2020
Wang, Terrance; Kelson, Suzanne J.; Greer, George; Thompson, Sally E.; Carlson., Stephanie M.
Tributary confluences are dynamic thermal refuges for a juvenile salmonid in a warming river network Journal Article
In: River Research and Applications, 2020.
Abstract | Links | BibTeX | Tags: climate change, Eel river, ERCZO, microhabitat, Oncorhynchus mykiss, stream temperatures, thermal refuges, thermal tolerance
@article{Wang2020,
title = {Tributary confluences are dynamic thermal refuges for a juvenile salmonid in a warming river network},
author = {Terrance Wang and Suzanne J. Kelson and George Greer and Sally E. Thompson and Stephanie M. Carlson.},
doi = {10.1002/rra.3634},
year = {2020},
date = {2020-04-28},
journal = {River Research and Applications},
abstract = {As rivers warm, cold‐water fish species may alleviate thermal stress by moving into localized thermal refuges such as cold‐water plumes created by cool tributary inflows. We quantified use of two tributary confluence plumes by juvenile steelhead, Oncorhynchus mykiss , throughout the summer, including how trout positioned themselves in relation to temperature within confluence plumes. At two confluences, Cedar and Elder creeks, along the South Fork Eel River, California, USA, we monitored temperatures using in situ logger grids throughout summer 2016. Fish were counted within confluences via snorkel surveys five times a day on 5 days at each site. We found diel and seasonal dependence on confluence use by steelhead, especially at the Cedar Creek confluence, where mainstem temperatures exceeded 28°C. At this site, fish moved into the confluence on the warmest days and warmest times of the day. Fish observed within the Cedar Creek confluence plume were most common in locations between 20–22°C, rather than the coldest locations (14.5°C). At Elder Creek, where mainstem temperatures remained below 24°C, there was little relationship between mainstem temperature and steelhead presence in the confluence plume. At both sites, steelhead distribution within plumes was influenced by spatial variation of temperature and mean temperature in surveyed grid cells. Our results show that cool tributaries flowing into warmer mainstem reaches (over 24°C) likely create important thermal refuges for juvenile steelhead. As mainstem rivers warm with climate change, cool‐water tributary inputs may become more important for sustaining cold‐water salmonids near the southern end of their range.},
keywords = {climate change, Eel river, ERCZO, microhabitat, Oncorhynchus mykiss, stream temperatures, thermal refuges, thermal tolerance},
pubstate = {published},
tppubtype = {article}
}
As rivers warm, cold‐water fish species may alleviate thermal stress by moving into localized thermal refuges such as cold‐water plumes created by cool tributary inflows. We quantified use of two tributary confluence plumes by juvenile steelhead, Oncorhynchus mykiss , throughout the summer, including how trout positioned themselves in relation to temperature within confluence plumes. At two confluences, Cedar and Elder creeks, along the South Fork Eel River, California, USA, we monitored temperatures using in situ logger grids throughout summer 2016. Fish were counted within confluences via snorkel surveys five times a day on 5 days at each site. We found diel and seasonal dependence on confluence use by steelhead, especially at the Cedar Creek confluence, where mainstem temperatures exceeded 28°C. At this site, fish moved into the confluence on the warmest days and warmest times of the day. Fish observed within the Cedar Creek confluence plume were most common in locations between 20–22°C, rather than the coldest locations (14.5°C). At Elder Creek, where mainstem temperatures remained below 24°C, there was little relationship between mainstem temperature and steelhead presence in the confluence plume. At both sites, steelhead distribution within plumes was influenced by spatial variation of temperature and mean temperature in surveyed grid cells. Our results show that cool tributaries flowing into warmer mainstem reaches (over 24°C) likely create important thermal refuges for juvenile steelhead. As mainstem rivers warm with climate change, cool‐water tributary inputs may become more important for sustaining cold‐water salmonids near the southern end of their range.
2015
Power, Mary E.; Bouma-Gregson, Keith; Higgins, Patrick; Carlson, Stephanie M.
In: Copeia, vol. 103, no. 1, pp. 200-211, 2015.
Abstract | Links | BibTeX | Tags: cyanobacteria, Eel river, ERCZO, salmonids
@article{Power2015,
title = {The Thirsty Eel: Summer and Winter Flow Thresholds that Tilt the Eel River of Northwestern California from Salmon-Supporting to Cyanobacterially Degraded States},
author = {Mary E. Power and Keith Bouma-Gregson and Patrick Higgins and Stephanie M. Carlson},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Power_2015_Copeia.pdf},
doi = {10.1643/CE-14-086},
year = {2015},
date = {2015-03-05},
journal = {Copeia},
volume = {103},
number = {1},
pages = {200-211},
abstract = {Although it flows through regions of northwestern California that are thought to be relatively well watered, the Eel River is increasingly stressed by drought and water withdrawals. We discuss how critical threshold changes in summer discharge can potentially tilt the Eel from a recovering salmon-supporting ecosystem toward a cyanobacterially degraded one. To maintain food webs and habitats that support salmonids and suppress harmful cyanobacteria, summer discharge must be sufficient to connect mainstem pools hydrologically with gently moving, cool base flow. Rearing salmon and steelhead can survive even in pools that become isolated during summer low flows if hyporheic exchange is sufficient. But if the ground water discharge that sustains river flow during summer drought drops below critical levels, warm stagnant conditions will kill salmonids, and cyanobacteria will thrive. Challenges and opportunities for restoring the Eel and increasing its resilience to climate extremes, water diversions, and excessive loading of fine sediments point toward exploring how land use and terrestrial vegetation affect delivery from uplands of water, heat, sediments, solutes, organic matter, and organisms—in ways that either heal or damage rivers.},
keywords = {cyanobacteria, Eel river, ERCZO, salmonids},
pubstate = {published},
tppubtype = {article}
}
Although it flows through regions of northwestern California that are thought to be relatively well watered, the Eel River is increasingly stressed by drought and water withdrawals. We discuss how critical threshold changes in summer discharge can potentially tilt the Eel from a recovering salmon-supporting ecosystem toward a cyanobacterially degraded one. To maintain food webs and habitats that support salmonids and suppress harmful cyanobacteria, summer discharge must be sufficient to connect mainstem pools hydrologically with gently moving, cool base flow. Rearing salmon and steelhead can survive even in pools that become isolated during summer low flows if hyporheic exchange is sufficient. But if the ground water discharge that sustains river flow during summer drought drops below critical levels, warm stagnant conditions will kill salmonids, and cyanobacteria will thrive. Challenges and opportunities for restoring the Eel and increasing its resilience to climate extremes, water diversions, and excessive loading of fine sediments point toward exploring how land use and terrestrial vegetation affect delivery from uplands of water, heat, sediments, solutes, organic matter, and organisms—in ways that either heal or damage rivers.
2007
Bode, CA; Power, ME
Eel River Flipchart [2007] Technical Report
2007.
Abstract | Links | BibTeX | Tags: Eel river
@techreport{Bode2024,
title = {Eel River Flipchart [2007]},
author = {CA Bode and ME Power},
url = {https://hdl.handle.net/11299/263889},
year = {2007},
date = {2007-01-01},
urldate = {2024-06-12},
abstract = {This is a 34 page flipchart of the Angelo Reserve. Each page is an 8.5x11 map of a river segment. The maps show the location of the highest accumulated streamflow (using DEM) as the river, even though the channel is wider, and use the vegetative canopy DEM colored by vegetation height. Note the decision to use canopy instead of the traditional bare-earth is to provide visual references while out in the field. Bare-earth provides little help when maps are zoomed in this close. Laminated versions will be availible at the ACCR Science Center to be used during field sampling. Sampling sites can be drawn directly on the maps with a sharpie then removed later using alcohol. Marked up maps are to be either copied using the xerox machine, or scanned. Scanned versions can be sent to Collin Bode to convert the points into a GIS coverage.
},
howpublished = {Data Repository for the University of Minnesota (DRUM)},
keywords = {Eel river},
pubstate = {published},
tppubtype = {techreport}
}
This is a 34 page flipchart of the Angelo Reserve. Each page is an 8.5×11 map of a river segment. The maps show the location of the highest accumulated streamflow (using DEM) as the river, even though the channel is wider, and use the vegetative canopy DEM colored by vegetation height. Note the decision to use canopy instead of the traditional bare-earth is to provide visual references while out in the field. Bare-earth provides little help when maps are zoomed in this close. Laminated versions will be availible at the ACCR Science Center to be used during field sampling. Sampling sites can be drawn directly on the maps with a sharpie then removed later using alcohol. Marked up maps are to be either copied using the xerox machine, or scanned. Scanned versions can be sent to Collin Bode to convert the points into a GIS coverage.