Internal Nutrient Loading Controls Macroalgal and Cyanobacterial Succession in a Coastal Lagoon Restored by Managed Realignment of Agricultural Land

Managed realignment (MR) has been increasingly applied as an adaptation strategy to sea level rise in low-lying coastal areas, but the ecological consequences after flooding agricultural land with seawater are not well known. The restored Gyldensteen Coastal Lagoon represents one of the largest MR projects in Europe to date. The area served as agricultural land for about 150 years before being deliberately flooded with seawater in 2014. This study monitored for 5 years the succession of macroalgae and benthic cyanobacteria driven by changing internal nutrient (DIN = NH4+ + NO2– + NO3–, DON = dissolved organic nitrogen, and DIP = PO43–) loadings in the lagoon after flooding. A massive bloom of opportunistic green macroalgae (dominated by Cladophora spp.) occurred during the first year as response to a substantial loading of DIN and DIP from the newly flooded soils. The macroalgal cover was sparse the following years and the species richness increased with lower loading of particularly DIN. A cyanobacterial bloom controlled by declining DIN and steady DIP concentrations in the water dominated the lagoon and covered all solid surfaces 4 years after flooding. Highest macroalgal species richness with dominance of perennial Fucus vesiculosus and Agarophyton vermiculophylla was recorded 5 years after flooding following a temperature-induced stimulation of soil nitrogen transformation, leading to increased water column DON concentrations and DIN:DIP ratios. The lagoon remains therefore at an unstable tipping point where small and random changes in the DIN:DIP ratio control the balance between blooms of benthic cyanobacteria and high macroalgal species richness. Future MR projects involving agricultural land should prepare the soil to prevent algal blooms driven by sustained internal nutrient loading. Particularly P loading should be avoided to minimize the chances for recurrent blooms of benthic cyanobacteria.

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The Effect of Climate and Human Pressures on Functional Diversity and Species Richness Patterns of Amphibians, Reptiles and Mammals in Europe

Diversity ◽

10.3390/d13060275 ◽

2021 ◽

Vol 13 (6) ◽

pp. 275

Author(s):

Mariana A. Tsianou ◽

Maria Lazarina ◽

Danai-Eleni Michailidou ◽

Aristi Andrikou-Charitidou ◽

Stefanos P. Sgardelis ◽

...

Keyword(s):

Species Richness ◽

Functional Diversity ◽

Agricultural Land ◽

Influential Factor ◽

Climatic Variables ◽

Quadratic Entropy ◽

Functional Richness ◽

Precipitation Seasonality ◽

Rao’S Quadratic Entropy ◽

Richness Patterns

The ongoing biodiversity crisis reinforces the urgent need to unravel diversity patterns and the underlying processes shaping them. Although taxonomic diversity has been extensively studied and is considered the common currency, simultaneously conserving other facets of diversity (e.g., functional diversity) is critical to ensure ecosystem functioning and the provision of ecosystem services. Here, we explored the effect of key climatic factors (temperature, precipitation, temperature seasonality, and precipitation seasonality) and factors reflecting human pressures (agricultural land, urban land, land-cover diversity, and human population density) on the functional diversity (functional richness and Rao’s quadratic entropy) and species richness of amphibians (68 species), reptiles (107 species), and mammals (176 species) in Europe. We explored the relationship between different predictors and diversity metrics using generalized additive mixed model analysis, to capture non-linear relationships and to account for spatial autocorrelation. We found that at this broad continental spatial scale, climatic variables exerted a significant effect on the functional diversity and species richness of all taxa. On the other hand, variables reflecting human pressures contributed significantly in the models even though their explanatory power was lower compared to climatic variables. In most cases, functional richness and Rao’s quadratic entropy responded similarly to climate and human pressures. In conclusion, climate is the most influential factor in shaping both the functional diversity and species richness patterns of amphibians, reptiles, and mammals in Europe. However, incorporating factors reflecting human pressures complementary to climate could be conducive to us understanding the drivers of functional diversity and richness patterns.

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Phosphorous runoff risk assessment and its potential management using wollastonite according to geochemical modeling

Open Agriculture ◽

10.1515/opag-2019-0075 ◽

2019 ◽

Vol 4 (1) ◽

pp. 787-794 ◽

Cited By ~ 1

Author(s):

Aneela Hayder ◽

Stephen Vanderburgt ◽

Rafael M. Santos ◽

Yi Wai Chiang

Keyword(s):

Risk Analysis ◽

Algal Blooms ◽

Agricultural Land ◽

Algal Bloom ◽

Risk Mitigation ◽

Geochemical Modeling ◽

Geochemical Modelling ◽

Water Runoff ◽

Phosphorus Pollution ◽

Contaminate Drinking Water

AbstractLoss of phosphorus from agricultural land through water runoff causes serious detrimental effects on the environment and on water quality. Phosphorous runoff from excessive use of fertilizers can cause algal blooms to grow in nearby water systems, producing toxins that contaminate drinking water sources and recreational water. In this study, a risk analysis of the algal toxin micro-cystin-LR and the mitigation of phosphorus from agriculture runoff is discussed. A risk analysis was performed on the algal bloom toxin microcystin-LR considering the Lake Erie algal bloom event of 2011 as a case study. Toxicity risk analysis results show that relatively low concentrations of microcystin-LR compared to recent case studies pose an acute health risk to both children and adults, and a significant increase in the risk of developing cancer is suggested but subject to further study given the assumptions made. This study investigated the potential of using wollastonite to mitigate phosphorus pollution, considering thermodynamic conditions of a constructed wetland receiving influent water from agriculture runoff, by using geochemical modelling. Geochemical modelling results show that wollastonite can react with phosphorus and capture it in the stable mineral form of hydroxyapatite, offering a possible strategy for risk mitigation of phosphorous runoff. A removal efficiency of 77% of phosphorus using wollastonite is calculated with the help of geochemical modelling.

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Hindcast and Near Real-Time Monitoring of Green Macroalgae Blooms in Shallow Coral Reef Lagoons Using Sentinel-2: A New-Caledonia Case Study

Remote Sensing ◽

10.3390/rs13020211 ◽

2021 ◽

Vol 13 (2) ◽

pp. 211

Author(s):

Maële Brisset ◽

Simon Van Wynsberge ◽

Serge Andréfouët ◽

Claude Payri ◽

Benoît Soulard ◽

...

Keyword(s):

Green Algae ◽

Algal Blooms ◽

New Caledonia ◽

Spectral Indices ◽

Green Macroalgae ◽

Spectral Bands ◽

Algae Blooms ◽

Trade Offs ◽

Sentinel 2

Despite the necessary trade-offs between spatial and temporal resolution, remote sensing is an effective approach to monitor macroalgae blooms, understand their origins and anticipate their developments. Monitoring of small tropical lagoons is challenging because they require high resolutions. Since 2017, the Sentinel-2 satellites has provided new perspectives, and the feasibility of monitoring green algae blooms was investigated in this study. In the Poé-Gouaro-Déva lagoon, New Caledonia, recent Ulva blooms are the cause of significant nuisances when beaching. Spectral indices using the blue and green spectral bands were confronted with field observations of algal abundances using images concurrent with fieldwork. Depending on seabed compositions and types of correction applied to reflectance data, the spectral indices explained between 1 and 64.9% of variance. The models providing the best statistical fit were used to revisit the algal dynamics using Sentinel-2 data from January 2017 to December 2019, through two image segmentation approaches: unsupervised and supervised. The latter accurately reproduced the two algal blooms that occurred in the area in 2018. This paper demonstrates that Sentinel-2 data can be an effective source to hindcast and monitor the dynamics of green algae in shallow lagoons.

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Indirect economic indicators in bio-economic fishery models: agricultural price indicators and fish stocks in Lake Victoria

ICES Journal of Marine Science ◽

10.1016/j.icesjms.2005.01.012 ◽

2005 ◽

Vol 62 (3) ◽

pp. 483-492 ◽

Cited By ~ 20

Author(s):

Silvio Simonit ◽

Charles Perrings

Keyword(s):

Nutrient Loading ◽

Agricultural Land ◽

Lake Victoria ◽

Leading Indicators ◽

Fish Stocks ◽

Chl A ◽

Run Off ◽

Fishery Model ◽

Agricultural Price ◽

Point Pollution

Abstract We consider the potential for using prices as leading indicators of changes in stocks and yields in the freshwater capture fishery in Lake Victoria. Fertilizer run-off from agricultural land is a major cause of nutrient loading, along with soil erosion, atmospheric deposition, and point pollution from industrial and domestic affluent. The interactions between fertilizer applications, water quality, fish stocks, and yields are modelled in order to predict the effect of changes in the price of fertilizers on the fishery. The fishery model includes a measure of Chl a concentration (a proxy for phytoplankton density). The consequences of changes in Chl a concentration for fish stocks are modelled using Ecopath. We show that fertilizer prices are effective leading indicators of changes in fish biomass and yield.

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Factors influencing early restoration progress of a Eucalyptus tereticornis open forest on former agricultural land.

Pacific Conservation Biology ◽

10.1071/pc120263 ◽

2012 ◽

Vol 18 (4) ◽

pp. 263 ◽

Cited By ~ 3

Author(s):

Tom Lewis ◽

David Taylor ◽

Scott Swift ◽

Valerie Debuse

Keyword(s):

Species Richness ◽

Plant Regeneration ◽

Woody Plant ◽

Agricultural Land ◽

Livestock Grazing ◽

Grass Species ◽

Eucalyptus Tereticornis ◽

Mature Trees ◽

Litter Biomass ◽

Open Forest

We monitored an area that was revegetated with the goal of restoring a Eucalyptus tereticornis open forest on former agricultural land in central, eastern Queensland. Revegetation involved: (1) planting 60 ha of previously cleared and heavily grazed land with eight local trees species; and (2) removing cattle grazing to encourage natural regeneration in areas where some mature trees remained. We compared the revegetation site to native pasture that had also been previously cleared, with only scattered paddock trees remaining, and continued to be managed for livestock production (an area similar to the revegetation site, prior to planting) and a remnant forest (reference area). Nine years since revegetation began there was some evidence that the revegetated site was diverging from pasture in terms of understorey plant composition, sapling density and topsoil C and N. There was little divergence in terms of plant species richness (native, introduced, grass, forb and woody plant richness), herbaceous biomass and woody plant regeneration. Some monitoring plots were subject to fire (prescribed fire and or wildfire) over the period of monitoring. With increasing time since fire, the richness of native species, introduced species and grass species (both native and introduced) declined, and forb and grass species richness declined with increasing litter biomass, suggesting that the occurrence of fire and the associated removal of litter biomass has a positive influence on herbaceous diversity in this ecosystem. Woody plant regeneration persisted through lignotubers at the revegetation site and at the pasture, but this regeneration was stunted at the pasture presumably due to livestock grazing. Hence areas of former E. tereticornis forest showed promising regenerative capacity where mature trees remained and where livestock grazing was removed.

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A review on acoustic methods of algal growth control by ultrasonication through existing and novel emerging technologies

Reviews in Chemical Engineering ◽

10.1515/revce-2016-0010 ◽

2017 ◽

Vol 33 (5) ◽

Cited By ~ 1

Author(s):

Aditi Mullick ◽

Sudarsan Neogi

Keyword(s):

Energy Consumption ◽

Algal Blooms ◽

Nutrient Loading ◽

Algal Growth ◽

High Energy ◽

Operating Conditions ◽

Process Efficiency ◽

Industrial Water ◽

Algal Toxins ◽

Algae Growth

AbstractThe uncontrolled proliferation of algae and algal blooms due to excessive nutrient loading in natural and industrial water bodies is a major issue for water quality maintenance. It reduces usability of the water, imposes hazardous effects of algal toxins released from algal blooms, and creates nuisance in the operation of several industrial water units. Among several existing water treatment methods to diminish the post-algae growth effects, ultrasonication has emerged as an environmentally safe technology that does not involve any use of algaecide. The interaction of several parameters, including climatic and environmental conditions with algae growth rate, have been reviewed in this article. The effects of different acoustic operating conditions for inhibition of algae growth have also been discussed. Concern about high energy consumption led other technologies to be integrated with ultrasonication. It has enhanced the process efficiency and reduced the energy consumption as reported in some long-term field investigations and patent proposals. Several issues that require further research for making this technology widely applicable or to install an effective system design have been highlighted in this article.

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Anabaenopsis morphospecies (Cyanobacteria, Nostocales) from Los Patos shallow lake (Province of Buenos Aires, Argentina)

Phytotaxa ◽

10.11646/phytotaxa.272.3.1 ◽

2016 ◽

Vol 272 (3) ◽

pp. 173 ◽

Cited By ~ 2

Author(s):

ANABELLA AGUILERA ◽

JIŘĺ KOMÁREK ◽

RICARDO O. ECHENIQUE

Keyword(s):

Population Dynamics ◽

Species Richness ◽

Shallow Lake ◽

Algal Blooms ◽

Buenos Aires ◽

Morphological Diversity ◽

Abundant Species ◽

American Continent ◽

First Report ◽

Almost All

The genus Anabaenopsis comprises about 20 morphospecies distributed in plankton of tropical, subtropical and temperate regions during warm periods. The morphological diversity and population dynamics of Anabaenopsis species from one artificial shallow lake from the Province of Buenos Aires, Argentina, was studied during summer 2005 and 2006; and from April 2012 to May 2014. The most common and abundant species were identified as A. elenkinii and A. cf. cunningtonii (first report in Argentina). Anabaenopsis circularis and A. milleri (first report in the American continent and Argentina) were less common, whereas A. nadsonii was rarely observed. Almost all species contributed to algal blooms during warm periods. However, some species were registered even under the lowest temperatures recorded (7.5 °C) and sustained biovolume also during winter (A. milleri, A. elenkinii and A. cf. cunningtonii). These results indicate that some species of the genus are capable of growing at temperatures much lower than 20°C. The species richness noted in this study suggests that there is likely much more diversity remaining on this genus to be reported in Argentina.

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Effect of filter-feeding mollusks on growth of green macroalgae and nutrient cycling in a heavily exploited coastal lagoon

Estuarine Coastal and Shelf Science ◽

10.1016/j.ecss.2020.106679 ◽

2020 ◽

Vol 239 ◽

pp. 106679 ◽

Cited By ~ 1

Author(s):

Mariachiara Naldi ◽

Daniele Nizzoli ◽

Marco Bartoli ◽

Pierpaolo Viaroli ◽

Pierluigi Viaroli

Keyword(s):

Nutrient Cycling ◽

Coastal Lagoon ◽

Filter Feeding ◽

Green Macroalgae

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Effect of major flow diversion on sediment nutrient release in a stratified reservoir

Marine and Freshwater Research ◽

10.1071/mf9950189 ◽

1995 ◽

Vol 46 (1) ◽

pp. 189 ◽

Cited By ~ 10

Author(s):

SG Schadlow ◽

DP Hamilton

Keyword(s):

Nutrient Loading ◽

Ecological Model ◽

Water Reservoir ◽

Nutrient Release ◽

Transport Processes ◽

Phytoplankton Production ◽

Drinking Water Reservoir ◽

The Relationship ◽

Oxygen Dynamics ◽

Internal Nutrient Loading

A process-based, hydrodynamic model that describes the mixing and transport processes in a stratified lake has been coupled to an ecological model to examine the relationship between the stratification and internal nutrient loading. The ecological model includes descriptions of algal production, nutrient cycling (including sediment release) and oxygen dynamics. An example is presented of the use of the model to examine interactions between stratification, sediment nutrient release and phytoplankton production when there is a major diversion of the inflow to a drinking water reservoir.

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Monitoring of groundwater, morphological and ecological development of the Perkpolder managed realignment following tidal restoration

10.5194/egusphere-egu2020-20115 ◽

2020 ◽

Author(s):

Wietse van de Lageweg ◽

Joao Salvador de Paiva ◽

Jebbe van der Werf ◽

Lodewijk de Vet ◽

Perry de Louw ◽

...

Keyword(s):

The Netherlands ◽

Sea Level Rise ◽

Sea Level ◽

Agricultural Land ◽

Sediment Dynamics ◽

Scheldt Estuary ◽

Biologically Active ◽

Management Approach ◽

Managed Realignment ◽

Tidal Area

Innovative, sustainable and cost-effective coastal protection solutions are required to adapt to environmental change and enhance ecosystem functioning. Managed realignment is an example of an ecosystem engineering coastal management approach motivated by concerns about biological conservation and sea-level rise. It involves relocating the line of defense landward, thereby mimicking what would normally happen with marine environments during a period of sea-level rise. The retreat allows new salt marshes to develop offering a range of ecosystem services. Despite the ongoing execution of managed realignment projects in, amongst others, the UK, Germany, the Netherlands, Belgium and Spain, it remains unclear whether management realignment is able to deliver on the expected socio-economic and environmental benefits.Here we report on the short-term (0-4 years) development of physical and ecological processes of the Perkpolder managed realignment area in the Scheldt estuary, the Netherlands, following tidal restoration in 2015. The overarching goal of the Perkpolder project was to realize 75 hectares of low-dynamic tidal nature contributing to Natura2000 conservation goals for the Western Scheldt estuary as well as serving as a compensation measure for the extension of the navigation channel for the Antwerp harbor.The Perkpolder managed realignment is considered a unique opportunity to monitor and study the biotic and abiotic changes in an area transforming from a freshwater agricultural area to a tidal saline natural area. An interdisciplinary monitoring framework was set up to record the abiotic and biotic developments of the Perkpolder realignment area, particularly focusing on morphological changes, colonization of the new tidal area by benthic macrofauna and vegetation, and its function as foraging area for water birds. Also the groundwater system is studied and its effect on the surrounding agricultural land.A mitigation measure, called &#8216;SeepCat&#8217;, was installed on the border of the new tidal area and the agricultural land to protect the freshwater lens used by farmers for irrigation. The lens was expected to shrink by this local sea level rise. From the groundwater measurements, it was concluded that the SeepCat system was functioning well enough to compensate for the effects of the new tidal area.Using a Delft3D numerical model simulation, it was shown that the design of the morphological template has a large impact on the rates of morphological change. Additionally, the sediment import, estimated from SPM concentration and discharge measurements, varied strongly in time, and sediment was also being exported for a number of tides. Controlled laboratory experiments show that seedlings of pioneer marsh plant species survive best in a well-drained soil without sediment dynamics. Yet, seedlings can tolerate some moderate sediment dynamics. From a benthic community perspective, the development of the managed realignment Perkpolder is encouraging. A biologically active intertidal area has formed within a short time frame. Within 3 years, the benthic macroinfaunal community shows a development towards a community found on natural tidal mudflats and is expected to reach a stable community in years rather than decades. The area is also frequently visited by birds, which forage during low tide and rest on the surrounding dikes during high tide.

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