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1
Zoidou, Maria, Nikolaos Kokkos e Georgios Sylaios. "Dynamics of Water, Salt, and Nutrients Exchange at the Inlets of Three Coastal Lagoons". Journal of Marine Science and Engineering 10, n. 2 (2 febbraio 2022): 205. http://dx.doi.org/10.3390/jmse10020205.
Testo completoAbstract (sommario):
The intertidal patterns at the inlet of three coastal lagoons (Agiasma, Porto Lagos, and Xirolimni) in Northern Greece were investigated by combining in situ samplings and computational efforts. These lagoons are Mediterranean, microtidal coastal systems, connected with the adjacent open sea (Thracian Sea) through their inlet canals and are highly affected by the lagoon–sea exchange processes. Limited freshwater enters their basins, mostly due to precipitation and agricultural drainage. An intense monitoring program of water flow and quality at the mouth of the three lagoons was carried out, aiming to quantify the transport mechanisms of water, salt, and nutrients across the inlet canal under different tidal/meteorological conditions. Ebb currents were recorded higher than flood currents, and the temporal variability of the longitudinal velocity was characterized by asymmetries. Residual currents were important to the water exchange, with the Eulerian water, salt, and nutrient fluxes being an order of magnitude larger than the Stokes drift. Eulerian transport and tidal pumping are considered as important mechanisms for salt and nutrients exchange through the inlets. The return flow factor varied from 1 to 17.5% of the water exiting the lagoons in ebb, while the residence time ranged from 0.7 days to 4.2 days.
2
Bleich, Monica Elisa, Roberto Moraes Lima Silveira e Flávia Maria Barros Nogueira. "Limnological patterns in northern pantanal lagoons". Brazilian Archives of Biology and Technology 52, n. 3 (giugno 2009): 755–64. http://dx.doi.org/10.1590/s1516-89132009000300028.
Testo completoAbstract (sommario):
The aim of this work was to correlate the limnological patterns recorded among ten lagoons in the northern part of the Pantanal of Mato Grosso with some aspects of the lagoons related to their physical and biological characteristics. Some lagoon characteristics, such as connection with the river and the presence of floating macrophytes were important to group similar lagoons into categories. Attempts were also made to determine which kind of the nutrients could be limiting phytoplankton productivity in the lagoons of the northern Pantanal. Data was collected in nine lagoons during the flooding stage in January 2004, and nutrient and chlorophyll a was followed in a tenth lagoon from June 2004 to October 2004. The phytoplankton biomass was significantly associated with the nitrogen concentration during the flooding and drought periods. All the studied lagoons were potentially limited by the nitrogen concentration with a strong negative relationship between the chlorophyll a biomass and ammonium concentration during the drought season. The drought season also had nearly three times more chlorophyll a biomass when compared to the flooding period.
3
Tay, Collins, Ruby Asmah e Charles A. Biney. "A comparative study of the pollution status of Sakumo II and Muni Lagoons in Ghana". Water Science and Technology 62, n. 5 (1 settembre 2010): 1067–75. http://dx.doi.org/10.2166/wst.2010.359.
Testo completoAbstract (sommario):
The pollution status of Sakumo II and Muni Lagoons and Mamahuma and Gbagbla Ankonu feeder streams, which feed Sakumo II along the coast of Ghana, were assessed and compared. As expected of saline waters, pH values of both lagoons fell within a slightly neutral to saline range whilst, the feeder streams were moderately saline. Conductivity distribution also showed saline (>5.0 mS cm−1) characteristics of the lagoons, while, the feeder streams are brackish (1.5–5.0 mS cm−1). DO concentrations in both lagoons indicated a wide variation. Relatively high BOD and nutrients content of Sakumo II and the feeder streams suggested that, Sakumo II and its feeder streams are moderately to grossly polluted. However, Muni Lagoon was characterized by relatively low BOD and nutrients content suggesting relatively low anthropogenic impact. The ionic dominance patterns for Sakumo II and Muni Lagoons were: Na+ > Mg2 + > Ca2 + and Cl− > HCO3− > SO42−, Na+ > Ca2 + > Mg2 + and Cl− > HCO3− > SO42−, respectively. Using water quality index (WQI), Sakumo II was found to be grossly polluted and requires mitigation measures, while, Muni Lagoon was of fairly good quality and requires monitoring.
4
Li, R. H., S. M. Liu, Y. W. Li, G. L. Zhang, J. L. Ren e J. Zhang. "Nutrient dynamics in tropical rivers, estuarine-lagoons, and coastal ecosystems along the eastern Hainan Island". Biogeosciences Discussions 10, n. 6 (5 giugno 2013): 9091–147. http://dx.doi.org/10.5194/bgd-10-9091-2013.
Testo completoAbstract (sommario):
Abstract. Nutrient dynamics were studied along the eastern Hainan Island based on field observations during 2006–2009, to understand nutrient biogeochemical processes and to have an overview of human perturbations on coastal ecosystems in this tropical region. The concentrations of nutrients in the rivers had seasonal variations enriched with dissolved inorganic nitrogen (DIN). High riverine concentrations of nitrate were mainly originated from agricultural fertilizer input. The ratios of DIN : PO43− ranged from 37 to 1063, suggesting preferential PO43− relative to nitrogen in the rivers. The areal yields of dissolved silicate (DSi) varied from 76 to 448 × 103 mol km−2 yr−1 due to erosion over the drainage area, inducing high levels of DSi among worldwide tropical systems. Aquaculture ponds contained high concentrations of NH4+ (up to 157 μM) and DON (up to 130 μM). Particulate phosphorus concentrations (0.5 ∼1.4 μM) were in lower level comparied with estuaries around the world. Particulate silicate levels in rivers and lagoons were lower than global average level. Nutrient biogeochemistry in coastal areas were affected by human activities (e.g. aquaculture, agriculture), as well as natural events such as typhoon. Nutrient concentrations were low because open sea water dispersed land-derived nutrients. Nutrient budgets were built based on a steady-state box model, which showed that riverine fluxes would be magnified by estuarine processes (e.g. regeneration, desorption) in the Wenchanghe/Wenjiaohe Estuary, Wanquan River estuary, and the Laoyehai Lagoon except in the Xiaohai Lagoon. Riverine and groundwater input were the major sources of nutrients to the Xiaohai Lagoon and the Laiyehai Lagoon, respectively. Riverine input and aquaculture effluent were the major sources of nutrients to the eastern coastal of Hainan Island. Nutrient inputs to the coastal ecosystem can be increased by typhoon-induced runoff of rainwater, and phytoplankton bloom in the sea would be caused.
5
Painter, Kristin J., Robert B. Brua, John Spoelstra, Geoff Koehler e Adam G. Yates. "Fate of bioavailable nutrients released to a stream during episodic effluent releases from a municipal wastewater treatment lagoon". Environmental Science: Processes & Impacts 22, n. 12 (2020): 2374–87. http://dx.doi.org/10.1039/d0em00315h.
Testo completoAbstract (sommario):
Fate of nutrients from episodic wastewater lagoon effluent release was studied. Quantity of labile P in pulses often exceeded uptake. Management of lagoons should thus be informed by stream processing.
6
Li, R. H., S. M. Liu, Y. W. Li, G. L. Zhang, J. L. Ren e J. Zhang. "Nutrient dynamics in tropical rivers, lagoons, and coastal ecosystems of eastern Hainan Island, South China Sea". Biogeosciences 11, n. 2 (30 gennaio 2014): 481–506. http://dx.doi.org/10.5194/bg-11-481-2014.
Testo completoAbstract (sommario):
Abstract. Nutrient dynamics based on field observations made along the eastern Hainan Island during the period 2006–2009 were investigated to understand nutrient biogeochemical processes, and to provide an overview of human perturbations of coastal ecosystems in this tropical region. The rivers showed seasonal variations in nutrient concentrations, with enrichment of dissolved inorganic nitrogen and dissolved silicate, and depletion of PO43−. High riverine concentrations of nitrate mainly originated from agricultural fertilizer inputs. The DIN : PO43− ratios ranged from 37 to 1063, suggesting preferential depletion of PO43− relative to nitrogen in rivers. Chemical weathering in the drainage area might explain the high levels of dissolved silicate. Aquaculture ponds contained high concentrations of NH4+ and dissolved organic nitrogen. The particulate phosphorus concentrations in the study area were lower than those reported for estuaries worldwide. The particulate silicate levels in rivers and lagoons were lower than the global average level. Nutrient biogeochemistry in coastal areas was affected by human activities (e.g., aquaculture, agriculture), and by natural phenomena including typhoons. The nutrient concentrations in coastal waters were low because of dispersion of land-derived nutrients in the sea. Nutrient budgets were built based on a steady-state box model, which showed that riverine fluxes are magnified by estuarine processes (e.g., regeneration, desorption) in estuaries and Laoyehai Lagoon, but not in Xiaohai Lagoon. Riverine and groundwater inputs were the major sources of nutrients to Xiaohai and Laoyehai lagoons, respectively, and riverine inputs and aquaculture effluents were the major sources for the eastern coast of Hainan Island. Nutrient inputs to the coastal ecosystem increased with typhoon-induced runoff of rainwater, elucidating the important influence of typhoons on small tropical rivers.
7
Giraldo, E., e A. Garzón. "The potential for water hyacinth to improve the quality of Bogota River water in the Muña Reservoir: comparison with the performance of waste stabilization ponds". Water Science and Technology 45, n. 1 (1 gennaio 2002): 103–10. http://dx.doi.org/10.2166/wst.2002.0014.
Testo completoAbstract (sommario):
The potential application of Water Hyacinth (Eichhornia crassipes) in organic matter degradation, sedimentation, nutrient and heavy metal absorption and sulfur reduction in the Muña Reservoir has been tested in experimental lagoons. The lagoons were operated at hydraulic retention times (HRT) of 6, 9 and 15 days. One lagoon was covered with Water Hyacinth, which is naturally growing in the Muña Reservoir, while another lagoon was operated as a conventional oxidation pond. The Water Hyacinth lagoon had better removal efficiencies for almost all parameters measured: BOD5, total suspended solids, COD, nitrogen, phosphorus and heavy metals. The oxidation lagoon was facultative for HRT of 9 and 15 days, and anoxic when operated at 6 days HRT. At HRT of 15 days the water quality in the effluent of the covered lagoon corresponded to 12 mg/l of BOD, 6 mg/l of suspended solids and 0.8 mg/l of hydrogen sulfide. Hydrogen sulfide levels in the Muña reservoir can be substantially reduced at HRT higher than 15 days in both lagoons. The uncovered lagoon had better hydrogen sulfide removal during the day but presents high levels at night. If the hydraulic retention time in the Muña reservoir is increased, the water quality of the Bogota river can be substantially improved for all the HRTs tested in the pilot units. HRT seems to give a better prediction of overall effluent water quality than surface loading. More research is needed in order to define the optimum water hyacinth density in the Muña reservoir to determine its influence on the water quality of the effluent. The influence is expected to be negative due to an internal increase of BOD, solids, nutrients and metals loads due to plant decay.
8
Henderson, Amy, Emek Kose, Allison Lewis e Ellen R. Swanson. "Mathematical modeling of algal blooms due to swine CAFOs in Eastern North Carolina". Discrete & Continuous Dynamical Systems - S 15, n. 3 (2022): 555. http://dx.doi.org/10.3934/dcdss.2021151.
Testo completoAbstract (sommario):
<p style='text-indent:20px;'>Dramatic strides have been made in treating human waste to remove pathogens and excess nutrients before discharge into the environment, to the benefit of ground and surface water quality. Yet these advances have been undermined by the dramatic growth of Confined Animal Feeding Operations (CAFOs) which produce voluminous quantities of untreated waste. Industrial swine routinely produce waste streams similar to that of a municipality, yet these wastes are held in open-pit "lagoons" which are at risk of rupture or overflow. Eastern North Carolina is a coastal plain with productive estuaries which are imperiled by more than 2000 permitted swine facilities housing over 9 million hogs; the associated 3,500 permitted manure lagoons pose a risk to sensitive estuarine ecosystems, as breaches or overflows send large plumes of nutrient and pathogen-rich waste into surface waters. Understanding the relationship between nutrient pulses and surface water quality in coastal environments is essential to effective CAFO policy formation. In this work, we develop a system of ODEs to model algae growth in a coastal estuary due to a manure lagoon breach and investigate nutrient thresholds above which algal blooms are unresolvable.</p>
9
Furtado, André Luiz dos Santos, Peter Casper e Francisco de Assis Esteves. "Methanogenesis in an impacted and two dystrophic coastal lagoons (Macaé, Brazil)". Brazilian Archives of Biology and Technology 45, n. 2 (giugno 2002): 195–202. http://dx.doi.org/10.1590/s1516-89132002000200011.
Testo completoAbstract (sommario):
This study investigated the methanogenic activity in sediment of the Imboacica (human impacted), Cabiúnas and Comprida coastal lagoons in Rio de Janeiro State (Brazil). Methane was not detected in water and sediment samples from the three lagoons. The measured nutrient concentrations in the pore-water indicated that methanogens activity was not limited by nutrients. Methanogenic activity was not detected under in vitro conditions, indicating that terminal organic carbon mineralisation via methanogenesis was negligible for the top 6 cm of sediment at the sampling time.
10
Padedda, B. M., S. Pulina, P. Magni, N. Sechi e A. Lugliè. "Phytoplankton dynamics in relation to environmental changes in a phytoplankton-dominated Mediterranean lagoon (Cabras Lagoon, Italy)". Advances in Oceanography and Limnology 3, n. 2 (4 settembre 2012): 147. http://dx.doi.org/10.4081/aiol.2012.5331.
Testo completoAbstract (sommario):
In Mediterranean lagoons, macrophytes often surpass phytoplankton as the most important primary producers. Less frequently, phytoplankton dominates throughout the year, thus knowledge of its dynamics is relatively limited and scattered. In this study, we assessed over two years the dynamics of phytoplankton assemblages, including potential harmful algal species (HAS), in relation to environmental changes in the phytoplankton-dominated Cabras Lagoon (Sardinia, Italy). The lagoon was characterised by uniform spatial conditions, wide temporal variations in salinity (40 PSU) and high nutrient availability. Phosphorus was highest in summer, possibly recycled within the system, while dissolved inorganic nitrogen increased in winter and spring due to watershed discharge. Chlorophyll a, positively correlated with nutrients and rainfall, showed a typical bimodal pattern with summer-winter blooms. Modifications in phytoplankton composition strongly correlated with extreme weather events, such as intense rainfall. This generated an abrupt salinity decrease that, combined with high nutrient availability, favoured the dominance of Cyanophyceae of reduced cell size, such as Cyanobium and Rhabdoderma species. We suggest that the prolonged and intense dominance of Cyanophyceae, added to other HAS, has a negative impact on the primary economic activities of the lagoon, such as fishery, and generally on the whole lagoon functioning.
11
Laut, Lazaro, Iara Clemente e Wellen Louzada. "The influence of organic matter compounds on foraminiferal and ostracode assemblages: a case study from the Marica-Guarapina Lagoon System (Rio de Janeiro, Brazil)". Micropaleontology 67, n. 5 (2021): 447–58. http://dx.doi.org/10.47894/mpal.67.5.02.
Testo completoAbstract (sommario):
The excessive nutrients discharge from industrial and domestic sources have been contributing to the establishment of eutrophication conditions, particularly in chocked lagoons in the Neotropical region. This study evaluates the influence of organic matter on the foraminiferal and ostracode assemblages by combining biopolymers concentrations, sediment grain size, and physical and chemical parameters in the Marica-Guarapina Lagoon System (MGLS, Rio de Janeiro, Brazil). The physical-chemical parameters show a well-defined confinement gradient from the channel to the innermost region. The biopolymers analysis indicates that the Guarapina and Barra Lagoons are characterized by the highest values of organicmatter from anthropic origin. Living organisms are absent or poorly represented in most of these regions of Marica and Barra lagoons. Seventeen living species of foraminifera and five of ostracodea are identified in the MGLS. Foraminifera and ostracodea exhibit a negative relationship with organic matter as evidenced by statistical analysis. Quinqueloculina seminula (foraminifera) and Cyprideis spp. (ostracodea) are associated with shallow and sandy regions and Ammonia spp. to eutrophic areas. The cluster analysis identifies six distinct regions in theMGLS based on species distribution and their relationship with environmental parameters: I - a region under the influence of marine waters; II - shallow and sandy region with high concentrations of proteins; III - a region characterized by high aerobic microorganisms activity; IV - an impacted region that is the channel passage between the lagoons; V - the most stressed region of the lagoons; and VI - the most confined area of the MGLS.
12
Mwachireya, S. A., A. M. Nzioka e D. N. Mutiso. "Coral Recruit-Algae Interactions in Coral Reef Lagoons Are Mediated by Riverine Influences". International Journal of Ecology 2017 (2017): 1–10. http://dx.doi.org/10.1155/2017/1351854.
Testo completoAbstract (sommario):
Coral recruit and algae abundance and diversity were studied in Kenyan reefs to determine the influence of terrestrial discharge (nutrients and sediments) and the recovery potential of coral reefs after disturbances. Reefs affected by sediments and nutrients were found to have high total, turf, and macroalgae but reduced coralline algae abundance and coral recruit density. Interestingly, this response was found to be the greatest in reefs close to nutrient sources relative to “pristine” reefs and those affected simultaneously by sediments and nutrients. Further, enhanced levels of brown algae and pocilloporid recruits were observed in reefs affected by terrestrial run-off whereas acroporid recruit, coralline, and calcareous algae abundance was high in reefs under low terrestrial input. Our results show that whereas increased sediment levels negatively affect coral recruit density individually, their interaction with nutrients improves recruit density in reefs simultaneously affected by sediment and nutrients. These findings suggest that the assessment of local factors that enhance inhibitory and those that suppress promotional processes involved in coral settlement and recruitment is an important aspect to consider in the conservation and management of coral reefs in the face of local anthropogenic stress as well as future climate disturbance dynamics and their interaction.
13
Attisano, Karina Kammer, Luis Felipe Hax Niencheski, Idel Cristiana Bigliardi Milani, Caroline dos Santos Machado, Márcio Raimundo Milani, Simoni Zarzur e Carlos Francisco Ferreira de Andrade. "Evidences of continental groundwater inputs to the shelf zone in Albardão, RS, Brazil". Brazilian Journal of Oceanography 56, n. 3 (settembre 2008): 189–200. http://dx.doi.org/10.1590/s1679-87592008000300004.
Testo completoAbstract (sommario):
The southern coastal region of Brazil is highly productive and many of its oceanographic processes are still poorly understood due to a great number of forces, such as the continental input from the Plata River and Patos Lagoon, several distinct oceanic water masses, and a complex contribution from groundwater. The shelf near Albardão is highly rich in dissolved nutrients, particularly in the coastal zone. The narrow sandy barrier that separates the ocean from Mangueira Lagoon has led us to wonder about the possibility of groundwater, and if it might play a role in the productivity of the surrounding area. In order to test this hypothesis, nutrient data from Mirim and Mangueira Lagoons and from Albardão were collected during a rainy period. The present work shows the need to include groundwater transport from Mangueira Lagoon to the coastal zone as one of the main sources for the productivity in that region. However, for such phenomenon to be quantified and better understood, it becomes necessary to use natural isotopes as tracers of the underground input.
14
Arévalo, E., J. S. P. Ibánhez, S. Papaspyrou e A. Nicolaidou. "The use of benthic metabolic processes as indicators for environmental quality assessment in coastal lagoons". Advances in Oceanography and Limnology 4, n. 2 (20 novembre 2013): 194. http://dx.doi.org/10.4081/aiol.2013.5344.
Testo completoAbstract (sommario):
The review highlights the various methods used for assessing environmental quality in Mediterranean coastal lagoons, with emphasis on benthic parameters and processes. The application of indices based on benthic macrofauna, extensively used in coastal areas, may fail in discerning between natural and anthropogenic pressures over naturally stressed coastal lagoons. Sediment can play an important regulatory role over the overlying water composition through the storage capacity for organic matter and pollutants, regeneration of nutrients or its buffering capacity. Descriptive classical measurements like sedimentary organic matter, Chlorophyll α and nutrient content are commonly included in monitoring efforts. However, other more complex indicators like primary production, sediment-water solute fluxes, solute sorption dynamics or microbial reaction rate determinations, have not been fully implemented for environmental quality assessment in coastal lagoons. These could offer crucial information on current and projected anthropogenic influence on ecosystem functioning. Irruption of novel techniques in benthic biogeochemistry like Excitation-Emission-Matrix (EEM) fluorescence for the study of dissolved organic matter dynamics shows high potential in combination with biological quality elements and other metabolic measurements for the evaluation of the environmental quality in coastal lagoons.
15
SFRISO, A., A. BUOSI e A. A. SFRISO. "On the occurrence of Uronema marinum Womersley (Chaetophorales, Chlorophyta) in the north-western lagoons of the Adriatic Sea, Mediterranean Sea (Italy)". Mediterranean Marine Science 15, n. 1 (15 settembre 2013): 101. http://dx.doi.org/10.12681/mms.517.
Testo completoAbstract (sommario):
We study the occurrence of the alien macroalga Uronema marinum in the lagoon of Venice, in the lagoons and ponds of the Po Delta and in Pialassa della Baiona in Emilia-Romagna. It was in summer 2012 that U. marinum was identified for the first time, even though it has been present at least since 2008. This species, originally described from South Australia and Western Australia and probably imported with the Manila clam Tapes philippinarum, is prevalently associated with thalli of another introduced species, Agardhiella subulata, and the invasive Gracilaria vermiculophylla, which also have a Pacific origin and have recently colonized the same lagoon areas. Uronema marinum is currently widespread in the whole lagoon surfaces, but is particularly abundant in stagnant waters, rich in nutrients, where Gracilariaceae and Solieriaceae prevail on Ulvaceae.
16
Rodellas, Valentí, Thomas C. Stieglitz, Aladin Andrisoa, Peter G. Cook, Patrick Raimbault, Joseph J. Tamborski, Pieter van Beek e Olivier Radakovitch. "Groundwater-driven nutrient inputs to coastal lagoons: The relevance of lagoon water recirculation as a conveyor of dissolved nutrients". Science of The Total Environment 642 (novembre 2018): 764–80. http://dx.doi.org/10.1016/j.scitotenv.2018.06.095.
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Morsy, Karim M., Amrit K. Mishra e Mona M. Galal. "Water Quality Assessment of the Nile Delta Lagoons". Air, Soil and Water Research 13 (gennaio 2020): 117862212096307. http://dx.doi.org/10.1177/1178622120963072.
Testo completoAbstract (sommario):
Nile Delta Lagoons have been formed 7000 years before the present. The lagoons were aqua-cultural and ecological keystones for the early Egyptian agricultural civilization. The water quality of Nile Delta Lagoons has been deteriorated with the economic development, population rapid increase, and the related industrialization, which exert high pressure on the surrounding environment. The 4 lagoons (1) Maryut, (2) Edku, (3) Burullus, and (4) Manzala are large is surface area, shallow in depth and located on the Nile Delta that receive great amounts of agricultural drainage, sewage, and industrial effluents before discharging into the Mediterranean Sea. The aim of this study is to monitor and assess the water and sediment quality of the lagoons. In light of this assessment, it was found that excessive nutrients are discharged into these lagoons causing severe eutrophication. In addition, relatively low values of dissolved oxygen were recorded causing fish mortality in the lagoons which amplifies in summer as the temperature increases. The article also examined the physical and biological parameters in addition to the chemical concentration of trace metals (Zn, Fe, Pb, Mn, Cr, and Cd) in the water and sediment samples that were collected from the 4 lagoons. High values of biological oxygen demand, chemical oxygen demand, total coliform, fecal coliform, fecal streptococci, ammonia (NH3), total nitrogen, and total phosphorus were recorded. In addition, high concentrations of trace metals were found in the water and sediments of the 4 lagoons.
18
González-De Zayas, Roberto, Martin Merino-Ibarra, Patricia M. Valdespino-Castillo, Yunier Olivera e Sergio F. Castillo-Sandoval. "Coexisting ecosystem states in a tropical coastal lagoon under progressive eutrophication in the northern Cuban keys". Scientia Marina 82, n. 3 (9 ottobre 2018): 139. http://dx.doi.org/10.3989/scimar.04682.22a.
Testo completoAbstract (sommario):
Through a nested suite of methods here we contrast the coexistence of different ecosystem states in a tropical coastal lagoon, the Laguna Larga, with increasing eutrophication stress between 2007 and 2009. Water temperature averaged 27.4°C in the lagoon and showed a slight positive trend during the study period. Salinity averaged 35.0±6.2, exhibiting high spatial and temporal variability, and also a slight positive trend in time. In contrast, dissolved oxygen showed a substantial decreasing trend (–0.83 ml L–1 y–1; –13.3% y–1) over the period, while nutrients increased dramatically, particularly total phosphorus (2.6 µM y–1), in both cases sustaining the progression of eutrophication in the lagoon during the three years we sampled. The Karydis nutrient load-based trophic index showed that the lagoon has a spatial pattern of increasing eutrophication from the sea and the outer sector (oligotrophic-mesotrophic) to the central (mesotrophic) and the inner sector (mesotrophic-eutrophic). Two ecosystem states were found within the lagoon. In the outer oligotrophic sector, the dominant primary producers were macroalgae, seagrasses and benthic diatoms, while mollusc assemblages were highly diverse. In the inner and central sectors (where trophic status increased toward the inner lagoon) a phytoplankton-dominated ecosystem was found where mollusc assemblages are less diverse. In spite of the progression of eutrophication in the lagoon, these two different ecosystems coexisted and remained unchanged during the study period. Apparently, the effect of water residence time, which increases dramatically toward the inner lagoon, dominated over that of nutrient loadings, which is relatively more homogeneously distributed along the lagoon. Therefore, we consider that actions that reduce the water residence time are likely the most effective management options for this and other similarly choked lagoons.
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Herrera-Silveira, Jorge A., e Javier Ramírez-Ramírez. "Salinity and nutrients in the coastal lagoons of Yucatan, Mexico". SIL Proceedings, 1922-2010 26, n. 3 (marzo 1998): 1473–78. http://dx.doi.org/10.1080/03680770.1995.11900971.
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Knapp, Melissa A., Naomi Geeraert, Kiho Kim e Karen L. Knee. "Submarine Groundwater Discharge (SGD) to Coastal Waters of Saipan (Commonwealth of the Northern Mariana Islands, USA): Implications for Nitrogen Sources, Transport and Ecological Effects". Water 12, n. 11 (28 ottobre 2020): 3029. http://dx.doi.org/10.3390/w12113029.
Testo completoAbstract (sommario):
Seagrass meadows and coral reefs along the coast of Saipan, a US commonwealth in the Northern Pacific, have been declining since the 1940s, possibly due to nutrient loading. This study investigated whether submarine groundwater discharge (SGD) contributes to nutrient loading and supports primary production on Saipan’s coast. SGD can be an important source of freshwater, nutrients, and other pollutants to coastal waters, especially in oceanic islands without well-developed stream systems. Ra and Rn isotopes were used as natural tracers of SGD. Nitrate, phosphate, and ammonium concentrations, ancillary water quality parameters, δ15N and δ18O of dissolved nitrate, and δ15N of primary producer tissue were measured. Our results pointed to discharge of low-salinity groundwater containing elevated concentrations of sewage-derived N at specific locations along Saipan’s coast. High SGD areas had lower salinity and pH, higher dissolved inorganic nitrogen concentrations, and elevated primary producer δ15N, indicative of sewage nitrogen inputs. We estimated that SGD could support 730–6400 and 3000–15,000 mol C d−1 of primary production in Tanapag and Garapan Lagoons, respectively, or up to approximately 60% of primary production in Garapan Lagoon. Efforts to improve water quality, reduce nutrient loading, and preserve coastal ecosystems must account for groundwater, since our results demonstrate that it is an important pathway of nitrogen delivery.
21
Zhai, W. D., e X. L. Yan. "Coupling the chemical dynamics of carbonate and dissolved inorganic nitrogen systems in the eutrophic and turbid inner Changjiang (Yangtze River) Estuary". Biogeosciences Discussions 12, n. 8 (30 aprile 2015): 6405–43. http://dx.doi.org/10.5194/bgd-12-6405-2015.
Testo completoAbstract (sommario):
Abstract. To better understand biogeochemical processes controlling CO2 dynamics in those eutrophic large-river estuaries and coastal lagoons, we investigated surface water carbonate system, nutrients, and relevant hydrochemical parameters in the inner Changjiang (Yangtze River) Estuary, covering its channel-like South Branch and the lagoon-like North Branch, shortly after a spring-tide period in April 2010. In the North Branch, with a water residence time of more than 2 months, biogeochemical additions of ammonium (7.4 to 65.7 μmol kg−1) and alkalinity (196 to 695 μmol kg−1) were detected along with high salinity of 4.5 to 17.4. In the South Branch upper-reach, unusual salinity values of 0.20 to 0.67 were detected, indicating spillover waters from the North Branch. The spillover waters enhanced the springtime Changjiang export fluxes of nutrients, dissolved inorganic carbon, and alkalinity. And they affected the biogeochemistry in the South Branch, by lowering water-to-air CO2 flux and continuing the nitrification reaction. In the North Branch, pCO2 was measured from 930 to 1518 μatm at the salinity range between 8 and 16, which was substantially higher than the South Branch pCO2 of 700 to 1100 μatm. Based on field data analyses and simplified stoichiometric equations, we suggest that the North Branch CO2 productions were quantified by biogeochemical processes combining organic matter decomposition, nitrification, CaCO3 dissolution, and acid-base reactions in the estuarine mixing zone. Although our study is subject to limited temporal and spatial coverage of sampling, we have demonstrated a procedure to quantificationally constrain net CO2 productions in eutrophic estuaries and/or coastal lagoons, by coupling the chemical dynamics of carbonate and dissolved inorganic nitrogen systems.
22
Dougherty, Brian, Myles Gray, Mark G. Johnson e Markus Kleber. "Can Biochar Covers Reduce Emissions from Manure Lagoons While Capturing Nutrients?" Journal of Environmental Quality 46, n. 3 (maggio 2017): 659–66. http://dx.doi.org/10.2134/jeq2016.12.0478.
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Petry, Ana Cristina, Angelo Antonio Agostinho e Luiz Carlos Gomes. "Fish assemblages of tropical floodplain lagoons: exploring the role of connectivity in a dry year". Neotropical Ichthyology 1, n. 2 (dicembre 2003): 111–19. http://dx.doi.org/10.1590/s1679-62252003000200005.
Testo completoAbstract (sommario):
Irregular rainfall and pronounced reductions of the hydrometric level in the year 2000 resulted in drastically altered hydrological connectivity of lentic environments in the upper Paraná River floodplain. The objective of the present work was to examine spatial and temporal patterns of fish assemblage attributes and structure in relation to limnological variables associated with hydrological connectivity. Fish were collected quarterly by seining in the marginal areas of 15 lagoons belonging to two biotopic categories (connected and disconnected). Variation in assemblage composition reflected the degree of hydrological connectivity. Values of assemblage attributes (species richness, density and biomass) were significantly lower in connected lagoons than in disconnected lagoons. Significantly higher values of species richness and biomass were recorded in November than in August. Rare species had the greatest effect on observed patterns in fish assemblage ordination (DCA). Observed patterns of variation in assemblage attributes were directly correlated with factors related to hydrological connectivity, such as depth, resources (zooplankton and chlorophyll a) and nutrients (total phosphorus).
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Stabili, Loredana, Lucia Rizzo, Rosa Caprioli, Giorgio Alabiso e Stefano Piraino. "How Much Recurrent Outbreaks of the Moon Jellyfish May Impact the Dynamics of Bacterial Assemblages in Coastal Lagoons?" Water 14, n. 23 (1 dicembre 2022): 3908. http://dx.doi.org/10.3390/w14233908.
Testo completoAbstract (sommario):
The moon jellyfish Aurelia coerulea (Scyphozoa) is one of the most common and largest jellyfish inhabiting coastal lagoons, confined bays, and marinas of temperate and subtropical coastal waters. The annual population dynamics of A. coerulea along with some bacterial parameters (bacterial size and biomass, total coliforms, faecal coliforms, intestinal enterococci, culturable Vibrio spp., and culturable bacteria at 37 °C), sea surface temperature (SST), salinity, and an array of nutrients (ammonia, nitrites, nitrates, phosphates, silicates, total nitrogen, and total phosphorus) were assessed in the Varano lagoon (Adriatic Sea) that is subject to anthropogenic pollution. Statistical analyses revealed that jellyfish outbreaks and their consequent biomass deposition significantly correlated to seawater temperature, total nitrogen, phosphates, and ammonia concentrations while negative correlations appeared with nitrite and nitrate concentrations. In addition, bacterial biomass and Vibrio abundance correlated with each other and temperature, jellyfish density, and total nitrogen. These findings suggest that environmental changes could trigger the occurrence of jellyfish bursts in the lagoon which, in turn, may act as one of the central drivers of processes regulating some bacterial components. The positive relationship between jellyfish flush-and-crash dynamics and SST suggests that ongoing global warming will seemingly increase jellyfish outbreaks.
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EL-RAVIS, OSMAN. "Environmental Conditions of Two Red Sea Coastal Lagoons in Jeddah. 2 -Nutrients". Journal of King Abdulaziz University-Marine Sciences 9, n. 1 (1998): 49–59. http://dx.doi.org/10.4197/mar.9-1.4.
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Nixon, Scott W., Betty A. Buckley, S. L. Granger, M. Entsua-Mensah, O. Ansa-Asare, M. J. White, Richard A. McKinney e E. Mensah. "ANTHROPOGENIC ENRICHMENT AND NUTRIENTS IN SOME TROPICAL LAGOONS OF GHANA, WEST AFRICA". Ecological Applications 17, sp5 (luglio 2007): S144—S164. http://dx.doi.org/10.1890/05-0684.1.
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Cerda, Mauricio, Conceição Denise Nunes-Barboza, Camila Nunes Scali-Carvalho, Kelly De Andrade-Jandre e Aguinaldo-Nepomuceno Marques Jr. "Nutrient budgets in the Piratininga-Itaipu lagoon system (southeastern Brazil): effects of sea-exchange management". Latin American Journal of Aquatic Research 41, n. 2 (2 maggio 2017): 226–38. http://dx.doi.org/10.3856/vol41-issue2-fulltext-3.
Testo completoAbstract (sommario):
The Piratininga-Itaipu Lagoon System and its drainage basin, located on the southeastern coast of Brazil, Niterói (RJ), has been the target of an intense process of urbanization over the last four decades. As a result of this process, both the lagoon and the adjacent sea area have shown signs of eutrophication due to the release of large quantities of domestic sewage semi (or not) treated. In an attempt to minimize these effects, in 2008 the government re-established a connection between the Piratininga lagoon and the sea. To evaluate changes and variations in the balance of dissolved inorganic nutrients, before and after interventions, the geochemical model of two stoichiometric mass balance boxes of the "LOICZ Program” (Land-Ocean Interactions in the Coastal Zone) was used. The salt and water balance showed different water residence times in the Piratininga lagoon for the two periods: 2005-2006 (before the opening of the connection between the Piratininga lagoon and the sea) and 2009-2010 (after the opening of the connection with the sea). The first period showed a value about two times higher than that obtained for 2009-2010, τ = 83 and 39 days respectively. The water residence time of the Itaipu lagoon did not show great variations between the two periods (τ = 9 and 8 days). For the period of 2005-2006, before the opening of the connection with the sea, both the lagoons were autotrophic (∆DIP > 0) and nitrogen loss was predominant (∆DIN < 0). The second period (2009-2010) was characterized by changes only in the trophic state of the Piratininga lagoon, which became heterotrophic (∆DIP > 0).
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Mardochee Ephraim, Achoh, Agadjihouede Hyppolite, Gangbe Luc, Aizonou Romaric, Ahouansou Montcho Simon e Chikou Antoine. "ESTIMATION OF PHOSPHORUS AND NITROGEN RELEASED BY THE BREEDING OF OREOCHROMIS NILOTICUS IN CAGES IN THE TOHO AND TODOUGBA LAGOONS(SOUTHER BENIN) BETWEEN 2017 AND 2020". International Journal of Advanced Research 9, n. 11 (30 novembre 2021): 422–30. http://dx.doi.org/10.21474/ijar01/13759.
Testo completoAbstract (sommario):
The present study aim to estimate the ratio of aquaculture in the phosphorus and nitrogen concentrations determined in the Toho - Todougba lagoons. For this purpose, the two lagoons were subdivided into 7 stations for the determination of phosphorus and nitrogen concentrations in the water column. Production data from 2017 to 2019 were collected from the Direction of the Ficheries Production and from the literature. Data for 2020 were collected directly from fish farmers. Annual tilapia production was estimated by year and the amounts of phosphorus and nitrogen released from aquaculture are deduced based on the ratio of Montanhini Neto & Ostrensky (2013). The concentration of each of these nutrients was estimated by station and compared to the concentration determined by laboratory analysis of the water. This methodology shows that the amount of phosphorus and nitrogen released to the environment varies from 0.49 mg/L to 0.18 mg/L for phosphorus and from 1.53 mg/L to 0.58 mg/L for nitrogen. The lowest values are obtained in 2020 and differ significantly from the other years (p <0.05). The quantity of phosphorus discharged is higher at the high production stations (Tonon 0.20 mg/L and Lokohoue 0.11 mg/L). Some of this is stored in the sediment. The nitrogen generated by aquaculture is significantly lower than the average determined in water (p <0.05). However, the concentration determined is still related to the amount of organic matter released due to aquaculture. Although aquaculture is not the only source of nutrient release to water, strategies for aquaculture with less nutrient release should be determined.
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Olguín, Eugenia J., e Gloria Sánchez-Galván. "Aquatic phytoremediation: Novel insights in tropical and subtropical regions". Pure and Applied Chemistry 82, n. 1 (3 gennaio 2010): 27–38. http://dx.doi.org/10.1351/pac-con-09-02-13.
Testo completoAbstract (sommario):
An overview of the state of the art in phytofiltration of nutrients and heavy metals (HMs) from wastewaters using tropical and subtropical plants in constructed wetlands (CWs) and lagoons is presented. Various mechanisms to remove these pollutants are discussed, in regard to three different types of systems: surface flow constructed wetlands (SFCWs), subsurface flow constructed wetlands (SSFCWs), and lagoons with floating plants. Only recent reports at laboratory, pilot and full scale, especially in tropical regions, are discussed. Most of the experiences around the world have shown that these systems are efficient and high removal percentages have been reported for both, nutrients and metals. However, there are still several unsolved or partially understood issues. Long-term studies at the mesocosms or large scale, in order to gain a full insight of the various mechanisms occurring in each system, are required. The understanding of the fate or compartmentalization of the pollutants in these complex artificial ecosystems, especially in the case of HMs, will permit us to establish the frequency of harvesting and the advantages of the use of specific species. The huge bio-diversity that is commonly found in tropical and subtropical regions represents a challenge for finding new species with outstanding characteristics for tolerance to toxic and recalcitrant pollutants or to extreme environmental conditions, such as high temperature or salinity.
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Matias, Tális Pereira, Vívian Ariane De Oliveira Costal, Carmino Hayashi, Adriana Maria Imperador e Luciana Botezelli. "LIMNOLOGICAL PROCESSES OF FACULTATIVE STABILIZATION LAGOONS IN THE TREATMENT OF LIQUID EFFLUENTS". Revista EVS - Revista de Ciências Ambientais e Saúde 47, n. 1 (21 dicembre 2020): 8675. http://dx.doi.org/10.18224/evs.v47i1.8675.
Testo completoAbstract (sommario):
Objective: To evaluate some of the main limnological aspects and discuss the relevance of effluent treatment efficacy by the FLs treatment system and provide fundamental information for technicians and environmental managers to make decisions about this type of treatment. Methods: The literature review was used as a methodology, specifically through scientific publications from 2016 to June 2020 on FL and limnology, applied in tropical climates. We selected articles written in Portuguese and English, and we chose to search in free terms, thus promoting a greater number of references on FLs and limnology. Results: The research showed the potential of FLs for the treatment of effluents and their contribution to sustainability. To this end, we show in this article the relevance of the environmental dynamics of FLs, contemplating characteristics related to their aerobic, anerobic, facultative processes, in addition to operational and limnological variables, such as the types of phytoplankton, effectiveness in removing nutrients and contributing to the landscape harmony and biodiversity conservation. We also emphasize that this is fundamental information for the operation and management of FLs. Conclusions: FLs, owing to their operational and limnological characteristics, are a type of favorable effluent treatment system in tropical climates as occurs in Brazil. Investment in this type of system can be favorable to the sustainability and harmony of the landscape, in addition to the fact that the limnological behavior of these ecosystems is favorable to the removal of nutrients, which in turn contributes to environmental conservation and pollution reduction.
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Freire, Rogério Herlon Furtado, Roseli Frederigi Benassi, Maria do Carmo Calijuri e Aline Alves Sanchez. "Influence of water fluctuations on the limnological characteristics of two floodplain lagoons (Ribeira do Iguape Valley, state of São Paulo, Brazil)". Acta Limnologica Brasiliensia 27, n. 4 (dicembre 2015): 431–40. http://dx.doi.org/10.1590/s2179-975x7613.
Testo completoAbstract (sommario):
Abstract Aim: Current study assessed the influence of hydrometric levels on the limnological characteristics of two river floodplain systems in the Ribeira do Iguape Basin (state of São Paulo, Brazil). Methods: Rainfall data were collected dailyfrom an automatic weather station in Jacupiranga SP Brazil and daily hydrometric level records were obtained from automatic linigraphs installed on the two adjacent rivers. Moreover, pH, electrical conductivity and dissolved oxygen were measured by a multiparametric probe. Water samples were collected to analyze nitrate, ammoniac nitrogen, total nitrogen and phosphorus, total alkalinity and suspended material. The samplings were carried out in April and July, representative months for low and high water periods, respectively. Results and Conclusions: Statistical analysis highlighted the “effect of homogenization”, attributed to the hydrological pulses in several studies carried out in river-floodplain systems. This effect in current study was more underscored at Lagoon 2, which remained connected for a longer period with the adjacent river, when compared to Lagoon 1- River Jacupiranguinha system. Higher dissolved oxygen concentrations at Lagoon 2, in contrast with the Lagoon 1 featuring anoxia during the whole period under analysis, were also attributed to the above-mentioned greater hydrological connectivity. Current study highlights that the water-mediated transferences during the high water period may contribute not only towards the fertilization of marginal lagoons (inputs of nutrients and organic matter) but also to significant pollutant loads, according to land use along the watersheds. In the case of Lagoon 1- River Jacupiranguinha system, even though further studies are needed and strongly recommended, it is reasonable to assume that the discharges of mining effluents into the river may result in ecological damage not only to the receiving water body but also to the connected ecosystems.
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Carstensen, Jacob, Daniel J. Conley, Elin Almroth-Rosell, Eero Asmala, Erik Bonsdorff, Vivi Fleming-Lehtinen, Bo G. Gustafsson et al. "Factors regulating the coastal nutrient filter in the Baltic Sea". Ambio 49, n. 6 (9 novembre 2019): 1194–210. http://dx.doi.org/10.1007/s13280-019-01282-y.
Testo completoAbstract (sommario):
Abstract The coastal zone of the Baltic Sea is diverse with strong regional differences in the physico-chemical setting. This diversity is also reflected in the importance of different biogeochemical processes altering nutrient and organic matter fluxes on the passage from land to sea. This review investigates the most important processes for removal of nutrients and organic matter, and the factors that regulate the efficiency of the coastal filter. Nitrogen removal through denitrification is high in lagoons receiving large inputs of nitrate and organic matter. Phosphorus burial is high in archipelagos with substantial sedimentation, but the stability of different burial forms varies across the Baltic Sea. Organic matter processes are tightly linked to the nitrogen and phosphorus cycles. Moreover, these processes are strongly modulated depending on composition of vegetation and fauna. Managing coastal ecosystems to improve the effectiveness of the coastal filter can reduce eutrophication in the open Baltic Sea.
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Taylor, D. I., S. W. Nixon, S. L. Granger e B. A. Buckley. "Impacts of different forms of nutrients on the roles of coastal lagoons as nutrient sources or sinks — A mesocosm study". Ophelia 42, n. 1 (settembre 1995): 353–70. http://dx.doi.org/10.1080/00785326.1995.10431513.
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Bocodaho, O. B. M. Lucinde, Waris Kéwouyèmi Chouti, Comlan Achille Dedjiho e Daouda Mama. "Evaluation de l’état trophique des eaux du complexe lagunaire côtier du Sud-Ouest Bénin en période de hautes eaux (de Togbin à l’Embouchure Mono)". International Journal of Biological and Chemical Sciences 14, n. 7 (7 dicembre 2020): 2618–28. http://dx.doi.org/10.4314/ijbcs.v14i7.20.
Testo completoAbstract (sommario):
Les lagunes servent de tanières pour un grand nombre d’espèces aquatiques et constituent de ce fait des richesses à entretenir. Malheureusement, la lagune côtière du Bénin fait face à un déséquilibre écologique qui se manifeste par une croissance excessive des végétaux aquatiques. En vue de caractériser l’état trophique de la lagune, une campagne d’échantillonnage a été effectuée en période de hautes eaux sur onze points représentatifs. La méthodologie de dosage au spectrophotomètre a été adoptée pour mettre en évidence les paramètres de diagnostic de pollution. Les analyses signalent de fortes concentrations en phosphore (28,75 mg/L) et en nitrites (10 mg/L) dans les eaux de la lagune. La lagune se trouve alors dans un état d’hyper-eutrophisation selon la grille de qualité établie par Ifremer. Le non-respect des mesures de protection des plans d’eau et la mauvaise gestion des déchets ménagers et des eaux usées entraînent la prolifération des nutriments responsables de l’eutrophisation de la lagune côtière. Vu l’ampleur de la pollution mise en relief par cette étude, l’institution d’un programme de surveillance s’avère indispensable afin de veiller au maintien de la qualité écologique des écosystèmes aquatiques en République du Bénin.Mots clés : Lagune côtière, eutrophisation, nutriments, pollution.
English Title: Assessment of the trophic state of the waters of the coastal lagoon complex of Southwest Benin during high water periods (from Togbin to Mono Mouth)The lagoons serve as places of residence for several aquatic species and therefore constitute riches to be properly maintained. Unfortunately, the coastal lagoon of Benin faces an ecological imbalance visibly manifested by an excessive growth of aquatic plants. In order to characterize the trophic state of the lagoon, a sampling campaign was carried out during high water periods according to eleven representative points. The spectrophotometer assay methodology was adopted to highlight the pollution diagnostic parameters. Analyzes report high concentrations of phosphorus (28.75 mg/L) and nitrites (10 mg/L) in lagoon waters. The lagoon is then in an enlarged state according to the quality grid established by Ifremer. Failure to comply with measures to protect water bodies and poor management of household waste and wastewater lead to the proliferation of nutrients responsible for eutrophication within the coastal lagoon. Given the magnitude of the pollution highlighted by this study, the implementation of a monitoring program is essential in order to ensure the maintenance of the ecological quality of aquatic ecosystems in the Republic of Benin.Keywords: Coastal lagoon, eutrophication, nutrients, pollution.
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Mwachireya, Shaaban A., Tim R. McClanahan, Isabelle M. Cote e Brian E. Hartwick. "Increased Terrestrial Perturbations Modify Skeletal Properties and Mechanical Strength of Hard Corals". Environment and Natural Resources Research 6, n. 4 (30 novembre 2016): 153. http://dx.doi.org/10.5539/enrr.v6n4p153.
Testo completoAbstract (sommario):
Skeleton properties determine coral survival by influencing the range of hydraulic conditions colonies can withstand, selection of suitable habitat, ability to compete for space and light, repair damage and the overall fitness and ecological success of scleractinian corals. Skeletal properties of 16 coral species comprising 3 growth forms collected from Kenyan coral reef lagoons were investigated and found to vary considerably not only between species but between reefs as well, with corals exposed to both sediment and nutrients showing consistent lower skeleton density and strength but high porosity compared to those from sediment-unaffected reefs. Further, high skeletal density and strength but low porosity values were measured in branching relative to other growth forms. The present findings also suggest that the negative effects of nutrients on skeleton properties may be counteracted by high hydrodynamic energy, resulting in stronger skeletons in high hydrodynamic energy-nutrient-polluted reef habitats relative to pristine reefs. These findings have important ecological and management implications with regard to the existence, persistence, productivity and protective value of reefs, damage risks, maintenance and conservation of biological diversity with respect to future global climate change events. Consequently, appropriate watershed, reef and fisheries management options the impacts of local anthropogenic stresses (sediments, nutrients, overexploitation) would be expected to alleviate the effects of these disturbances and have the potential to minimize future large-scale coral reef damage resulting from increased and frequent global climate change events, such as increased ocean acidification (due to elevated atmospheric CO2) and sea surface temperature.
36
Thebaldi, M. S., A. V. Silva, N. M. S. Vilela, B. P. Leal, I. C. Borges, I. P. Martins e L. R. Fernandes. "CONCENTRAÇÃO DE NUTRIENTES NA ÁGUA DE DUAS LAGOAS URBANAS DO MUNICÍPIO DE FORMIGA / NUTRIENTS CONCENTRATION ON THE WATER OF TWO URBAN LAGOONS FO FORMIGA CITY - MG". Revista Brasileira de Engenharia de Biossistemas 11, n. 2 (30 giugno 2017): 172. http://dx.doi.org/10.18011/bioeng2017v11n2p172-184.
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Zink, Klaus-Gerhard, André L. S. Furtado, Peter Casper e Lorenz Schwark. "Organic matter composition in the sediment of three Brazilian coastal lagoons: district of Macaé, Rio de Janeiro (Brazil)". Anais da Academia Brasileira de Ciências 76, n. 1 (marzo 2004): 29–47. http://dx.doi.org/10.1590/s0001-37652004000100004.
Testo completoAbstract (sommario):
Freshwater lagoons comprise important coastal ecosystems and natural buffers between urbanized land areas and open ocean in the Rio de Janeiro State, Brazil. Studies of sediment and water chemistry, zooplankton and bacterial communities to assess the extent of anthropogenic disturbance are available. Here we contribute with an organic-geochemical approach supplemented by some microbiological aspects to complete the characterization of these lagoonal ecosystems. Bulk organic matter and extractable lipids (aliphatic hydrocarbons, alcohols and fatty acids, sterols) were investigated from two locations per lagoon: at the seaward site and landward ends - and at two depth intervals (0-3 and 3-6 cm) per site. Urbanized Imboacica Lagoon received increased anthropogenic input over the most recent years represented by the topmost 3 cm of sediment, whereas deeper sediment layers are less affected by human influence. Eutrophication or nutrient availability favored enhanced algal/cyanobacterial growth. In remote Cabiúnas and Comprida Lagoons pristine conditions are preserved. Organic matter from vascular plants dominates (chain length of free lipids up to C36), which is exceptionally well preserved by acidic lagoonal waters. Differentiation between landward and seaward sites in these two lagoons is less well established due to much smaller surface/volume to catchment ratios. No anthropogenic influences are yet detectable in sediments of Cabiúnas and Comprida Lagoons.
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Leruste, A., F. Guilhaumon, R. De Wit, N. Malet, Y. Collos e B. Bec. "Phytoplankton strategies to exploit nutrients in coastal lagoons with different eutrophication status during re-oligotrophication". Aquatic Microbial Ecology 83, n. 2 (25 luglio 2019): 131–46. http://dx.doi.org/10.3354/ame01906.
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Velez, Maria, Daniel Conde, Juan Lozoya, James Rusak, Felipe García-Rodríguez, Carina Seitz, Thomas Harmon, Gerardo Perillo, Jaime Escobar e Sandra Vilardy. "Paleoenvironmental Reconstructions Improve Ecosystem Services Risk Assessment: Case Studies from Two Coastal Lagoons in South America". Water 10, n. 10 (28 settembre 2018): 1350. http://dx.doi.org/10.3390/w10101350.
Testo completoAbstract (sommario):
Paleoenvironmental reconstructions are increasingly being used in conservation biology, ecosystem management, and evaluations of ecosystem services (ES), but their potential to contribute to the ES risk assessment process has not been explored. We propose that the long-term history of the ecosystem provides valuable information that augments and strengthens an ES risk assessment and that it should be considered routinely when undertaking risk assessments. We adjusted a standard ecosystem-based risk management (EBRM) protocol to include paleoenvironmental data, and tested the modified approach on two coastal lagoons in South America. Paleolimnological reconstructions in both lagoons indicate that salinity and nutrients (in Laguna de Rocha), and salinity (in Ciénaga Grande de Santa Marta), as controlled by hydrologic connectivity with the ocean and freshwater tributaries, have been the key variables behind ecosystem’s function. This understanding, applied to inform various components and steps in the EBRM protocol, suggests that the maintenance of hydrological connections should be a management priority to minimize risk to ES. This work illustrates the utility of including paleoenvironmental data in an EBRM context and highlights the need for a more holistic approach to risk management by incorporating the long-term history of ecosystem function.
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Pradhan, S., R. N. Samal, S. B. Choudhury e P. K. Mohanty. "HYDRODYNAMIC AND COHESIVE SEDIMENT TRANSPORT MODELING IN CHILIKA LAGOON". ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-5 (15 novembre 2018): 141–49. http://dx.doi.org/10.5194/isprs-annals-iv-5-141-2018.
Testo completoAbstract (sommario):
<p><strong>Abstract.</strong> Chilika lagoon, one of the largest brackish water lagoons in Asia located along the east coast of India. The rivers draining into the lagoon carry about 13 million tonnes of sediments annually. Because of the cohesiveness properties of the fine sediments, nutrients, heavy metals and other polluted substances tend to bind to the sediment’s surface. Consequently, pollutants can be concentrated in the inlets/estuaries, thus being of great environmental interest. In addition, the mudflats occurring are important biotopes for a large number of micro- and macro-faunal species and act as feeding places for a number of birds. To understand the cohesive sediment dynamics, a numerical model, MIKE 21 Mud Transport (MT) coupled with hydrodynamic (HD) was used. The model simulated the relative bed level height and suspended sediment concentrations. The sediment interchange and accumulation between each sectors and Bay of Bengal were evaluated. The suspended sediment concentration is high in the north-east portion of the lagoon while medium and low suspended loads are observed in the eastern and western portion of the lagoon. Bed thickness is very high in the north-western corner of the lagoon covered with Phragmites Karka which facilitate sediment trap. Total bed thickness change is very much pronounced in the northern sector which receives most of the sediments from the Mahanadi river systems as well along the periphery of the lagoon due to drainage. The eastern lagoon shows a net deposition accumulated fraction (5–15<span class="thinspace"></span>kg/m<sup>2</sup>) and hence gives enough indication of the sedimentation processes in the lagoon. Further, the results also warrant immediate attention to check and monitor suspended sediment concentration to find out the net deposition trend in the lagoon environment in order to take decisions in minimizing the sediment load.</p>
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Bozic, M., G. Nikolic, Z. Rudic, V. Raicevic e B. Lalevic. "Constructed wetlands as an alternative restoration measure for shallow lakes". Water Science and Technology 68, n. 7 (1 ottobre 2013): 1672–78. http://dx.doi.org/10.2166/wst.2013.412.
Testo completoAbstract (sommario):
This paper deals with the consequences of cultural eutrophication and unconventional solutions for shallow lake restoration. Cultural eutrophication is the primary problem that affects especially shallow lakes, due to their physical characteristics (e.g. shallow depth, lack of stratification). Palic Lake, a very shallow Pannonian lake, received treated municipal wastewaters coming from the lagoons of a wastewater treatment plant. The sewage discharge mainly increased the nutrient load to the lake in the last decades. The lake sustainability is affected by inappropriate quality of water that flows into the lake, and abundance of deposited sediment. The technology that can provide both improvement of water quality and resolution of the sediment problem is a constructed wetland, which is designed to utilise the natural processes involving wetland vegetation, soil and their associated microbial assemblages to assist in additional water treatment. The technical solution is based on three key aspects: quality and quantity of deposited sediment, enriched by nutrients; effluent quality; desired lake water quality. A designed constructed wetland can accomplish the desired water quality and gradually remediate deposited sediment.
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Battista, Nicholas A., Julia E. Samson, Shilpa Khatri e Laura A. Miller. "Under the sea: Pulsing corals in ambient flow". Texts in Biomathematics 1 (6 dicembre 2017): 22. http://dx.doi.org/10.11145/texts.2017.11.197.
Testo completoAbstract (sommario):
While many organisms filter feed and exchange heat or nutrients in flow, few benthic organisms also actively pulse to enhance feeding and exchange. One example is the pulsing soft coral (Alcyonacea: Xeniidae). Pulsing corals live in colonies, where each polyp actively pulses through contraction and relaxation of their tentacles. The pulses are typically out of phase and without a clear pattern. These corals live in lagoons and bays found in the Red Sea and Indian Ocean where they at times experience strong ambient flows. In this paper, 3D fluid-structure interaction simulations are used to quantify the effects of ambient flow on the exchange currents produced by the active contraction of pulsing corals. We find a complex interaction between the flows produced by the coral and the background flow. The dynamics can either enhance or reduce the upward jet generated in a quiescent medium. The pulsing behavior also slows the average horizontal flow near the polyp when there is a strong background flow. The dynamics of these flows have implications for particle capture and nutrient exchange.
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Raper, W. G., e J. M. Green. "Simple process for nutrient removal from food processing effluents". Water Science and Technology 43, n. 3 (1 febbraio 2001): 123–30. http://dx.doi.org/10.2166/wst.2001.0127.
Testo completoAbstract (sommario):
Food processing effluents often contain high levels of nutrients, particularly N. Conventionally, anaerobic ponds are used to purify these effluents in Australia, giving cost-effective removal of BOD but little nutrient removal. It has become apparent that disposal by irrigation as presently practised normally exceeds sustainable N application rates, thus reduction of nutrient levels before irrigation is becoming mandatory. Meatworks effluent is often discharged to country town sewers, frequently accounting for 50-75% of the nutrient load. Meatworks effluents contain 1,000-4,000 mg/L BOD, 200-400 mg/L TKN and 20-50 mg/L P. Conventional BNR technology can readily remove nutrients from such effluents, either alone or in combination with anaerobic ponds but sludge handling on such a small scale poses economic problems. Laboratory scale trials showed that both BOD removal from meatworks effluent and sludge disposal could be achieved readily in conventional anaerobic ponds. The pond effluent, together with the town sewage if required, could be treated in a sequencing batch reactor (SBR) designed for nitrification/denitrification service. Optimisation of the anaerobic pond operation was required to ensure production of the minimum BOD:N ratio needed for N removal. This paper will describe the design and commissioning of two plants; a demonstration plant installed at a typical sized meatworks in Gippsland, Victoria, and a full scale plant for treatment of combined domestic sewage and effluent from a large meatworks at Longford, Tasmania. In neither case (for different reasons) has P removal yet been required. It was demonstrated that 98% of BOD and up to 95% N removal may be cheaply and readily achieved in the SBR. Where lagoons are used, levels of N suitable for river discharge can be achieved. P can be readily removed by alum treatment when required.
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Abril, Gwenaël, Luiz C. Cotovicz Jr., Aguinaldo Nepomuceno, Thais Erbas, Suzan Costa, Vinicius V. Ramos, Gleyci Moser et al. "SPREADING EUTROPHICATION AND CHANGING CO2 FLUXES IN THE TROPICAL COASTAL OCEAN: A FEW LESSONS FROM RIO DE JANEIRO". Arquivos de Ciências do Mar 55, Especial (21 marzo 2022): 461–76. http://dx.doi.org/10.32360/acmar.v55iespecial.78518.
Testo completoAbstract (sommario):
In Brazil and in many other tropical countries, large urban cities and populations are still growing on the coast and coverage in terms of sewage treatments is far from desirable. Cultural eutrophication is not solely a threat for the coastal ocean; it is now acting as one of its major biogeochemical and ecological driver. Along the littoral of the state of Rio de Janeiro, semi-enclosed marine bays and lagoons show clear spatial and temporal pattern of increasing concentrations of chlorophyll a (Chl a), organic carbon, and nutrients in their waters and sediments in urbanized regions. Acting as a buffer, the nearshore ecosystems have turned highly eutrophic and their autotrophic metabolism has been enhanced creating strong carbon dioxide (CO2) sinks. We compile here data of CO2fluxes recently gathered in four coastal marine ecosystems in the state of Rio de Janeiro: the Guanabara Bay and the Araruama, Saquarema and Jacarepagua lagoons. We observed intense CO2 sources in restricted areas at the vicinity of sewage loads, where microbial degradation of organic matter predominates, and large CO2 sinks in confined and nearshore brackish, marine and hypersaline waters, where phytoplankton blooms occur. We also report a correlation across the four ecosystems between the partial pressure of CO2 in waters and the Chl a concentration. Chl a satellite data all along the Brazilian coast suggest that the CO2 sink induced by eutrophication probably occurs in many coastal ecosystems including bays, lagoon and shelf waters, and could contribute to an additional blue carbon. Part of the additional organic carbon is stored in sediments, and part is exported offshore. However, this additional blue carbon has dramatic environment impacts as it would evolve toward the formation of marine dead zones, and could contribute to a production of methane (CH4) a more powerful greenhouse gas. We emphasize an urgent need for multidisciplinary research to promote simultaneously the storage of atmospheric carbon, and the preservation of biodiversity and socio-economic goods in the eutrophic tropical coastal ocean.
Keywords: tropical coastal ecosystems, cultural eutrophication, phytoplankton blooms, marine dead zones, blue carbon
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Bellehumeur, C., L. Vasseur, C. Ansseau e B. Marcos. "Multielement Relationships Characterizing the Chemical Composition of Municipal Sewage Sludge in Southern Quebec". Water Quality Research Journal 32, n. 4 (1 novembre 1997): 751–70. http://dx.doi.org/10.2166/wqrj.1997.041.
Testo completoAbstract (sommario):
Abstract Disposal of sewage sludge on agricultural or forest lands has been shown to be an economical means of sludge disposal which reduces the amount of waste going to landfills and returns nutrients to the soil. The heavy metal content of sludge generally depends on the composition of influents and on the treatment process. The present study considers the sludge chemical composition of 23 municipalities in southern Quebec and the heavy metal concentrations in their respective drinking water supplies. This study attempts to determine the main multielement relationships characterizing sludge composition, and to verify the occurrence of a possible link between chemical element concentration in sludge and in water supplies. The main phenomena influencing the chemical composition of municipal sewage sludge were modeled by using principal component analysis. The analysis shows that Cu concentration in sludges highly correlates with the organic nitrogen, and a series of metals (Cd-Co-Cr-Ni-Pb) are deposited independently of N and P. The activated sludge process removes a greater quantity of N than aerated lagoons, but heavy metals are generally more concentrated in aerated lagoons. The metal level found in water supplies slightly correlates with the metal content of sludge. Treatment plants showing metal contamination problems are found in regions with high natural geo-chemical levels of metals.
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Yavuzcan Yıldız, Hijran, e Serap Pulatsü. "Towards zero waste: Sustainable waste management in aquaculture". Ege Journal of Fisheries and Aquatic Sciences 39, n. 4 (15 dicembre 2022): 341–48. http://dx.doi.org/10.12714/egejfas.39.4.11.
Testo completoAbstract (sommario):
Increases in aquaculture production due to higher demand for aquatic foods result in an increase in the amount of aquaculture wastewater. This situation highlights the need for the effective treatment of wastewater in sustainable aquaculture. Today, instead of traditional physical and chemical methods in the treatment of wastewater originating from aquaculture, ecosystem-sensitive and by-product-oriented systems have begun to be adopted. The main principle of the zero-waste approach is the recycling of the nutrients in the wastewater to produce another food. In this new innovative approach, the production of other organisms from the different trophic levels using the wastewater of aquaculture in the integrated multi-trophic systems (such as aquaponics) is possible to recycle the nutrients. It has been considered the integrated multi-trophic systems (IMTA) more valuable as these systems can be used both in environment-friendly wastewater treatment and in the conversion of nutrients in wastewater to biomass. The nutrients such as nitrogen and phosphorus in aquaculture wastewater can be utilized to produce two organisms (i.e. fish+mussel) or three organisms (i.e. fish+mussel+seaweed) through IMTA. Aquaculture wastewater can be used to reduce the nutrients in constructed wetlands and plant lagoons representing the reasonable approach for sustainable aquaculture and wastewater treatment. Here, the innovative approach to sustainable aquaculture wastewater treatment was reviewed for the current and innovative technologies. It was emphasized that the need for environment-friendly wastewater treatment Technologies such as aquaponics, enlargement of constructed wetlands, or increase in using the integrated multi-trophic production systems (IMTA) in practice are recommended for sustainable aquaculture.
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Sepúlveda-Muñoz, Cristian A., Ignacio de Godos e Raúl Muñoz. "Wastewater Treatment Using Photosynthetic Microorganisms". Symmetry 15, n. 2 (16 febbraio 2023): 525. http://dx.doi.org/10.3390/sym15020525.
Testo completoAbstract (sommario):
Wastewaters are mainly classified as domestic, industrial and agro-industrial based on their production source. Piggery wastewater (PWW) is a livestock wastewater characterized by its high concentrations of organic matter and ammonium, and by its odour nuisance. Traditionally, PWW has been treated in open anaerobic lagoons, anaerobic digesters and activated sludge systems, which exhibit high greenhouse gas emissions, a limited nutrients removal and a high energy consumption, respectively. Photosynthetic microorganisms can support a sustainable wastewater treatment in engineered photobioreactors at low operating costs and with an efficient recovery of carbon, nitrogen and phosphorous. These microorganisms are capable of absorbing solar irradiation through the photosynthesis process to obtain energy, which is used for their growth and associated carbon and nutrients assimilation. Purple phototrophic bacteria (PPB) represent the photosynthetic microorganisms with the most versatile metabolism in nature, whereas microalgae are the most-studied photosynthetic microorganisms in recent years. This review describes the fundamentals, symmetry and asymmetry of wastewater treatment using photosynthetic microorganisms such as PPB and microalgae. The main photobioreactor configurations along with the potential of PPB and microalgae biomass valorisation strategies are also discussed.
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Stefanova, Anastassi, Cornelia Hesse, Valentina Krysanova e Martin Volk. "Assessment of Socio-Economic and Climate Change Impacts on Water Resources in Four European Lagoon Catchments". Environmental Management 64, n. 6 (8 novembre 2019): 701–20. http://dx.doi.org/10.1007/s00267-019-01188-1.
Testo completoAbstract (sommario):
Abstract This study demonstrates the importance of considering potential land use and management changes in climate impact research. By taking into account possible trends of economic development and environmental awareness, we assess effects of global warming on water availability and quality in the catchments of four European lagoons: Ria de Aveiro (Portugal), Mar Menor (Spain), Vistula Lagoon (Poland and Russia), and Tyligulskyi Liman (Ukraine). Different setups of the process-based soil and water integrated model (SWIM), representing one reference and four socio-economic scenarios for each study area: the “business as usual”, “crisis”, “managed horizons”, and “set-aside” scenarios are driven by sets of 15 climate scenarios for a reference (1971–2000) and near future (2011–2040) scenario period. Modeling results suggest a large spatial variability of potential impacts across the study areas, due to differences in the projected precipitation trends and the current environmental and socio-economic conditions. While climate change may reduce water and nutrients input to the Ria de Aveiro and Tyligulsyi Liman and increase water inflow to the Vistula Lagoon the socio-economic scenarios and their implications may balance out or reverse these trends. In the intensely managed Mar Menor catchment, climate change has no notable direct impact on water resources, but changes in land use and water management may certainly aggravate the current environmental problems. The great heterogeneity among results does not allow formulating adaptation or mitigation measures at pan-European level, as initially intended by this study. It rather implies the need of a regional approach in coastal zone management.
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Brito-Espino, Saulo, Alejandro Ramos-Martín, Sebastian O. Pérez-Báez, Carlos Mendieta-Pino e Federico Leon-Zerpa. "A Framework Based on Finite Element Method (FEM) for Modelling and Assessing the Affection of the Local Thermal Weather Factors on the Performance of Anaerobic Lagoons for the Natural Treatment of Swine Wastewater". Water 13, n. 7 (24 marzo 2021): 882. http://dx.doi.org/10.3390/w13070882.
Testo completoAbstract (sommario):
Anaerobic lagoons are natural wastewater treatment systems suitable for swine farms in small communities due to its low operational and building costs, as well as for the environmental sustainability that these technologies enable. The local weather is one of the factors which greatly influences the efficiency of the organic matter degradation within anaerobic lagoons, since microbial growth is closely related to temperature. In this manuscript, we propose a mathematical model which involves the two-dimensional Stokes, advection–diffusion-reaction and heat transfer equations for an unstirred fluid flow. Furthermore, the Anaerobic Digestion Model No1 (ADM1), developed by the International Water Association (IWA), has been implemented in the model. The partial differential equations resulting from the model, which involve a large number of state variables that change according to the position and the time, are solved through the use of the Finite Element Method. The results of the simulations indicated that the methodology is capable of predicting reasonably well the steady-state of the concentrations for all processes that take place in the anaerobic digestion and for each one of the variables considered; cells, organic matter, nutrients, etc. In view of the results, it can be concluded that the model has significant potential for the design and the study of anaerobic cells’ behaviour within free flow systems.
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Webster, Ian T., e Graham P. Harris. "Anthropogenic impacts on the ecosystems of coastal lagoons: modelling fundamental biogeochemical processes and management implications". Marine and Freshwater Research 55, n. 1 (2004): 67. http://dx.doi.org/10.1071/mf03068.
Testo completoAbstract (sommario):
This paper presents a biogeochemical model of a coastal lagoon intended to be representative of lagoons occurring along the south-east and south-west coasts of Australia. Many of these lagoons are threatened by increased nutrient loads because of land use change, by alterations to their freshwater inflows and by modification to their tidal flushing regimens. The model simulates the biogeochemical response of the lagoon to nutrient (nitrogen) loading and includes nutrient transformation processes in the sediments, as well as in the water column. The paper focuses on the response of primary producers to increasing and decreasing nutrient loads and how the response is altered by changes in the flushing rate of the lagoon with the sea. In common with lakes, the modelled lagoon exhibits alternative stable states representing macrophyte or phytoplankton dominance depending on nutrient loading and history. A third state representing severe degradation occurs when denitrification shuts down. A characteristic of Australian coastal lagoon systems is that, due to highly sporadic rainfall patterns, nutrient inflows are dominated by intermittent extreme events. The modelling demonstrates that such a loading regimen may be expected to generally increase the vulnerability of the lagoon to increasing nutrient loads. The results of the analysis presented are pertinent to several questions raised by coastal managers, such as what are the expected benefits of improving flushing by dredging and what are the consequences of altering the timing and magnitudes of the loads reaching the lagoons?