sources for urban stream restoration.
{"title":"Optimizing stormwater management to facilitate urban stream restoration via a science-based approach","authors":"M. Wooten, R. Hawley, C. Rust","doi":"10.1086/721031","DOIUrl":"https://doi.org/10.1086/721031","url":null,"abstract":"Stormwater management affecting an urban stream is most effective when managers design programs tailored to the physical characteristics of the stream and the political and socioeconomic characteristics of the community it serves. Likewise, restoration projects and policy implementation should be designed to address the needs of the local community. This paper documents the development and implementation of a science-based, community-driven approach to stormwater management by a United States regional stormwater utility, Sanitation District No. 1 (SD1) of Northern Kentucky, USA, that manages stormwater in 3 suburban counties in the greater metropolitan area of Cincinnati, Ohio, USA. SD1 began by establishing a hydrogeomorphic and biological monitoring program from 2006 to 2008 to gather the data needed to design a locally calibrated stormwater management program. SD1’s monitoring network has facilitated multiple cross-jurisdictional partnerships and provides validation for stormwater management rules and regulations that are tailored to Northern Kentucky. Moreover, the monitoring data has informed the activities of a watershed restoration program that prioritizes cost-effective geomorphic recovery by retrofitting existing stormwater management facilities. Furthermore, diverse stakeholders, such as local land developers, engineers, and members of the regulatory community, have embraced the data-driven approach and are currently collaborating with SD1 to incorporate hydrologic restoration via stormwater management activities into an existing program that generates stream mitigation credits. The sale of these credits, designed to mitigate the loss of stream habitat due to development, could then further fund the expansion of these restoration efforts. SD1’s approach could serve as a road map for other regional utilities hoping to tailor stormwater management to their streams and communities and find innovative funding sources for urban stream restoration.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"477 - 488"},"PeriodicalIF":1.8,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42936304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Denitrification can remove substantial amounts of NO3− from stream networks, but controls on the magnitude and distribution of network-scale denitrification remain poorly understood. Prior research using an empirical relationship between stream [NO3−] and denitrification efficiency to construct a stream network denitrification model suggested that smaller, lower order streams contributed disproportionately to whole-network NO3− removal when NO3− loads were low. We expanded this model by incorporating an empirical relationship between whole-stream aerobic respiration rate and denitrification efficiency, which decreased the simulated sensitivity of NO3− removal to [NO3−] and displayed additional heterogeneity in NO3− removal associated with variation in respiration rates. We explored the sensitivity of the expanded model across a set of scenarios representing variation in stream respiration and NO3−-loading rates. Stream respiration rates used in these scenarios were determined from a theoretical relationship between aerobic respiration rate and stream temperature and were calculated for model scenarios representing warm (high respiration rate) and cool (low respiration rate) conditions. Our results indicated that reach- and network-scale denitrification is apt to be strongly influenced by respiration rates when NO3− supplies are high relative to removal rates. Therefore, the distribution of respiration rates across stream networks likely plays a more important role in determining spatial patterns of denitrification rates than previously described, highlighting a mechanism by which larger (higher order) streams may contribute substantially to whole-network denitrification.
{"title":"Influences of stream ecosystem respiration on stream network denitrification: Results from a simulation modeling experiment","authors":"S. Carlson, G. Poole","doi":"10.1086/720720","DOIUrl":"https://doi.org/10.1086/720720","url":null,"abstract":"Denitrification can remove substantial amounts of NO3− from stream networks, but controls on the magnitude and distribution of network-scale denitrification remain poorly understood. Prior research using an empirical relationship between stream [NO3−] and denitrification efficiency to construct a stream network denitrification model suggested that smaller, lower order streams contributed disproportionately to whole-network NO3− removal when NO3− loads were low. We expanded this model by incorporating an empirical relationship between whole-stream aerobic respiration rate and denitrification efficiency, which decreased the simulated sensitivity of NO3− removal to [NO3−] and displayed additional heterogeneity in NO3− removal associated with variation in respiration rates. We explored the sensitivity of the expanded model across a set of scenarios representing variation in stream respiration and NO3−-loading rates. Stream respiration rates used in these scenarios were determined from a theoretical relationship between aerobic respiration rate and stream temperature and were calculated for model scenarios representing warm (high respiration rate) and cool (low respiration rate) conditions. Our results indicated that reach- and network-scale denitrification is apt to be strongly influenced by respiration rates when NO3− supplies are high relative to removal rates. Therefore, the distribution of respiration rates across stream networks likely plays a more important role in determining spatial patterns of denitrification rates than previously described, highlighting a mechanism by which larger (higher order) streams may contribute substantially to whole-network denitrification.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"363 - 375"},"PeriodicalIF":1.8,"publicationDate":"2022-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47100421","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pengyuan Liu, B. Zhao, Jiaen Zhang, Z. Qin, Chunxia Zhang, Qinglin Jing, Jing Guo
The Golden Apple Snail Pomacea canaliculata (Lamark, 1822) is one of the most aggressive invasive freshwater snails and has been found in tropical and subtropical regions around the world. Their presence threatens trophic structure in invaded ecosystems (e.g., wetlands) and harms human health both directly (e.g., as a vector of parasites) and indirectly (e.g., through altering the provision of ecosystem services from uninvaded ecosystems). The tolerance of Golden Apple Snails to saltwater is of concern because they may pose an invasion risk into estuary habitats. We studied the salinity tolerance of Golden Apple Snails by determining differences in their survival, growth, and feeding at 5 salinity levels (0, 2.5, 5.0, 7.5, and 10.0 practical salinity units [PSU]) over 30 d. Artificial seawater was prepared with aerated tap water and synthetic sea salt, consisting of NaCl (68.88%), KCl (1.79%), CaCl2 (2.55%), MgCl2 (8.67%), MgSO4 (5.36%), and NaHCO3 (12.75%). Snails were classified into 3 life stages based on shell length: juvenile (10–19.99 mm), mature (20–29.99 mm), and old snails (30–39.99 mm). Snails at all 3 life stages survived in salinities of 0 to 5.0 PSU but died within 9 d in salinities of 7.5 and 10.0 PSU. The survival percentage of snails decreased in the order: mature > old > juvenile. Snails across all life stages had reduced shell and mass growth with salinity exposure, but their feeding rate in salinity 2.5 and 5.0 PSU became similar to the control group after 23 d. Generally, Golden Apple Snails may live in waters of ≤5.0 PSU. Therefore, special attention should be paid to the activity of Golden Apple Snails in tropical and subtropical areas with salinities ≤5.0 PSU, which would be important for protecting against the snails’ destructive effects on productive resources.
{"title":"Responses of survival, growth, and feeding of the invasive Golden Apple Snail (Pomacea canaliculata) to salinity stress","authors":"Pengyuan Liu, B. Zhao, Jiaen Zhang, Z. Qin, Chunxia Zhang, Qinglin Jing, Jing Guo","doi":"10.1086/721026","DOIUrl":"https://doi.org/10.1086/721026","url":null,"abstract":"The Golden Apple Snail Pomacea canaliculata (Lamark, 1822) is one of the most aggressive invasive freshwater snails and has been found in tropical and subtropical regions around the world. Their presence threatens trophic structure in invaded ecosystems (e.g., wetlands) and harms human health both directly (e.g., as a vector of parasites) and indirectly (e.g., through altering the provision of ecosystem services from uninvaded ecosystems). The tolerance of Golden Apple Snails to saltwater is of concern because they may pose an invasion risk into estuary habitats. We studied the salinity tolerance of Golden Apple Snails by determining differences in their survival, growth, and feeding at 5 salinity levels (0, 2.5, 5.0, 7.5, and 10.0 practical salinity units [PSU]) over 30 d. Artificial seawater was prepared with aerated tap water and synthetic sea salt, consisting of NaCl (68.88%), KCl (1.79%), CaCl2 (2.55%), MgCl2 (8.67%), MgSO4 (5.36%), and NaHCO3 (12.75%). Snails were classified into 3 life stages based on shell length: juvenile (10–19.99 mm), mature (20–29.99 mm), and old snails (30–39.99 mm). Snails at all 3 life stages survived in salinities of 0 to 5.0 PSU but died within 9 d in salinities of 7.5 and 10.0 PSU. The survival percentage of snails decreased in the order: mature > old > juvenile. Snails across all life stages had reduced shell and mass growth with salinity exposure, but their feeding rate in salinity 2.5 and 5.0 PSU became similar to the control group after 23 d. Generally, Golden Apple Snails may live in waters of ≤5.0 PSU. Therefore, special attention should be paid to the activity of Golden Apple Snails in tropical and subtropical areas with salinities ≤5.0 PSU, which would be important for protecting against the snails’ destructive effects on productive resources.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"376 - 385"},"PeriodicalIF":1.8,"publicationDate":"2022-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45393130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The threshold discharge (Qc) for streambed mobilization is both biologically and geomorphically relevant to stream ecosystems. Excess streambed mobilization can disturb benthic organisms and initiate cycles of channel instability. The mechanistic relevance of Qc gives it great utility for aquatic ecosystem studies, stormwater management, and stream restoration design. However, field and laboratory data document considerable variability in Qc across hydrogeomorphic settings, underscoring the importance of using field data to calibrate the Qc estimate for a given stream or region. This paper shows how both high- and low-tech monitoring protocols can be used to constrain a Qc estimate, depending on monitoring program goals and budgets. Data from 3 hydrogeomorphically distinct settings in the USA and Australia show that the departure of Qc from theoretical estimates increases with watershed imperviousness. Although Qc estimates derived from conventional critical Shields stress values tend to be a reasonable and conservative starting point for stormwater management in streams that lack site-specific or regional data, streambed mobility monitoring is recommended to calibrate and validate Qc estimates for a stream or region prior to making large investments in stormwater interventions aimed at mitigating the urban streambed disturbance regime.
{"title":"Qc threshold departs from theoretical Qc in urban watersheds: The role of streambed mobility data in managing the urban disturbance regime","authors":"R. Hawley, Kathryn L. Russell, L. Olinde","doi":"10.1086/720939","DOIUrl":"https://doi.org/10.1086/720939","url":null,"abstract":"The threshold discharge (Qc) for streambed mobilization is both biologically and geomorphically relevant to stream ecosystems. Excess streambed mobilization can disturb benthic organisms and initiate cycles of channel instability. The mechanistic relevance of Qc gives it great utility for aquatic ecosystem studies, stormwater management, and stream restoration design. However, field and laboratory data document considerable variability in Qc across hydrogeomorphic settings, underscoring the importance of using field data to calibrate the Qc estimate for a given stream or region. This paper shows how both high- and low-tech monitoring protocols can be used to constrain a Qc estimate, depending on monitoring program goals and budgets. Data from 3 hydrogeomorphically distinct settings in the USA and Australia show that the departure of Qc from theoretical estimates increases with watershed imperviousness. Although Qc estimates derived from conventional critical Shields stress values tend to be a reasonable and conservative starting point for stormwater management in streams that lack site-specific or regional data, streambed mobility monitoring is recommended to calibrate and validate Qc estimates for a stream or region prior to making large investments in stormwater interventions aimed at mitigating the urban streambed disturbance regime.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"489 - 506"},"PeriodicalIF":1.8,"publicationDate":"2022-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45550388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kelsey J. Solomon, R. Bixby, S. Wenger, C. Pringle
Terrestrial and stream ecosystems are interconnected, with changes in one system cascading to affect the other. Tree mortality related to nonnative pest infestation has increased, yet we do not understand the effects that riparian tree species losses will have on the structural characteristics of stream ecosystems. We compared riparian canopy cover, algal standing crop, and diatom assemblage composition in 8 southern Appalachian headwater stream reaches within the Coweeta Hydrologic Laboratory in North Carolina, USA, before and after a massive die-off of riparian eastern hemlock (Tsuga canadensis [L.] Carr.) related to the introduction of hemlock woolly adelgid (Adelges tsugae Annand), an invasive insect. We analyzed historical preserved algal samples collected prior to hemlock die-off, in both summer (September 2005) and winter (January 2006), and used multivariate analyses to compare them to samples collected in the same 8 reaches and seasons 13 y following hemlock die-off (2018–2019). We predicted that increased canopy openness following hemlock death would change light availability and lead to higher standing crop and increases in the relative biovolume of high-profile diatoms. Contrary to our expectations, we found little difference in canopy cover and lower algal standing crop 13 y post-hemlock die-off, likely due to increased basal area of the understory shrub, Rhododendron maximum L., that replaced shade cover formerly provided by hemlock. Diatom assemblages were dominated by acidophilic taxa (e.g., Eunotia spp.) across all stream reaches before and after hemlock die-off. We observed some shifts in diatom assemblage composition, but the relative biovolume of a majority of the top 20 most abundant taxa, including Eunotia incisa W. Sm. ex W. Greg., Nupela lapidosa (Krasske) Lange-Bert., and Meridion alansmithii Brant (an endemic taxon), remained relatively unchanged 13 y after hemlock mortality. Diatom assemblages differed post-hemlock die-off in summer but not winter due to a decrease in the relative biovolume of Eunotia metamondon complex and an increase in the relative biovolume of Eunotia rhomboidea complex. Our study highlights the relative stability of diatom assemblage composition in southern Appalachian streams and the importance of long-term studies following a major riparian disturbance.
陆地生态系统和河流生态系统是相互关联的，一个系统的变化会连锁影响另一个系统。与非本地害虫侵染相关的树木死亡率增加，但我们不了解河岸树种损失将对河流生态系统结构特征产生的影响。在美国北卡罗莱纳州Coweeta水文实验室内，我们比较了东部铁杉(Tsuga canadensis [L.])大规模死亡前后，美国南部阿巴拉契亚山脉8个源头河段的河岸冠层覆盖、藻类生长作物和硅藻组合组成。[Carr.])与引进一种入侵昆虫——铁杉绵蚜(Adelges tsugae Annand)有关。我们分析了铁杉死亡前夏季(2005年9月)和冬季(2006年1月)收集的历史保存藻类样本，并使用多变量分析将其与铁杉死亡后相同8个河段和季节(2018-2019年)收集的样本进行比较。我们预测，铁杉死亡后冠层开度的增加会改变光照利用率，导致高姿态硅藻的相对生物体积增加。与我们的预期相反，我们发现在铁杉死亡后，冠层覆盖和低赤潮直立作物13的差异不大，这可能是由于林下灌木杜鹃(Rhododendron maximum L.)的基底面积增加，取代了铁杉以前提供的遮荫覆盖。在铁杉枯死前后的所有河段，硅藻组合以嗜酸类群(如Eunotia spp.)为主。我们观察到硅藻组合组成发生了一些变化，但前20个最丰富的分类群中大多数的相对生物体积都发生了变化，包括Eunotia incisa W. Sm。前W.格雷格。兰格-伯特。在铁杉死亡13 y后，其分布基本保持不变。铁杉死后硅藻群落在夏季有明显的差异，但在冬季无明显差异，这是由于铁杉复合群落的相对生物量减少，而菱形复合群落的相对生物量增加。我们的研究强调了阿巴拉契亚南部河流中硅藻组合组成的相对稳定性，以及在主要河岸扰动后进行长期研究的重要性。
{"title":"Have stream diatom assemblages changed a decade after the loss of a foundation riparian tree species in a headwater Appalachian watershed?","authors":"Kelsey J. Solomon, R. Bixby, S. Wenger, C. Pringle","doi":"10.1086/720136","DOIUrl":"https://doi.org/10.1086/720136","url":null,"abstract":"Terrestrial and stream ecosystems are interconnected, with changes in one system cascading to affect the other. Tree mortality related to nonnative pest infestation has increased, yet we do not understand the effects that riparian tree species losses will have on the structural characteristics of stream ecosystems. We compared riparian canopy cover, algal standing crop, and diatom assemblage composition in 8 southern Appalachian headwater stream reaches within the Coweeta Hydrologic Laboratory in North Carolina, USA, before and after a massive die-off of riparian eastern hemlock (Tsuga canadensis [L.] Carr.) related to the introduction of hemlock woolly adelgid (Adelges tsugae Annand), an invasive insect. We analyzed historical preserved algal samples collected prior to hemlock die-off, in both summer (September 2005) and winter (January 2006), and used multivariate analyses to compare them to samples collected in the same 8 reaches and seasons 13 y following hemlock die-off (2018–2019). We predicted that increased canopy openness following hemlock death would change light availability and lead to higher standing crop and increases in the relative biovolume of high-profile diatoms. Contrary to our expectations, we found little difference in canopy cover and lower algal standing crop 13 y post-hemlock die-off, likely due to increased basal area of the understory shrub, Rhododendron maximum L., that replaced shade cover formerly provided by hemlock. Diatom assemblages were dominated by acidophilic taxa (e.g., Eunotia spp.) across all stream reaches before and after hemlock die-off. We observed some shifts in diatom assemblage composition, but the relative biovolume of a majority of the top 20 most abundant taxa, including Eunotia incisa W. Sm. ex W. Greg., Nupela lapidosa (Krasske) Lange-Bert., and Meridion alansmithii Brant (an endemic taxon), remained relatively unchanged 13 y after hemlock mortality. Diatom assemblages differed post-hemlock die-off in summer but not winter due to a decrease in the relative biovolume of Eunotia metamondon complex and an increase in the relative biovolume of Eunotia rhomboidea complex. Our study highlights the relative stability of diatom assemblage composition in southern Appalachian streams and the importance of long-term studies following a major riparian disturbance.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"342 - 361"},"PeriodicalIF":1.8,"publicationDate":"2022-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41713727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. A. Holgerson, Martha Barnard, Byung-Gu Ahn, M. Hayes, A. Strecker
Species introductions are common in freshwater environments and have the potential to transform community and ecosystem structure. Predatory centrarchid fishes and American Bullfrogs (Lithobates catesbeianus Shaw, 1802 previously Rana catesbeiana) are both widespread aquatic invaders implicated in native amphibian declines. In lowland ecosystems, co-occurrence between native and nonnative amphibian and fish taxa is common; however, the mechanisms that facilitate their co-occurrence are poorly studied. Stable isotope analysis offers a tool to examine trophic interactions among native and nonnative taxa, including predation, competition, and shifting food resource availability, which may provide mechanistic insight into the drivers of co-occurrence. In this study, we used stable isotopes (δ13C and δ15N) to determine how the trophic structure of native fishes and amphibians differs between waterbodies with and without nonnative centrarchid fishes and bullfrogs across a floodplain in southwestern Washington, USA. We hypothesized that native species alter their feeding strategies to reduce niche overlap with nonnative taxa. In the presence of nonnative taxa, Three-spine Stickleback (Gasterosteus aculeatus Linnaeus, 1758), all native larval salamander species (Ambystoma gracile Baird, 1859 and Ambystoma macrodactylum Baird, 1850), and 1 of 2 native larval frog species (Rana aurora Baird and Girard, 1852) exhibited shifts in food resources or trophic position. Despite trophic differences, only 1 species (A. macrodactylum) had a smaller niche size in the presence of nonnatives. The observed trophic shifts reflect changes in habitat or food resources, which may reduce competition or predation and promote co-occurrence between nonnative and native taxa. Our results suggest that the co-occurrence of native and nonnative amphibians and fishes in lowland floodplain habitats may be facilitated by a broad range of food resources and complex habitat structure.
{"title":"Freshwater floodplain habitats buffer native food webs from negative effects of nonnative centrarchids and bullfrogs","authors":"M. A. Holgerson, Martha Barnard, Byung-Gu Ahn, M. Hayes, A. Strecker","doi":"10.1086/720137","DOIUrl":"https://doi.org/10.1086/720137","url":null,"abstract":"Species introductions are common in freshwater environments and have the potential to transform community and ecosystem structure. Predatory centrarchid fishes and American Bullfrogs (Lithobates catesbeianus Shaw, 1802 previously Rana catesbeiana) are both widespread aquatic invaders implicated in native amphibian declines. In lowland ecosystems, co-occurrence between native and nonnative amphibian and fish taxa is common; however, the mechanisms that facilitate their co-occurrence are poorly studied. Stable isotope analysis offers a tool to examine trophic interactions among native and nonnative taxa, including predation, competition, and shifting food resource availability, which may provide mechanistic insight into the drivers of co-occurrence. In this study, we used stable isotopes (δ13C and δ15N) to determine how the trophic structure of native fishes and amphibians differs between waterbodies with and without nonnative centrarchid fishes and bullfrogs across a floodplain in southwestern Washington, USA. We hypothesized that native species alter their feeding strategies to reduce niche overlap with nonnative taxa. In the presence of nonnative taxa, Three-spine Stickleback (Gasterosteus aculeatus Linnaeus, 1758), all native larval salamander species (Ambystoma gracile Baird, 1859 and Ambystoma macrodactylum Baird, 1850), and 1 of 2 native larval frog species (Rana aurora Baird and Girard, 1852) exhibited shifts in food resources or trophic position. Despite trophic differences, only 1 species (A. macrodactylum) had a smaller niche size in the presence of nonnatives. The observed trophic shifts reflect changes in habitat or food resources, which may reduce competition or predation and promote co-occurrence between nonnative and native taxa. Our results suggest that the co-occurrence of native and nonnative amphibians and fishes in lowland floodplain habitats may be facilitated by a broad range of food resources and complex habitat structure.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"327 - 341"},"PeriodicalIF":1.8,"publicationDate":"2022-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47269805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jennifer L. Gosselin, James J. Anderson, B. Sanderson, Mollie A. Middleton, B. Sandford, L. Weitkamp
Decision triggers, used in adaptive management frameworks to decide when a specific management action will be implemented, are often informed by monitoring data. The identification and application of decision triggers is highly relevant to endangered fishes migrating through regulated rivers, as examined in the current study. The main goal was to determine whether seasonal patterns of behavioral, physical, and physiological indices of juveniles were related to subsequent smolt-to-adult return (SAR) survival and, if so, to determine whether these indices could be used to guide decisions related to the mitigation strategy of the juvenile fish transportation program in the Federal Columbia River Power System (Pacific Northwest, USA). Hatchery yearling Chinook Salmon (Oncorhynchus tshawytscha Walbaum in Artedi, 1792) were collected over the migration season at 3 dams in the hydrosystem and measured for fork length, wet mass, Fulton’s K (or condition factor), Na+/K+-ATPase (NKA) activity (or smoltification index), and % dry mass (or index of energetic reserves and smoltification). We estimated SAR survival from passive integrated transponder-tagged fish representative of our field samples and assessed its relationship to our fish indices, as well as indices of transported vs run-of-river passage and distance of sampling site to ocean. SAR survival was associated to interaction effects between juvenile fish transportation and % dry mass or NKA activity. Transported hatchery Chinook Salmon with dry mass <23% of whole fish wet mass and NKA activity >7 µmol ADP mg protein−1 h−1 showed greater SAR survival than their run-of-river counterparts. Fish with the highest predicted SAR survival had been transported and had fish indices consistent with smolts that were more developed (i.e., lower % dry mass and higher NKA activity). Furthermore, our results on % dry mass provided support for the hypothesis that greater lipid content increases fish buoyancy leading to greater susceptibility to predation. The buoyancy effect is expected to be greatest in hatchery fish. Overall, this study shows that decision triggers based on biological indices of migrating fish are potentially useful tools for in-season management.
自适应管理框架中用于决定何时实施具体管理行动的决策触发器通常由监测数据提供信息。如本研究所述，决策触发器的识别和应用与通过受管制河流迁徙的濒危鱼类高度相关。主要目标是确定青少年的行为、身体和生理指标的季节性模式是否与随后的闷烧-成年回归（SAR）存活率有关，如果是，以确定这些指数是否可用于指导与联邦哥伦比亚河电力系统（美国西北太平洋地区）幼鱼运输计划的缓解策略相关的决策。在迁徙季节，在水生系统的3个水坝采集了孵化一年的奇努克鲑鱼（Oncorhynchus tshawytscha-Wallbaum in Artedi，1792），并测量了叉长、湿质量、富尔顿K（或条件因子）、Na+/K+-ATP酶（NKA）活性（或闷烧指数）和%干质量（或能量储备和闷烧的指数）。我们估计了无源集成转发器标记的鱼类（代表我们的现场样本）的SAR生存率，并评估了其与我们的鱼类指数的关系，以及运输与河道流量的指数和采样点与海洋的距离。SAR存活率与幼鱼运输和%干物质或NKA活性之间的相互作用有关。干质量为7µmol ADP mg蛋白−1 h−1的运输孵化场奇努克三文鱼的SAR存活率高于河流中的同类。预测SAR存活率最高的鱼类已被运输，其鱼类指数与更发达的smots一致（即较低的干物质百分比和较高的NKA活性）。此外，我们关于%干质量的结果支持了这样一种假设，即更高的脂质含量会增加鱼类的浮力，从而更容易被捕食。预计孵化场鱼类的浮力效应最大。总的来说，这项研究表明，基于洄游鱼类生物学指数的决策触发器是季节管理的潜在有用工具。
{"title":"Assessing seasonal and biological indices of juvenile Chinook Salmon for freshwater decision triggers that increase ocean survival","authors":"Jennifer L. Gosselin, James J. Anderson, B. Sanderson, Mollie A. Middleton, B. Sandford, L. Weitkamp","doi":"10.1086/720007","DOIUrl":"https://doi.org/10.1086/720007","url":null,"abstract":"Decision triggers, used in adaptive management frameworks to decide when a specific management action will be implemented, are often informed by monitoring data. The identification and application of decision triggers is highly relevant to endangered fishes migrating through regulated rivers, as examined in the current study. The main goal was to determine whether seasonal patterns of behavioral, physical, and physiological indices of juveniles were related to subsequent smolt-to-adult return (SAR) survival and, if so, to determine whether these indices could be used to guide decisions related to the mitigation strategy of the juvenile fish transportation program in the Federal Columbia River Power System (Pacific Northwest, USA). Hatchery yearling Chinook Salmon (Oncorhynchus tshawytscha Walbaum in Artedi, 1792) were collected over the migration season at 3 dams in the hydrosystem and measured for fork length, wet mass, Fulton’s K (or condition factor), Na+/K+-ATPase (NKA) activity (or smoltification index), and % dry mass (or index of energetic reserves and smoltification). We estimated SAR survival from passive integrated transponder-tagged fish representative of our field samples and assessed its relationship to our fish indices, as well as indices of transported vs run-of-river passage and distance of sampling site to ocean. SAR survival was associated to interaction effects between juvenile fish transportation and % dry mass or NKA activity. Transported hatchery Chinook Salmon with dry mass <23% of whole fish wet mass and NKA activity >7 µmol ADP mg protein−1 h−1 showed greater SAR survival than their run-of-river counterparts. Fish with the highest predicted SAR survival had been transported and had fish indices consistent with smolts that were more developed (i.e., lower % dry mass and higher NKA activity). Furthermore, our results on % dry mass provided support for the hypothesis that greater lipid content increases fish buoyancy leading to greater susceptibility to predation. The buoyancy effect is expected to be greatest in hatchery fish. Overall, this study shows that decision triggers based on biological indices of migrating fish are potentially useful tools for in-season management.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"253 - 269"},"PeriodicalIF":1.8,"publicationDate":"2022-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44781024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Climate change predictions for Southern Europe indicate an increase in the frequency and duration of summer low flows and water scarcity in streams. Droughts can cause substantial changes in aquatic communities and biogeochemical processes because they modify stream environmental conditions. Among the many physical, chemical, and biological variables that influence stream metabolism, nutrients may affect algae and heterotrophic microorganisms, and nutrient concentrations may vary with reduction in water discharge. We experimentally manipulated stream discharge and used a before–after control–impact paired design to assess how reduction of stream discharge affected metabolism (i.e., ecosystem respiration [ER] and gross primary production [GPP]). The study was done in 2 lowland forested streams in northwestern Spain with contrasting nutrient concentrations (i.e., mesotrophic: Caselas stream; eutrophic: Pego stream). In the 2 streams, metabolism was estimated before and after discharge manipulation. Prior to discharge reduction, the 2 streams were heterotrophic (i.e., GPP∶ER < 1), and GPP and ER were related in the eutrophic Pego. Discharge reduction increased GPP at the impacted reaches of the mesotrophic Caselas and decoupled GPP and ER at the Pego. An information-theoretic approach was used to assess which combinations of physical, chemical, and biological variables were most important to explain the variation in ER and GPP under the different hydrologic conditions. The observed differences between the 2 streams suggest that the metabolic response to stream drought can be modulated by the interplay between nutrient availability and the density of consumers feeding on resources, among other environmental variables. We show that longer summer periods and reduced stream discharge have the potential to increase daily hypoxia in nutrient-rich lowland stream ecosystems. Increased hypoxia can threaten biodiversity of stream ecosystems and reduce consumer pressure on basal instream resources, such as algae, bacteria, and fungi, which may, in turn, favor instream GPP. In addition, drying conditions seemed to favor autotrophic over heterotrophic activity under moderate nutrient availability (i.e., increase in the GPP∶ER ratio in the impacted Caselas reaches). Therefore, drought conditions not only affect overall daily rates of metabolic activity, but also the relative importance of different energy sources and organic matter for instream function. Our results show that discharge reduction caused by increased water scarcity, due to both climate change and water demand by human activities, can influence energy flow and organic matter dynamics through effects on the metabolism of forested lowland streams.
{"title":"Nutrient availability modulates the effect of water abstraction on the metabolism of 2 lowland forested streams","authors":"I. Pardo, Lenka Kuglerová, L. García, E. Martí","doi":"10.1086/719990","DOIUrl":"https://doi.org/10.1086/719990","url":null,"abstract":"Climate change predictions for Southern Europe indicate an increase in the frequency and duration of summer low flows and water scarcity in streams. Droughts can cause substantial changes in aquatic communities and biogeochemical processes because they modify stream environmental conditions. Among the many physical, chemical, and biological variables that influence stream metabolism, nutrients may affect algae and heterotrophic microorganisms, and nutrient concentrations may vary with reduction in water discharge. We experimentally manipulated stream discharge and used a before–after control–impact paired design to assess how reduction of stream discharge affected metabolism (i.e., ecosystem respiration [ER] and gross primary production [GPP]). The study was done in 2 lowland forested streams in northwestern Spain with contrasting nutrient concentrations (i.e., mesotrophic: Caselas stream; eutrophic: Pego stream). In the 2 streams, metabolism was estimated before and after discharge manipulation. Prior to discharge reduction, the 2 streams were heterotrophic (i.e., GPP∶ER < 1), and GPP and ER were related in the eutrophic Pego. Discharge reduction increased GPP at the impacted reaches of the mesotrophic Caselas and decoupled GPP and ER at the Pego. An information-theoretic approach was used to assess which combinations of physical, chemical, and biological variables were most important to explain the variation in ER and GPP under the different hydrologic conditions. The observed differences between the 2 streams suggest that the metabolic response to stream drought can be modulated by the interplay between nutrient availability and the density of consumers feeding on resources, among other environmental variables. We show that longer summer periods and reduced stream discharge have the potential to increase daily hypoxia in nutrient-rich lowland stream ecosystems. Increased hypoxia can threaten biodiversity of stream ecosystems and reduce consumer pressure on basal instream resources, such as algae, bacteria, and fungi, which may, in turn, favor instream GPP. In addition, drying conditions seemed to favor autotrophic over heterotrophic activity under moderate nutrient availability (i.e., increase in the GPP∶ER ratio in the impacted Caselas reaches). Therefore, drought conditions not only affect overall daily rates of metabolic activity, but also the relative importance of different energy sources and organic matter for instream function. Our results show that discharge reduction caused by increased water scarcity, due to both climate change and water demand by human activities, can influence energy flow and organic matter dynamics through effects on the metabolism of forested lowland streams.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"299 - 314"},"PeriodicalIF":1.8,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47314470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reaches are a fundamental unit for lotic biogeochemical characterization, yet a functional classification of nutrient processing at the reach scale is currently lacking. Here, we introduce nutrient processing domains (NPDs) to integrate routing (nutrient delivery) and local (benthic uptake and transformation) processes that dictate longitudinal patterns of lotic biogeochemical function. An NPD is defined as a realm in functional space occupied by reaches that share similar biogeochemical character. Occupation of a given NPD reflects characteristic net material balance (NMB), exchange potential, and availability, associated with changes in solute load, the extent of hydrologic gain or loss, and changes in concentration from the head to the base of a reach, respectively. Using a mass-balance approach, we represent NMB as the effective solute flux (Feff, M L−2 T−1, where M = mass, L = length, and T = time), designating reaches as sources (+Feff) or sinks (−Feff). Discharge change along a reach is measured as the change in hydraulic load (ΔHL, L/T), reflecting the potential for import and export to influence solute loads. Finally, the ratio of downstream-to-upstream concentration (Cdwn:up) represents the net effect that processes have on nutrient availability. Using a 20-y historical record for N and P in the Upper Clark Fork River, Montana, USA, we employed this approach to 3 consecutive reaches covering nearly 90 km of channel length to address spatial and temporal dynamics in NPD behavior in a nutrient-rich, productive river system. For total N and total P, reaches typically occupied compiler or enhancer NPDs, displaying load increases without or with concomitant increases in concentration, respectively. In contrast, reaches were NO3− consumers, acting as sinks for NO3-N during summer and autumn. NO3− load reductions were typically accompanied by striking declines in concentration, despite positive exchange potential (i.e., +ΔHL). Measured Feff magnitudes for NO3− (−1.2 to −60.0 mg N m−2 d−1) were similar to those reported in the literature associated with autotrophic N demand. Individual reaches occupied contrasting NPDs for NO3-N and soluble reactive P by simultaneously serving as a sink for one and a source for the other. Hence, alternating reaches acted as enhancers or consumers, sequentially along the river, reflecting geologic and biological influences with implications for whole river behavior. The NPD approach combines routing influences of material exchange and local biological stream processes to provide a biogeochemical taxonomy for stream reaches with application to theory and practice.
河段是乳液生物地球化学特征的基本单元，但目前缺乏河段尺度的营养处理功能分类。在这里，我们引入了营养加工域（NPD），以整合路径（营养输送）和局部（底栖生物吸收和转化）过程，这些过程决定了乳液生物地球化学功能的纵向模式。NPD被定义为具有相似生物地球化学特征的河段所占据的功能空间领域。给定NPD的占用反映了特征净物质平衡（NMB）、交换潜力和可用性，分别与溶质负荷的变化、水文损益的程度以及从河段顶部到底部的浓度变化有关。使用质量平衡方法，我们将NMB表示为有效溶质通量（Feff，M L−2 T−1，其中M=质量，L=长度，T=时间），将河段指定为源（+Feff）或汇（−Feff）。河段的流量变化被测量为水力负荷的变化（ΔHL，L/T），反映了进出口影响溶质负荷的潜力。最后，下游浓度与上游浓度之比（Cdwn:up）表示工艺对养分有效性的净影响。利用美国蒙大拿州克拉克福克河上游20年的N和P历史记录，我们对覆盖近90公里河道长度的3个连续河段采用了这种方法，以解决营养丰富、多产的河流系统中NPD行为的空间和时间动力学问题。对于总N和总P，达到通常被占用的编译器或增强器NPD，分别显示负载增加而没有或伴随浓度增加。相比之下，河段是NO3消费者，在夏季和秋季充当NO3-N的汇。NO3负荷的减少通常伴随着浓度的显著下降，尽管存在正交换潜力（即+ΔHL）。NO3−（−1.2至−60.0 mg N m−2 d−1）的Feff测量值与文献中报道的自养氮需求量相似。个体通过同时充当NO3-N和可溶性反应性P的汇点和源点，占据了NO3-N的对比NPD。因此，交替河段起到了增强子或消费者的作用，沿着河流顺序排列，反映了地质和生物影响，对整个河流的行为产生了影响。NPD方法结合了物质交换和当地生物流过程的路径影响，为河段提供了一种可应用于理论和实践的生物地球化学分类法。
{"title":"Nutrient processing domains: Spatial and temporal patterns of material retention in running waters","authors":"H. Valett, M. Peipoch, G. Poole","doi":"10.1086/719991","DOIUrl":"https://doi.org/10.1086/719991","url":null,"abstract":"Reaches are a fundamental unit for lotic biogeochemical characterization, yet a functional classification of nutrient processing at the reach scale is currently lacking. Here, we introduce nutrient processing domains (NPDs) to integrate routing (nutrient delivery) and local (benthic uptake and transformation) processes that dictate longitudinal patterns of lotic biogeochemical function. An NPD is defined as a realm in functional space occupied by reaches that share similar biogeochemical character. Occupation of a given NPD reflects characteristic net material balance (NMB), exchange potential, and availability, associated with changes in solute load, the extent of hydrologic gain or loss, and changes in concentration from the head to the base of a reach, respectively. Using a mass-balance approach, we represent NMB as the effective solute flux (Feff, M L−2 T−1, where M = mass, L = length, and T = time), designating reaches as sources (+Feff) or sinks (−Feff). Discharge change along a reach is measured as the change in hydraulic load (ΔHL, L/T), reflecting the potential for import and export to influence solute loads. Finally, the ratio of downstream-to-upstream concentration (Cdwn:up) represents the net effect that processes have on nutrient availability. Using a 20-y historical record for N and P in the Upper Clark Fork River, Montana, USA, we employed this approach to 3 consecutive reaches covering nearly 90 km of channel length to address spatial and temporal dynamics in NPD behavior in a nutrient-rich, productive river system. For total N and total P, reaches typically occupied compiler or enhancer NPDs, displaying load increases without or with concomitant increases in concentration, respectively. In contrast, reaches were NO3− consumers, acting as sinks for NO3-N during summer and autumn. NO3− load reductions were typically accompanied by striking declines in concentration, despite positive exchange potential (i.e., +ΔHL). Measured Feff magnitudes for NO3− (−1.2 to −60.0 mg N m−2 d−1) were similar to those reported in the literature associated with autotrophic N demand. Individual reaches occupied contrasting NPDs for NO3-N and soluble reactive P by simultaneously serving as a sink for one and a source for the other. Hence, alternating reaches acted as enhancers or consumers, sequentially along the river, reflecting geologic and biological influences with implications for whole river behavior. The NPD approach combines routing influences of material exchange and local biological stream processes to provide a biogeochemical taxonomy for stream reaches with application to theory and practice.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"195 - 214"},"PeriodicalIF":1.8,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44809253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Lansac‐Tôha, P. R. B. Buosi, M. T. Baumgartner, M. Progênio, B. R. Meira, A. Cabral, B. T. Segovia, M. Dunthorn, Guillaume Lentendu, F. Lansac-Tôha, L. Velho
One of the major goals in microbial ecology is to understand whether the empirical biogeographic patterns of macroorganisms also apply to microorganisms. Here, we used morphological data from live organisms, along with molecular data, to investigate the importance of spatial factors and environmental variables in influencing ciliate composition from floodplain lakes. Our main goal was to use 2 different approaches (morphological and molecular) to compare ciliate diversity and distribution patterns as well as to compare how these methods differ in their ability to detect distribution patterns and the roles of spatial and environmental factors that shape ciliate assemblages in the 4 largest floodplains in Brazil. Planktonic water samples were gathered from 33 lakes associated with 4 different river floodplain systems in Brazil. We analyzed ciliates in vivo and sequenced surface water DNA using a metabarcoding approach with general eukaryotic primers. We showed that the diversity of operational taxonomic units was much higher than that of morphospecies. Regardless of the method of identification, we found a consistent spatial assembly pattern of ciliate assemblages across the 4 floodplain systems. We also found that environmental filters had a stronger association with the morphological than with the molecular site-by-site dissimilarities. Meanwhile, biogeographic factors and the distance among sites limited the distribution of molecular-based composition, resulting in strong differences among the floodplain lakes analyzed. This finding suggests that ecological research and biomonitoring activities should find an equilibrium between morphological and molecular approaches because each approach provides unique insights.
{"title":"Molecular insight reveals broad-scale spatial patterns in floodplain ciliate assemblages, whereas morphology reflects local environmental controls","authors":"F. Lansac‐Tôha, P. R. B. Buosi, M. T. Baumgartner, M. Progênio, B. R. Meira, A. Cabral, B. T. Segovia, M. Dunthorn, Guillaume Lentendu, F. Lansac-Tôha, L. Velho","doi":"10.1086/719992","DOIUrl":"https://doi.org/10.1086/719992","url":null,"abstract":"One of the major goals in microbial ecology is to understand whether the empirical biogeographic patterns of macroorganisms also apply to microorganisms. Here, we used morphological data from live organisms, along with molecular data, to investigate the importance of spatial factors and environmental variables in influencing ciliate composition from floodplain lakes. Our main goal was to use 2 different approaches (morphological and molecular) to compare ciliate diversity and distribution patterns as well as to compare how these methods differ in their ability to detect distribution patterns and the roles of spatial and environmental factors that shape ciliate assemblages in the 4 largest floodplains in Brazil. Planktonic water samples were gathered from 33 lakes associated with 4 different river floodplain systems in Brazil. We analyzed ciliates in vivo and sequenced surface water DNA using a metabarcoding approach with general eukaryotic primers. We showed that the diversity of operational taxonomic units was much higher than that of morphospecies. Regardless of the method of identification, we found a consistent spatial assembly pattern of ciliate assemblages across the 4 floodplain systems. We also found that environmental filters had a stronger association with the morphological than with the molecular site-by-site dissimilarities. Meanwhile, biogeographic factors and the distance among sites limited the distribution of molecular-based composition, resulting in strong differences among the floodplain lakes analyzed. This finding suggests that ecological research and biomonitoring activities should find an equilibrium between morphological and molecular approaches because each approach provides unique insights.","PeriodicalId":48926,"journal":{"name":"Freshwater Science","volume":"41 1","pages":"270 - 283"},"PeriodicalIF":1.8,"publicationDate":"2022-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44856286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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