Production of Epilithiphyton in Two Lakes of the Experimental Lakes Area, Northwestern Ontario

1973 ◽  
Vol 30 (10) ◽  
pp. 1511-1524 ◽  
Author(s):  
D. W. Schindler ◽  
V. E. Frost ◽  
R. V. Schmidt
Keyword(s):  
Liquid Scintillation ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Seasonal Effects ◽  
Algal Flora ◽  
Experimental Lakes Area ◽  
New Techniques ◽  
Natural Lakes ◽  
Northwestern Ontario

Two new techniques for measuring photosynthesis by benthic algal flora in waters low in dissolved inorganic carbon are described. The first uses gas chromatography to measure changes in DIC in incubation chambers directly. The second is a variation of the usual 14C procedure, in which disappearance of 14C from the water is measured by liquid scintillation instead of uptake of 14C by the algae. This procedure is simpler than measuring the uptake of 14C, because digestion and/or combustion of samples is not necessary. Results are compared with the commonly employed 14C uptake and O2 release techniques.Tests showed that heterogeneity of substrate was the major source of variation in in situ results, being large enough to make interpretation of seasonal effects and other causal factors extremely difficult.Annual production by epilithiphyton in two natural lakes in the Experimental Lakes Area (ELA) was 5.19 g C and 5.18 g C/m2 of substrate annually for lakes 239 and 240, respectively. These are the lowest values recorded for freshwater lakes at temperate latitudes.Because DIC and O2 concentrations could be measured simultaneously, it was possible to calculate photosynthetic quotients on several dates. These were extremely high, averaging 2.6 for the summer of 1971.

Diurnal Variation of Dissolved Inorganic Carbon and its Use in Estimating Primary Production and CO2 Invasion in Lake 227

1973 ◽  
Vol 30 (10) ◽  
pp. 1501-1510 ◽  
Author(s):  
D. W. Schindler ◽  
E. J. Fee
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Community Respiration ◽  
Phytoplankton Production ◽  
Carbon Limitation ◽  
Low Carbon ◽  
Nitrogen And Phosphorus ◽  
Natural Lakes ◽  
Tracer Techniques

Standard in situ measurements of phytoplankton production and 14C bottle bioassays gave erroneous results when applied to lake 227, a eutrophic softwater lake in the Canadian Shield. Errors were found to be due to diurnal variations in the degree of carbon limitation of phytoplankton, and to invasion of CO2 from the atmosphere and hypolimnion.A method based on diurnal measurements of dissolved inorganic carbon, community respiration, and invasion of CO2, using gas chromatography, is described. Production by phytoplankton in lakes fertilized with nitrogen and phosphorus was found to be several times higher than in natural lakes of the area. Net production during summer stratification was found to equal invasion of CO2 from the atmosphere.The new technique should have application in other eutrophic low carbon lakes, where 14C tracer techniques are encumbered by serious technical complications.

Phosphorus, Nitrogen, and Carbon Dynamics of Experimental Lake 303 during Recovery from Eutrophication

1989 ◽  
Vol 46 (1) ◽  
pp. 2-10 ◽  
Author(s):  
S. N. Levine ◽  
D. W. Schindler
Keyword(s):  
Organic Nitrogen ◽  
Dissolved Inorganic Carbon ◽  
Phosphorus Concentration ◽  
First Year ◽  
Nitrogen And Phosphorus ◽  
Experimental Lakes Area ◽  
Total Phosphorus Concentration ◽  
Northwestern Ontario ◽  
Cycling Of Nutrients

Little is known about the recovery of lakes from eutrophication, especially as it effects the cycling of nutrients other than phosphorus. We fertilized a naturally oligotrophic lake (Lake 303) in the Experimental Lakes Area, northwestern Ontario, with nitrogen and phosphorus over two summers and examined the subsequent recovery using mass balance and large in situ mesocosms. While large amounts of ammonium and smaller amounts of dissolved inorganic carbon (DIC) were released from the lake's aerobic sediments during the first year of recovery, phosphorus input from the sediments was not detectable during the same period. Chlorophyll a concentration closely tracked total phosphorus concentration, and both returned to prefertilization levels within 1 yr. In contrast, ammonium, nitrate, DIC, and dissolved organic carbon (DOC) needed almost 2 yr to reach baseline levels, and dissolved organic nitrogen (DON) even longer. The results show that different elements may recover at different rates and that the release of stored pools of nitrogen and carbon in the sediments plays a major role in delaying the recovery of these elements.

Primary Production and Phytoplankton in the Experimental Lakes Area, Northwestern Ontario, and other Low-Carbonate Waters, and a Liquid Scintillation Method for Determining 14C Activity in Photosynthesis

1971 ◽  
Vol 28 (2) ◽  
pp. 189-201 ◽  
Author(s):  
D. W. Schindler ◽  
S. K. Holmgren
Keyword(s):  
Primary Production ◽  
Liquid Scintillation ◽  
Species Abundance ◽  
Euphotic Zone ◽  
Phytoplankton Production ◽  
Phytoplankton Species ◽  
Experimental Lakes Area ◽  
Phytoplankton Species Composition ◽  
Northwestern Ontario ◽  
Filtration Error

A modified 14C method is described for measuring phytoplankton production in low-carbonate waters. The procedure includes the use of the Arthur and Rigler (Limnol. Oceanogr. 12: 121–124, 1967) technique for determining filtration error, liquid scintillation counting for determining the radioactivity of membrane filters and stock 14C solutions, and gas chromatography for measuring total CO2.Primary production, chlorophyll a, and total CO2 were measured for two dates in midsummer from each of several lakes in the Experimental Lakes Area (ELA), ranging from 1 to 1000 ha in area and from 2 to 117 m in maximum depth. Phytoplankton species abundance and biomass were determined for the same dates. Production ranged from 0.02 to 2.12 gC/m3∙day and from 0.179 to 1.103 g C/m2∙day. Chlorophyll ranged from 0.4 to 44 mg/m3 and from 5 to 98 mg/m2 in the euphotic zone. The corresponding ranges for live phytoplankton biomass were 120–5400 mg/m3 and 2100–13,400 mg/m2. Chrysophyceae dominated the phytoplankton of most of the lakes.A system for classifying the lakes in terms of phytoplankton species composition and production–depth curves is developed.

Evaluation of reagentless pH modification for in situ ocean analysis: determination of dissolved inorganic carbon using mass spectrometry

2013 ◽  
Vol 27 (5) ◽  
pp. 635-642 ◽  
Author(s):  
Andres M. Cardenas-Valencia ◽  
Lori R. Adornato ◽  
Ryan J. Bell ◽  
Robert H. Byrne ◽  
R. Timothy Short
Keyword(s):  
Mass Spectrometry ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Analysis Determination

Methyl mercury in aquatic insects from an experimental reservoir

1998 ◽  
Vol 55 (9) ◽  
pp. 2036-2047 ◽  
Author(s):  
B D Hall ◽  
D M Rosenberg ◽  
A P Wiens
Keyword(s):  
Aquatic Insects ◽  
Methyl Mercury ◽  
Fold Increase ◽  
Fish Tissue ◽  
Functional Feeding Groups ◽  
Experimental Lakes Area ◽  
Major Pathway ◽  
Natural Lakes ◽  
Northwestern Ontario ◽  
Before And After

Our objective was to study the effects of experimental flooding of a small wetland lake on the methyl mercury (MeHg) concentrations in aquatic insects and to compare MeHg concentrations in insects with those in water and fish from the same system. Insects were collected from the shorelines of the experimental reservoir before and after flooding, an undisturbed wetland lake, and an oligotrophic lake, all in the Experimental Lakes Area in northwestern Ontario. Samples were identified to the lowest possible taxon and categorized into functional feeding groups (FFGs; predators or collector/shredders). The insects were analyzed for MeHg and total Hg using clean techniques. Contamination was not a problem because levels of MeHg in insects were much higher than background concentrations. Odonata, Corixidae, Gerridae, Gyrinidae, and Phryganeidae/Polycentropodidae exhibited increases in MeHg concentrations in response to flooding. When data were grouped into FFGs, increases were observed in predators. There were insufficient numbers of collector/shredders collected to make a definitive conclusion on MeHg increases. Predators exhibited an approximately threefold increase in MeHg concentrations after flooding compared with a 20-fold increase in water concentrations and a four- to five-fold increase in fish concentrations. Trends in MeHg concentrations in aquatic insects from reservoirs and natural lakes in Finland and northern Québec were similar to ours. Evidence of an increase in MeHg concentrations in the lower food web helps explain increases in MeHg concentrations in fish from reservoirs because food is the major pathway of MeHg uptake in fish tissue.

Distributions of Ferrous Iron and Sulfide in an Anoxic Hypolimnion

1984 ◽  
Vol 41 (2) ◽  
pp. 286-293 ◽  
Author(s):  
Robert B. Cook
Keyword(s):  
Pore Water ◽  
Solubility Product ◽  
Iron Sulfide ◽  
Water Flux ◽  
Sediment Pore Water ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Anoxic Hypolimnion ◽  
Decomposition Of Organic Matter

In the anoxic hypolimnion of Lake 227, Experimental Lakes Area, northwestern Ontario, ΣH2S exhibits a mid-depth maximum, while Fe2+ increases with depth. At the mid-depth ΣH2S maximum and below, saturation with respect to amorphous FeS is reached, and the concentration of ΣH2S is limited by the high Fe2+ concentrations, in accord with the FeS solubility product. Values for pKsp[Formula: see text] for FeS determined from the ΣH2S maximum and below averaged 3.16 in 1979 and agree well with other in situ and laboratory measurements. In the top 10 cm of sediment, pore water ΣH2S and Fe2+ are in equilibrium with amorphous FeS. Analyses of cores confirms the existence of an iron sulfide phase. Fe2+, which is produced in the pore water from the decomposition of organic matter, increases to concentrations at which siderite may form, although the presence of siderite has not been verified. Comparison of calculated pore water fluxes of Fe2+ with the observed increase of Fe2+ in the anoxic hypolimnion reveals that about 90% of the observed flux originates at the sediment–water interface, while the remainder is derived from pore water flux.

In Situ Sensor Technology for Simultaneous Spectrophotometric Measurements of Seawater Total Dissolved Inorganic Carbon and pH

2015 ◽  
Vol 49 (7) ◽  
pp. 4441-4449 ◽  
Author(s):  
Zhaohui Aleck Wang ◽  
Frederick N. Sonnichsen ◽  
Albert M. Bradley ◽  
Katherine A. Hoering ◽  
Thomas M. Lanagan ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Sensor Technology ◽  
Total Dissolved Inorganic Carbon ◽  
In Situ Sensor

Controls on in situ oxygen and dissolved inorganic carbon dynamics in peats of a temperate fen

2012 ◽  
Vol 117 (G2) ◽  
pp. n/a-n/a ◽  
Author(s):  
Cristian Estop-Aragonés ◽  
Klaus-Holger Knorr ◽  
Christian Blodau
Keyword(s):  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Carbon Dynamics

Growth characteristics of bloom-forming filamentous green algae in the littoral zone of an experimentally acidified lake

1995 ◽  
Vol 52 (10) ◽  
pp. 2251-2263 ◽  
Author(s):  
Michael A. Turner ◽  
Leif J. Sigurdson ◽  
David L. Findlay ◽  
E. Todd Howell ◽  
Gordon G. C. Robinson ◽  
...  
Keyword(s):  
Water Temperature ◽  
Green Algae ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Benthic Algae ◽  
Growth Characteristics ◽  
Experimental Lakes Area ◽  
Filamentous Green Algae ◽  
High Photosynthetic Capacity ◽  
Major Factors

Filamentous green algae, predominantly Mougeotia and Zygogonium, bloom frequently in the littoral zones of acidified lakes. Growth characteristics of Zygogonium-dominated filamentous green algae were studied for 4 yr in an experimentally acidified (pH 4.5) lake at the Experimental Lakes Area of northwestern Ontario. They were present in low abundance as periphyton (algal associations attached to surfaces) during spring, and as blooms of metaphyton (benthic algae unconstrained by surfaces) beginning in midsummer and reaching a maximum in early fall. Metaphytic filamentous green algae displayed high photosynthetic capacity in summer despite the oligotrophic nature of the acidified lake. The major factors controlling photosynthetic rates of Zygogonium were similar to those controlling Mougeotia, and included algal crowding, irradiance, dissolved inorganic carbon, and water temperature. Rates of photosynthesis were negatively dependent upon algal crowding, so that highest rates were associated with minimum algal crowding. Light requirements for photosynthesis were higher than those of the epilithon, which were dominant prior to acidification. The dependence of photosynthesis on ambient concentrations of dissolved inorganic carbon was partly regulated by water temperature. Anthropogenically caused releases from growth limitations (e.g., increased availability of limiting nutrients, increased water temperature, and extension of the growing season) may cause proliferation of filamentous green algae in the future.

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