2021
Bouma-Gregson, Keith; Power, Mary E.; Furey, Paula C.; Huckins, Casey J.; Vadeboncoeur, Yvonne
Taxon-specific photosynthetic responses of attached algal assemblages to experimental translocation between river habitats Journal Article
In: Freshwater Science, vol. 40, no. 1, 2021.
Abstract | Links | BibTeX | Tags: algae, benthic, Cladophora, cyanobacteria, electron transport rate, flow, Microcoleus, microhabitat, PAM, photosynthesis, temperature
@article{Bouma-Gregson2021,
title = {Taxon-specific photosynthetic responses of attached algal assemblages to experimental translocation between river habitats},
author = {Keith Bouma-Gregson and Mary E. Power and Paula C. Furey and Casey J. Huckins and Yvonne Vadeboncoeur},
url = {https://www.journals.uchicago.edu/doi/pdf/10.1086/713095},
doi = {10.1086/713095},
year = {2021},
date = {2021-02-25},
journal = {Freshwater Science},
volume = {40},
number = {1},
abstract = {Attached algal and cyanobacterial taxa differ in their ability to exploit and tolerate the diversity of flow, irradiance, and temperature regimes typical of a heterogeneous riverscape. Understanding the drivers of the small-scale variation in algal taxonomic composition helps us predict the riverscape-scale effects of altered flow regimes, but microhabitat-scale variation in algal taxonomy complicates the interpretation of ecosystem-scale estimates of biomass or primary production. Using pulse-amplitude modulated (PAM) fluorometry, we performed 2 manipulative field experiments (in 2014 and 2015) to measure photosynthetic responses of algae and cyanobacteria to depth, temperature, and flow modifications. In 2014, we exposed 6 attached algal assemblages common to the South Fork Eel River (California, USA) to a 24-h incubation on either the river bottom (20 cm deep) or floating at the water surface. In 2015, we incubated 3 algal assemblages for 1 wk in either the thalweg or at the river’s edge. For PAM measurements, we developed a novel method (Photosynthesis–Irradiance Periphyton Experimental System [PIPES]) for manipulating attached filamentous algae, a morphology common in aquatic habitats but underrepresented in photosynthesis experiments. To make the PIPES, we sandwiched thin (<1 mm) layers of filamentous attached algae between 2 layers of mesh so that the algae could be isolated and manipulated for repeated PAM measurements. In the 2014 experiment, incubating Cladophora, Rivularia, Microcoleus, and Anabaena at the water surface tended to decrease photosynthetic rates relative to submerged controls, whereas for Nostoc, the photosynthetic rates were higher in floating treatments. In the 2015 experiment, Cladophora and Oedogonium incubated in the warmer, low-flow river margin had persistently lower photosynthesis rates than their counterparts incubated in the thalweg. The PIPES method improves our ability to make PAM measurements on attached algae. PIPES can be used in conjunction with other methods to evaluate taxon-specific responses to environmental conditions and to help us predict how algal assemblages will shift in dominance under different river management regimes.},
keywords = {algae, benthic, Cladophora, cyanobacteria, electron transport rate, flow, Microcoleus, microhabitat, PAM, photosynthesis, temperature},
pubstate = {published},
tppubtype = {article}
}
Attached algal and cyanobacterial taxa differ in their ability to exploit and tolerate the diversity of flow, irradiance, and temperature regimes typical of a heterogeneous riverscape. Understanding the drivers of the small-scale variation in algal taxonomic composition helps us predict the riverscape-scale effects of altered flow regimes, but microhabitat-scale variation in algal taxonomy complicates the interpretation of ecosystem-scale estimates of biomass or primary production. Using pulse-amplitude modulated (PAM) fluorometry, we performed 2 manipulative field experiments (in 2014 and 2015) to measure photosynthetic responses of algae and cyanobacteria to depth, temperature, and flow modifications. In 2014, we exposed 6 attached algal assemblages common to the South Fork Eel River (California, USA) to a 24-h incubation on either the river bottom (20 cm deep) or floating at the water surface. In 2015, we incubated 3 algal assemblages for 1 wk in either the thalweg or at the river’s edge. For PAM measurements, we developed a novel method (Photosynthesis–Irradiance Periphyton Experimental System [PIPES]) for manipulating attached filamentous algae, a morphology common in aquatic habitats but underrepresented in photosynthesis experiments. To make the PIPES, we sandwiched thin (<1 mm) layers of filamentous attached algae between 2 layers of mesh so that the algae could be isolated and manipulated for repeated PAM measurements. In the 2014 experiment, incubating Cladophora, Rivularia, Microcoleus, and Anabaena at the water surface tended to decrease photosynthetic rates relative to submerged controls, whereas for Nostoc, the photosynthetic rates were higher in floating treatments. In the 2015 experiment, Cladophora and Oedogonium incubated in the warmer, low-flow river margin had persistently lower photosynthesis rates than their counterparts incubated in the thalweg. The PIPES method improves our ability to make PAM measurements on attached algae. PIPES can be used in conjunction with other methods to evaluate taxon-specific responses to environmental conditions and to help us predict how algal assemblages will shift in dominance under different river management regimes.
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.
2003
Howard, Jeanette K.; Cuffey, Kurt M.
Freshwater mussels in a California North Coast Range river: occurrence, distribution, and controls Journal Article
In: Journal of the North American Benthological Society, vol. 22, no. 1, pp. 63-77, 2003.
Abstract | Links | BibTeX | Tags: California, freshwater mussels, geomorphology, hydraulic model, hydrology, microhabitat, shear stress, South Fork Eel River
@article{Howard2003,
title = {Freshwater mussels in a California North Coast Range river: occurrence, distribution, and controls},
author = {Jeanette K. Howard and Kurt M. Cuffey},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Howard_2003_JouNorthAmerBenthoSoc.pdf},
doi = {10.2307/1467978},
year = {2003},
date = {2003-03-01},
journal = {Journal of the North American Benthological Society},
volume = {22},
number = {1},
pages = {63-77},
abstract = {We report the occurrence and habitat of mussel populations within a continuous 8-km section of the South Fork Eel River in the Northern Coast Range of California. The primary goals of our study were 1) to compile information on species composition and population density, and 2) to examine whether spatial distribution and variability were related to geomorphology and hydrology. High discharges almost certainly provide more of a constraint on the distribution and persistence of
mussels in the South Fork Eel than do low summer flows, so we used the Hydrologic Engineering Center’s River Analysis System (HEC-RAS) hydraulic model to estimate physical conditions during high flows when in-channel investigations were not feasible. We found numerous individuals of 2 species (Margaritifera falcata and Anodonta californiensis), with the spatial distribution of both species
characterized by high variability. Mussels in this system live almost exclusively in pools (with a few in runs), near the channel banks, and especially among sedge root-mat substrate. In all flow regimes (summer, winter, 5-y flood, and the largest floods on record), we found mussels in areas of lower boundary shear stresses and lower velocities. Our study suggests that, at various spatial scales, mussels appear to be distributed in a manner that protects them from the highest flow-induced stresses.},
keywords = {California, freshwater mussels, geomorphology, hydraulic model, hydrology, microhabitat, shear stress, South Fork Eel River},
pubstate = {published},
tppubtype = {article}
}
We report the occurrence and habitat of mussel populations within a continuous 8-km section of the South Fork Eel River in the Northern Coast Range of California. The primary goals of our study were 1) to compile information on species composition and population density, and 2) to examine whether spatial distribution and variability were related to geomorphology and hydrology. High discharges almost certainly provide more of a constraint on the distribution and persistence of
mussels in the South Fork Eel than do low summer flows, so we used the Hydrologic Engineering Center’s River Analysis System (HEC-RAS) hydraulic model to estimate physical conditions during high flows when in-channel investigations were not feasible. We found numerous individuals of 2 species (Margaritifera falcata and Anodonta californiensis), with the spatial distribution of both species
characterized by high variability. Mussels in this system live almost exclusively in pools (with a few in runs), near the channel banks, and especially among sedge root-mat substrate. In all flow regimes (summer, winter, 5-y flood, and the largest floods on record), we found mussels in areas of lower boundary shear stresses and lower velocities. Our study suggests that, at various spatial scales, mussels appear to be distributed in a manner that protects them from the highest flow-induced stresses.
mussels in the South Fork Eel than do low summer flows, so we used the Hydrologic Engineering Center’s River Analysis System (HEC-RAS) hydraulic model to estimate physical conditions during high flows when in-channel investigations were not feasible. We found numerous individuals of 2 species (Margaritifera falcata and Anodonta californiensis), with the spatial distribution of both species
characterized by high variability. Mussels in this system live almost exclusively in pools (with a few in runs), near the channel banks, and especially among sedge root-mat substrate. In all flow regimes (summer, winter, 5-y flood, and the largest floods on record), we found mussels in areas of lower boundary shear stresses and lower velocities. Our study suggests that, at various spatial scales, mussels appear to be distributed in a manner that protects them from the highest flow-induced stresses.