2021
Bouma-Gregson, K; Crits-Christoph, A; Olm, MR; Power, ME; Banfield, JF
Microcoleus (Cyanobacteria) form watershed-wide populations without strong gradients in population structure Journal Article
In: Molecular Ecology, vol. 31, pp. 86-103, 2021.
Links | BibTeX | Tags: cyanobacteria, ERCZO, population ecology, population structure
@article{Bouma-Gregson2021b,
title = {Microcoleus (Cyanobacteria) form watershed-wide populations without strong gradients in population structure},
author = {K Bouma-Gregson and A Crits-Christoph and MR Olm and ME Power and JF Banfield},
url = {https://angelo.berkeley.edu/bouma-gregson_microcoleus_cyanobacteria_populations-2/},
doi = {https://doi.org/10.1111/mec.16208},
year = {2021},
date = {2021-10-04},
urldate = {2021-10-04},
journal = {Molecular Ecology},
volume = {31},
pages = {86-103},
keywords = {cyanobacteria, ERCZO, population ecology, population structure},
pubstate = {published},
tppubtype = {article}
}
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.
2019
Bouma-Gregson, Keith; Olm, Matthew R.; Probst, Alexander J.; Anantharaman, Karthik; Power, Mary E.; Banfield, Jillian F.
Impacts of microbial assemblage and environmental conditions on the distribution of anatoxin-a producing cyanobacteria within a river network Journal Article
In: The ISME Journal, vol. 13, pp. 1618–1634, 2019.
Abstract | Links | BibTeX | Tags: algae, cyanobacteria, ERCZO
@article{Bouma-Gregson2019,
title = {Impacts of microbial assemblage and environmental conditions on the distribution of anatoxin-a producing cyanobacteria within a river network},
author = {Keith Bouma-Gregson and Matthew R. Olm and Alexander J. Probst and Karthik Anantharaman and Mary E. Power and Jillian F. Banfield},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/ACFrOgCi6hBdMfYejhSBBRhowH7uEzKdYcuAjfK9v1rJWg3ajgn9fFrFZmnWAY1cjZKhRQuhAhjSjhR6b_fShyPM32lKV7Coi7lFfnbS4xgM02VVqWdiTojYom8fl1nvtqMdQfs3mn-oTmwNlMoG-1.pdf},
doi = {10.1038/s41396-019-0374-3},
year = {2019},
date = {2019-02-26},
journal = {The ISME Journal},
volume = {13},
pages = {1618–1634},
abstract = {Blooms of planktonic cyanobacteria have long been of concern in lakes, but more recently, harmful impacts of riverine benthic cyanobacterial mats been recognized. As yet, we know little about how various benthic cyanobacteria are distributed in river networks, or how environmental conditions or other associated microbes in their consortia affect their biosynthetic capacities. We performed metagenomic sequencing for 22 Oscillatoriales-dominated (Cyanobacteria) microbial mats collected across the Eel River network in Northern California and investigated factors associated with anatoxin-a producing cyanobacteria. All microbial communities were dominated by one or two cyanobacterial species, so the key mat metabolisms involve oxygenic photosynthesis and carbon oxidation. Only a few metabolisms fueled the growth of the mat communities, with little evidence for anaerobic metabolic pathways. We genomically defined four cyanobacterial species, all which shared <96% average nucleotide identity with reference Oscillatoriales genomes and are potentially novel species in the genus Microcoleus. One of the Microcoleus species contained the anatoxin-a biosynthesis genes, and we describe the first anatoxin-a gene cluster from the Microcoleus clade within Oscillatoriales. Occurrence of these four Microcoleus species in the watershed was correlated with total dissolved nitrogen and phosphorus concentrations, and the species that contains the anatoxin-a gene cluster was found in sites with higher nitrogen concentrations. Microbial assemblages in mat samples with the anatoxin-a gene cluster consistently had a lower abundance of Burkholderiales (Betaproteobacteria) species than did mats without the anatoxin-producing genes. The associations of water nutrient concentrations and certain co-occurring microbes with anatoxin-a producing Microcoleus motivate further exploration for their roles as potential controls on the distributions of toxigenic benthic cyanobacteria in river networks.},
keywords = {algae, cyanobacteria, ERCZO},
pubstate = {published},
tppubtype = {article}
}
Blooms of planktonic cyanobacteria have long been of concern in lakes, but more recently, harmful impacts of riverine benthic cyanobacterial mats been recognized. As yet, we know little about how various benthic cyanobacteria are distributed in river networks, or how environmental conditions or other associated microbes in their consortia affect their biosynthetic capacities. We performed metagenomic sequencing for 22 Oscillatoriales-dominated (Cyanobacteria) microbial mats collected across the Eel River network in Northern California and investigated factors associated with anatoxin-a producing cyanobacteria. All microbial communities were dominated by one or two cyanobacterial species, so the key mat metabolisms involve oxygenic photosynthesis and carbon oxidation. Only a few metabolisms fueled the growth of the mat communities, with little evidence for anaerobic metabolic pathways. We genomically defined four cyanobacterial species, all which shared <96% average nucleotide identity with reference Oscillatoriales genomes and are potentially novel species in the genus Microcoleus. One of the Microcoleus species contained the anatoxin-a biosynthesis genes, and we describe the first anatoxin-a gene cluster from the Microcoleus clade within Oscillatoriales. Occurrence of these four Microcoleus species in the watershed was correlated with total dissolved nitrogen and phosphorus concentrations, and the species that contains the anatoxin-a gene cluster was found in sites with higher nitrogen concentrations. Microbial assemblages in mat samples with the anatoxin-a gene cluster consistently had a lower abundance of Burkholderiales (Betaproteobacteria) species than did mats without the anatoxin-producing genes. The associations of water nutrient concentrations and certain co-occurring microbes with anatoxin-a producing Microcoleus motivate further exploration for their roles as potential controls on the distributions of toxigenic benthic cyanobacteria in river networks.
2017
Bouma-Gregson, Keith
The Ecology of Benthic Toxigenic Anabaena and Phormidium (Cyanobacteria) in the Eel River, California PhD Thesis
University of California, Berkeley, 2017, ISBN: 978-0-355-94920-9.
Abstract | BibTeX | Tags: Anabaena, Anatoxin-a, Biological sciences, cyanobacteria, Cyanotoxin, ERCZO, metagenomics, Phormidium
@phdthesis{Bouma-Gregson2017c,
title = {The Ecology of Benthic Toxigenic Anabaena and Phormidium (Cyanobacteria) in the Eel River, California},
author = {Keith Bouma-Gregson},
isbn = {978-0-355-94920-9},
year = {2017},
date = {2017-12-31},
school = {University of California, Berkeley},
abstract = {Cyanobacteria are ubiquitous in aquatic ecosystems across the earth. In many environments they are present at low abundances, however under certain environmental conditions cyanobacteria bloom and become one of the dominant organisms in an waterbody, degrading aquatic food webs and water quality. Cyanobacteria evolved over 2 billion years ago, and cyanobacterial harmful algal blooms (cyanoHABs) have been documented for decades. Of particular concern is the production of cyanotoxins, secondary metabolites toxic to humans and other organisms, by certain strains of cyanobacteria. Most research of cyanoHABs has been of planktonic blooms in lakes or estuaries, and cyanotoxin production by benthic cyanobacteria in rivers has been more recent, but in many rivers benthic cyanobacteria are the primary source of cyanotoxins. With field surveys and monitoring, manipulative field experiments, and genome-resolved metagenomics, this dissertation investigated the ecology of benthic cyanobacteria in the Eel River, California.},
keywords = {Anabaena, Anatoxin-a, Biological sciences, cyanobacteria, Cyanotoxin, ERCZO, metagenomics, Phormidium},
pubstate = {published},
tppubtype = {phdthesis}
}
Cyanobacteria are ubiquitous in aquatic ecosystems across the earth. In many environments they are present at low abundances, however under certain environmental conditions cyanobacteria bloom and become one of the dominant organisms in an waterbody, degrading aquatic food webs and water quality. Cyanobacteria evolved over 2 billion years ago, and cyanobacterial harmful algal blooms (cyanoHABs) have been documented for decades. Of particular concern is the production of cyanotoxins, secondary metabolites toxic to humans and other organisms, by certain strains of cyanobacteria. Most research of cyanoHABs has been of planktonic blooms in lakes or estuaries, and cyanotoxin production by benthic cyanobacteria in rivers has been more recent, but in many rivers benthic cyanobacteria are the primary source of cyanotoxins. With field surveys and monitoring, manipulative field experiments, and genome-resolved metagenomics, this dissertation investigated the ecology of benthic cyanobacteria in the Eel River, California.
Vadeboncoeur, Yvonne; Power, Mary
Attached Algae: The Cryptic Base of Inverted Trophic Pyramids in Freshwaters Journal Article
In: Annual Review of Ecology, Evolution, and Systematics, vol. 48, no. 1, pp. 255-279, 2017.
Abstract | Links | BibTeX | Tags: Cladophora, cyanobacteria, diatoms, ERCZO, grazers, lakes, microphytobenthos, periphyton, primary consumer, primary producer, rivers
@article{Vadeboncoeur2017,
title = {Attached Algae: The Cryptic Base of Inverted Trophic Pyramids in Freshwaters},
author = {Yvonne Vadeboncoeur and Mary Power},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Annu.-Rev.-Ecol.-Evol.-Syst.-2017-Vadeboncoeur.pdf},
doi = {https://doi.org/10.1146/annurev-ecolsys-121415-032340},
year = {2017},
date = {2017-08-11},
urldate = {2017-08-11},
journal = {Annual Review of Ecology, Evolution, and Systematics},
volume = {48},
number = {1},
pages = {255-279},
abstract = {It seems improbable that a thin veneer of attached algae coating submerged surfaces in lakes and rivers could be the foundation of many freshwater food webs, but increasing evidence from chemical tracers supports this view. Attached algae grow on any submerged surface that receives enough light for photosynthesis, but animals often graze attached algae down to thin, barely perceptible biofilms. Algae in general are more nutritious and digestible than terrestrial plants or detritus, and attached algae are particularly harvestable, being concentrated on surfaces. Diatoms, a major component of attached algal assemblages, are especially nutritious and tolerant of heavy grazing. Algivores can track attached algal productivity over a range of spatial scales and consume a high proportion of new attached algal growth in high-light, low-nutrient ecosystems. The subsequent efficient conversion of the algae into consumer production in freshwater food webs can lead to low-producer, high-consumer biomass, patterns that Elton (1927) described as inverted trophic pyramids. Human perturbations of nutrient, sediment, and carbon loading into freshwaters and of thermal and hydrologic regimes can weaken consumer control of algae and promote nuisance attached algal blooms.},
keywords = {Cladophora, cyanobacteria, diatoms, ERCZO, grazers, lakes, microphytobenthos, periphyton, primary consumer, primary producer, rivers},
pubstate = {published},
tppubtype = {article}
}
It seems improbable that a thin veneer of attached algae coating submerged surfaces in lakes and rivers could be the foundation of many freshwater food webs, but increasing evidence from chemical tracers supports this view. Attached algae grow on any submerged surface that receives enough light for photosynthesis, but animals often graze attached algae down to thin, barely perceptible biofilms. Algae in general are more nutritious and digestible than terrestrial plants or detritus, and attached algae are particularly harvestable, being concentrated on surfaces. Diatoms, a major component of attached algal assemblages, are especially nutritious and tolerant of heavy grazing. Algivores can track attached algal productivity over a range of spatial scales and consume a high proportion of new attached algal growth in high-light, low-nutrient ecosystems. The subsequent efficient conversion of the algae into consumer production in freshwater food webs can lead to low-producer, high-consumer biomass, patterns that Elton (1927) described as inverted trophic pyramids. Human perturbations of nutrient, sediment, and carbon loading into freshwaters and of thermal and hydrologic regimes can weaken consumer control of algae and promote nuisance attached algal blooms.
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.