Reduction of Cladophora Biomass and Tissue Phosphorus in Lake Ontario, 1972–83

1987 ◽  
Vol 44 (12) ◽  
pp. 2212-2215 ◽  
Author(s):  
D. S. Painter ◽  
G. Kamaitis

Cladophora biomass and tissue phosphorus concentrations at seven sites in Lake Ontario have decreased from 1972 to 1983 in response to phosphorus control programs introduced in the early 1970's. Biomass and tissue phosphorus were significantly different between 1972 and 1982–83 (ANOVA, P < 0.001) but not significantly different between 1982 and 1983. The lakewide average tissue phosphorus was 0.49% in 1972 but by 1982 and 1983 had dropped to 0.26 and 0.20%, respectively, on an ash-free dry weight basis. Tissue phosphorus concentrations did not limit growth in 1972 but in 1983 had begun to limit growth. Model-predicted net production for a 6-wk sampling period in 1983 was 1.7 times greater in the western end of the lake than at a remote site in eastern Lake Ontario due to higher soluble reactive phosphorus concentrations.

1984 ◽  
Vol 41 (6) ◽  
pp. 985-988 ◽  
Author(s):  
A. H. El-Shaarawi ◽  
M. A. Neilson

Water samples were collected on Lake Ontario during April and November, filtered (0.45 μm), and immediately analyzed onboard ship for the nutrients soluble reactive phosphorus, nitrate-plus-nitrite, and ammonia. Replicates were stored in glass bottles at 4 °C and reanalyzed within 8 d. Statistical analysis showed that soluble reactive phosphorus decreased by 11 and 13% and nitrate-plus-nitrite by 7 and 6%, whereas ammonia increased by 75% on one cruise and decreased by 37% on the other.


1969 ◽  
Vol 47 (3) ◽  
pp. 405-413 ◽  
Author(s):  
C. Nalewajko ◽  
L. Marin

In four species of planktonic algae both carbon fixation and excretion on an ash-free dry weight basis increase with relative growth rate (K) of the culture measured in log10 units. In natural populations percentage excretion values are positively correlated with K values; however, environmental factors may be of relatively greater importance and determine the extent of excretion.


2021 ◽  
Author(s):  
Yulia Markunas ◽  
Vadim Bostan ◽  
Andrew Laursen ◽  
Michael Payne ◽  
Lynda McCarthy

The impacts of biosolids land application on soil phosphorus and subsequent vertical migration to tile drainage were assessed in a laboratory setup. Soil, representing typical “nonresponse” Ontario soil as specified by Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA), was amended with anaerobically digested biosolids at a rate of 8Mgha−1 (dry weight). Over five months, these amended soil samples from two different depths were sequentially fractionated to determine various inorganic and organic phosphorus pools in order to evaluate phosphorus vertical migration within a soil profile. Soil leachate was analyzed for soluble reactive phosphorus.The results indicated that biosolids application did not significantly affect phosphorus concentrations in soil and did not cause phosphorus vertical migration. The concentrations of soluble reactive phosphorus also were not significantly affected by biosolids.


2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Yulia Markunas ◽  
Vadim Bostan ◽  
Andrew Laursen ◽  
Michael Payne ◽  
Lynda McCarthy

The impacts of biosolids land application on soil phosphorus and subsequent vertical migration to tile drainage were assessed in a laboratory setup. Soil, representing typical “nonresponse” Ontario soil as specified by Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA), was amended with anaerobically digested biosolids at a rate of 8 Mg ha−1 (dry weight). Over five months, these amended soil samples from two different depths were sequentially fractionated to determine various inorganic and organic phosphorus pools in order to evaluate phosphorus vertical migration within a soil profile. Soil leachate was analyzed for soluble reactive phosphorus. The results indicated that biosolids application did not significantly affect phosphorus concentrations in soil and did not cause phosphorus vertical migration. The concentrations of soluble reactive phosphorus also were not significantly affected by biosolids.


1987 ◽  
Vol 44 (12) ◽  
pp. 2059-2068 ◽  
Author(s):  
R. J. J. Stevens ◽  
M. A. Neilson

Total phosphorus (TP) loading to Lake Ontario has declined from 14 600 t∙yr−1 in 1969 to 8900 t∙yr−1 in 1982. Midlake spring TP has responded rapidly to these reductions, decreasing at the rate of 1.09 μg∙L−1∙yr−1 from a maximum of 30.6 μg∙L−1 in 1973 to 12.8 μg∙L−1 in 1982. Spring soluble reactive phosphorus (SRP) exhibited a proportionally larger decrease than TP such that 1982 SRP was 33% of 1973 levels, compared with 42% for TP. A multiple regression equation indicated an 80% response time of spring TP within 2 yr and a 90% response time within 4 yr. Spring nitrate plus nitrite has increased since 1969 at the rate of 9.5 μg∙L−1∙yr−1 causing N:P ratios to increase from 10 to 32. Mean summer epilimnetic TP declined at the rate of only 0.3 μg∙L−1∙yr−1 from 1977 to 1982 so that mean summer TP levels now exceed spring TP by 1–2 μg∙L−1. This suggests that loading to the lake during the stratified period has not shown a similar decline and may be responsible for the lack of a trend in algal biomass indicators during this period.


1984 ◽  
Vol 62 (11) ◽  
pp. 2290-2296 ◽  
Author(s):  
J. P. Hoffmann ◽  
J. A. Colman ◽  
K. M. Kutchera ◽  
E. V. Nordheim ◽  
J. H. Andrews

A biphasic system was designed for growing rooted Eurasian water milfoil, Myriophyllum spicatum L., to avoid artificial characteristics of flask culture. Aquaria (21 L) containing undergravel filters, air-lift pumps, 50-W heaters, and Plexiglas lids were sterilized in 70% ethanol and assembled aseptically. Plant shoots were rooted separately in polypropylene cups containing 60 g of artificial sediment approximating natural marl. The sediment provided over 90% of the nitrogen and phosphorus in the plants after 22 days growth. Plants were immersed in a mineral-salts medium with levels of nitrogen and phosphorus comparable with lake concentrations. Aeration was at 0.15 L ∙ min−1 and ranges of temperature and light intensity were from 17 to 32 °C and 30 to 250 μE ∙ m−2 ∙ s−1, respectively. The peak photosynthetic rate was 14 mg O2 ∙ g dry weight−1 ∙ h−1. The maximum specific growth rate, 0.14 mg ∙ mg−1 ∙ day−1, occurred at 27 °C and 250 μE ∙ m−2 ∙ s−1 and lasted for about 3 weeks before light became limiting. Bacterial density, ammonium nitrogen, soluble reactive phosphorus, and total phosphorus exhibited rapid changes during the first 12 days of the growth period, after which fluctuations diminished. The between-aquaria variance in shoot growth rate was insignificant (P > 0.70). When inorganic carbon in the liquid medium and phosphorus in the sediment were lowered from 2.86 to 1.14 mmol C ∙ L−1 and from 0.7 to 0.2 mg P ∙ g dry weight−1, milfoil growth was reduced by 47 and 74%, respectively. Control of the physiochemical environment, small variability, and high reproducibility make this a sensitive system for discerning various treatment effects, including those of pathogens.


1987 ◽  
Vol 44 (12) ◽  
pp. 2192-2203 ◽  
Author(s):  
M. A. Neilson ◽  
R. J. J. Stevens

During spring, Lake Ontario was vertically homogeneous except for the bottom 2 m where soluble reactive silica (SRS) and temperature (TEMP) were significantly (p < 0.05) elevated and dissolved oxygen was depleted. With stratification, soluble reactive phosphorus (SRP) and total filtered phosphorus, SRS, and nitrate-plus-nitrite were depleted in the epilimnion due to phytoplankton uptake. Total unfiltered phosphorus (TP) and ammonia (NH3) exhibited higher epilimnetic concentrations, the former being attributed to tributary inputs which were maintained throughout the stratified period, even though inputs from Niagara River served to dilute the epilimnion. Increased levels of TP, SRP, and SRS were also evident within the nepheloid layer. Horizontal distributions of TP and NH3 were governed by point-source inputs throughout the study period. Distributions of the soluble nutrients were governed by phytoplankton uptake in the spring, point/nonpoint inputs and upwelling in the summer, and differential breakdown of stratification in the fall. Spring distribution of particulate organic matter (POM) was strongly related to nutrient availability and water column stability, while phytoplankton species composition determined fall POM distribution. Significantly higher (p < 0.05) POM levels, detrital content, and productivity were observed nearshore of the thermal bar.


2021 ◽  
Author(s):  
Yulia Markunas ◽  
Vadim Bostan ◽  
Andrew Laursen ◽  
Michael Payne ◽  
Lynda McCarthy

The impacts of biosolids land application on soil phosphorus and subsequent vertical migration to tile drainage were assessed in a laboratory setup. Soil, representing typical “nonresponse” Ontario soil as specified by Ontario Ministry of Agriculture, Food, and Rural Affairs (OMAFRA), was amended with anaerobically digested biosolids at a rate of 8Mgha−1 (dry weight). Over five months, these amended soil samples from two different depths were sequentially fractionated to determine various inorganic and organic phosphorus pools in order to evaluate phosphorus vertical migration within a soil profile. Soil leachate was analyzed for soluble reactive phosphorus.The results indicated that biosolids application did not significantly affect phosphorus concentrations in soil and did not cause phosphorus vertical migration. The concentrations of soluble reactive phosphorus also were not significantly affected by biosolids.


Author(s):  
I.M. Ritchie ◽  
C.C. Boswell ◽  
A.M. Badland

HERBACE DISSECTION is the process in which samples of herbage cut from trials are separated by hand into component species. Heavy reliance is placed on herbage dissection as an analytical tool ,in New Zealand, and in the four botanical analysis laboratories in the Research Division of the Ministry of Agriculture and Fisheries about 20 000 samples are analysed each year. In the laboratory a representative subsample is taken by a rigorous quartering procedure until approximately 400 pieces of herbage remain. Each leaf fragment is then identified to species level or groups of these as appropriate. The fractions are then dried and the composition calculated on a percentage dry weight basis. The accuracy of the analyses of these laboratories has been monitored by a system of interchanging herbage dissection samples between them. From this, the need to separate subsampling errors from problems of plant identification was, appreciated and some of this work is described here.


1996 ◽  
Vol 31 (2) ◽  
pp. 411-432 ◽  
Author(s):  
Michael E. Comba ◽  
Janice L. Metcalfe-Smith ◽  
Klaus L.E. Kaiser

Abstract Zebra mussels were collected from 24 sites in Lake Erie, Lake Ontario and the St. Lawrence River between 1990 and 1992. Composite samples of whole mussels (15 sites) or soft tissues (9 sites) were analyzed for residues of organochlo-rine pesticides and PCBs to evaluate zebra mussels as biomonitors for organic contaminants. Mussels from most sites contained measurable quantities of most of the analytes. Mean concentrations were (in ng/g, whole mussel dry weight basis) 154 ΣPCB, 8.4 ΣDDT, 3.5 Σchlordane, 3.4 Σaldrin, 1.4 ΣBHC, 1.0 Σendosulfan, 0.80 mirex and 0.40 Σchlorobenzene. Concentrations varied greatly between sites, i.e., from 22 to 497 ng/g for ΣPCB and from 0.08 to 11.6 ng/g for ΣBHC, an indication that mussels are sensitive to different levels of contamination. Levels of ΣPCB and Σendosulfan were highest in mussels from the St. Lawrence River, whereas mirex was highest in those from Lake Ontario. Overall, mussels from Lake Erie were the least contaminated. These observations agree well with the spatial contaminant trends shown by other biomoni-toring programs. PCB congener class profiles in zebra mussels are also typical for nearby industrial sources, e.g., mussels below an aluminum casting plant contained 55% di-, tri- and tetrachlorobiphenyls versus 31% in those upstream. We propose the use of zebra mussels as biomonitors of organic contamination in the Great Lakes.


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