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[D-Leu1]MC-LY (1) ([M + H]+ m/z 1044.5673, Δ 2.0 ppm), a new microcystin, was isolated from Microcystis aeruginosa strain CPCC-464. The compound was characterized by 1H and 13C NMR spectroscopy, liquid chromatography–high resolution tandem mass spectrometry (LC–HRMS/MS) and UV spectroscopy. A calibration reference material was produced after quantitation by 1H NMR spectroscopy and LC with chemiluminescence nitrogen detection. The potency of 1 in a protein phosphatase 2A inhibition assay was essentially the same as for MC-LR (2). Related microcystins, [D-Leu1]MC-LR (3) ([M + H]+ m/z 1037.6041, Δ 1.0 ppm), [D-Leu1]MC-M(O)R (6) ([M + H]+ m/z 1071.5565, Δ 2.0 ppm) and [D-Leu1]MC-MR (7) ([M + H]+ m/z 1055.5617, Δ 2.2 ppm), were also identified in culture extracts, along with traces of [D-Leu1]MC-M(O2)R (8) ([M + H]+ m/z 1087.5510, Δ 1.6 ppm), by a combination of chemical derivatization and LC–HRMS/MS experiments. The relative abundances of 1, 3, 6, 7 and 8 in a freshly extracted culture in the positive ionization mode LC–HRMS were ca. 84, 100, 3.0, 11 and 0.05, respectively. These and other results indicate that [D-Leu1]-containing MCs may be more common in cyanobacterial blooms than is generally appreciated but are easily overlooked with standard targeted LC–MS/MS screening methods.
Patricia Leblanc; Nadine Merkley; Krista Thomas; Nancy I. Lewis; Khalida Békri; Susan LeBlanc Renaud; Frances R. Pick; Pearse McCarron; Christopher O. Miles; Michael A. Quilliam. Isolation and Characterization of [D-Leu1]microcystin-LY from Microcystis aeruginosa CPCC-464. Toxins 2020, 12, 77 .
AMA StylePatricia Leblanc, Nadine Merkley, Krista Thomas, Nancy I. Lewis, Khalida Békri, Susan LeBlanc Renaud, Frances R. Pick, Pearse McCarron, Christopher O. Miles, Michael A. Quilliam. Isolation and Characterization of [D-Leu1]microcystin-LY from Microcystis aeruginosa CPCC-464. Toxins. 2020; 12 (2):77.
Chicago/Turabian StylePatricia Leblanc; Nadine Merkley; Krista Thomas; Nancy I. Lewis; Khalida Békri; Susan LeBlanc Renaud; Frances R. Pick; Pearse McCarron; Christopher O. Miles; Michael A. Quilliam. 2020. "Isolation and Characterization of [D-Leu1]microcystin-LY from Microcystis aeruginosa CPCC-464." Toxins 12, no. 2: 77.
Cyanobacteria are notorious for their potential to produce hepatotoxic microcystins (MCs), but other bioactive compounds synthesized in the cells could be as toxic, and thus present interest for characterization. Ultra performance liquid chromatography and high-resolution accurate mass spectrometry (UPLC-QTOF-MS/MS) combined with untargeted analysis was used to compare the metabolomes of five different strains of the common bloom-forming cyanobacterium, Microcystis aeruginosa. Even in microcystin-producing strains, other classes of oligopeptides including cyanopeptolins, aeruginosins, and aerucyclamides, were often the more dominant compounds. The distinct and large variation between strains of the same widespread species highlights the need to characterize the metabolome of a larger number of cyanobacteria, especially as several metabolites other than microcystins can affect ecological and human health.
Marianne Racine; Ammar Saleem; Frances R. Pick. Metabolome Variation between Strains of Microcystis aeruginosa by Untargeted Mass Spectrometry. Toxins 2019, 11, 723 .
AMA StyleMarianne Racine, Ammar Saleem, Frances R. Pick. Metabolome Variation between Strains of Microcystis aeruginosa by Untargeted Mass Spectrometry. Toxins. 2019; 11 (12):723.
Chicago/Turabian StyleMarianne Racine; Ammar Saleem; Frances R. Pick. 2019. "Metabolome Variation between Strains of Microcystis aeruginosa by Untargeted Mass Spectrometry." Toxins 11, no. 12: 723.
Cyanobacterial blooms increasingly impair inland waters, with the potential for a concurrent increase in cyanotoxins that have been linked to animal and human mortalities. Microcystins (MCs) are among the most commonly detected cyanotoxins, but little is known about the distribution of different MC congeners despite large differences in their biomagnification, persistence, and toxicity. Using raw-water intake data from sites around the Great Lakes basin, we applied multivariate canonical analyses and regression tree analyses to identify how different congeners (MC-LA, -LR, -RR, and -YR) varied with changes in meteorological and nutrient conditions over time (10 years) and space (longitude range: 77°2'60 to 94°29'23 W). We found that MC-LR was associated with strong winds, warm temperatures, and nutrient-rich conditions, whereas the equally toxic yet less commonly studied MC-LA tended to dominate under intermediate winds, wetter, and nutrient-poor conditions. A global synthesis of lake data in the peer-reviewed literature showed that the composition of MC congeners differs among regions, with MC-LA more commonly reported in North America than Europe. Global patterns of MC congeners tended to vary with lake nutrient conditions and lake morphometry. Ultimately, knowledge of the environmental factors leading to the formation of different MC congeners in freshwaters is necessary to assess the duration and degree of toxin exposure under future global change.
Zofia E. Taranu; Frances R. Pick; Irena F. Creed; Arthur Zastepa; Sue B. Watson. Meteorological and Nutrient Conditions Influence Microcystin Congeners in Freshwaters. Toxins 2019, 11, 620 .
AMA StyleZofia E. Taranu, Frances R. Pick, Irena F. Creed, Arthur Zastepa, Sue B. Watson. Meteorological and Nutrient Conditions Influence Microcystin Congeners in Freshwaters. Toxins. 2019; 11 (11):620.
Chicago/Turabian StyleZofia E. Taranu; Frances R. Pick; Irena F. Creed; Arthur Zastepa; Sue B. Watson. 2019. "Meteorological and Nutrient Conditions Influence Microcystin Congeners in Freshwaters." Toxins 11, no. 11: 620.
Pilon S, Zastepa A, Taranu ZE, Gregory-Eaves I, Racine M, Blais JM, Poulain AJ, Pick FR. 2018. Contrasting histories of microcystin-producing cyanobacteria in two temperate lakes as inferred from quantitative sediment DNA analyses. Lake Reserv Manage. XX:XXX–XXX. The incidence and abundance of microcystin-producing cyanobacteria were compared between 2 temperate lakes over the past ∼150–175 yr by combining analyses of sediment DNA (qPCR of 4 target genes and high-throughput sequencing of a cyanobacterial 16S rRNA gene fragment) and sediment microcystin concentrations. In Lake of the Woods (LoW), toxic cyanobacteria were only detected beginning in the early 1980s based on gene copy numbers of the microcystin-synthesizing gene (mcyD), and by the early 2000s based on sediment microcystins; both these proxies for toxic cyanobacteria were significantly correlated. In contrast, in Baptiste Lake (Alberta), both mcyD gene copy numbers and microcystins were detected as far back as ∼1830, before European settlement of the region. Total sediment microcystins in this lake were not correlated with mcyD gene copy numbers, but the latter correlated with 2 other cyanobacterial genes targeted. These results point to a relatively recent emergence and increasing dominance of microcystin-producing cyanobacteria in LoW that coincides with the documented rise in regional temperatures rather than changes in nutrient loading. In contrast, toxic blooms are not a new phenomenon in Baptiste Lake, as microcystin-producing cyanobacteria were clearly part of the ecosystem prior to anthropogenic perturbations; this lake has also experienced a recent increase in microcystins coincident with further nutrient enrichment. High-throughput sequencing of the cyanobacterial 16S rRNA gene indicated that bloom-forming and potentially toxigenic Dolichospermum (including related Nostocales) and Microcystis were present but the former has been the dominant genus over the past 175 yr.
Shinjini Pilon; Arthur Zastepa; Zofia E. Taranu; Irene Gregory-Eaves; Marianne Racine; Jules M. Blais; Alexandre Poulain; Frances R. Pick. Contrasting histories of microcystin-producing cyanobacteria in two temperate lakes as inferred from quantitative sediment DNA analyses. Lake and Reservoir Management 2019, 35, 102 -117.
AMA StyleShinjini Pilon, Arthur Zastepa, Zofia E. Taranu, Irene Gregory-Eaves, Marianne Racine, Jules M. Blais, Alexandre Poulain, Frances R. Pick. Contrasting histories of microcystin-producing cyanobacteria in two temperate lakes as inferred from quantitative sediment DNA analyses. Lake and Reservoir Management. 2019; 35 (1):102-117.
Chicago/Turabian StyleShinjini Pilon; Arthur Zastepa; Zofia E. Taranu; Irene Gregory-Eaves; Marianne Racine; Jules M. Blais; Alexandre Poulain; Frances R. Pick. 2019. "Contrasting histories of microcystin-producing cyanobacteria in two temperate lakes as inferred from quantitative sediment DNA analyses." Lake and Reservoir Management 35, no. 1: 102-117.
The herbicide diquat dibromide is used in North America to manage nuisance macrophytes. However, its effect on native macrophytes is less clear and it could cause indirect effects on other aquatic biota. This study determined the sensitivity of both native and non-native macrophytes grown in test systems with varying complexity to diquat dibromide applied directly to water following label directions. In an outdoor mesocosm experiment and single species greenhouse concentration-response tests, Elodea canadensis Michx., Myriophyllum spicatum L., Ceratophyllum demersum L. and Hydrocharis morsus-ranae L. were exposed to a range of diquat dibromide concentrations (4.7 – 1153 µg/L), corresponding to 0.4 – 100% of the recommended label rate of the formulated product. The mesocosm experiment contained all four plant taxa in the same system along with caged amphipods (Hyalella azteca Saus.), tadpoles (Lithobates pipiens Schreber), phytoplankton and periphyton; however, this study focuses on the macrophytes only. In both test systems, severe direct effects of diquat dibromide on macrophytes were detected, with almost 100% mortality of all macrophytes in both test systems at 74 µg/L. The most sensitive species in the single species tests, E. canadensis, showed almost 100% mortality at concentrations below the HPLC-based method detection limit of 5 µg/L. Effects occurred very rapidly and showed no difference in severity between native and non-native macrophytes or complexity of test systems. These results suggest that diquat dibromide could be applied at a considerably lower label rate, depending on the characteristics of the waterbody, while still achieving effective control of nuisance macrophytes.
V. Sesin; R.L. Dalton; C. Boutin; S.A. Robinson; Adrienne Bartlett; Frances Pick. Macrophytes are highly sensitive to the herbicide diquat dibromide in test systems of varying complexity. Ecotoxicology and Environmental Safety 2018, 165, 325 -333.
AMA StyleV. Sesin, R.L. Dalton, C. Boutin, S.A. Robinson, Adrienne Bartlett, Frances Pick. Macrophytes are highly sensitive to the herbicide diquat dibromide in test systems of varying complexity. Ecotoxicology and Environmental Safety. 2018; 165 ():325-333.
Chicago/Turabian StyleV. Sesin; R.L. Dalton; C. Boutin; S.A. Robinson; Adrienne Bartlett; Frances Pick. 2018. "Macrophytes are highly sensitive to the herbicide diquat dibromide in test systems of varying complexity." Ecotoxicology and Environmental Safety 165, no. : 325-333.
Stormwater retention ponds can play a critical role in mitigating the detrimental effects of urbanization on receiving waters that result from increases in polluted runoff. However, the benthic oxygen demand of stormwater facilities may cause significant hypoxia and trigger the production of hydrogen sulfide (H2S). This process is not well-documented and further research is needed to characterize benthic processes in stormwater retention ponds in order to improve their design and operation. In this study, sediment oxygen demand (SOD), sediment ammonia release (SAR) and sediment sulfide production (SSP) kinetics were characterized in situ and in the laboratory. In situ SOD and SSP data were utilized to develop a stormwater retention pond water sulfide concentration model which demonstrates strong correlation with sulfide concentrations observed in situ (r = 0.724, N = 91, p < 0.001) and in laboratory experiments (r = 0.691, N = 38, p < 0.001). At 4 °C, in situ rates of SOD, SAR and SSP were higher than those measured in laboratory. Sulfate-reducing bacteria (SRB) represented 4.99% of the bacteria present in the top 30 cm of the pond sediment, with Desulfobulbaceae spp., Desulfobacteraceae spp. and Desulfococcus spp. being the dominant SRB taxa identified.
Patrick M. D'Aoust; Frances Pick; R. Wang; Alexandre Poulain; C. Rennie; L. Chen; C. Kinsley; R. Delatolla. Sulfide production kinetics and model of stormwater retention ponds. Water Science and Technology 2018, 77, 2377 -2387.
AMA StylePatrick M. D'Aoust, Frances Pick, R. Wang, Alexandre Poulain, C. Rennie, L. Chen, C. Kinsley, R. Delatolla. Sulfide production kinetics and model of stormwater retention ponds. Water Science and Technology. 2018; 77 (10):2377-2387.
Chicago/Turabian StylePatrick M. D'Aoust; Frances Pick; R. Wang; Alexandre Poulain; C. Rennie; L. Chen; C. Kinsley; R. Delatolla. 2018. "Sulfide production kinetics and model of stormwater retention ponds." Water Science and Technology 77, no. 10: 2377-2387.
David R.S. Lean; William J. Cooper; Frances R. Pick. Hydrogen Peroxide Formation and Decay in Lake Waters. Aquatic and Surface Photochemistry 2018, 207 -214.
AMA StyleDavid R.S. Lean, William J. Cooper, Frances R. Pick. Hydrogen Peroxide Formation and Decay in Lake Waters. Aquatic and Surface Photochemistry. 2018; ():207-214.
Chicago/Turabian StyleDavid R.S. Lean; William J. Cooper; Frances R. Pick. 2018. "Hydrogen Peroxide Formation and Decay in Lake Waters." Aquatic and Surface Photochemistry , no. : 207-214.
Improper design and maintenance of stormwater ponds (SWPs) may lead to hypoxic conditions, poor water quality and the production of hydrogen sulfide (H2S). The objective of this study is to develop a comprehensive understanding of hypoxic conditions of SWPs, with a focus on the potential for H2S production and emission. This study was conducted at two retention SWPs in Ottawa, Canada; a problematic pond with the propensity for H2S emission and a reference pond that did not demonstrate H2S emission. The investigation illustrated a significant impact of low dissolved oxygen (DO) concentrations, hypoxic conditions, on the concentration of total sulfides in the water column. Both ponds were shown to periodically experience hypoxic conditions at depth, especially during summer periods with less precipitation and across longer periods of winter, ice-covered conditions. The problem pond, however, was shown to experience lower DO and longer hypoxic conditions than the reference pond in both non-ice-covered and ice-covered conditions due to greater depth and a longer hydraulic retention time. Hypoxic conditions were initiated at the deepest locations in the problem pond and subsequently were spread across the entirety of the pond under winter, ice-covered conditions. Algal biomass (Chlorophyll-a) and soluble biochemical oxygen demand concentrations were shown to not likely be significant factors in the development of hypoxia in the H2S-generating pond. Algal blooms of colonial Chrysophyceae, Synura, a known mixotroph, were observed during ice-covered conditions in the problem pond possibly due to stress-coping mechanisms of algae.
Liyu Chen; Robert Delatolla; Patrick M. D’Aoust; Ru Wang; Frances Pick; Alexandre Poulain; Colin D. Rennie. Hypoxic conditions in stormwater retention ponds: potential for hydrogen sulfide emission. Environmental Technology 2017, 40, 642 -653.
AMA StyleLiyu Chen, Robert Delatolla, Patrick M. D’Aoust, Ru Wang, Frances Pick, Alexandre Poulain, Colin D. Rennie. Hypoxic conditions in stormwater retention ponds: potential for hydrogen sulfide emission. Environmental Technology. 2017; 40 (5):642-653.
Chicago/Turabian StyleLiyu Chen; Robert Delatolla; Patrick M. D’Aoust; Ru Wang; Frances Pick; Alexandre Poulain; Colin D. Rennie. 2017. "Hypoxic conditions in stormwater retention ponds: potential for hydrogen sulfide emission." Environmental Technology 40, no. 5: 642-653.
Zastepa A, Pick FR, Blais JM. 2017. Distribution and flux of microcystin congeners in lake sediments. Lake Reserv Manage. 33:444–451. Sediment concentrations of microcystin congeners and exchange across the sediment–water interface were determined in Lake of the Woods, a large water body between Canada and the United States experiencing cyanobacterial blooms. Dated sediment cores were used to examine historical occurrence of microcystins and showed that microcystins were below detection prior to the 2000s. In more recent sediments the most abundant congeners were MC-LA and -LR with -RR, -YR, -7dmLR, -WR, -LF, -LY, and -LW also present. MC-LA and -LR were also distributed in the pore waters whereas MC-RR and -YR were more strongly adsorbed to sediment particles. Sediment burial rates for MC-LA and -LR were determined from the product of the microcystin concentration on sediment particles (ng/g dw) and the burial rate (based on 210Pb radiochronology [g/m2/d]). Diffusion from sediments was estimated from the concentration gradient between pore water of surficial sediments and overlying water using Fick's first law. Overall, burial rates were low across sites (2.6 to 298.1 ng/m2/d) when compared to diffusion of microcystins from sediments to overlying water (303.1 to 1078.0 ng/m2/d) suggesting that sediments can be a source of microcystins to the water column. However, the relatively high diffusive flux may be short term and the result of a temporal disconnect between water column productivity and sediment processes. The higher diffusion fluxes and lower burial rates of MC-LA compared to MC-LR point to differences in environmental fate. Given that microcystin congeners vary in their toxicity, these results highlight the need for congener-specific measurements of environmental fate and persistence.
Arthur Zastepa; France R. Pick; Jules M. Blais. Distribution and flux of microcystin congeners in lake sediments. Lake and Reservoir Management 2017, 33, 444 -451.
AMA StyleArthur Zastepa, France R. Pick, Jules M. Blais. Distribution and flux of microcystin congeners in lake sediments. Lake and Reservoir Management. 2017; 33 (4):444-451.
Chicago/Turabian StyleArthur Zastepa; France R. Pick; Jules M. Blais. 2017. "Distribution and flux of microcystin congeners in lake sediments." Lake and Reservoir Management 33, no. 4: 444-451.
This lecture (∼ 45-55 slides) will be aimed at senior undergraduate students and graduate students in aquatic sciences with little background in phycology. This lecture could be used in a Aquatic Ecology or Sciences (Limnology) course, an Ecology course, a Phycology course, Environmental Science.Cyanobacteria that may lead to blooms encompass a wide range of different functional groups. We will present:1) the evolutionary history of cyanobacteria (2-3 slides) (this helps explain some of their present-day traits)2) basic biology and physiological/ecological traits of planktonic cyanobacteria that are most often associated with visible biomass accumulations (“blooms”) in freshwater/brackish systems of various regions of the world. Traits to be considered include: capacity for N fixation, nutrient uptake and storage (C, N, P), siderochromes, buoyancy regulation (gas vacuoles, mucilage), life cycles, growth rates vs. loss rates (resistance to grazing), allelopathy (negative vs. positive biotic interactions) Functional groups. Planktonic genera may also produce toxins, contributing to harmful algal blooms. (∼12-14 slides).3) Cyanotoxins: the principal types of toxins produced and their effects (persistence) will be compared, along with theories as to the biological function of these compounds. (∼ 6 slides)4) Specific case studies of blooms types under different climates: e.g. scum-forming, metalimnetic, dispersed (∼6)5) The factors that appear to explain and control cyanobacterial dominance will be presented, including nutrient effects, temperature, and food chain changes. These factors vary across temporal and spatial scales. Evidence for eutrophication and climate change in mediating directly or indirectly the frequency and severity of freshwater cyanobacterial blooms will be considered (∼8-10).6) Research avenues Controversial or unresolved topics: e.g. invasiveness?, cosmopolitan or geographically restricted (e.g. endemism? in hot spring taxa), toxin concerns and bioaccumulation), nitrogen fixation (“pretenders”), nutrient stoichiometry. Unexplored diversity at different levels (molecular, chemical, taxonomic), techniques for controlling cyanobacteria blooms, the future for cyanobacteria under climate change scenarios (∼4)7) General references, web resourcess and primary articles. (∼2)8) Questions and potential experiments for instructors and students will be provided at the end of the lecture (supplementary slides).
Sylvia Bonilla; Frances R. Pick. Freshwater bloom-forming cyanobacteria and anthropogenic change. Limnology and Oceanography e-Lectures 2017, 7, 1 -62.
AMA StyleSylvia Bonilla, Frances R. Pick. Freshwater bloom-forming cyanobacteria and anthropogenic change. Limnology and Oceanography e-Lectures. 2017; 7 (2):1-62.
Chicago/Turabian StyleSylvia Bonilla; Frances R. Pick. 2017. "Freshwater bloom-forming cyanobacteria and anthropogenic change." Limnology and Oceanography e-Lectures 7, no. 2: 1-62.
Sulfide production in stormwater ponds is a result of increased ubiquitous SRB activity. Stormwater retention ponds have become an integral component of stormwater management across the world. Under prolonged hypoxia, these ponds are capable of releasing large quantities of hydrogen sulfide (H 2 S) gas. In this study, water quality constituents and bacterial communities in sediment were analyzed in two stormwater retention ponds, RSP1 (reference pond) and RSP2 (problematic pond) over a period of two years, to identify the factors driving H 2 S production and understand the microbial community associated with H 2 S production in stormwater ponds. It was found that the background total sulfide concentrations were not statistically different between the two ponds during summer (RSP2: 0.012 ± 0.001 mg L-S −1 ; RSP1: 0.010 ± 0.001 mg L-S −1 ) and were statistically different during ice covered winter operation (RSP2: 6.375 ± 1.135 mg L-S −1 ; RSP1: 0.016 ± 0.009 mg L-S −1 ). The study showed a lack of correlation between total sulfide concentrations in RSP2 and soluble chemical oxygen demand, sulfate, soluble total phosphorus, total ammonia nitrogen, nitrate, nitrite and pH. However, DO concentrations demonstrated a strong negative correlation with total sulfides concentrations in RSP2 ( p < 0.006, r = −0.58, n = 26), which confirmed DO as the critical water quality parameter linked to H 2 S production in stormwater ponds. Finally, it was found that seasonal change, ice covered versus non-ice covered operation and a comparison between a H 2 S emitting pond and non-emitting pond all did not promote a measurable proliferation of sulfate-reducing bacteria nor a community shift in the sulfate-reducing bacterial population. Hence, the study demonstrates that sulfide production is a result of increased ubiquitous SRB activity in stormwater retention ponds and the emission of H 2 S gas is not indicative of SRB proliferation or a population shift towards specific SRB taxa.
Patrick M. D'aoust; Robert Delatolla; Alexandre Poulain; Galen Guo; Ru Wang; Colin Rennie; Liyu Chen; Frances R. Pick. Emerging investigators series: hydrogen sulfide production in municipal stormwater retention ponds under ice covered conditions: a study of water quality and SRB populations. Environmental Science: Water Research & Technology 2017, 3, 686 -698.
AMA StylePatrick M. D'aoust, Robert Delatolla, Alexandre Poulain, Galen Guo, Ru Wang, Colin Rennie, Liyu Chen, Frances R. Pick. Emerging investigators series: hydrogen sulfide production in municipal stormwater retention ponds under ice covered conditions: a study of water quality and SRB populations. Environmental Science: Water Research & Technology. 2017; 3 (4):686-698.
Chicago/Turabian StylePatrick M. D'aoust; Robert Delatolla; Alexandre Poulain; Galen Guo; Ru Wang; Colin Rennie; Liyu Chen; Frances R. Pick. 2017. "Emerging investigators series: hydrogen sulfide production in municipal stormwater retention ponds under ice covered conditions: a study of water quality and SRB populations." Environmental Science: Water Research & Technology 3, no. 4: 686-698.
Historically, a morphological species concept has applied shape subjectively in the delimitation of diatom species. This has led to confusion between taxa within the benthic diatom genus Neidium. Samples from Ontario, Quebec, Nova Scotia, Newfoundland (Canada) and New York (USA) were examined for Neidium taxa under LM and SEM. Fourier shape analysis showed that shape as a taxonomic character was not able to discern all species. Isolated individuals from the samples were amplified and sequenced for three chloroplast molecular markers (rbcL, psbC, and psbA) and one nuclear ribosomal molecular marker (18S). Phylogenetic reconstructions were completed with the concatenated chloroplast and 18S dataset using Maximum Likelihood and Bayesian analyses. The concatenated chloroplast dataset exhibited a species-level resolution phylogeny of Neidium taxa. The 18S dataset had a lower level of sequence divergence and was unable to differentiate between Neidium taxa. We present emended species descriptions and sequence data for four previously described species: Neidium sacoense, N. longiceps, N. fossum, and N. affine. We describe three novel species (Neidium lowei, N. promontorium, and N. potapovae) and identify two forms with unique molecular signatures. The distinguishing features of N. lowei are its size, valve shape, and longitudinal canal structure. Distinguishing features of N. promontorium are its valve shape, longitudinal canal and apex formation, and surface depression along the axial area. Neidium potapovae is distinguished by its size, formation of valve and apices and single longitudinal canal. This paper demonstrates how future phylogenetic treatments using single cell multigene sequencing can help resolve taxonomic confusion within diatoms.
Keely E. Lefebvre; Paul B. Hamilton; Frances Pick. A comparison of molecular markers and morphology for Neidium taxa (Bacillariophyta) from eastern North America. Journal of Phycology 2017, 53, 680 -702.
AMA StyleKeely E. Lefebvre, Paul B. Hamilton, Frances Pick. A comparison of molecular markers and morphology for Neidium taxa (Bacillariophyta) from eastern North America. Journal of Phycology. 2017; 53 (3):680-702.
Chicago/Turabian StyleKeely E. Lefebvre; Paul B. Hamilton; Frances Pick. 2017. "A comparison of molecular markers and morphology for Neidium taxa (Bacillariophyta) from eastern North America." Journal of Phycology 53, no. 3: 680-702.
Based on an analysis of sediment cores from Baptiste Lake (Alberta, Canada), we quantified century-scale trends in cyanobacteria and cyanotoxins, and identified possible drivers of toxigenic cyanobacteria. We measured concentrations of microcystins and pigments preserved in the sediment as proxies of toxigenic cyanobacteria and phytoplankton communities, respectively, while fossil diatom assemblages were used to infer past nutrient concentrations. Microcystins were detected in older sediments (ca. 1800s), pre-dating any significant alteration to the watershed. This demonstrates that toxigenic cyanobacteria may not be a recent phenomenon in eutrophic ecosystems. The dominant variants of microcystin throughout the sediment core were microcystin-LA and microcystin-LR. Other congeners including -LY, -7dmLR, -WR, -LF, -YR, and -LW (-RR was not detected) were mainly found in the upper layers of sediment (post 1980s). Starting in the 1990s, concentrations of microcystins both in the water column and in the sediment record increased in parallel. Total sediment microcystins were strongly correlated with historical nitrogen and phosphorus concentrations inferred from diatom assemblages (r = 0.80–0.81, p < 0.001, n = 22); both nutrients increased over the past two decades coincident with the intensification of agriculture. Microcystins also tracked the rise in cyanobacterial pigments present throughout the core. In contrast, we found no relationship between climate-related variables and sediment microcystin concentrations, although such relationships were detected over the monitoring record with respect to water column concentrations. Overall, the rise in sediment microcystins was much greater than the rise in sediment cyanobacteria and diatom inferred nutrient concentrations. Furthermore, we demonstrate that the reconstruction of the microcystin sediment record can provide important insight for the development of realistic lake management goals. Applying this analytical approach to different lakes and regions of the world, where both natural and anthropogenic gradients vary, has the potential to markedly improve our understanding of long-term drivers of cyanotoxin production.
Arthur Zastepa; Z.E. Taranu; L.E. Kimpe; Jules Blais; Irene Gregory-Eaves; Ron Zurawell; Frances Pick. Reconstructing a long-term record of microcystins from the analysis of lake sediments. Science of The Total Environment 2016, 579, 893 -901.
AMA StyleArthur Zastepa, Z.E. Taranu, L.E. Kimpe, Jules Blais, Irene Gregory-Eaves, Ron Zurawell, Frances Pick. Reconstructing a long-term record of microcystins from the analysis of lake sediments. Science of The Total Environment. 2016; 579 ():893-901.
Chicago/Turabian StyleArthur Zastepa; Z.E. Taranu; L.E. Kimpe; Jules Blais; Irene Gregory-Eaves; Ron Zurawell; Frances Pick. 2016. "Reconstructing a long-term record of microcystins from the analysis of lake sediments." Science of The Total Environment 579, no. : 893-901.
Algal bloom reports are on the rise across Canada. While eutrophication is the main driver, other stressors of aquatic ecosystems, specifically climate change and food web alterations from the spread of invasive species and overfishing, are compounding factors acting in concert or independently. Current models can predict the average algal and cyanobacterial biomass concentrations across temperate lakes as a function of nutrients, but models to specifically predict harmful algal composition and toxicity are lacking. At the within-lake scale, where management occurs, strong year to year variations in cyanobacterial blooms remain challenging to explain, let alone predict. The most common cyanotoxins, the hepatotoxic microcystins, are chemically diverse with some variants more toxic than others and with greater propensity for persistence and bioaccumulation. These differences have been largely overlooked, as current guidelines have been based on microcystin-LR, considered the most common variant. Microcystin-LA is also encountered in Canadian waters and appears to exhibit greater persistence and bioaccumulation. With cyanobacterial blooms most likely to increase across the country, including the north, guidelines and policies for cyanotoxins in drinking and recreational waters as well as fish will need to be developed for the protection of ecosystem and human health. Ultimately, control of eutrophication is the most important option for managing toxic cyanobacterial blooms; nitrogen and phosphorus need to be considered as environmental contaminants, as both play a role in controlling the dominance of toxigenic cyanobacteria.
Frances Pick. Blooming algae: a Canadian perspective on the rise of toxic cyanobacteria. Canadian Journal of Fisheries and Aquatic Sciences 2016, 73, 1149 -1158.
AMA StyleFrances Pick. Blooming algae: a Canadian perspective on the rise of toxic cyanobacteria. Canadian Journal of Fisheries and Aquatic Sciences. 2016; 73 (7):1149-1158.
Chicago/Turabian StyleFrances Pick. 2016. "Blooming algae: a Canadian perspective on the rise of toxic cyanobacteria." Canadian Journal of Fisheries and Aquatic Sciences 73, no. 7: 1149-1158.
Agrochemicals, including fertilizers and herbicides, are significant contributors of non-point source pollution to surface waters and have the potential to negatively affect periphyton. We characterized periphyton communities using pigment markers to assess the effects of nutrient enrichment and the herbicide atrazine with in situ experimental manipulations and by examining changes in community structure along existing agrochemical gradients. In 2008, the addition of nutrients (20 mg/L nitrate and 1.25 mg/L reactive phosphate), atrazine (20 μg/L) and a combination of both nutrients and atrazine had no significant effect on periphyton biomass or community structure in a stream periphytometer experiment. In 2009, similar experiments with higher concentrations of atrazine (200 μg/L) at two stream sites led to some minor effects. In contrast, at the watershed scale (2010) periphyton biomass (mg/m(2) chlorophyll a) increased significantly along correlated gradients of nitrate and atrazine but no direct effects of reactive phosphate were observed. Across the watershed, the average periphyton community was composed of Bacillariophyceae (60.9%), Chlorophyceae (28.1%), Cryptophyceae (6.9%) and Euglenophyceae (4.1%), with the Bacillariophyceae associated with high turbidity and the Chlorophyceae with nitrate enrichment. Overall, effects of nitrate on periphyton biomass and community structure superseded effects of reactive phosphate and atrazine.
Rebecca L. Dalton; Céline Boutin; Frances R. Pick. Determining in situ periphyton community responses to nutrient and atrazine gradients via pigment analysis. Science of The Total Environment 2015, 515-516, 70 -82.
AMA StyleRebecca L. Dalton, Céline Boutin, Frances R. Pick. Determining in situ periphyton community responses to nutrient and atrazine gradients via pigment analysis. Science of The Total Environment. 2015; 515-516 ():70-82.
Chicago/Turabian StyleRebecca L. Dalton; Céline Boutin; Frances R. Pick. 2015. "Determining in situ periphyton community responses to nutrient and atrazine gradients via pigment analysis." Science of The Total Environment 515-516, no. : 70-82.
The fate and persistence of microcystin cyanotoxins in aquatic ecosystems remains poorly understood in part due to the lack of analytical methods for microcystins in sediments. Existing methods have been limited to the extraction of a few extracellular microcystins of similar chemistry. We developed a single analytical method, consisting of accelerated solvent extraction, hydrophilic-lipophilic balance solid phase extraction, and reversed phase high performance liquid chromatography-tandem mass spectrometry, suitable for the extraction and quantitation of both intracellular and extracellular cyanotoxins in sediments as well as pore waters. Recoveries of nine microcystins, representing the chemical diversity of microcystins, and nodularin (a marine analogue) ranged between 75 and 98% with one, microcystin-RR (MC-RR), at 50%. Chromatographic separation of these analytes was achieved within 7.5 min and the method detection limits were between 1.1 and 2.5 ng g(-1) dry weight (dw). The robustness of the method was demonstrated on sediment cores collected from seven Canadian lakes of diverse geography and trophic states. Individual microcystin variants reached a maximum concentration of 829 ng g(-1) dw on sediment particles and 132 ng mL(-1) in pore waters and could be detected in sediments as deep as 41 cm (>100 years in age). MC-LR, -RR, and -LA were more often detected while MC-YR, -LY, -LF, and -LW were less common. The analytical method enabled us to estimate sediment-pore water distribution coefficients (K(d)), MC-RR had the highest affinity for sediment particles (log K(d)=1.3) while MC-LA had the lowest affinity (log K(d)=-0.4), partitioning mainly into pore waters. Our findings confirm that sediments serve as a reservoir for microcystins but suggest that some variants may diffuse into overlying water thereby constituting a new route of exposure following the dissipation of toxic blooms. The method is well suited to determine the fate and persistence of different microcystins in aquatic systems.
Arthur Zastepa; Frances Pick; Jules Blais; Ammar Saleem. Analysis of intracellular and extracellular microcystin variants in sediments and pore waters by accelerated solvent extraction and high performance liquid chromatography-tandem mass spectrometry. Analytica Chimica Acta 2015, 872, 26 -34.
AMA StyleArthur Zastepa, Frances Pick, Jules Blais, Ammar Saleem. Analysis of intracellular and extracellular microcystin variants in sediments and pore waters by accelerated solvent extraction and high performance liquid chromatography-tandem mass spectrometry. Analytica Chimica Acta. 2015; 872 ():26-34.
Chicago/Turabian StyleArthur Zastepa; Frances Pick; Jules Blais; Ammar Saleem. 2015. "Analysis of intracellular and extracellular microcystin variants in sediments and pore waters by accelerated solvent extraction and high performance liquid chromatography-tandem mass spectrometry." Analytica Chimica Acta 872, no. : 26-34.
Rebecca L. Dalton; Céline Boutin; Frances R. Pick. Nutrients override atrazine effects on riparian and aquatic plant community structure in a North American agricultural catchment. Freshwater Biology 2015, 60, 1292 -1307.
AMA StyleRebecca L. Dalton, Céline Boutin, Frances R. Pick. Nutrients override atrazine effects on riparian and aquatic plant community structure in a North American agricultural catchment. Freshwater Biology. 2015; 60 (7):1292-1307.
Chicago/Turabian StyleRebecca L. Dalton; Céline Boutin; Frances R. Pick. 2015. "Nutrients override atrazine effects on riparian and aquatic plant community structure in a North American agricultural catchment." Freshwater Biology 60, no. 7: 1292-1307.
Reports of cyanobacterial blooms in temperate lakes have been increasing over the last few decades. If blooms are indeed becoming more frequent or intense, this poses a problem for water and ecosystem management as blooms can be toxic to wildlife and humans. Here we used a paleolimnological approach to determine whether cyanobacteria have been increasing in Western Quebec, a region with thousands of lakes and a lack of historical surface water monitoring data. We compared lakes within and outside of Gatineau Park, a protected conservation area since 1938. Sediment cores dating back to pre-European settlement of the region were analyzed for temporal trends in cyanobacteria, in order to assess the effect of land use change and/or climate change before and after the Park’s creation. We extracted sediment DNA and analyzed for the 16S rRNA gene specific to cyanobacteria based on a qPCR assay for absolute gene copy numbers. These results were compared with analyses of the carotenoid pigments zeaxanthin and echinenone, specific to cyanobacteria, along with analyses of diatoxanthin and β-carotene, representative of diatoms and all algae respectively. Overall, gene copy numbers of cyanobacterial 16S rRNA pointed to a significant increase in cyanobacteria in all five lakes over the past 30 years and also since the Park’s creation, when compared to the historical average (past 150 years). In contrast, qPCR analyses of eubacterial gene copies for glutamine synthesis indicated that total microbial abundance exhibited a relatively smaller change over the same time periods. No significant difference in the percent increase of cyanobacteria, quantified by both gene copies and carotenoid pigments, was observed between lakes within and outside of the Park. This would suggest that other factors, such as a warming climate documented in this region, may be driving the increase in cyanobacteria. Sediment DNA has the potential to corroborate more classical fossil remains and provide novel information on microbial structure and function of past ecosystems.
S. Pal; Irene Gregory-Eaves; F. R. Pick. Temporal trends in cyanobacteria revealed through DNA and pigment analyses of temperate lake sediment cores. Journal of Paleolimnology 2015, 54, 87 -101.
AMA StyleS. Pal, Irene Gregory-Eaves, F. R. Pick. Temporal trends in cyanobacteria revealed through DNA and pigment analyses of temperate lake sediment cores. Journal of Paleolimnology. 2015; 54 (1):87-101.
Chicago/Turabian StyleS. Pal; Irene Gregory-Eaves; F. R. Pick. 2015. "Temporal trends in cyanobacteria revealed through DNA and pigment analyses of temperate lake sediment cores." Journal of Paleolimnology 54, no. 1: 87-101.
Increases in atmospheric temperature and nutrients from land are thought to be promoting the expansion of harmful cyanobacteria in lakes worldwide, yet to date there has been no quantitative synthesis of long‐term trends. To test whether cyanobacteria have increased in abundance over the past ~ 200 years and evaluate the relative influence of potential causal mechanisms, we synthesised 108 highly resolved sedimentary time series and 18 decadal‐scale monitoring records from north temperate‐subarctic lakes. We demonstrate that: (1) cyanobacteria have increased significantly since c. 1800 ce, (2) they have increased disproportionately relative to other phytoplankton, and (3) cyanobacteria increased more rapidly post c. 1945 ce. Variation among lakes in the rates of increase was explained best by nutrient concentration (phosphorus and nitrogen), and temperature was of secondary importance. Although cyanobacterial biomass has declined in some managed lakes with reduced nutrient influx, the larger spatio‐temporal scale of sedimentary records show continued increases in cyanobacteria throughout the north temperate‐subarctic regions.
Zofia E. Taranu; Irene Gregory-Eaves; Peter Leavitt; Lynda Bunting; Teresa Buchaca; Jordi Catalan; Isabelle Domaizon; Piero Guilizzoni; Andrea Lami; Suzanne McGowan; Heather Moorhouse; Giuseppe Morabito; Frances Pick; Mark Stevenson; Patrick Thompson; Rolf D. Vinebrooke. Acceleration of cyanobacterial dominance in north temperate-subarctic lakes during the Anthropocene. Ecology Letters 2015, 18, 375 -384.
AMA StyleZofia E. Taranu, Irene Gregory-Eaves, Peter Leavitt, Lynda Bunting, Teresa Buchaca, Jordi Catalan, Isabelle Domaizon, Piero Guilizzoni, Andrea Lami, Suzanne McGowan, Heather Moorhouse, Giuseppe Morabito, Frances Pick, Mark Stevenson, Patrick Thompson, Rolf D. Vinebrooke. Acceleration of cyanobacterial dominance in north temperate-subarctic lakes during the Anthropocene. Ecology Letters. 2015; 18 (4):375-384.
Chicago/Turabian StyleZofia E. Taranu; Irene Gregory-Eaves; Peter Leavitt; Lynda Bunting; Teresa Buchaca; Jordi Catalan; Isabelle Domaizon; Piero Guilizzoni; Andrea Lami; Suzanne McGowan; Heather Moorhouse; Giuseppe Morabito; Frances Pick; Mark Stevenson; Patrick Thompson; Rolf D. Vinebrooke. 2015. "Acceleration of cyanobacterial dominance in north temperate-subarctic lakes during the Anthropocene." Ecology Letters 18, no. 4: 375-384.
The discovery of hybridization between the invasive Eurasian watermilfoil (Myriophyllum spicatum L.) and native northern watermilfoil (Myriophyllum sibiricum Kom.) has generated interest in establishing the hybrid’s distribution and invasiveness. Identification of hybrid M. spicatum × M. sibiricum requires molecular genetic analysis, however, as the hybrid’s morphology overlaps with both parent species. Using plants collected from 10 lakes in Ontario, Canada, we compared a previous method of identification (sequencing the nuclear ITS region) with a simpler screening method (PCR-RFLP of the ITS region). Both methods agreed on the identification of hybrid M. spicatum × M. sibiricum and both parent species, supporting the suitability of PCR-RFLP to screen for the hybrid. Four of 29 samples were identified as hybrid M. spicatum × M. sibiricum, which were all found in three adjacent lakes associated with the Rideau Canal Waterway. The PCR-RFLP method should enable greater sampling effort to screen for hybrid M. spicatum × M. sibiricum and establish its geographic distribution across connected waterways.
Simon F. Grafe; Céline Boutin; Frances R. Pick; Roger D. Bull. A PCR-RFLP method to detect hybridization between the invasive Eurasian watermilfoil (Myriophyllum spicatum) and the native northern watermilfoil (Myriophyllum sibiricum), and its application in Ontario lakes. Botany 2015, 93, 117 -121.
AMA StyleSimon F. Grafe, Céline Boutin, Frances R. Pick, Roger D. Bull. A PCR-RFLP method to detect hybridization between the invasive Eurasian watermilfoil (Myriophyllum spicatum) and the native northern watermilfoil (Myriophyllum sibiricum), and its application in Ontario lakes. Botany. 2015; 93 (2):117-121.
Chicago/Turabian StyleSimon F. Grafe; Céline Boutin; Frances R. Pick; Roger D. Bull. 2015. "A PCR-RFLP method to detect hybridization between the invasive Eurasian watermilfoil (Myriophyllum spicatum) and the native northern watermilfoil (Myriophyllum sibiricum), and its application in Ontario lakes." Botany 93, no. 2: 117-121.