Taste and odour and cyanobacterial toxins: impairment, prediction, and management in the Great Lakes

2008 ◽  
Vol 65 (8) ◽  
pp. 1779-1796 ◽  
Author(s):  
Susan B. Watson ◽  
Jeff Ridal ◽  
Gregory L. Boyer
Keyword(s):  
Water Treatment ◽  
Great Lakes ◽  
Nutrient Management ◽  
Management Strategies ◽  
Remedial Action ◽  
Management Framework ◽  
Biomass Models ◽  
Plankton Biomass ◽  
Nuisance Species ◽  
Broad Scale

This paper reviews the issues associated with algal–cyanobacterial taste–odour (T&O) compounds and toxins in the Great Lakes. As with other remediated water bodies, the Great Lakes have undergone significant shifts in nutrient and food-web regimes and are exhibiting erratic blooms and noxious algal metabolite (NAM) outbreaks, despite reduced offshore nutrient levels. We appraise the chemistry, biota, and distribution of NAM impairments and conclude that management strategies based on lakewide monitoring and remedial action plans are often unsuccessful because they attempt NAM control through an unsustainable reliance on water treatment and broad-scale nutrient–biomass models. This approach is undermined by several factors: (i) only some species produce NAMs; (ii) different taxa show disparate patterns across nutrient and mixing regimes; (iii) nuisance species may be planktonic or benthic and located outside remedial boundaries; and (iv) species differ significantly in NAM biochemistry and release. Thus, there are no robust relationships between total plankton biomass, toxins, and T&O compounds in these and other source waters. Given the potential ecological and socioeconomic threats posed by NAM outbreaks, there is a critical need to develop a multistep management framework based on more stringent restoration targets, combining broad-scale screening and nutrient management with system and taxa-specific approaches.

Connecting Crop Nutrient Use Efficiency to Future Soil Productivity

2018 ◽  
Vol 102 (4) ◽  
pp. 8-10
Author(s):  
Fernando García ◽  
Andrés Grasso ◽  
María González Sanjuan ◽  
Adrián Correndo ◽  
Fernando Salvagiotti
Keyword(s):  
Nutrient Management ◽  
Nutrient Use Efficiency ◽  
Management Strategies ◽  
Crop Productivity ◽  
Soil Productivity ◽  
Nutrient Use ◽  
Grain Crop ◽  
Wide Scale ◽  
Use Efficiency

Trends over the past 25 years indicate that Argentina’s growth in its grain crop productivity has largely been supported by the depletion of the extensive fertility of its Pampean soils. Long-term research provides insight into sustainable nutrient management strategies ready for wide-scale adoption.

Considerations in the Design of the Primary Treatment for Ballast Systems

2003 ◽  
Vol 40 (01) ◽  
pp. 49-60
Author(s):  
Michael G. Parsons
Keyword(s):  
Water Treatment ◽  
Great Lakes ◽  
Ballast Water ◽  
Primary Treatment ◽  
Coast Guard ◽  
Secondary Treatment ◽  
Bulk Carrier ◽  
Ballast Water Treatment ◽  
Mechanical Separation ◽  
Hierarchy Process

Investigations are currently underway to establish effective primary and secondary ballast water treatment methods to minimize the potential for the introduction of additional nonindigenous aquatic species into the Great Lakes and other U.S. coastal waters. This treatment could be used in place of mid-ocean ballast exchange currently required by the U.S. Coast Guard for all vessels entering the Great Lakes in ballast from beyond the Exclusive Economic Zone (EEZ). Primary and secondary treatment could provide environmental protection for both Ballast On Board (BOB) vessels, which are required to perform mid-ocean ballast exchange before entering the Great Lakes, and No Ballast On Board (NOBOB) vessels, which are currently exempt from any ballast exchange requirements. Primary treatment using some form of mechanical separation to 100 urn or 50 um followed by secondary treatment using 254 nm UV irradiation or some form of chemical treatment are currently leading candidates. Over the past six years, the Great Lakes Ballast Technology Demonstration Project (GLBTDP) has undertaken the full-scale evaluation of 340 m3/h (1500 U.S. gpm) ballast water mechanical separation using an automatic backwashing screen filter, hydrocyclone, and automatic backwashing disk filter. This experience provides the basis for the investigation of various ballast system design issues that must be considered in the selection and design of the primary ballast water treatment. This investigation is based upon the ballast system of a typical Seaway size bulk carrier using port and starboard 2000 m3/h (8800 U.S. gpm) main ballast pumps. A discrete multicriterion optimization tradeoff study using the Analytical Hierarchy Process (AHP) is also presented to illustrate a rational method for determining the best choice for primary ballast water treatment for such a Seaway size bulk carrier.

Management inferences from a demographic analysis of sea lamprey (Petromyzon marinus) in the Laurentian Great Lakes

2008 ◽  
Vol 65 (2) ◽  
pp. 227-244 ◽  
Author(s):  
Luis Antonio Vélez-Espino ◽  
Robert L McLaughlin ◽  
Thomas C Pratt
Keyword(s):  
Great Lakes ◽  
Life Stage ◽  
Petromyzon Marinus ◽  
Management Strategies ◽  
Sea Lamprey ◽  
Management Plan ◽  
Laurentian Great Lakes ◽  
Alternative Methods ◽  
Vital Rates ◽  
Population Growth Rates

We use matrix models incorporating uncertainty in values of life history traits and density-dependent survival to assess pest management strategies implemented by the Great Lakes Fishery Commission to control nonnative sea lamprey (Petromyzon marinus) in the Laurentian Great Lakes. The primary method of sea lamprey control has been treatment of rearing tributaries with chemical lampricides, but release of sterilized males and deployment of migratory barriers and traps are important components of the management plan. Uncertainties in the effectiveness of alternative control remain, however. Our models demonstrated that the management target of reducing lampricide use by 20% while maintaining current levels of control could be achieved if alternative methods are used to suppress current lake-wide fecundity rates by 49%–65%, assuming equal lampricide efficiency on larvae and metamorphosing individuals, or by 42%–55% when lampricide mortality on larvae is assumed to be half of that on metamorphosing individuals. At current levels of lampricide use, reduction to 72%–88% of current fecundity rates is recommended to ensure long-term control of sea lamprey populations in the face of uncertainty in current estimates of population growth rates. New control options targeting additional vital rates, such as survival of the parasitic life stage, could further reduce reliance on lampricides while maintaining effective sea lamprey control.

scholarly journals Effects of Irrigation and Fertilization on the Morphophysiological Traits of Populus sibirica Hort. Ex Tausch and Ulmus pumila L. in the Semiarid Steppe Region of Mongolia

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2407
Author(s):  
Ser-Oddamba Byambadorj ◽  
Byung Bae Park ◽  
Jonathan O. Hernandez ◽  
Enkhchimeg Tsedensodnom ◽  
Otgonsaikhan Byambasuren ◽  
...  
Keyword(s):  
Leaf Area ◽  
Nutrient Management ◽  
Sustainable Forest Management ◽  
Management Strategies ◽  
Semiarid Region ◽  
Leaf Biomass ◽  
Ulmus Pumila ◽  
Rainfall Events ◽  
Arid And Semiarid Ecosystems ◽  
Arid And Semiarid

Desertification is impeding the implementation of reforestation efforts in Mongolia. Many of these efforts have been unsuccessful due to a lack of technical knowledge on water and nutrient management strategies, limited financial support, and short-lived rainfall events. We investigated the effects of irrigation and fertilization on the morphophysiological traits of Populus sibirica Hort. Ex Tausch and Ulmus pumila L. and to suggest irrigation and fertilization strategies for reforestation. Different irrigation and fertilizer treatments were applied: no irrigation, 2 L h−1, 4 L h−1, and 8 L h−1 of water; no fertilizer, 2 L h−1 + NPK, 4 L h−1 + NPK, and 8 L h−1 + NPK; and no compost, 2 L h−1 + compost, 4 L h−1 + compost, and 8 L h−1 + compost. The leaf area (LA) and specific leaf area (SLA) of both species responded positively to 4 and 8 L h−1. Results also showed that the addition of either NPK or compost to 4 or 8 L h−1 irrigation resulted in a higher LA, SLA, and leaf biomass (LB). Total chlorophyll content decreased with irrigation in both species. The same pattern was detected when a higher amount of irrigation was combined with fertilizers. Lastly, we found that both diurnal and seasonal leaf water potential of plants grown in 4 or 8 L h−1 were significantly higher than those of plants grown in control plots. Therefore, 4 or 8 L h−1 with either NPK or compost has shown to be the optimal irrigation and fertilization strategy for the species in an arid and semiarid region of Mongolia. Results should provide us with a better understanding of tree responses to varying amounts of irrigation with or without fertilizer in pursuit of sustainable forest management in arid and semiarid ecosystems.

scholarly journals Seasonal Nearshore Occurrence of the Neurotoxin β N methylamino L alanine (BMAA) in Lake Winnipeg, Canada

2016 ◽  
Vol 5 (1) ◽  
pp. 110 ◽  
Author(s):  
Eva Pip ◽  
Kimber Munford ◽  
Lindsay Bowman
Keyword(s):  
Chlorophyll A ◽  
Nutrient Management ◽  
Management Strategies ◽  
Seasonal Fluctuation ◽  
Inverse Correlation ◽  
Water Quality Monitoring ◽  
Inorganic Phosphorus ◽  
Lake Winnipeg ◽  
Nitrate N ◽  
Shading Effects

Seasonal fluctuation patterns of the neurotoxic amino acid β N methylamino L alanine (BMAA) were examined at four-day intervals during the ice-free season in water at three nearshore stations in the south basin of Lake Winnipeg, Canada. BMAA patterns were significantly exponentially correlated with concurrent phaeophytin, and inversely with chlorophyll a, indicating that free BMAA concentrations increased as blooms declined. BMAA was also significantly related to preceding microcystin concentrations, and as chlorophyll a declined, the proportion of BMAA relative to microcystin increased. Cross correlations identified significant relationships between BMAA and immediately preceding nitrate-N/inorganic phosphorus ratios, nitrate-N, rainfall, and a marginal inverse correlation with inorganic phosphorus. Total suspended solids levels were also significantly associated with BMAA, likely due to shading effects. A very high BMAA concentration was found under collapse of intense bloom conditions. These results have implications for water quality monitoring, nutrient management strategies and public health.

Enhanced nitrogen management strategies for winter wheat production in the Canadian prairies

2018 ◽  
Vol 98 (3) ◽  
pp. 683-702 ◽  
Author(s):  
B.L. Beres ◽  
R.J. Graf ◽  
R.B. Irvine ◽  
J.T. O’Donovan ◽  
K.N. Harker ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Nutrient Management ◽  
Management Strategies ◽  
Maximum Yield ◽  
Nitrification Inhibitor ◽  
Early Spring ◽  
Nitrification Inhibitors ◽  
Side Band ◽  
Application Method

To address knowledge gaps around enhanced efficiency urea fertilizer efficacy for nitrogen (N) management, a study was designed to improve integrated nutrient management systems for western Canadian winter wheat producers. Three factors were included in Experiment 1: (i) urea type [urea, urea + urease inhibitor—Agrotain®; urea + urease and nitrification inhibitor—SuperU®, polymer-coated urea—Environmentally Smart Nitrogen® (ESN®), and urea ammonium nitrate (UAN)], (ii) application method (side-band vs. spring-broadcast vs. 50% side-band: 50% spring-broadcast), and (iii) cultivar (AC Radiant hard red winter wheat vs. CDC Ptarmigan soft white winter wheat). The Agrotain® and CDC Ptarmigan treatments were removed in Experiment 2 to allow for additional application methods: (i) fall side-band, (ii) 50% side-band — 50% late fall broadcast, (iii) 50% side-band — 50% early spring broadcast, (iv) 50% side-band — 50% mid-spring broadcast, and (v) 50% side-band — 50% late spring broadcast. CDC Ptarmigan produced superior grain yield and N utilization over AC Radiant. Grain yield and protein content were influenced by N form and application method. Split applications of N usually provided the maximum yield and protein, particularly with Agrotain® or SuperU®. An exception to the poor fall-application results was the SuperU® treatments, which produced similar yield to the highest-yielding treatments. The results suggest that split applications of N might be most efficient for yield and protein optimization when combined with an enhanced efficiency urea product, particularly with urease or urease + nitrification inhibitors, and if the majority of N is applied in spring.

Nutrient Management Strategies on Heterogeneously Fertile Granitic-Derived Soils in Subhumid Zimbabwe

2015 ◽  
Vol 107 (3) ◽  
pp. 1068-1076 ◽  
Author(s):  
Natasha Kurwakumire ◽  
Regis Chikowo ◽  
Shamie Zingore ◽  
Florence Mtambanengwe ◽  
Paul Mapfumo ◽  
...  
Keyword(s):  
Nutrient Management ◽  
Management Strategies

scholarly journals Micronutrient fractionation and plant availability in bauxite-processing residue sand

Soil Research ◽  
2009 ◽  
Vol 47 (5) ◽  
pp. 518 ◽  
Author(s):  
Chitdeshwari Thiyagarajan ◽  
I. R. Phillips ◽  
B. Dell ◽  
Richard W. Bell
Keyword(s):  
Nutrient Management ◽  
Total Concentration ◽  
Management Strategies ◽  
Sodium Content ◽  
Sand Particle ◽  
Leaf Analysis ◽  
Mn Oxide ◽  
Fe And Mn ◽  
Poor Nutritional Status ◽  
Low Levels

Bauxite-processing residue must be disposed of in specifically designed facilities for long-term management. Consideration of alkalinity, salinity, sodium content, and poor nutritional status is essential for successful rehabilitation of residue disposal areas (RDA). The aim of this study was to examine the availability and distribution of the micronutrients, B, Cu, Fe, Mn, and Zn, in (i) fresh bauxite-processing residue sand (particle size >150 μm) with and without gypsum amendment, and (ii) aged residue sand from a 4-year-old rehabilitated RDA that had received past gypsum and fertiliser addition. Samples of fresh residue sand from India and Australia exhibited high alkalinity, high salinity, and sodicity. Gypsum addition significantly lowered pH, soluble Na, and alkalinity. Aged residue sand had low levels of all micronutrients, with low extractability for Zn and Mn followed by B, Cu, and Fe. Fractionation showed that 30–78% of Zn and Mn and 40–60% of B existed in non-available (residual) forms. The next most dominant fractions were the Fe and Mn oxide-bound and carbonate-bound fractions. Plant-available fractions (i.e. exchangeable and organically bound) contributed <1% of the total concentration. Total concentration was found to be a reliable indicator for Zn, Cu, and B extractability but not for DTPA-extractable forms of Fe and Mn. Leaf analysis of vegetation grown on aged residue sand indicated deficiencies of Mn and B. Results demonstrated that bauxite-processing residue sand contained very low levels of B, Mn, and Zn and these concentrations may be limiting to plant growth. Distribution of micronutrients among chemical pools was significantly influenced by pH, organic carbon, exchangeable Na, and alkalinity of residue. Nutrient management strategies that account for the characteristics of residue sand need to be developed for residue rehabilitation. Importantly, strategies to limit the conversion of nutrients to non-available forms are required to minimise micronutrient disorders.

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