Preliminary Chemical Characterization of Waters in the Experimental Lakes Area, Northwestern Ontario

1971 ◽  
Vol 28 (2) ◽  
pp. 171-187 ◽  
Author(s):  
F. A. J. Armstrong ◽  
D. W. Schindler
Keyword(s):  
Chemical Characterization ◽  
Specific Conductance ◽  
Canadian Shield ◽  
Nitrogen And Phosphorus ◽  
Experimental Lakes Area ◽  
Mean Values ◽  
Dissolved Phosphorus ◽  
Dissolved Nitrogen ◽  
Total Dissolved Nitrogen ◽  
Northwestern Ontario

Water analyses in 1968 and 1969 from 40 small lakes within a small area of the Canadian Shield in northwestern Ontario gave mean values for Ca, Na, Mg, and K of 1.6, 0.9, 0.9, and 0.4 mg/liter with Ca > Na > Mg > K on a molar basis. HCO3, SO4, and Cl (on a smaller number of samples) were 4.1, 3.0, and 1.4 mg/liter. Total CO2 was variable in the range 0.3–12.0 mg/liter. Specific conductance was in the range 10–35 μmho/cm at 25 C and pH 5.4–7.5. Color was < 5–150 Hazen units, and plant pigments (as chlorophyll a) < 1–21 μg/liter. Total dissolved nitrogen was in the range 110–300 mg N/liter and total dissolved phosphorus 3–20 μg P/liter. NO3-N and PO4-P were often undetectable in summer, and reached winter maxima around 100 and 10 μg/liter.Total dissolved nitrogen and phosphorus contents of five lakes were computed at the beginning and end of periods of several weeks during summer stagnation. Changes were negligibly small in three of the deeper lakes, but the two shallowest showed increases of 0.22 and 0.62 g N/m2 and 0.03 and 0.13 g P/m2. Analyses of precipitation and stream waters were used, with stream flow rates, to calculate input and output of nutrients from four of these lakes during the same periods. Retention of nutrients had occurred in all, and it was concluded that in the two deeper lakes nutrients had been lost to the sediments, whereas in the two shallower ones the increases in dissolved nutrients found were derived from the sediments.Analyses of 33 other Canadian Shield lake areas and of 13 other dilute lakes in other regions are tabulated. Comparison with the Experimental Lakes Area (ELA) lakes shows that the latter are more dilute than any in the Shield area except for some in the Northwest Territories, and much more dilute than any others in the world except for some alpine lakes in California.

scholarly journals Distributions and stoichiometry of dissolved nitrogen and phosphorus in the iron-fertilized region near Kerguelen (Southern Ocean)

2015 ◽  
Vol 12 (2) ◽  
pp. 623-635 ◽  
Author(s):  
S. Blain ◽  
J. Capparos ◽  
A. Guéneuguès ◽  
I. Obernosterer ◽  
L. Oriol
Keyword(s):  
Southern Ocean ◽  
Organic Nitrogen ◽  
Organic Phosphorus ◽  
Polar Front ◽  
Nitrogen And Phosphorus ◽  
Phosphorus Species ◽  
Dissolved Phosphorus ◽  
Dissolved Nitrogen ◽  
Total Dissolved Nitrogen ◽  
Preferential Uptake

Abstract. During KEOPS2 (Kerguelen Ocean and Plateau Compared Study 2), we determined dissolved inorganic and organic nitrogen and phosphorus species in the naturally fertilized region of Kerguelen Island (Southern Ocean). Above 150 m, stations were clearly separated by the polar front (PF), with concentrations of NO3-, NO2- and PO43- overall lower north of the PF than south. Though less pronounced, a similar trend was detectable for dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP). At all stations offshore and above the plateau, a subsurface maximum of NH4+ was observed between 50 and 150 m. We examined nutrient stoichiometry by calculating the linear combination N* = [NO3-]-16 [PO43-]. The majority of stations and depths revealed N* close to −3 μM; however, for surface waters north of the PF, N* increased up to 6 μM. This suggests a preferential uptake of PO43- versus NO3- by fast-growing diatoms. Using the tracer TNxs = [TDN]-16[TDP] (TDN, total dissolved nitrogen; TDP, total dissolved phosphorus) revealed that the dissolved organic fraction significantly contributed to changes in TNxs. TNxs values were negative for most stations and depths, and relatively constant in the 0–500 m layer. As for N*, the stations north of the PF had higher TNxs in the 0–100 m layer. We discuss this stoichiometric anomaly with respect to possible external sources and sinks of N and P. Additional data collected in February 2013 at two sites revealed the occurrence of a subsurface minimum of N* located just below the pycnocline, which denotes a layer where remineralization of particulate organic matter with low N : P ratio P, possibly associated with preferential remineralization of P versus N, persists throughout the season.

scholarly journals New insights on resource stoichiometry: assessing availability of carbon, nitrogen, and phosphorus to bacterioplankton

2017 ◽  
Vol 14 (6) ◽  
pp. 1527-1539 ◽  
Author(s):  
Ana R. A. Soares ◽  
Ann-Kristin Bergström ◽  
Ryan A. Sponseller ◽  
Joanna M. Moberg ◽  
Reiner Giesler ◽  
...  
Keyword(s):  
General Pattern ◽  
Relative Bioavailability ◽  
Boreal Lakes ◽  
Base Flow ◽  
Nitrogen And Phosphorus ◽  
Dissolved Phosphorus ◽  
Dissolved Nitrogen ◽  
Total Dissolved Nitrogen ◽  
Main Fraction ◽  
High Bioavailability

Abstract. Boreal lake and river ecosystems receive large quantities of organic nutrients and carbon (C) from their catchments. How bacterioplankton respond to these inputs is not well understood, in part because we base our understanding and predictions on total pools, yet we know little about the stoichiometry of bioavailable elements within organic matter. We designed bioassays with the purpose of exhausting the pools of readily bioavailable dissolved organic carbon (BDOC), bioavailable dissolved nitrogen (BDN), and bioavailable dissolved phosphorus (BDP) as fast as possible. Applying the method in four boreal lakes at base-flow conditions yielded concentrations of bioavailable resources in the range 105–693 µg C L−1 for BDOC (2 % of initial total DOC), 24–288 µg N L−1 for BDN (31 % of initial total dissolved nitrogen), and 0.2–17 µg P L−1 for BDP (49 % of initial total dissolved phosphorus). Thus, relative bioavailability increased from carbon (C) to nitrogen (N) to phosphorus (P). We show that the main fraction of bioavailable nutrients is organic, representing 80 % of BDN and 61 % of BDP. In addition, we demonstrate that total C : N and C : P ratios are as much as 13-fold higher than C : N and C : P ratios for bioavailable resource fractions. Further, by applying additional bioavailability measurements to seven widely distributed rivers, we provide support for a general pattern of relatively high bioavailability of P and N in relation to C. Altogether, our findings underscore the poor availability of C for support of bacterial metabolism in boreal C-rich freshwaters, and suggest that these ecosystems are very sensitive to increased input of bioavailable DOC.

scholarly journals New insights on resource stoichiometry: assessing availability of carbon, nitrogen and phosphorus to bacterioplankton

2016 ◽  
Author(s):  
Ana R. A. Soares ◽  
Ann-Kristin Bergström ◽  
Ryan A. Sponseller ◽  
Joanna M. Moberg ◽  
Reiner Giesler ◽  
...  
Keyword(s):  
General Pattern ◽  
Relative Bioavailability ◽  
Boreal Lakes ◽  
Base Flow ◽  
Limiting Factor ◽  
Nitrogen And Phosphorus ◽  
Dissolved Phosphorus ◽  
Dissolved Nitrogen ◽  
Total Dissolved Nitrogen ◽  
Nutrient Resources

Abstract. Boreal lake and river ecosystems receive large quantities of organic nutrients and carbon (C) from their 10 catchments. How bacterioplankton respond to these inputs is not well understood, in part because we base our understanding and predictions on "total pools", yet we know little about the stoichiometry of bioavailable elements within the organic matter. We designed bioassays with the purpose to exhaust the pools of readily bioavailable dissolved organic carbon (BDOC), bioavailable dissolved nitrogen (BDN) and bioavailable dissolved phosphorus (BDP) as fast as possible. Applying the method in four boreal lakes at base flow conditions yielded concentrations of bioavailable resources that ranged from 105–693 μg C L−1 for BDOC (2 % of total DOC), 24–288 μg N L−1 for BDN (31 % of total dissolved nitrogen) and 0.2–17 μg P L−1 for BDP (49 % of total dissolved phosphorus). Thus, relative bioavailability increased from carbon (C) to nitrogen (N) to phosphorus (P). We show that the main part of bioavailable nutrient resources is organic, representing 80 % of BDN and 61 % of BDP. In addition, we demonstrate that total C : N and C : P ratios are as much as 13-fold higher than C : N and C : P ratios for bioavailable resource fractions. Further, by applying additional bioavailability measurements to seven widely 20 distributed rivers, we provide support for a general pattern of relatively high bioavailability of P and N in relation to C. Altogether, our findings underscore the role of C as limiting factor for bacterial growth in boreal C-rich freshwaters, and suggest that these ecosystems are very sensitive to increased input of bioavailable DOC.

scholarly journals Efficiency of aquatic macrophytes to treat Nile tilapia pond effluents

2006 ◽  
Vol 63 (5) ◽  
pp. 433-438 ◽  
Author(s):  
Gustavo Gonzaga Henry-Silva ◽  
Antonio Fernando Monteiro Camargo
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Nile Tilapia ◽  
Aquatic Macrophytes ◽  
Fish Farming ◽  
Pistia Stratiotes ◽  
Fish Pond ◽  
Nitrogen And Phosphorus ◽  
Dissolved Phosphorus ◽  
Dissolved Nitrogen

The effluents from fish farming can increase the quantity of suspended solids and promote the enrichment of nitrogen and phosphorus in aquatic ecosystems. In this context, the aim of this work was to evaluate the efficiency of three species of floating aquatic macrophytes (Eichhornia crassipes, Pistia stratiotes and Salvinia molesta) to treat effluents from Nile tilapia culture ponds. The effluent originated from a 1,000-m² pond stocked with 2,000 male Nile tilapia Oreochromis niloticus. The treatment systems consisted of 12 experimental tanks, three tanks for each macrophyte species, and three control tanks (without plants). Water samples were collected from the: (i) fish pond source water, (ii) effluent from fish pond and (iii) effluents from the treatment tanks. The following water variables were evaluated: turbidity, total and dissolved nitrogen, ammoniacal-N, nitrate-N, nitrite-N, total phosphorus and dissolved phosphorus. E. crassipes and P. stratiotes were more efficient in total phosphorus removal (82.0% and 83.3%, respectively) and total nitrogen removal (46.1% and 43.9%, respectively) than the S. molesta (72.1% total phosphorus and 42.7% total nitrogen) and the control (50.3% total phosphorus and 22.8% total nitrogen), indicating that the treated effluents may be reused in the aquaculture activity.

Long-term changes in climate, streamflow, and nutrient budgets for first-order catchments at the Experimental Lakes Area (Ontario, Canada)This paper is part of the series “Forty Years of Aquatic Research at the Experimental Lakes Area”.

2009 ◽  
Vol 66 (11) ◽  
pp. 1848-1863 ◽  
Author(s):  
Brian R. Parker ◽  
David W. Schindler ◽  
Ken G. Beaty ◽  
Michael P. Stainton ◽  
Susan E.M. Kasian
Keyword(s):  
Forest Succession ◽  
Summer Precipitation ◽  
Experimental Lakes Area ◽  
Dissolved Nitrogen ◽  
Total Dissolved Nitrogen ◽  
Apparent Relationship ◽  
Central United States ◽  
Long Term Trends ◽  
Lake Catchment

We analyzed 36 years of records for climate, hydrology, and the chemistry of precipitation and runoff from the Lake 239 (Rawson Lake) catchment at the Experimental Lakes Area (Ontario, Canada). No evidence of significant periodicity was found for any variable in the Experimental Lakes Area records. The longer (67-year) record from nearby Kenora, Ontario, revealed a 31-year cycle in precipitation but not temperature. Significant increasing long-term trends at the Experimental Lakes Area were found for annual and winter temperature and summer precipitation and deposition of ammonium, total nitrogen (TN), and total dissolved nitrogen (TDN). Large (80%) increases in ammonium deposition appear to be related to higher emissions in the central United States. A significant negative trend for dissolved organic carbon (DOC) in precipitation cannot be explained. In runoff, significant positive trends were found for TDN and DOC in the northeast catchment and TN, TDN, ammonium, and DOC in the northwest. Significant negative trends were found for TDP and nitrate in the northeast. Significant increases were found for retention of ammonium in all catchments and DOC in the northeast and northwest. There was no apparent relationship between forest succession and retention of nutrients. Results are compared with those from three other long-term monitoring sites in eastern North America.

Pelagic distribution of lake trout (Salvelinus namaycush) in small Canadian Shield lakes with respect to temperature, dissolved oxygen, and light

1998 ◽  
Vol 55 (1) ◽  
pp. 170-179 ◽  
Author(s):  
Todd J Sellers ◽  
Brian R Parker ◽  
David W Schindler ◽  
William M Tonn
Keyword(s):  
Light Intensity ◽  
Dissolved Oxygen ◽  
Lake Trout ◽  
Salvelinus Namaycush ◽  
Canadian Shield ◽  
Small Lakes ◽  
Experimental Lakes Area ◽  
Northwestern Ontario ◽  
Oxygenated Water ◽  
Shield Lakes

The distribution of lake trout (Salvelinus namaycush) with respect to water temperature, dissolved oxygen, and light intensity was surveyed in three small Canadian Shield lakes at the Experimental Lakes Area, northwestern Ontario. Based on hydroacoustic and gillnet surveys, there was considerable variation among lakes in temperatures occupied by lake trout during the summer. During the day, lake trout were concentrated at 4-8°C in Lake 375, broadly distributed from 6 to 15°C in Lake 442, and concentrated in the epilimnion at 19°C in Lake 468. At night, lake trout in all lakes occupied epilimnetic waters at 19-20°C. Lake trout inhabited highly oxygenated water, with 75-90% of fish at >6 mg dissolved oxygen ·L-1 throughout the spring and summer in all three lakes. Light intensity did not affect lake trout distribution in Lake 468 but may have contributed to lake trout daytime descent into cool waters in Lakes 375 and 442. We suggest that previously assumed niche boundaries of lake trout do not adequately describe critical habitat for the species in small lakes, the same lakes that are likely most sensitive to erosion of such habitat.

Aquatic acetylene-reduction techniques: solutions to several problems

1976 ◽  
Vol 22 (1) ◽  
pp. 43-51 ◽  
Author(s):  
R. J. Flett ◽  
R. D. Hamilton ◽  
N. E. R. Campbell
Keyword(s):  
Nitrogen Fixation ◽  
Depth Profile ◽  
Acetylene Reduction ◽  
Canadian Shield ◽  
Experimental Lakes Area ◽  
Reduction Techniques ◽  
Northwestern Ontario ◽  
Refined Technique

Previous methods of performing aquatic acetylene-reduction assays are described and several problems associated with them are discussed. A refinement of these older techniques is introduced and problems that it overcomes are also discussed. A depth profile of nitrogen fixation (C2H4 production), obtained by the refined technique, is shown for a fertilized Canadian Shield lake in the Experimental Lakes Area of northwestern Ontario.

scholarly journals Investigation of nitrogen and phosphorus contents in water in the tributaries of Danjiangkou Reservoir

2018 ◽  
Vol 5 (1) ◽  
pp. 170624 ◽  
Author(s):  
Yan Liu ◽  
Yuanyuan Zhu ◽  
Xiaocui Qiao ◽  
Binghui Zheng ◽  
Sheng Chang ◽  
...  
Keyword(s):  
Inorganic Nitrogen ◽  
Organic Pollution ◽  
Test Results ◽  
Nitrogen And Phosphorus ◽  
Danjiangkou Reservoir ◽  
Dissolved Phosphorus ◽  
Dissolved Nitrogen ◽  
Quality Water ◽  
The Government ◽  
Surface Water Samples

As part of the efforts to ensure adequate supply of quality water from Danjiangkou Reservoir to Beijing, surface water samples were taken from the tributaries of Danjiangkou Reservoir in the normal (May), flood (August) and dry (December) seasons of 2014, and characterized for nitrogen and phosphorus contents as specified in the applicable standards. Test results indicated that (i) the organic pollution in the Sihe and Shendinghe rivers was more serious than those in other tributaries, and the concentrations of nitrogen and phosphorus favoured the growth of most algae; (ii) total phosphorus (TP), total nitrogen (TN) and dissolved inorganic nitrogen (DIN) were in the forms of dissolved phosphorus (DTP), dissolved nitrogen (DTN) and nitrate nitrogen ( NO 3 − -N ) , respectively, in these seasons; (iii) compared with nitrogen, phosphorus was more likely to block an overrun of phytoplankton; (iv) TN, TP, permanganate index (COD Mn ) and other ions were positively correlated. These findings are helpful for the government to develop effective measures to protect the source water in Danjingkou Reservoir from pollution.

scholarly journals Responses of Free-Living Vibrio Community to Seasonal Environmental Variation in a Subtropical Inland Bay

2020 ◽  
Vol 11 ◽  
Author(s):  
Xing Chen ◽  
Huaxian Zhao ◽  
Gonglingxia Jiang ◽  
Jinli Tang ◽  
Qiangsheng Xu ◽  
...  
Keyword(s):  
Inorganic Nitrogen ◽  
Environmental Variation ◽  
Mantel Test ◽  
Beibu Gulf ◽  
Test Analysis ◽  
Dissolved Phosphorus ◽  
Dissolved Nitrogen ◽  
Β Diversity ◽  
Total Dissolved Nitrogen ◽  
Filtering Effect

Vibrio are widely distributed in aquatic environments and strongly associated with eutrophic environments and human health through the consumption of contaminated seafood. However, the response of the Vibrio community to seasonal variation in eutrophic environments is poorly understood. In this study, we used a Vibrio-specific 16S rRNA sequencing approach to reveal the seasonal distribution pattern and diversity of the Vibrio community in the Maowei Sea, Beibu Gulf of China. The Shannon diversity of the Vibrio community was highest in the summer, while β-diversity analysis showed that Vibrio community structures were significantly different between seasons. Distance-based redundancy analysis (dbRDA) and Mantel test analysis suggested that total dissolved nitrogen (TDN), total dissolved phosphorus (TDP), dissolved inorganic nitrogen (DIN), salinity, and temperature were the key environmental factors shaping the Vibrio community structure, indicating a strong filtering effect of trophic condition on Vibrio communities. Furthermore, through random forest analysis, V. fluvialis, V. alginolyticus, V. proteolyticus, V. splendidus, and the other eight Vibrio species were more sensitive to eutrophic changes. This study revealed seasonal changes in Vibrio communities and the influence of environmental variation on Vibrio community composition, contributing to a better understanding of their potential ecological roles in a subtropical inland bay.

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