Numerical simulation of water quality response to nutrient loading and sediment resuspension in Mikawa Bay, central Japan: quantitative evaluation of the effects of nutrient-reduction measures on algal blooms

<em>Abstract</em>.—A CE-QUAL-W2 water quality model was used to characterize the availability of striped bass <em>Morone saxatilis</em> habitat in Lake Greenwood, South Carolina, during 2004 and 2005. Although the lake has a productive fishery, water quality and aquatic habitat are affected by nutrient loading, algal blooms, and extensive oxygen depletion in the bottom waters. The main objectives were to characterize habitat availability and predict the implications of a change in phosphorus loading from the Saluda and Reedy rivers. The baseline scenario of the model showed that habitat was most critical during July and August, when as little of 5% of the reservoir contained tolerable habitat (temperature <28°C and dissolved oxygen >2 mg/L). Favorable habitat (temperature <25°C and dissolved oxygen >2 mg/L) was usually absent for most of July and August. Pulses of higher inflow or freshets produced short-term increases in tolerable habitat, especially in the upper end of the reservoir. Phosphorus-loading scenarios predicted that large reductions (50% or more) would be required to improve habitat substantially during midsummer. For the manager of a striped bass fishery, water quality models can be useful tools for evaluating habitat, especially under marginal conditions, and for predicting the impact of altered water management practices.

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On the potential for saturated buffers in northwest Ohio to remediate nutrients from agricultural runoff

PeerJ ◽

10.7717/peerj.9007 ◽

2020 ◽

Vol 8 ◽

pp. e9007

Author(s):

Stephen J. Jacquemin ◽

Greg McGlinch ◽

Theresa Dirksen ◽

Angela Clayton

Keyword(s):

Algal Blooms ◽

Nutrient Loading ◽

Riparian Zone ◽

Suspended Sediments ◽

Agricultural Runoff ◽

Controlled Drainage ◽

Nutrient Reduction ◽

Nitrogen And Phosphorus ◽

Western Basin ◽

Nutrient Runoff

Nutrient loading from nonpoint source runoff in the Midwest has emerged as one of the largest threats to water quality as the frequency of harmful algal blooms, hypoxic zones, and issues associated with human-resource interactions have risen abruptly over the past several decades. In this study, a saturated buffer ~500 m in length located in the western basin of the Lake Erie watershed was evaluated for its potential to reduce edge of field runoff and nutrient loading. Saturated buffers reduce runoff by routing subsurface tile drainage water into the riparian zone, providing an opportunity for drainage volume as well as nutrient reduction of runoff waters. Over a 12-month study period, controlled drainage was used to redirect nearly 25% of the total tile flow into the riparian zone from a subwatershed in corn/soybean rotation with near complete reductions of dissolved nitrogen and phosphorus from tile inflows averaging 4.7 and 0.08 mg/L, respectively, as well as total reduction of suspended sediments (average 10.4 mg/L). This study provides additional evidence that riparian areas are an important part of nutrient reduction strategies as they can act as both controlled drainage points by raising water tables in fields as well as nutrient sinks which couple to help mitigate nutrient runoff in the region.

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Nutrient Loading and Viral Memory Drive Accumulation of Restriction Modification Systems in Bloom-Forming Cyanobacteria

mBio ◽

10.1128/mbio.00873-21 ◽

2021 ◽

Author(s):

Spiridon E. Papoulis ◽

Steven W. Wilhelm ◽

David Talmy ◽

Erik R. Zinser

Keyword(s):

Water Quality ◽

Microcystis Aeruginosa ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Nutrient Loading ◽

Major Contributor ◽

Content Type ◽

Global Threat ◽

Restriction Modification ◽

Restriction Modification Systems

Harmful algal blooms (HABs), caused by cyanobacteria like Microcystis aeruginosa , are a global threat to water quality and use across the planet. Researchers have agreed that nutrient loading is a major contributor to HAB persistence.

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Nonlinear Water Quality Response to Numerical Simulation of In Situ Phosphorus Control Approaches

Water ◽

10.3390/w13050725 ◽

2021 ◽

Vol 13 (5) ◽

pp. 725

Author(s):

Baichuan Zhang ◽

Ningya Lin ◽

Xi Chen ◽

Qiaoming Fan ◽

Xing Chen ◽

...

Keyword(s):

Numerical Simulation ◽

Water Quality ◽

Engineering Design ◽

Cost Effective ◽

Control Measures ◽

Design Parameters ◽

Small Scale ◽

Plateau Lake ◽

Quality Response

The nonlinear and heterogeneous responses of nutrients to eutrophication control measures are a major challenge for in situ treatment engineering design, especially for large water bodies. Tackling the problem calls for a full understanding of potential water quality responses to various treatment schemes, which cannot be fulfilled by empirical-based methods or small-scale tests. This paper presents a methodology for Phoslock application based on the idea of object-oriented intelligent engineering design (OOID), which includes numerical simulation to explore the features of responses to numerous assumed schemes. A large plateau lake in Southwestern China was employed as a case study to illustrate the characteristics of the water quality response and demonstrate the applicability of this new approach. It was shown by the simulation and scenario analysis that the water quality response to Phoslock application always reflected nonlinearity and spatiotemporal heterogeneity, and always varied with objects, boundary conditions, and engineering design parameters. It was also found that some design parameters, like release position, had a significant impact on efficiency. Thus, a remarkable improvement could be obtained by cost-effective analysis based on scenarios using combinations of design parameters.

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A global scan of how the issue of nutrient loading and harmful algal blooms is being addressed by governments, non-governmental organizations, and volunteers

Water Quality Research Journal ◽

10.2166/wqrj.2019.013 ◽

2019 ◽

Vol 55 (1) ◽

pp. 1-23

Author(s):

Étienne Foulon ◽

Alain N. Rousseau ◽

Glenn Benoy ◽

Rebecca L. North

Keyword(s):

Water Quality ◽

Case Studies ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Nutrient Loading ◽

Risk Mitigation ◽

National Standards ◽

Quality Issue ◽

Non Governmental Organizations ◽

The Usa

Abstract Harmful algal blooms (HABs) in aquatic ecosystems are of concern worldwide. This review deals with how jurisdictions around the world are addressing this water quality issue to inform recommendations regarding nutrient loading and HABs in Missisquoi Bay-Lake Champlain and Lake Memphremagog; transboundary lakes located in the USA and Canada that suffer from symptoms of eutrophication. A global scan of the literature resulted in the consideration of 12 case studies of large water bodies within large watersheds, excluding in-lake geoengineering approaches. Although all of the systems experience excessive nutrient loading, they vary in two key ways: sources of nutrients and manifestations of eutrophication ranging from HABs, to limited recreational uses, to the additional complexity of internal loadings and fish kills, up to drinking water shutdowns. The case studies were analyzed with respect to four categories of approaches, namely: (i) regulatory; (ii) incentive-based; (iii) risk mitigation; and (iv) outreach, engagement, and educational. We found that the management frameworks are based on integrated watershed management planning and national standards. National water quality standards, however, are not stringent enough to prevent HABs. Overall, identified case studies did not successfully remediate HABs, they simply managed them.

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Global change and eutrophication of coastal waters

ICES Journal of Marine Science ◽

10.1093/icesjms/fsp047 ◽

2009 ◽

Vol 66 (7) ◽

pp. 1528-1537 ◽

Cited By ~ 515

Author(s):

Nancy N. Rabalais ◽

R. Eugene Turner ◽

Robert J. Díaz ◽

Dubravko Justić

Keyword(s):

Water Quality ◽

Global Change ◽

Coastal Waters ◽

Harmful Algal Blooms ◽

Algal Blooms ◽

Nutrient Loading ◽

Global Climate ◽

Oxygen Depletion ◽

Negative Consequences ◽

Storm Activity

Abstract Rabalais, N. N., Turner, R. E., Díaz, R. J., and Justić, D. 2009. Global change and eutrophication of coastal waters. – ICES Journal of Marine Science, 66: 1528–1537. The cumulative effects of global change, including climate change, increased population, and more intense industrialization and agribusiness, will likely continue and intensify the course of eutrophication in estuarine and coastal waters. As a result, the symptoms of eutrophication, such as noxious and harmful algal blooms, reduced water quality, loss of habitat and natural resources, and severity of hypoxia (oxygen depletion) and its extent in estuaries and coastal waters will increase. Global climate changes will likely result in higher water temperatures, stronger stratification, and increased inflows of freshwater and nutrients to coastal waters in many areas of the globe. Both past experience and model forecasts suggest that these changes will result in enhanced primary production, higher phytoplankton and macroalgal standing stocks, and more frequent or severe hypoxia. The negative consequences of increased nutrient loading and stratification may be partly, but only temporarily, compensated by stronger or more frequent tropical storm activity in low and mid-latitudes. In anticipation of the negative effects of global change, nutrient loadings to coastal waters need to be reduced now, so that further water quality degradation is prevented.

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Legacy Phosphorus in Lake Okeechobee (Florida, USA) Sediments: A Review and New Perspective

Water ◽

10.3390/w13010039 ◽

2020 ◽

Vol 13 (1) ◽

pp. 39

Author(s):

Thomas M. Missimer ◽

Serge Thomas ◽

Barry H. Rosen

Keyword(s):

Algal Blooms ◽

Nutrient Loading ◽

Sediment Resuspension ◽

Eutrophic Lake ◽

The United States ◽

Nutrient Ratios ◽

Lake Okeechobee ◽

Organic Sediment ◽

Legacy Nutrients ◽

New Perspective

Lake Okeechobee is one of the largest freshwater lakes in the United States. As a eutrophic lake, it has frequent algal blooms composed predominantly of the cyanobacterium genus Microcystis. Many of the algal blooms are associated with the resuspension of a thixotropic benthic mud containing legacy nutrients. Since Lake Okeechobee has an area of 1732 km2 (40–50 km radius) and a mean depth of only 2.7 m, there is sufficient fetch and shallow water depth to allow frequent wind, wave, and current generated events, which cause sediment resuspension. Three types of mud exist in the lake including an immobile dark-colored, consolidated mud, a brownish-colored mud, which is poorly consolidated and mobile, and a dark-colored thixotropic, highly mobile mud that is a mixture of organic matter and clay-sized minerals. Altogether, these muds contain an estimated 4.6 × 106 kg of total phosphorus and commensurate high amounts of labile nitrogen. The thixotropic mud covers most of the lakebed and contains the suitable nutrient ratios to trigger algal blooms. A bioassay analysis of the thixotropic mud compared to the consolidated mud showed that it produced up to 50% more nutrient mass compared to the consolidated mud. The thixotropic mud does not consolidate, thus remains mobile. The mobility is maintained by the dynamics of the algal blooms and bacterial decay of extracellular secretions (transparent exopolymer particles) that bind sediment, transfer it to the bottom, and undergo bacterial digestion causing gas emissions, thus maintaining the organic/sediment matrix in suspension. Despite major efforts to control external nutrient loading into the lake, the high frequency of algal blooms will continue until the muds bearing legacy nutrients are removed from the lake.

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Field Observation and Simulation of Sediment Resuspension in a Shallow Lake

Water Science & Technology ◽

10.2166/wst.1988.0211 ◽

1988 ◽

Vol 20 (6-7) ◽

pp. 263-270 ◽

Cited By ~ 4

Author(s):

K. Otsubo ◽

K. Muraoka

Keyword(s):

Numerical Simulation ◽

Shallow Lake ◽

Water Wave ◽

Field Data ◽

Sediment Resuspension ◽

Field Research ◽

Lake Kasumigaura ◽

Bed Erosion ◽

Current Water ◽

Good Agreement

The dispersion and resuspension of sediments in Takahamairi Bay basin of Lake Kasumigaura were studied by means of field research and numerical simulation. The field data on wind direction and velocity, lake current, water wave, and turbidity were shown. Based on these results, we discuss how precipitated sediments were resuspended in this shallow lake. To predict the turbidity and the depth of bed erosion, a simulation model was established for this lake. The calculated turbidity showed good agreement with the field data. According to the simulated results, the turbidity reaches 200 ppm, and the bed is eroded several millimeters deep when the wind velocity exceeds 12 m/s in the lake.

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