Hedy Kling - Academia.edu (original) (raw)
Papers by Hedy Kling
Estuarine Coastal and Shelf Science, Aug 1, 2019
For shorebirds, long distance migration is an energy-demanding activity, and lipids (largely comp... more For shorebirds, long distance migration is an energy-demanding activity, and lipids (largely comprised of fatty acids) with their high energy density are an ideal fuel. Diatoms in intertidal biofilms provide a rich source of fatty acids for fuel and for critical physiological functions. We compared the composition of intertidal biofilm on mudflats at Roberts Bank, a major stopover site for shorebirds in the Fraser River estuary, between two seasons: spring, during the northward breeding migration of Western Sandpipers (Calidris mauri), and winter, when no migrating shorebirds are present. Mass fractions of fatty acids in biofilm (µg fatty acids/g sample in the upper 2 mm of biofilm-containing sediment) in April were 3-7× higher than in winter (January and February). This difference included total saturated, monounsaturated, polyunsaturated, omega-3 (n-3), and omega-6 (n-6) fatty acids, as well as individual fatty acids such as palmitoleic acid (16:1n-7), eicosapentaenoic acid (EPA; 20:5n-3), and docosahexaenoic acid (DHA; 22:6n-3). In addition, organic content was ~25% higher in spring compared to winter. The microphytobenthos in spring biofilm was dominated by marine-influenced diatoms (primarily from the genera Nitzschia and Navicula) which made up >50% (µg/ml) of total biofilm biomass. Higher fatty acid and organic content in biofilm during spring provide shorebirds with both energy and physiologically important fatty acids to support their migration. These findings are consistent with the 'green wave' hypothesis, whereby bird migration broadly coincides temporally with the availability of energy and essential nutrients. The role of diatoms as purveyors of important fatty acids to shorebirds underscores the need for new conservation policies that protect the abundance of organic and fatty acid content of intertidal biofilm at estuarine stopover sites.
Journal of Great Lakes Research, 1998
Canadian Journal of Fisheries and Aquatic Sciences, Oct 1, 1994
A freeze core taken from Experimental Lakes Area Lake 227 in 1988 contained 321 rhythmically pair... more A freeze core taken from Experimental Lakes Area Lake 227 in 1988 contained 321 rhythmically paired, dark and light laminations in the upper 60.7 cm. Tape peels revealed cyclic, seasonal abundance peaks in organic and inorganic remains, which suggested that the couplets are varves. However, comparison between varve chronology and 22 yr of experimental changes in phosphorus (P) and nitrogen (N) loading and their influence on the planktonic community confirmed that the most recent varve-year estimates were 5 or 6 yr too old; this was caused by irregular sedimentation and multiple algal blooms resulting from experimental fertilization since 1969, and indistinct laminations that hampered precise couplet identification and separation. Dated horizons determined from biostratigraphic markers were used to generate compatible profiles between 1-cm slices of Lake 227 137Cs flux and reference fallout records. Nutrient concentration profiles were less helpful, as increases in carbon, N, and, P were gradual and no distinct horizon was identified as a clear marker of eutrophication. Long-term assessment of the varve chronology using 210Pb was hindered by experimental additions of 226Ra to the lake in 1970, although similar sedimentation rates from varve years 1860–1934 suggested that the varve and the deep part of the 210Pb chronologies were comparable.
Journal of the Fisheries Research Board of Canada, Apr 1, 1976
The seasonal mortality pattern and the causes of the mortality of planted rainbow trout (Salmo ga... more The seasonal mortality pattern and the causes of the mortality of planted rainbow trout (Salmo gairdneri) were studied in eight small eutrophic lakes in central Canada used for extensive aquaculture. Two periods of mortality were revealed. The first occurred in all lakes during the first 60 days of residence in the lakes and resulted in the mortality of 60–90% of the numbers of fish stocked. The second period occurred in about 20% of the lakes and was due to low oxygen levels following the collapse of a bloom of Aphanizomenonflos-aquae. Rainbow trout are close to their physiological upper tolerance levels in these lakes. Possible environmental and biological causes of mortality during the first period are discussed.
Diatom Research, Aug 1, 1988
Cyclotella species from several Canadian lakes have been investigated and their morphology illust... more Cyclotella species from several Canadian lakes have been investigated and their morphology illustrated by light and electron microscopy. Cyclotella antiqua W. Smith, C. bodanica var. bodanica Grun., C. bodanica var. affinis Grun., C. meneghiniana Kütz. and C. michiganiana Skvortzow have been identified with certainty although their cell diameters were smaller than those previously recorded in the literature. Differences and similarities in the C. bodanical/radiosa (Syn. comta)/comensis complex and in the Cyclotella stelligera group are discussed. One species appears to be identical to the newly described Stephanocostis chantaicus Genkal and Kuzmina. A new species (Cyclotella gordonensis nov. sp.) has been found so far only in deep, oligotrophic lakes of the Canadian Arctic.
Hydrobiologia, 2005
Blooms of the nuisance alga Gonyostomum semen occurred in Lake 979 (Experimental Lakes Area), a s... more Blooms of the nuisance alga Gonyostomum semen occurred in Lake 979 (Experimental Lakes Area), a small brown-water lake, that was subjected to several years of an experimental flooding regime. During periods of flooding, blooms of G. semen developed when light decreased below 100 lmol m)2 s)1 and total phosphorous concentrations increased to >30 lg l)1. Gonyostomum semen biomass was significantly correlated with total P and DOC concentrations. In addition, G. semen abundance increased at times when Daphnia rosea had rapidly declined to <10 animals l)1. Daphnia egg ratios suggest that declines in Daphnia abundance were the result of shifts in mortality and not causally linked to changes in G. semen densities. The results observed in Lake 979 were supported by a laboratory experiment where the appearance of G. semen from Lake 979 sediment was stimulated by altering chemical and biological variables. The stimulation of G. semen blooms appears to be dependant on multiple variables rather than a single variable.
Journal of the Fisheries Research Board of Canada, Oct 1, 1973
Lake 227, a small lake with extremely low concentrations of dissolved inorganic carbon, was ferti... more Lake 227, a small lake with extremely low concentrations of dissolved inorganic carbon, was fertilized with PO4 and NO3 for 4 years, beginning in 1969. The additions increased natural inputs of phosphorus and nitrogen about five times.Phytoplankton standing crop increased nearly two orders of magnitude, and the Cryptophyceae and Chrysophyceae present in natural lakes of the area were replaced by Chlorophyta and Cyanophyta. The standing crop of phytoplankton per square meter was near the maximum which could theoretically be maintained by surface light, in spite of the low carbon concentrations. Added phosphate and nitrate were rapidly removed by phytoplankton, so that concentrations in the lake remained low.Almost all of the added nutrient was retained by the lake, in spite of relatively fast water renewal times. An average of 80% of the phosphorus income of the lake was sedimented. There was no return of phosphorus from sediments in spite of anoxic conditions in the hypolimnion.Photosynthesizing plankton reduced dissolved inorganic carbon concentrations severely, causing a flux of atmospheric CO2 into the lake. From 69 to 95% of the inorganic + particulate carbon supplied to the lake was from the atmosphere. Results demonstrate that low carbon concentrations do not hinder eutrophication if phosphorus and nitrogen supplies are adequate.
Limnology and Oceanography, May 1, 1981
The seasonal cycle of phytoplankton and protozooplankton 1 iomass observed at two widely separate... more The seasonal cycle of phytoplankton and protozooplankton 1 iomass observed at two widely separated pelagic stations in the euphotic zone of Lake Tanganyika from February through November 1975 could be divided into three phases, based oil algal abundance and species succession and coinciding with three phases of annual thermal stratification. Phytoplankton biomass was minimal (as low as 60 mg*m-") during the phase of stable stratification and maximal, as high as 930 mg* me 3, at the end of the period of deep mixing. Diatoms, especially Nitzschin spp., were abundant only during the period of mixing, while filamentous blucgreens, principally Anahaena sp., were prominent during a p :riod of rapid surface warming which produced shallow mixed layers following the period o-deepest mixing. The biomass of Stromhidizcm cf. virile nearly equaled or exceeded the >hytoplankton biomass during much of the stably stratified period; this protozoan probably h: s a symbiotic relationship with zoochlorellae, which were always present in it. Lake Tanganyika showed a greater relative annual range bei wecn maximum and minimum phytoplankton and chlorophyll a concentrations than other tropical lakes and the temperate Great Lakes. Chlorophyll a ral.nged from 0.1 to 4.5 mg* np3 in he ellphotic zone and frorn 0.2 to 20.4 in surface waters; phytoplankton biomass ranged frctm 25 to 1,570 rng.n+ in the cuphotic zone. Annllal mean concentrations were among the Lowest known, 140 mg.rnm3 for phytoplankton biomass and 1.2 rng. mm3 for chlorophyll cc. Explanations for both the low annual means and the high annual variabilities may lie in 'he lake's steep morphometry, which affects nutrient regeneration, and in high loss rates kyrhich cause high algal growth rates but low algal biomass much of the year. the bacterial counts ancl the Analytical Unit of the Freshwater, Institute for performing the chemical analyses. This paper was enhanced through the criticism of W. M. Lewis, Jr. Methods ' The work of I1.J.K. in Burlmdi was done under contract to the IJNFAO which also paid air fares Pelagic phytoplankton and protozooand freight costs under a cooperative agreement plankton u'ere sampled at Bujumbura, 9 with the Freshwater Institute.
Diatom Research, May 1, 1996
ABSTRACT
Verhandlungen, Oct 1, 1975
With 6 figures and l table in the text Ultraoligotrophic Char Lake and sewage polluted Meretta La... more With 6 figures and l table in the text Ultraoligotrophic Char Lake and sewage polluted Meretta Lake located near Resolute Bay, Canada (74° 42' N 94° 57' W) have been studied as one of Canada's contributions to the Intemational Biological Programme. The lakes and aspects of their primary production have been reported (KALFF et al. 1972; SCHINDLER et al. 1974 a, b; KALFF & WELCH 1974; WELCH & KALFF 1974). The purpose of the present paper is to compare the biomass and biomass cycles as well as community and some species growth rates in these two lakes, between May 1969 and February 1971.
Lake and reservoir management, Jun 23, 2017
This study evaluated the phytoplankton and trophic status in Lake of the Woods (LOW; Ontario, Can... more This study evaluated the phytoplankton and trophic status in Lake of the Woods (LOW; Ontario, Canada), a large, multi-basin waterbody with marked gradients in water quality and annual cyanobacterial blooms. We combined a broad comparison of average total phosphorus (TP)-biomass relationships in LOW and other north temperate lakes with a detailed spatiotemporal analysis of net-, nanno-, and picoplankton, total bacterioplankton, nutrient status, and water quality across six hydrological sectors of the lake between 2008 and 2010. Average total phytoplankton biomass (TB) varied considerably among zones and years but, similar to TP, was highest in the shallower, more eutrophic southern zones with a generally lower than average TB/TP yield within the among-lakes dataset. Summer-fall blooms of N 2-fixing cyanobacteria were dominated by Aphanizomenon across most sectors except in the north, where Dolichospermum predominated. Unlike the larger size fractions, patterns in picoplankton suggested non-nutrient constraints: phycoerythrin-rich picocyanobacteria (<2 µm) showed a distinct south-north increase correlated with water transparency, while the more abundant phycocyanin-rich fraction was related to dissolved organic material with no distinct spatial patterns. Bacterial numbers were higher in surface layers and significantly related to temperature but not nutrients; spatial distribution indicated they were not directly introduced from riverine inputs. Overall, planktonic P deficiency was higher in the north and increased in late summer concurrent with N co-limitation and increases in N 2-fixers. The combined data suggest that P ultimately limits LOW plankton, but short-term N and Si deficiencies influence the plankton community composition. Recent studies of Lake of the Woods (LOW) phytoplankton have focused on cyanobacteria and the annual appearance of dense, mid-late summer blooms of these taxa (Chen et al. 2007, Chen et al. 2009, DeSellas et al. 2009). Harmful cyanobacterial blooms (cHABs) can produce toxins that seriously affect humans and other organisms, and have multiple other adverse impacts on drinking water supplies, beaches and shorelines, recreational activities, property value, fisheries, and tourist, hospitality, and other industries (e.g., Watson and Molot 2013, Clapper and Caudill 2014). The ecological impacts of cHABs are pervasive, and affect water quality, transparency, and dissolved oxygen, and may result in harmful or lethal effects on fish, waterfowl and other food web levels. Public awareness and concern with cHABs in LOW has increased over the past decade, although it is not
Canadian Journal of Fisheries and Aquatic Sciences, Oct 1, 1994
Aphanizomenon schindleri sp.nov., a new nostocacean, bluegreen, cyanoprokaryote (cyanobacterium),... more Aphanizomenon schindleri sp.nov., a new nostocacean, bluegreen, cyanoprokaryote (cyanobacterium), is described from artificially eutrophied Canadian Shield lakes in the Experimental Lakes Area, northwestern Ontario. It is unique to low conductivity Canadian Shield waters to which nutrients have been added, and it became the dominant bloom species after years of phosphorus (P) and nitrogen (N) loading followed by N limitation (N:P ≤ 5:1 by mass) (Findlay et al. 1994. Can. J. Fish. Aquat. Sci. 51: 2254–2266). The new Aphanizomenon species appears to be most closely related to A. gracile but also resembles species of Anabaena with straight filaments. It differs from other species of Aphanizomenon in cell dimensions, length and width of akinetes and heterocytes, and in akinete and end cell shape.
Fottea, Mar 1, 2009
Cylindrospermopsis raciborskii (Wołoszyńska) seenayya et subba Raju is a freshwater planktonic ni... more Cylindrospermopsis raciborskii (Wołoszyńska) seenayya et subba Raju is a freshwater planktonic nitrogen fixing filamentous toxic cyanobacterium (blue-green alga, cyanoprokaryote) belonging to the order Nostocales. Historically, it was thought to be a tropical or subtropical alga but in the past 26 years since it was recorded in Hungary in 1978, it has been found in increasing abundance in rivers and shallow water bodies in temperate regions of Asia, Africa, Australia, Europe, North America and South America by several researchers including most recently bRanco & senna (1991), Padisák (1997), chaPman & schelske (1997), FabbRo et al. (1996), dvořák & hašleR (2007). komáRek & komáRková (2003) give a comprehensive summary of the nomenclature changes, phenotypic plasticity and historic distribution record to 2002. komáRek & komáRková (2003) note the first European record was by SKUJA in his 1937 documentation of Greek and middle Asian algae.
Canadian Journal of Fisheries and Aquatic Sciences, Dec 1, 1994
Toxins, Jun 27, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Diatom Research, Nov 1, 1992
Clonal isolates of Stephanodiscus hantzschii Grunow were grown in batch culture and growth rates ... more Clonal isolates of Stephanodiscus hantzschii Grunow were grown in batch culture and growth rates were measured during the exponential growth phase. Clones differing in size grew at significantly different rates at 20°C but not at 12°C. The reduction in cell size (diameter) over a period of time was variable within and among clones at 12°C over the course of one
Environmental pollution, Mar 1, 1978
Five shallow eutrophic prairie lakes in the Erickson-Elphinstone area of Manitoba were treated wi... more Five shallow eutrophic prairie lakes in the Erickson-Elphinstone area of Manitoba were treated with copper sulphate in order to control Aphanizomenon flos-aquae blooms and prevent summer fish kills. Copper sulphate was added at concentrations of 25 to 360 I~g/l Cu to lakes and 100 to 3000 lag/l Cu to experimental tubes in early July when A. flos-aquae filaments were about 10 mm in length. Pretreatment chlorophyll a concentrations were 48 to 55 #g/litre and bloom species compositions were 90 to 98 % of A. flos-aquae. Excellent algal control was achieved at all treatment concentrations. Typically chlorophyll a declined to 2 to 4 #g/litre after 4 days and A. flos-aquae completely disappeared. Algal biomass remained low for 2 to 3 weeks and then gradually increased. Often Chlorophyta, diatoms and chrysophytes dominated the algal community for the rest of the ice-free season, although in two lakes other species of o'anophyta (Microcystis sp.) were predominant. Low concentrations ranging between 25 and 40 #g/litre Cu proved to be effective enough in these lakes. Copper concentration in the water returned to background levels after 8 to 10 days.
Elsevier eBooks, 2003
Benthic marine cyanobacteria are ubiquitous oxygenic photosynthetic bacteria and they form major ... more Benthic marine cyanobacteria are ubiquitous oxygenic photosynthetic bacteria and they form major components of various communities, including epiphytic, epilithic and microbial mats, in coral reef environments. Filamentous groups may form almost monospecific macroscopic colonies, and sometimes make potentially harmful algal blooms (HABs). HABs bring serious problems for marine tourism but marine filamentous cyanobacteria are good resource for drug discovery. However, cultivation and identification of such filamentous cyanobacteria are difficult and there are taxonomic confusions. In this study, we investigate 17 samples from coral reef area of 10 localities in Okinawa. Macroscopic mats or cushions of filamentous cyanobacteria were collected. The samples were divided into three parts: (1) for morphological observation, (2) for molecular work, and (3) cultivation for further study. Dominant cyanobacteira of each sample identified morphologically as Anabaena, Hydrocoleum, Lyngbya, Oscillatoria, Phormidium, Schizothrix and Symploca. Molecular results of partial 16S rDNA sequences revealed six groups that composed of heterocystous group, Leptolyngbya group, Symploca group, Moorea group, Oscillatoria group and unknown group, respectively. Some samples corroborated between morphology and molecular results but some were not. In addition, four out of six groups closely related with natural product producers. These results suggest that there are high
Estuarine Coastal and Shelf Science, Aug 1, 2019
For shorebirds, long distance migration is an energy-demanding activity, and lipids (largely comp... more For shorebirds, long distance migration is an energy-demanding activity, and lipids (largely comprised of fatty acids) with their high energy density are an ideal fuel. Diatoms in intertidal biofilms provide a rich source of fatty acids for fuel and for critical physiological functions. We compared the composition of intertidal biofilm on mudflats at Roberts Bank, a major stopover site for shorebirds in the Fraser River estuary, between two seasons: spring, during the northward breeding migration of Western Sandpipers (Calidris mauri), and winter, when no migrating shorebirds are present. Mass fractions of fatty acids in biofilm (µg fatty acids/g sample in the upper 2 mm of biofilm-containing sediment) in April were 3-7× higher than in winter (January and February). This difference included total saturated, monounsaturated, polyunsaturated, omega-3 (n-3), and omega-6 (n-6) fatty acids, as well as individual fatty acids such as palmitoleic acid (16:1n-7), eicosapentaenoic acid (EPA; 20:5n-3), and docosahexaenoic acid (DHA; 22:6n-3). In addition, organic content was ~25% higher in spring compared to winter. The microphytobenthos in spring biofilm was dominated by marine-influenced diatoms (primarily from the genera Nitzschia and Navicula) which made up >50% (µg/ml) of total biofilm biomass. Higher fatty acid and organic content in biofilm during spring provide shorebirds with both energy and physiologically important fatty acids to support their migration. These findings are consistent with the 'green wave' hypothesis, whereby bird migration broadly coincides temporally with the availability of energy and essential nutrients. The role of diatoms as purveyors of important fatty acids to shorebirds underscores the need for new conservation policies that protect the abundance of organic and fatty acid content of intertidal biofilm at estuarine stopover sites.
Journal of Great Lakes Research, 1998
Canadian Journal of Fisheries and Aquatic Sciences, Oct 1, 1994
A freeze core taken from Experimental Lakes Area Lake 227 in 1988 contained 321 rhythmically pair... more A freeze core taken from Experimental Lakes Area Lake 227 in 1988 contained 321 rhythmically paired, dark and light laminations in the upper 60.7 cm. Tape peels revealed cyclic, seasonal abundance peaks in organic and inorganic remains, which suggested that the couplets are varves. However, comparison between varve chronology and 22 yr of experimental changes in phosphorus (P) and nitrogen (N) loading and their influence on the planktonic community confirmed that the most recent varve-year estimates were 5 or 6 yr too old; this was caused by irregular sedimentation and multiple algal blooms resulting from experimental fertilization since 1969, and indistinct laminations that hampered precise couplet identification and separation. Dated horizons determined from biostratigraphic markers were used to generate compatible profiles between 1-cm slices of Lake 227 137Cs flux and reference fallout records. Nutrient concentration profiles were less helpful, as increases in carbon, N, and, P were gradual and no distinct horizon was identified as a clear marker of eutrophication. Long-term assessment of the varve chronology using 210Pb was hindered by experimental additions of 226Ra to the lake in 1970, although similar sedimentation rates from varve years 1860–1934 suggested that the varve and the deep part of the 210Pb chronologies were comparable.
Journal of the Fisheries Research Board of Canada, Apr 1, 1976
The seasonal mortality pattern and the causes of the mortality of planted rainbow trout (Salmo ga... more The seasonal mortality pattern and the causes of the mortality of planted rainbow trout (Salmo gairdneri) were studied in eight small eutrophic lakes in central Canada used for extensive aquaculture. Two periods of mortality were revealed. The first occurred in all lakes during the first 60 days of residence in the lakes and resulted in the mortality of 60–90% of the numbers of fish stocked. The second period occurred in about 20% of the lakes and was due to low oxygen levels following the collapse of a bloom of Aphanizomenonflos-aquae. Rainbow trout are close to their physiological upper tolerance levels in these lakes. Possible environmental and biological causes of mortality during the first period are discussed.
Diatom Research, Aug 1, 1988
Cyclotella species from several Canadian lakes have been investigated and their morphology illust... more Cyclotella species from several Canadian lakes have been investigated and their morphology illustrated by light and electron microscopy. Cyclotella antiqua W. Smith, C. bodanica var. bodanica Grun., C. bodanica var. affinis Grun., C. meneghiniana Kütz. and C. michiganiana Skvortzow have been identified with certainty although their cell diameters were smaller than those previously recorded in the literature. Differences and similarities in the C. bodanical/radiosa (Syn. comta)/comensis complex and in the Cyclotella stelligera group are discussed. One species appears to be identical to the newly described Stephanocostis chantaicus Genkal and Kuzmina. A new species (Cyclotella gordonensis nov. sp.) has been found so far only in deep, oligotrophic lakes of the Canadian Arctic.
Hydrobiologia, 2005
Blooms of the nuisance alga Gonyostomum semen occurred in Lake 979 (Experimental Lakes Area), a s... more Blooms of the nuisance alga Gonyostomum semen occurred in Lake 979 (Experimental Lakes Area), a small brown-water lake, that was subjected to several years of an experimental flooding regime. During periods of flooding, blooms of G. semen developed when light decreased below 100 lmol m)2 s)1 and total phosphorous concentrations increased to >30 lg l)1. Gonyostomum semen biomass was significantly correlated with total P and DOC concentrations. In addition, G. semen abundance increased at times when Daphnia rosea had rapidly declined to <10 animals l)1. Daphnia egg ratios suggest that declines in Daphnia abundance were the result of shifts in mortality and not causally linked to changes in G. semen densities. The results observed in Lake 979 were supported by a laboratory experiment where the appearance of G. semen from Lake 979 sediment was stimulated by altering chemical and biological variables. The stimulation of G. semen blooms appears to be dependant on multiple variables rather than a single variable.
Journal of the Fisheries Research Board of Canada, Oct 1, 1973
Lake 227, a small lake with extremely low concentrations of dissolved inorganic carbon, was ferti... more Lake 227, a small lake with extremely low concentrations of dissolved inorganic carbon, was fertilized with PO4 and NO3 for 4 years, beginning in 1969. The additions increased natural inputs of phosphorus and nitrogen about five times.Phytoplankton standing crop increased nearly two orders of magnitude, and the Cryptophyceae and Chrysophyceae present in natural lakes of the area were replaced by Chlorophyta and Cyanophyta. The standing crop of phytoplankton per square meter was near the maximum which could theoretically be maintained by surface light, in spite of the low carbon concentrations. Added phosphate and nitrate were rapidly removed by phytoplankton, so that concentrations in the lake remained low.Almost all of the added nutrient was retained by the lake, in spite of relatively fast water renewal times. An average of 80% of the phosphorus income of the lake was sedimented. There was no return of phosphorus from sediments in spite of anoxic conditions in the hypolimnion.Photosynthesizing plankton reduced dissolved inorganic carbon concentrations severely, causing a flux of atmospheric CO2 into the lake. From 69 to 95% of the inorganic + particulate carbon supplied to the lake was from the atmosphere. Results demonstrate that low carbon concentrations do not hinder eutrophication if phosphorus and nitrogen supplies are adequate.
Limnology and Oceanography, May 1, 1981
The seasonal cycle of phytoplankton and protozooplankton 1 iomass observed at two widely separate... more The seasonal cycle of phytoplankton and protozooplankton 1 iomass observed at two widely separated pelagic stations in the euphotic zone of Lake Tanganyika from February through November 1975 could be divided into three phases, based oil algal abundance and species succession and coinciding with three phases of annual thermal stratification. Phytoplankton biomass was minimal (as low as 60 mg*m-") during the phase of stable stratification and maximal, as high as 930 mg* me 3, at the end of the period of deep mixing. Diatoms, especially Nitzschin spp., were abundant only during the period of mixing, while filamentous blucgreens, principally Anahaena sp., were prominent during a p :riod of rapid surface warming which produced shallow mixed layers following the period o-deepest mixing. The biomass of Stromhidizcm cf. virile nearly equaled or exceeded the >hytoplankton biomass during much of the stably stratified period; this protozoan probably h: s a symbiotic relationship with zoochlorellae, which were always present in it. Lake Tanganyika showed a greater relative annual range bei wecn maximum and minimum phytoplankton and chlorophyll a concentrations than other tropical lakes and the temperate Great Lakes. Chlorophyll a ral.nged from 0.1 to 4.5 mg* np3 in he ellphotic zone and frorn 0.2 to 20.4 in surface waters; phytoplankton biomass ranged frctm 25 to 1,570 rng.n+ in the cuphotic zone. Annllal mean concentrations were among the Lowest known, 140 mg.rnm3 for phytoplankton biomass and 1.2 rng. mm3 for chlorophyll cc. Explanations for both the low annual means and the high annual variabilities may lie in 'he lake's steep morphometry, which affects nutrient regeneration, and in high loss rates kyrhich cause high algal growth rates but low algal biomass much of the year. the bacterial counts ancl the Analytical Unit of the Freshwater, Institute for performing the chemical analyses. This paper was enhanced through the criticism of W. M. Lewis, Jr. Methods ' The work of I1.J.K. in Burlmdi was done under contract to the IJNFAO which also paid air fares Pelagic phytoplankton and protozooand freight costs under a cooperative agreement plankton u'ere sampled at Bujumbura, 9 with the Freshwater Institute.
Diatom Research, May 1, 1996
ABSTRACT
Verhandlungen, Oct 1, 1975
With 6 figures and l table in the text Ultraoligotrophic Char Lake and sewage polluted Meretta La... more With 6 figures and l table in the text Ultraoligotrophic Char Lake and sewage polluted Meretta Lake located near Resolute Bay, Canada (74° 42' N 94° 57' W) have been studied as one of Canada's contributions to the Intemational Biological Programme. The lakes and aspects of their primary production have been reported (KALFF et al. 1972; SCHINDLER et al. 1974 a, b; KALFF & WELCH 1974; WELCH & KALFF 1974). The purpose of the present paper is to compare the biomass and biomass cycles as well as community and some species growth rates in these two lakes, between May 1969 and February 1971.
Lake and reservoir management, Jun 23, 2017
This study evaluated the phytoplankton and trophic status in Lake of the Woods (LOW; Ontario, Can... more This study evaluated the phytoplankton and trophic status in Lake of the Woods (LOW; Ontario, Canada), a large, multi-basin waterbody with marked gradients in water quality and annual cyanobacterial blooms. We combined a broad comparison of average total phosphorus (TP)-biomass relationships in LOW and other north temperate lakes with a detailed spatiotemporal analysis of net-, nanno-, and picoplankton, total bacterioplankton, nutrient status, and water quality across six hydrological sectors of the lake between 2008 and 2010. Average total phytoplankton biomass (TB) varied considerably among zones and years but, similar to TP, was highest in the shallower, more eutrophic southern zones with a generally lower than average TB/TP yield within the among-lakes dataset. Summer-fall blooms of N 2-fixing cyanobacteria were dominated by Aphanizomenon across most sectors except in the north, where Dolichospermum predominated. Unlike the larger size fractions, patterns in picoplankton suggested non-nutrient constraints: phycoerythrin-rich picocyanobacteria (<2 µm) showed a distinct south-north increase correlated with water transparency, while the more abundant phycocyanin-rich fraction was related to dissolved organic material with no distinct spatial patterns. Bacterial numbers were higher in surface layers and significantly related to temperature but not nutrients; spatial distribution indicated they were not directly introduced from riverine inputs. Overall, planktonic P deficiency was higher in the north and increased in late summer concurrent with N co-limitation and increases in N 2-fixers. The combined data suggest that P ultimately limits LOW plankton, but short-term N and Si deficiencies influence the plankton community composition. Recent studies of Lake of the Woods (LOW) phytoplankton have focused on cyanobacteria and the annual appearance of dense, mid-late summer blooms of these taxa (Chen et al. 2007, Chen et al. 2009, DeSellas et al. 2009). Harmful cyanobacterial blooms (cHABs) can produce toxins that seriously affect humans and other organisms, and have multiple other adverse impacts on drinking water supplies, beaches and shorelines, recreational activities, property value, fisheries, and tourist, hospitality, and other industries (e.g., Watson and Molot 2013, Clapper and Caudill 2014). The ecological impacts of cHABs are pervasive, and affect water quality, transparency, and dissolved oxygen, and may result in harmful or lethal effects on fish, waterfowl and other food web levels. Public awareness and concern with cHABs in LOW has increased over the past decade, although it is not
Canadian Journal of Fisheries and Aquatic Sciences, Oct 1, 1994
Aphanizomenon schindleri sp.nov., a new nostocacean, bluegreen, cyanoprokaryote (cyanobacterium),... more Aphanizomenon schindleri sp.nov., a new nostocacean, bluegreen, cyanoprokaryote (cyanobacterium), is described from artificially eutrophied Canadian Shield lakes in the Experimental Lakes Area, northwestern Ontario. It is unique to low conductivity Canadian Shield waters to which nutrients have been added, and it became the dominant bloom species after years of phosphorus (P) and nitrogen (N) loading followed by N limitation (N:P ≤ 5:1 by mass) (Findlay et al. 1994. Can. J. Fish. Aquat. Sci. 51: 2254–2266). The new Aphanizomenon species appears to be most closely related to A. gracile but also resembles species of Anabaena with straight filaments. It differs from other species of Aphanizomenon in cell dimensions, length and width of akinetes and heterocytes, and in akinete and end cell shape.
Fottea, Mar 1, 2009
Cylindrospermopsis raciborskii (Wołoszyńska) seenayya et subba Raju is a freshwater planktonic ni... more Cylindrospermopsis raciborskii (Wołoszyńska) seenayya et subba Raju is a freshwater planktonic nitrogen fixing filamentous toxic cyanobacterium (blue-green alga, cyanoprokaryote) belonging to the order Nostocales. Historically, it was thought to be a tropical or subtropical alga but in the past 26 years since it was recorded in Hungary in 1978, it has been found in increasing abundance in rivers and shallow water bodies in temperate regions of Asia, Africa, Australia, Europe, North America and South America by several researchers including most recently bRanco & senna (1991), Padisák (1997), chaPman & schelske (1997), FabbRo et al. (1996), dvořák & hašleR (2007). komáRek & komáRková (2003) give a comprehensive summary of the nomenclature changes, phenotypic plasticity and historic distribution record to 2002. komáRek & komáRková (2003) note the first European record was by SKUJA in his 1937 documentation of Greek and middle Asian algae.
Canadian Journal of Fisheries and Aquatic Sciences, Dec 1, 1994
Toxins, Jun 27, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Diatom Research, Nov 1, 1992
Clonal isolates of Stephanodiscus hantzschii Grunow were grown in batch culture and growth rates ... more Clonal isolates of Stephanodiscus hantzschii Grunow were grown in batch culture and growth rates were measured during the exponential growth phase. Clones differing in size grew at significantly different rates at 20°C but not at 12°C. The reduction in cell size (diameter) over a period of time was variable within and among clones at 12°C over the course of one
Environmental pollution, Mar 1, 1978
Five shallow eutrophic prairie lakes in the Erickson-Elphinstone area of Manitoba were treated wi... more Five shallow eutrophic prairie lakes in the Erickson-Elphinstone area of Manitoba were treated with copper sulphate in order to control Aphanizomenon flos-aquae blooms and prevent summer fish kills. Copper sulphate was added at concentrations of 25 to 360 I~g/l Cu to lakes and 100 to 3000 lag/l Cu to experimental tubes in early July when A. flos-aquae filaments were about 10 mm in length. Pretreatment chlorophyll a concentrations were 48 to 55 #g/litre and bloom species compositions were 90 to 98 % of A. flos-aquae. Excellent algal control was achieved at all treatment concentrations. Typically chlorophyll a declined to 2 to 4 #g/litre after 4 days and A. flos-aquae completely disappeared. Algal biomass remained low for 2 to 3 weeks and then gradually increased. Often Chlorophyta, diatoms and chrysophytes dominated the algal community for the rest of the ice-free season, although in two lakes other species of o'anophyta (Microcystis sp.) were predominant. Low concentrations ranging between 25 and 40 #g/litre Cu proved to be effective enough in these lakes. Copper concentration in the water returned to background levels after 8 to 10 days.
Elsevier eBooks, 2003
Benthic marine cyanobacteria are ubiquitous oxygenic photosynthetic bacteria and they form major ... more Benthic marine cyanobacteria are ubiquitous oxygenic photosynthetic bacteria and they form major components of various communities, including epiphytic, epilithic and microbial mats, in coral reef environments. Filamentous groups may form almost monospecific macroscopic colonies, and sometimes make potentially harmful algal blooms (HABs). HABs bring serious problems for marine tourism but marine filamentous cyanobacteria are good resource for drug discovery. However, cultivation and identification of such filamentous cyanobacteria are difficult and there are taxonomic confusions. In this study, we investigate 17 samples from coral reef area of 10 localities in Okinawa. Macroscopic mats or cushions of filamentous cyanobacteria were collected. The samples were divided into three parts: (1) for morphological observation, (2) for molecular work, and (3) cultivation for further study. Dominant cyanobacteira of each sample identified morphologically as Anabaena, Hydrocoleum, Lyngbya, Oscillatoria, Phormidium, Schizothrix and Symploca. Molecular results of partial 16S rDNA sequences revealed six groups that composed of heterocystous group, Leptolyngbya group, Symploca group, Moorea group, Oscillatoria group and unknown group, respectively. Some samples corroborated between morphology and molecular results but some were not. In addition, four out of six groups closely related with natural product producers. These results suggest that there are high