Search

Recirculating aquaculture systems (RAS) present a problem involving the accumulation of NO3 - and PO4 3- at the end of the culture. The study aimed to identify native aquatic plants of Pistia stratiotes, Lemna minor, Salvinia molesta, and Eichhornia crassipes with wastewater treatment capabilities in RAS. The catfish, Clarias macrocephalus, weighing 60 g each, were stocked at a density of 65 fish/100L and fed a diet of floating pellets containing 41% crude protein. Pistia stratiotes was the most effective macrophyte for treating wastewater from the catfish culture system during the first 10 days of the experiment. Following treatment with P. stratiotes, the concentrations of CO2, COD, TAN, N-NO3-, P-PO43-, and TP in the wastewater decreased by 65.83, 34.28, 40.70, 46.70, 24.56, and 9.16%, respectively, while dissolved oxygen increased by 37.68% compared to the initial concentrations. Further research is required to thoroughly comprehend the efficacy and longterm effects of the P. stratiotes in RAS. [ABSTRACT FROM AUTHOR]

Salvinia, Salvinia molesta Mitchell (Salviniaceae) is a free-floating aquatic fern native to Brazil and considered one of the worst weeds in the world. When left unchecked, salvinia forms dense mats on the water surface, limiting sunlight penetration and altering water quality that disrupt ecosystem processes. In 2016, salvinia was first reported in Lake Ossa, Cameroon, and by summer 2021, had expanded to cover almost 49 % of the lake’s 4,000-hectare surface. A multinational team initiated a biological control and monitoring program, importing the salvinia weevil, Cyrtobagous salviniae Calder & Sands (Coleoptera: Curculionidae) from Louisiana, USA, in summer 2021. The objectives of this study were to: quantify the changes in salvinia cover and other floating vegetation, document the establishment and impact of the biological control program, and deliver a tool for near-real time monitoring of floating vegetation. We developed a satellite-based remote sensing application to document in near real-time the changes in coverage of floating vegetation. Using this tool, we quantified the reduction in the salvinia coverage by 80 % within three years of the release of the weevil. Field surveys in 2022 and 2023, demonstrated weevil establishment in the lake and widespread salvinia browning that was associated with weevil damage. Linear regressions of the percent cover of floating vegetation over time, demonstrated that after the weevil release, the rate of change decreased to −1.7 % per 60 days. Field monitoring and satellite imagery showed the establishment of a sedge (Oxycaryum sp., Cyperaceae) within the salvinia mat in late 2021. This secondary invasion slowed the reduction in coverage of floating vegetation from −1.7 % to −0.6 % per 60 days, and warrants further research. By late 2023, the revitalization of Lake Ossa restored fishing and transportation opportunities for the community, and also the comeback the emblematic African manatee. The success of the biological control of salvinia in Lake Ossa is not surprising due to its tropical conditions. However, it highlights the importance of early intervention and continuous monitoring. We propose that the integration of biological control and remote sensing technology is becoming more accessible and can be automated; therefore, a replicable model for future invasive weed programs around the world.

In addition to water repellency, superhydrophobic leaves of plants such as Salvinia molesta adsorb oil and separate it from water surfaces. This phenomenon has been the inspiration for a new method of oil–water separation, the bionic oil adsorber (BOA). In this paper, we show how the biological effect can be abstracted and transferred to technical textiles, in this case knitted spacer textiles hydrophobized with a layered silicate, oriented at the biology push approach. Subsequently, the transport of the oil within the bio-inspired textile is analyzed by a three-dimensional fluid simulation. This fluid simulation shows that the textile can be optimized by reducing the pile yarn length, increasing the pile yarn spacing, and increasing the pile yarn diameter. For the first time, it has been possible with this simulation to optimize the bio-inspired textile with regard to oil transport with little effort and thus enable the successful implementation of a self-driven and sustainable oil removal method. [ABSTRACT FROM AUTHOR]

Salvinia molesta D.S.Mitch, identified as a troublesome invasive aquatic plant in Malaysia and recognized as the world's most invasive alien species in the Global Invasive Species Database (GISD) since 2013, underwent a comprehensive study to explore its phytochemical composition, antioxidant potential, and antibacterial properties. The leaves were meticulously extracted using both distilled water and ethanol, and subsequent quantification involved assessing phenolic, flavonoid, tannin, alkaloid, and saponin contents using standard methods. Additionally, the antioxidant activity of the extracts was evaluated through DPPH, ABTS, and FRAP assays. The ethanol extract stood out with notably higher phytochemical content, particularly in tannin (275.98 ± 3.70 mg TAE/g), followed by phenolic, saponin, flavonoid, and alkaloids. Impressively, the ethanol extract exhibited substantial antioxidant capacity, as evidenced by IC50 values of 4.90 ± 0.25 µg/mL (DPPH), 15.22 ± 1.91 µg/mL (ABTS), and a FRAP value of 298.27 ± 4.04 mg TE/g. Moving beyond antioxidant properties, the ethanol extract showcased robust antibacterial activity, notably against Bacillus cereus, followed by Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa in disc-diffusion tests. Further analysis through minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays underscored the ethanol extract's capacity to inhibit growth and effectively eliminate all tested bacterial strains. In summary, this research highlights the ethanol extract of Salvinia molesta as a promising source of phytochemicals with substantial antioxidant and antibacterial properties, surpassing the aqueous extract in efficacy. [ABSTRACT FROM AUTHOR]

The present investigation provides a kinetic study for the removal of hexamethyl pararosaniline chloride, a hazardous dye, by phytoremediation using a water plant. It reveals Salvinia molesta has a phytoremediation tendency. The ability of Salvinia molesta to remove crystal violet (CV) dye is investigated with kinetic study in this research. Phytoremediation is done for different concentrations of hexamethyl pararosaniline chloride with varying pH and weight of Salvinia molesta Mitchell. About 88% of hexamethyl pararosaniline chloride has been decolourised from 50 mg L−1 solution at pH of 6 with 4 g of Salvinia molesta Mitchell. The results obtained for hexamethyl pararosaniline chloride removal at pH of 6 are studied for pseudo-first order, pseudo-second order and Elovich kinetics. The resulting curve for removal of hexamethyl pararosaniline chloride indicates that phytoremediation process follows pseudo-second order kinetics with correlation value R2 ≥ 0.985. The Salvinia molesta used at pH 6 has been reused and the decolourisation has been achieved at about 84% for 50 mg L−1 solution of CV dye. The FTIR results reveal the phytoextraction of CV in the roots by interaction of functional groups. From the experimental results, Salvinia molesta Mitchell can be used to treat textile wastewater and wet land. [ABSTRACT FROM AUTHOR]

Parit Lake is one of the Oxbow Lakes located in Parit Baru Village, Tambang District, Riau Parovince. The lake is overgrown with various kinds of aquatic plants that almost cover the surface of the lake. This study aims to determine the diversity and percent covers of aquatic plants carried out in July 2022. The method use in this study is a survey method, where Parit Lake is used as a research area and the method use in observation of aquatic plants is the Belt Transek method. Menwhile, the method use in measuring water quality is direct observation and laboratory scale. Sampling of aquatic plants is carried out 1 times in a period of one month. The aquatic plants obtained were identified based on Van Steenis (1981). The results showed that there are 5 species of aquatic plants divided into 3 classes and 5 families, namely Eichhornia crassipes, Salvinia molesta, Limnocharis flava, Ipomea aquatica, and Cyperus rotundus. The diversity index of aquatic plants species in Parit Lake is relatively low with a value of 0,7. The percent covers of aquatic plants is relatively tight with a value of 60% with the highest covers of the Salvinia molesta species at 25%, while the lowest in the species Limnocaris flava is 3,75%. [ABSTRACT FROM AUTHOR]

Phenolic compounds are very effective for the cure of various neurological and pathological diseases. Current study was conducted to estimate the Phenolic compounds through HPLC and to perform the anti-Alzheimer activity from two aquatic Leptosporangiate ferns; Marsilea quadrifolia L. and Salvinia molesta D. Crushed leaves were subjected to Microwave Assisted Extraction to prepare plant leave ethanolic extract of plants under study. Aluminum chloride induced Alzheimer's disease model in rats by estimating behavioural and biochemical parameters were measured for ethanolic extract of both plants. Different behavioural tests were performed for neuromuscular coordination estimation and hole board test for exploratory behaviour were performed. The levels of AChE inhibitory activity and antioxidant enzymes were estimated on brain homogenates and Histopathological analysis were also performed. Phenolic compounds of leaf extracts were noted for HPLC chromatograms of standard compounds with Gallic acid (33.76 ± 0.08) higher in M. quadrifolia L. and Salicylic acid (12.45 ± 0.07) higher in S. molesta D. S Mitchel. Histopathological analysis showed that M. quadrifolia and S. molesta reversed the neurofibrillary tangles, degenerative changes, neuronal loss and neuroinflammation in the brain architecture. Both ferns at a dose of 500 mg/kg and 1000mg/kg significantly improved the Aluminium chloride induced neurotoxicity by modulating cognitive disabilities and motor dysfunctions, and normalized the biochemical alteration of acetylcholinesterase and antioxidant enzymes. In conclusion, both plants M. quadrifolia and S. molesta improved behavioural and biochemical parameters and therefore will be effective in treatment of neurodegenerative disorders via countless underlying mechanistic pathways. [ABSTRACT FROM AUTHOR]

SUMMARY: Significant changes have occurred in plant cell wall composition during evolution and diversification of tracheophytes. As the sister lineage to seed plants, knowledge on the cell wall of ferns is key to track evolutionary changes across tracheophytes and to understand seed plant‐specific evolutionary innovations. Fern cell wall composition is not fully understood, including limited knowledge of glycoproteins such as the fern arabinogalactan proteins (AGPs). Here, we characterize the AGPs from the leptosporangiate fern genera Azolla, Salvinia, and Ceratopteris. The carbohydrate moiety of seed plant AGPs consists of a galactan backbone including mainly 1,3‐ and 1,3,6‐linked pyranosidic galactose, which is conserved across the investigated fern AGPs. Yet, unlike AGPs of angiosperms, those of ferns contained the unusual sugar 3‐O‐methylrhamnose. Besides terminal furanosidic arabinose, Ara (Araf), the main linkage type of Araf in the ferns was 1,2‐linked Araf, whereas in seed plants 1,5‐linked Araf is often dominating. Antibodies directed against carbohydrate epitopes of AGPs supported the structural differences between AGPs of ferns and seed plants. Comparison of AGP linkage types across the streptophyte lineage showed that angiosperms have rather conserved monosaccharide linkage types; by contrast bryophytes, ferns, and gymnosperms showed more variability. Phylogenetic analyses of glycosyltransferases involved in AGP biosynthesis and bioinformatic search for AGP protein backbones revealed a versatile genetic toolkit for AGP complexity in ferns. Our data reveal important differences across AGP diversity of which the functional significance is unknown. This diversity sheds light on the evolution of the hallmark feature of tracheophytes: their elaborate cell walls. [ABSTRACT FROM AUTHOR]

Incorrect labelling of plants in trade and misidentification are widespread. Likewise, in trade numerous names are being used for the ornamental aquatic plant known as 'Kariba weed', but rarely the correct scientific name Salvinia molesta Mitch. For inspection services of EPPO member countries, correct identification of S. molesta has become important since the species was added to the EPPO A2 List and the List of Union concern in accordance with EU regulation 1143/2014 based on an EPPO Pest Risk Analysis (PRA) for the species. Inspections and a targetted survey of Salvinia plants in trade in the Netherlands were performed and additional material was obtained from wild sources in South Africa, Hungary and the United States. Specimen identification was verified by comparison with the herbarium collection at Naturalis Biodiversity Center in Leiden and with the sequences available in NCBI GenBank database. This paper provides the tools to correctly identity the relevant Salvinia species. [ABSTRACT FROM AUTHOR]

The African manatee (Trichechus senegalensis) is an elusive, data-deficient, and endangered species which inhabits marine and freshwater systems throughout Western and Central Africa. A major challenge in understanding the species ecology and distribution is the difficulty in detecting it using traditional visual surveys. The recent invasion of Giant Salvinia (Salvinia molesta) at the most important site for the species in Cameroon further limits their detectability and may restrict their movements and habitat use. To investigate methods’ effectiveness in detecting African manatees, we conducted monthly vessel surveys from which visual point scans, 360° sonar scans, and passive acoustic monitoring were conducted simultaneously at ten locations and over 12 months in Lake Ossa, Cameroon. Manatee detection frequency was calculated for each method and the influence of some environmental conditions on the methods’ effectiveness and manatee detection likelihood was assessed by fitting a binary logistic regression to our data. Detection frequencies were significantly different between methods (p < 0.01) with passive acoustics being the most successful (24.17%; n = 120), followed by the 360° sonar scan (11.67%; n = 120), and the visual point scan (3.33%; n = 120). The likelihood of detecting manatees in Lake Ossa was significantly influenced by water depth (p = 0.02) and transparency (p < 0.01). It was more likely to detect manatees in shallower water depths and higher water transparency. Passive acoustic detections were more effective in uninvaded areas of the Lake. We recommend using passive acoustics to enhance African manatee detections in future surveys.

Rawapening is one of Indonesia's national priority lakes, which is experiencing environmental damage and urgently needs rehabilitation. The decline in water quality is caused by sedimentation and organic and inorganic waste that triggers eutrophication. Rehabilitation of Lake Rawapening is important to improve the health of freshwater resources. The ecological engineering approach is the most appropriate choice to rehabilitate these water conditions. The character of the macrophyte is the key factor for successful rehabilitation. Three macrophytes, Hydrilla verticillata (L. f.) Royle, Eichhornia crassipes (Mart.) Solms and Salvinia molesta D.Mitch., charactierized. Their characteristics, including growth rate, salt tolerance, dissolved oxygen production and consumption, nutritive value, and preferred food by herbivore fish were evaluated. The results indicated that H. verticillata has the highest growth rate, is the most tolerant to salinity change, produces more oxygen, has the highest nutritive value, and is the most preferred food for herbivore fish. H. verticilata is recommended as the best candidate to be used as a forcing function to drive the Rawapening lake into more economic and environmentally valuable for a resident. As the other two species also have high nutritive value, they can be recommended as a source of feed for animals as well. For better management, these two macrophytes required more often regular removal. Other economic and environmental values can also be achieved from E. crassipes and S. molesta. [ABSTRACT FROM AUTHOR]

Heavy metals, especially Pb (lead), are generally toxic to living things. Pb can contaminate organisms in the water through the food chain. The purpose of this study is to enhance water quality by using Salvinia molesta to phytoremediate Pb-polluted water. This study aims to evaluate the ability of S. molesta as a Pb phytoremediator. We evaluated total protein, free amino acids produced by the plant, and plant growth (dry biomass). S. molesta was grown in a hydroponic system exposed to Pb at dosages of 0, 5, 10, and 15 ppm for 7 and 14 days. Pb level was analyzed using Atomic Absorption Spectrophotometer and amino acids were analyzed using High-Pressure Liquid Chromatography. Data were statistically analyzed using analysis of variance (ANOVA) followed by Tukey's test (α < 0.05). Results showed a significant change in Pb content in the roots and leaves of Pb-exposed S. molesta Mitch compared to control. In Pb-exposed plants, total protein and amino acids, especially cysteine, were lowered. S. molesta could be used as a Pb phytoremediator due to its high potential to survive Pb exposure and its ability to absorb Pb. [ABSTRACT FROM AUTHOR]

Clean water is an inevitable necessity in human life apart from food and shelter. Surface and underground water are the major sources of clean water. However, with the rapid growth in population and increasing industrial development in Malaysia, many water sources have become polluted. Hence, wastewater must be adequately treated prior to discharge into the environment. Currently, conventional treatment methods are not always effective towards complete removal of water contaminants. Phytoremediation technique is a branch of bioremediation that employs the application of plants for the remediation of wastewater. Aquatic plants have the capacity to absorb excess contaminants such as organic and inorganic, heavy metals, and pharmaceutical pollutants present in agricultural, domestic and industrial wastewater. Among the aquatic plants, Salvinia molesta and Pistia stratiotes have been widely used for the treatment of agricultural, domestic and industrial wastewater. The wide application of these plants is due to their availability, resilience in a toxic environment, bioaccumulation potentials, invasive mechanism and biomass potentials. This review paper covers the major roles and potentials of aquatic plants in phytoremediation of wastewater. It has also reviewed recent research work on the efficiency of Salvinia molesta and Pistia stratiotes plants in wastewater remediation and identified areas for further studies as we find stoichiometric homeostatic index and resource pulse effects studies of these plants is necessary in wastewater phytoremediation processes.

The dye removal using phytoremediation has demonstrated its potential to degrade many recalcitrant dyes. The kinetic investigations for phytoremediation ability of Salvinia molesta Mitchell (S. molesta) were evaluated for Direct Red 28 (DR28) dye in the present research work. The potential of S. molesta was analysed at different pH and different initial dye concentrations. About 90 % of dye decolorization was achieved for 50 mg L−1 dye solution with 4 g of S. molesta plant at pH 6.5. The experimental results were evaluated with pseudo-first, pseudo-second and Elovich kinetic models. The validation indicated the most suitable curve with Pseudo-second order having the correlation value R2 ≥ 0.99. FTIR studies supported the phytoextraction of DR28 through functional group interaction between plant hairy roots and dye molecules. The results of the present studies suggests that S. molesta can be utilized for remediation of water bodies and wetlands contaminated with dye wastewater in natural conditions. [ABSTRACT FROM AUTHOR]

Urease plays a significant role in the pathogenesis of urolithiasis pyelonephritis, urinary catheter encrustation, hepatic coma, hepatic encephalopathy, and peptic acid duodenal ulcers. Salvinia molesta was explored to identify new bioactive compounds with particular emphasis on urease inhibitors. The aqueous methanol extract was fractionated using solvents of increasing polarity. A series of column chromatography and later HPLC were performed on butanol extract. The structures of the resulting pure compounds were resolved using NMR (1D and 2D), infrared, and mass spectroscopy. The novel isolate was evaluated for antioxidant activity (using DPPH, superoxide anion radical scavenging, oxidative burst, and Fe+2 chelation assays), anti‐glycation behavior, anticancer activity, carbonic anhydrase inhibition, phosphodiesterase inhibition, and urease inhibition. One new glucopyranose derivative 6′‐O‐(3,4‐dihydroxybenzoyl)‐4′‐O‐(4‐hydroxybenzoyl)‐α/β‐D‐glucopyranoside (1) and four known glycosides were identified. Glycoside 1 demonstrated promising antioxidant potential with IC50 values of 48.2 ± 0.3, 60.3 ± 0.6, and 42.1 ± 1.8 μM against DPPH, superoxide radical, and oxidative burst, respectively. Its IC50 in the Jack bean urease inhibition assay was 99.1 ± 0.8 μM. The mechanism‐based kinetic studies presented that compound 1 is a mixed‐type inhibitor of urease with a Ki value of 91.8 ± 0.1 μM. Finally, molecular dynamic simulations exploring the binding mode of compound 1 with urease provided quantitative agreement between estimated binding free energies and the experimental results. The studies corroborate the use of compound 1 as a lead for QSAR studies as an antioxidant and urease inhibitor. Moreover, it needs to be further evaluated through the animal model, that is, in vivo or tissue culture‐based ex‐vivo studies, to establish their therapeutic potential against oxidative stress phosphodiesterase‐II and urease‐induced pathologies. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the efficacy of imazamox for control of S. molesta and to assess the effects of plant decomposition on environmental indicators after application of this herbicide in microcosm conditions. The following rates were used: 600, 700, 800 and 900 g ai ha−1 and spray volume 50 L ha−1. Control efficacy was determined as the percentage (from 0 to 100%) of visible injury symptoms in the plants, biochemical and chemical oxygen demand (BOD5 and COD), water quality variables, chlorophyll a and pheophytin a at 0, 7, 15, 30, 45 and 60 days after application (DAA) and fresh and dry biomass at 60 DAA. Imazamox was effective in controlling 94% of S. molesta with 900 g ai ha−1; it reduced 95% of fresh weight and 92% of dry weight of plant at 60 DAA, and reduced chlorophyll a of the plants for all rates. For BOD5, there was an increase for all rates at 15, 30 and 45 DAA with restoration of the parameters at 60 DAA, and for COD, there was an increase at 60 DAA with 700 and 900 g ai ha−1. For temperature, pH, dissolved oxygen and electrical conductivity, there was no significant effect after spraying. Imazamox was effective in controlling S. molesta with 900 g ai ha−1 without causing significant effects on the physical-chemical parameters of water quality. [ABSTRACT FROM AUTHOR]

The non-native aquatic fern giant salvinia, Salvinia molesta Mitchell (Salviniaceae), poses a risk to freshwater ecosystems through limiting light penetration, decreasing submerged aquatic vegetation (SAV) abundance, altering water quality, and potentially leading to changes in macroinvertebrate community structure. Here, we conducted repeated quarterly field surveys and measured light, nutrients, water quality, and aquatic macroinvertebrate community composition and energetic value to detect effects from giant salvinia invasion. Giant salvinia reduced dissolved oxygen, pH and light availability in the aquatic environment, and increased the concentration of orthophosphate and ammonium. Following initial colonization, macroinvertebrate communities in giant salvinia resembled SAV communities dominated by aquatic insects, however, richness and relative abundance in giant salvinia decreased over time, resulting in a community populated by few taxa, primarily crustaceans. Total macroinvertebrate energetic value in giant salvinia was significantly lower than SAV communities. Giant salvinia invasion changed habitat composition, triggered internal nutrient loading, and reduced macroinvertebrate abundance, diversity, and ecosystem productivity. Our findings demonstrate larger ecological impacts from giant salvinia than previously reported, including potential disruption to the transfer of energy between trophic levels. [ABSTRACT FROM AUTHOR]

Aquatic insects are important to the transfer of energy in freshwater wetlands. They link primary producers and organic matter to higher trophic levels, and pass energy from the aquatic environment to the terrestrial ecosystem via predation of adults. Introduction of the invasive free-floating aquatic fern giant salvinia, Salvinia molesta Mitchell, threatens aquatic insect communities and life cycle completion, specifically colonization, through mat formation and habitat changes. We examined how aerial colonization and assemblage structure of aquatic insects were affected by giant salvinia coverage. Mesocosms were established with three giant salvinia coverages, 25%, 50%, and 100%, and a native submerged macrophyte, 0% coverage; and environmental conditions and community structure were sampled monthly, over four months. After four weeks, all giant salvinia coverages reduced dissolved oxygen, pH, and light availability in the aquatic environment. In the 100% cover treatment, aquatic insect colonization was impeded, resulting in communities with lower abundance and richness, which were dominated by a coleopteran. The 25% and 50% giant salvinia coverages changed habitat complexity, which yielded different aquatic insect communities from the 0% and from 100% coverages. Regardless of the coverage, giant salvinia changed environmental conditions and putatively the 100% coverage disrupted the aquatic insect life cycle by limiting aerial colonization. This inability to complete their life cycle means aquatic insects cannot replenish themselves, leading to a diminished species pool and reduced energy potential. Our results highlight new, previously unreported, negative impacts from giant salvinia on ecosystem structure and function. [ABSTRACT FROM AUTHOR]

Superhydrophobic surfaces are widely used in many industrial settings, and mainly consist of rough solid protrusions that entrap air to minimize the liquid/solid area. The stability of the superhydrophobic state favors relatively small spacing between protrusions. However, this in turn increases the lateral adhesion force that retards the mobility of drops. Here we propose a novel approach that optimizes both properties simultaneously. Inspired by the hydrophobic leaves of Salvinia molesta and the slippery Nepenthes pitcher plants, we designed a Salvinia -like slippery surface (SSS) consisting of protrusions with slippery heads. We demonstrate that compared to a control surface, the SSS exhibits increased stability against pressure and impact, and enhanced lateral mobility of water drops as well as reduced hydrodynamic drag. We also systematically investigate the wetting dynamics on the SSS. With its easy fabrication and enhanced performance, we envision that SSS will be useful in a variety of fields in industry. [ABSTRACT FROM AUTHOR]

Clean water is an inevitable necessity in human life apart from food and shelter. Surface and underground water are the major sources of clean water. However, with the rapid growth in population and increasing industrial development in Malaysia, many water sources have become polluted. Hence, wastewater must be adequately treated prior to discharge into the environment. Currently, conventional treatment methods are not always effective towards complete removal of water contaminants. Phytoremediation technique is a branch of bioremediation that employs the application of plants for the remediation of wastewater. Aquatic plants have the capacity to absorb excess contaminants such as organic and inorganic, heavy metals, and pharmaceutical pollutants present in agricultural, domestic and industrial wastewater. Among the aquatic plants, Salvinia molesta and Pistia stratiotes have been widely used for the treatment of agricultural, domestic and industrial wastewater. The wide application of these plants is due to their availability, resilience in a toxic environment, bioaccumulation potentials, invasive mechanism and biomass potentials. This review paper covers the major roles and potentials of aquatic plants in phytoremediation of wastewater. It has also reviewed recent research work on the efficiency of Salvinia molesta and Pistia stratiotes plants in wastewater remediation and identified areas for further studies as we find stoichiometric homeostatic index and resource pulse effects studies of these plants is necessary in wastewater phytoremediation processes. [ABSTRACT FROM AUTHOR]

Little is known about the effects of weeds on nutrient concentration changes in aquatic environments. We examined alterations to nutrient dynamics from the biocontrol process of Salvinia molesta by the weevil Cyrtobagous salviniae in the Lake Xini of Okavango, Botswana. The abundance of weevils steadily increased from March to December 2009 in the range of 15 to 62 ind. kg−1 fresh biomass with 93% bud damage at the time of mat sinking. Dissolved oxygen was 1.2 mg l−1 with >90% salvinia coverage in March 2009 and increased to 4.56 mg l−1 after 12 months of biocontrol, when salvinia cover was reduced to <10% cover. The study was conducted by placing plastic containers in the lake containing 1 kg weevil infested salvinia and water from the lake. The declines in weevil-damaged 'floating salvinia' were inversely proportional to the increases in 'salvinia detritus' in the study containers. Leaching of nutrients (N and P) and major ions (Ca, Mg, Na and K) in floating salvinia and salvinia detritus, as a result of weevil damage, showed P and K consistently leached at higher rates. Nutrients in the lake were high during biocontrol process, compared with after control. Biocontrol resulted in an increase in dissolved oxygen and re-emergence of native vegetation. [ABSTRACT FROM AUTHOR]

This study aimed to perform an assessment of economic performance and meat cholesterol profiles of Kampong chickens fed diets with the increasing levels of Salvinia molesta. One hundred male Kampong chickens were divided into 4 treatments containing 0% (T0), 6% (T1), 12% (T2), and 18% (T3) of S. molesta leaf (SML) in the diet. Then, an economic analysis was performed by calculating revenue, feed cost, and income over feed cost (IOFC). Investment analysis was computed when the farmers raised 1000 heads of Kampong Chicken utilized SML in the feed. NPV, PP, and B/C ratio were calculated for each treatment. The performance of the Kampong chickens fed the diet with SML content of 18% gave the best feed consumption, the final weight, and FCR. Kampong chickens fed diet with SML content of 18% gave the best IOFC. In the investment analysis, the Kampong chicken fed diet contained 18% SML gave the best NPV, PP, and B/C ratio. Regression analysis was conducted on the level of SML in the diet of kampong chicken on some parameters. Kampong chicken fed diet contained SML had significantly higher HDL and lower LDL concentrations. The optimum inclusion level of SML leading to a reduced feed cost and increased IOFC, as well as feasibility, was 18%. Based on the study, utilization of SML up to 18% in the diet of kampong chicken technically and economically gave the best performances.

Rhizoctonia solani merupakan salah satu patogen penting penyebab penyakit hawar seludang pada tanaman padi. Patogen ini termasuk yang sulit dikendalikan karena bersifat kosmopolit, mampu bertahan di dalam tanah, dan memiliki kisaran inang yang banyak. Pengendalian secara biologi dengan bakteri endofit merupakan salah satu alternatif yang potensial karena kemampuannya hidup di dalam jaringan tanaman tanpa menimbulkan gejala penyakit dan dapat meningkatkan pertumbuhan serta ketahanan tanaman. Tujuan penelitian ini ialah mengeksplorasi bakteri endofit dari bagian batang akar dari tiga jenis tumbuhan paku yang berbeda, yaitu Salvinia molesta (paku air), Pteris ensiformis (paku terestrial), dan Drymoglossum pilosolloides (paku epifit) dan mengevaluasi potensinya sebagai agens hayati R. solani dan pemacu pertumbuhan tanaman. Isolasi bakteri dilakukan pada medium tripsic soy agar (TSA) dan nutrient agar (NA). Isolat bakteri dimurnikan dan diuji keamanan hayati dengan uji hipersensitifitas dan hemolisis. Hasil penelitian diperoleh 178 isolat bakteri endofit dan sebanyak 88 isolat menunjukkan reaksi negatif pada uji hipersensitisfitas dan uji hemolisis. Selanjutnya, isolat tersebut diuji dual test secara in vitro terhadap R. solani dan didapatkan 4 isolat bakteri endofit (APE15, APE22, APE33, dan APE35) dengan daya hambat dari 27–76% pada medium TSA, agar-agar dekstrosa kentang (ADK), dan TSA + ADK. Hasil uji pertumbuhan empat isolat terhadap benih padi varietas Situ Bagendit menunjukkan bahwa bakteri endofit mampu meningkatkan persentase perkecambahan padi 4.9% – 48.8%, meningkat panjang akar padi 68.3%–95.4%, panjang pucuk 53.2%–87.3%, bobot segar 49.07%–90.65%, dan bobot kering 48.1%–87.3%. Hasil ini menunjukkan bahwa tumbuhan paku mengandung beberapa bakteri endofit yang dapat dikulturkan dan memiliki senyawa antimikrob yang efektif, serta dapat digunakan sebagai sumber agens hayati terhadap patogen R. solani dan pemacu pertumbuhan tanaman.

Wastewater contamination which causes health, environmental and economic impacts is one of the most common environmental issues. Several methods have been used for the upgrade of the existing wastewater treatment facilities, nevertheless, the application of phytoremediation treatment is a promising and environmentally friendly method to avoid the secondary contaminations posed by the treatment dosage in other advanced treatment methods. The current work aimed to assess the phytoremediation treatment of the pre-treated domestic wastewater using the Salvinia molesta and water hyacinth plants. The water quality tests were performed in the current research to evaluate the effects of the phytoremediation treatment using the Salvinia molesta and water hyacinth plants on the responses of the water quality parameters. The study focused on varying two main parameters, namely the pH and the hydraulic retention time (HRT), while the removal rate was determined based on the reduction in the chemical oxygen demand (COD), total dissolved solids (TDS), total nitrogen (TN) and turbidity. The optimal removal of COD, TDS, TN and turbidity in the current study was 56.47, 83.00, 52.12, and 79.98% for Salvinia molesta as well as 48.81, 24.00, 13.56 and 19.89% for water hyacinth. [ABSTRACT FROM AUTHOR]

This study aimed to perform an assessment of economic performance and meat cholesterol pro- files of Kampong chickens fed diets with the increasing levels of Salvinia molesta. One hundred male Kampong chickens were divided into 4 treatments containing 0% (T0), 6% (T1), 12% (T2), and 18% (T3) of S. molesta leaf (SML) in the diet. Then, an economic analysis was performed by calculating revenue, feed cost, and income over feed cost (IOFC). Investment analysis was computed when the farmers raised 1000 heads of Kampong Chicken utilized SML in the feed. NPV, PP, and B/C ratio were calculated for each treatment. The performance of the Kampong chickens fed the diet with SML content of 18% gave the best feed consumption, the final weight, and FCR. Kampong chickens fed diet with SML content of 18% gave the best IOFC. In the investment analysis, the Kampong chicken fed diet contained 18% SML gave the best NPV, PP, and B/C ratio. Regression analysis was conducted on the level of SML in the diet of kampong chicken on some parameters. Kampong chicken fed diet contained SML had significantly higher HDL and lower LDL concentrations. The optimum inclusion level of SML leading to a reduced feed cost and increased IOFC, as well as feasibility, was 18%. Based on the study, utilization of SML up to 18% in the diet of kampong chicken technically and economically gave the best performances. [ABSTRACT FROM AUTHOR]

In aquatic system, plant- microbe interactions are common in root, leaves, shoot or sediment and their ability to mitigate pollution in the water. However, there is a little study about the bacterial communities in the plant roots of aquatic plant which can be categorised into emergent, submerged and floating leaves plant. Therefore, this study was conducted to fill in the knowledge gap. The objective of this study was to isolate and identify the associated bacteria present in the roots of aquatic plants at UMT water bodies. Four species of aquatic plants root were examined included Eichhornia crassipes (Water hyacinth), Limnocharis flava (Yellow velvetleaf), Salvinia molesta (Giant salvinia) and Nymphaea lotus (White lotus). The identification of bacteria was done by a series of cultivation and characterization of bacteria using biochemical test. Gram- staining were used to identify the morphology of bacteria and the genus of the bacteria. Ten species of isolated bacteria were preliminary identified such as Enterobacter aerogenes, Pseudomonas aeruginosa, Alcaligenes faecalis, Aeromonas hydrophila, Proteus vulgaris, Erwinia amylovora, Pseudomonas sp., Neisseria sp., Micrococcus luteus, and Corynebacterium xerosis using biochemical test. Among 10 species of bacteria detected in the four aquatic plants, only three classes includes Gammaproteobacteria, Betaproteobacteria and Actinobacteria were shared among the plant sample. The result showed that the bacteria composition among four aquatic plants root were clearly different and these finding suggest that the aquatic plants root has an important role for various type of bacteria. [ABSTRACT FROM AUTHOR]

Invasion from giant salvinia (Salvinia molesta Mitchell, Salviniaceae) blocks sunlight entering waterbodies, reducing submerged aquatic macrophytes, thus lowering dissolved oxygen and stressing aquatic organisms. Due to its rapid growth and ease of dispersal through fragmentation, giant salvinia can quickly become problematic and difficult to eradicate. Since invasion of giant salvinia is persistent, land managers need a cost-effective method of control. Biological control by the salvinia weevil (Cyrtobagous salviniae Calder and Sands, Coleoptera: Curculionidae) has proven successful in controlling giant salvinia, and at a fraction of the cost of chemical and mechanical control. To maintain a source of salvinia weevils for field releases, mass rearing in outdoor ponds by natural resource managers is common practice in tropical regions. Using number of freezing hours and degree-day calculator, we examined how winter and spring conditions impacted the production of weevils in mass rearing ponds across southern Louisiana, USA. We found that winter temperature determined adult weevil mortality while spring temperature dictated reproduction, larval appearance, and timing of pond harvest. During winters with <55 h of freezing temperatures, ponds maintained densities of at least 13 adult salvinia weevils kg−1. Winter with >200 hours of freezing temperature reduced adult density in the ponds nearly extirpating the population. Larvae were found on samples on average at 89 degree-days which began accumulating in January 1st. This study suggested that winter and spring conditions are critical for mass rearing operations and population growth of C. salviniae. [ABSTRACT FROM AUTHOR]

The process of phytoremediation by using aquatic plants is a new, low cost and ecofriendly method for improving water quality and waste water. In the present study the ability of Azolla pinnata R.Br. and Salvinia molesta Mitchell to uptake Cr (VI) from aqueous environment as well as their potential application for phytoremediation were assessed. During 15 days of the experiment the ferns were grown on the nutrient solution containing hexavalent chromium ions, each in a concentration of control, 0.07, 0.09, 0.11 and 0.13 mg/l. The biomass productivity and relative growth of Azolla pinnata R.Br. was increased and in case of Salvinia molesta Mitchell it was decreased with increase in the metal concentration of the treatment medium. The protein content in different concentration of chromium was more as compared to the control but showed a decreasing trend with increasing concentration. After 15 days of treatment, the concentration of Cr (VI) in the medium decreased between 72.86 - 97.69 % and 75.71 - 90 % by Azolla pinnata R.Br. and Salvinia molesta Mitchell respectively. Both the fern took a lesser quantity of metal from 0.07 mg/l treatments compared to 0.09 mg/l, 0.11 mg/l and 0.13 mg/l treatments. In the Azolla pinnata R.Br. tissue the concentration of heavy metal under investigation ranged from 0.106 - 0.216 mg/gm dry weight and for Salvinia molesta Mitchell ranged from 0.094 - 0.321 mg/gm dry weight. Increasing concentration of Cr (VI) in the growth medium increased the bioconcentration factor of Azolla pinnata R.Br. and Salvinia molesta Mitchell up to an optimum value of 1630.76 and 2469.23 respectively. In the present study the higher BCF of Salvinia molesta Mitchell shows that it is a better candidate for phytoremediation of Cr (VI) from the treatment solution than Azolla pinnata R.Br. Overall results indicate that Azolla pinnata R.Br. and Salvinia molesta Mitchell can be used for phytoremediation of Cr (VI) from polluted water as it is a low cost method satisfying the discharge standards. [ABSTRACT FROM AUTHOR]

The purpose of this research was to analyze the biogas production from co-digestion of Salvinia molesta and rice straw. Ratio of Salvinia molesta and rice straw was 5:0, 4:1, 3:2. Lab-scale-batch digesters (600 mL) were operated at room temperature (30 oC) and pressure of 1 atm. Total basis of Salvinia molesta and rice straw was 10 gr, water was added with ratio of organic matter:water = 1:7 (w/w), rumen fluid was added as inoculum, initial pH was adjusted to be 7. Fermentation process was conducted for 30 days. The results showed that total biogas volume for ratio of 5:0, 4:1, 3:2 was 6.30±0.00; 32.76±18.32; 107.54±18.51 mL/g VS respectively. The pH of substrate was changing from 7.00 to 6.77±0.19; 6.60±0.14; 6.73±0.09 for all variables respectively.

Aquatic weeds cause severe productivity loss in agriculture. These plants invade lakes, ponds, rivers, canals and agricultural fields, becoming noxious weeds. The study was conducted at the vermicomposting unit of the Coconut Research Institute, Lunuwila, in the Low country Dry Zone of North Western province of Sri Lanka from August 2012 to May 2013 to find out the feasibility of producing vermicompost from three aquatic weeds; Salvinia molesta, Eichhornia crassipes and Lagenandra toxicaria. Vermicompost and compost were prepared separately from aquatic weeds and Gliricidia and Guinea grass combinations. During the vermicomposting process, growth parameters of earthworms; number of earthworms, was taken in every ten days interval further, physical, chemical and biological properties of compost and vermicompost were analyzed. Experiment was carried out in a Complete Randomized Design (CRD) with eight treatment and five replicates in each treatment. Eichhornia and Salvinia recorded the highest adult earthworm number and juvenile number with the lowest mortality rate. Electrical conductivity (6.75 dSm-1), organic carbon (13.21%), phosphorous (3.61%), potassium (5.03%) and calcium (6.12%) were significantly high in Lagenandra toxicaria, Gliricidia and Guinea grass treatment was significantly high in nitrogen content (3.93%) and low in C: N ratio (2.51), compared to aquatic weeds. Salvinia showed comparatively higher nitrogen content and lower C: N ratio among aquatic weeds. Both Eichhornia and Lagenandra showed significantly higher microbial activity. Vermicompost was superior in all the properties compared to compost in the same substrate. The study revealed that aquatic weeds such as Salvinia molesta, Eichhornia crassipes and Lagenandra toxicaria which are readily available in the coconut triangle can be successfully used to produce Vermicompost. It can be concluded that the Vermicompost produced from aquatic weeds locally could be a suitable organic fertilizer for organic coconut farming in Sri Lanka.

The biological control agent, Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) (salvinia weevil), is being used for management of the highly invasive fern Salvinia molesta Mitchell (Salvinaceae) in Louisiana and Texas, USA. The weevils and plants are transported from the nurseries and rearing facilities to the field release sites in plastic totes. Despite the increased transport of weevil-infested plants during the warmer months, limited data exist on the impact of heat stress and survivability of adult C. salviniae. Therefore, research was conducted to determine temperatures inside totes during summer transport, and to determine the upper temperature threshold for adult weevil survival. Field data demonstrated that temperatures within the totes were capable of exceeding 35 °C, and the type of lid used to secure plant material influenced internal temperature. In addition, there were no differences in temperature within the totes. Growth chamber trials determined the upper lethal time to kill 50 and 90% of the test population (ULt50 and ULt90) at 35 °C was 27.5 and 42.8 hours, respectively, while at 40 °C, the ULt50 and ULt90 was 15.0 and 25.0 hours, respectively. As the temperature increased to 50 °C, the calculated ULt50 and ULt90 values were 5.0 and 11.0 minutes, respectively. These data provided evidence that C. salviniae mortality occurs more rapidly as the temperature increases, especially > 45 °C, and that extreme temperatures can occur within transportation totes. [ABSTRACT FROM AUTHOR]

We investigated the effect of CO2 and nutrient enrichment on competition between two free-floating fern species that co-occur in south-eastern Australia—native Azolla filiculoides and invasive exotic Salvinia molesta. The species were grown in monoculture and competition in a glasshouse experiment where the nutrient medium was replaced weekly to simulate a dynamic system. We found that the relative growth rate (RGR) of both species was greater under high resource conditions, with neither showing a suppressive response due to competition. On the contrary, A. filiculoides had a facilitative effect on S. molesta. In addition, A. filiculoides gained more biomass under high resource conditions relative to S. molesta and the opposite was true under low resource conditions. We conclude that [CO2] and nutrient concentration did not mediate competition between the species but instead influenced RGR independent of competition. These findings suggest that species composition in dynamic water bodies under future conditions may be determined by the species' responses to environmental changes rather than by changes in competitive interactions. [ABSTRACT FROM AUTHOR]

We compared the cold tolerance of three populations of the salvinia weevil, Cyrtobagous salviniae. When exposed to 0°C, lethal time to kill 90% of adults from the Bayou Nicholas population was greater than the Houma and Natchitoches populations. This weevil exhibited phenotypic plasticity which could be used in mass rearing. [ABSTRACT FROM AUTHOR]

The plant leaf of Salvinia molesta can retain an air layer underwater due to the hydrophobic and elastic eggbeater-shaped hairs on its surface, which have potential applications in thermal insulation devices. In this research, terry fabrics are explored to mimic the air-retaining ability of the salvinia leaf for potential application in overwater life-saving appliances. The surface structure of the fabric is analyzed and the superhydrophobicity is obtained by hydrophobic treatment combined with microscale roughness brought by the fabric texture. The air volume change and the thermal insulation tests demonstrated that terry fabrics, F1 and F3, can retain an air layer on their surfaces and hold air in between the fibers and inside the loops for a long time underwater, which would provide thermal insulation and buoyancy force—the two key features of life-saving appliances. [ABSTRACT FROM AUTHOR]

Highlights • We studied responses of three freshwater plant species to elevated CO 2. • Elevated CO 2 promoted biomass production of nitrogen-fixing Azolla filiculoides. • Salvinia molesta and Vallisneria spiralis were unaffected by CO 2 concentration. • Freshwater plant species responsiveness to CO 2 enrichment is context-dependent. Abstract Rising atmospheric CO 2 concentration is one of the most important ways human activity is contributing to global change. It has led to climate-related changes that affect physiological performance, phenology, and distributions of species globally. Elevated [CO 2 ] enhances growth in many plant species through increased photosynthetic rates, improved water and nitrogen use efficiency, and altered functional traits. In this study, we investigated the growth, reproduction and functional trait responses to elevated [CO 2 ] of two free-floating ferns, the native Azolla filiculoides (Azollaceae) and the exotic invasive Salvinia molesta (Salviniaceae), and a submerged native angiosperm, Vallisneria spiralis (Hydrocharitaceae). The species were grown in monocultures under ambient (∼400 ppm) and elevated (∼600 ppm) [CO 2 ] in a greenhouse experiment. We found that A. filiculoides had enhanced relative growth rate and reproduction under elevated [CO 2 ]. However, its root to shoot ratio was unaffected while its specific leaf area was reduced under elevated [CO 2 ]. In contrast, S. molesta and V. spiralis did not differ in their growth, reproduction or functional trait responses between the CO 2 treatments. We conclude that freshwater plant responses to elevated [CO 2 ] may vary across species, with functional differences potentially driving differential responses as exemplified by the lack of response of the CAM physiology species Vallisneria spiralis and the strong response of the nitrogen-fixing A. filiculoides compared to the non nitrogen-fixing species in this study. Future work should focus on the impact of elevated CO 2 on plant growth in the context of environmental conditions such as pH, temperature and light availability in freshwater systems. [ABSTRACT FROM AUTHOR]

The production of dye is usually associated with several intermediate products and waste which are usually toxic and bio-hazardous and often disturb the environmental equilibrium. The present study is aimed at selecting macrophytes with the highest efficiency in the remediation of wastewater generated from dyeing activities. The test macrophytes were introduce into three different troughs for each plant containing 100% wastewater, 50% wastewater and control (100% borehole water). After 21 days the macrophytes were removed for further analysis. The reduction efficiency, Heavy metal bioconcentration and bio translocation factor of the macrophytes was determined. The result obtained shows that the test macrophytes improved the pH but were not able to improve the color of the wastewater. Lemna minor have the highest reduction efficiency for BOD, COD, Oil, and Grease while Pistia stratiotes have the highest reduction efficiency for TDS and TSS, Eicchornia crassipes have the highest reduction efficiency for Cl- and Salvinia molesta have the highest reduction efficiency for phenol and ammonical Nitrogen. All macrophytes recorded high reduction efficiency for heavy metal removal but Pistia stratiotes and Eicchornia crassipes had the highest bioconcentration and translocation. These macrophytes should be introduced to the local dye users as a costless and environmentally friendly way of treating wastewater resulting from dyeing activity. [ABSTRACT FROM AUTHOR]

Macrophytes have been used to mitigate eutrophication and upgrade effluent quality via their nutrient removal capability. However, the available data are influenced by factors such as microbial activities, weather, and wastewater quality, making comparison between nutrient removal performance of different macrophytes almost impossible. In this study, phytoremediation by Spirodela polyrhiza, Salvinia molesta and Lemna sp. were carried out axenically in synthetic wastewater under controlled condition to precisely evaluate nutrient removal efficiency of NO3−-N, PO43−, NH3-N, COD and pH in the water sample. The results showed that ammonia removal was rapid, significant for S. polyrhiza and Lemna sp., with efficiency of 60% and 41% respectively within 2 days. S. polyrhiza was capable of reducing 30% of the nitrate. Lemna sp. achieved the highest phosphate reduction of 86% at day 12 to mere 1.07 mg/L PO43−-P. Correlation was found between COD and TC, suggesting the release of organic substances by macrophytes into the medium. All the macrophytes showed biomass increment. S. polyrhiza outperformed other macrophytes in nutrient removal despite lower biomass production. The acquired nutrient removal profiles can serve as a guideline for the selection of suitable macrophytes in wastewater treatment and to evaluate microbial activity in non-aseptic phytoremediation system. [ABSTRACT FROM AUTHOR]

Highlights • We compared exotic and native freshwater plant species responses to low nitrate. • Increased nitrate levels resulted in faster RGR in a species-specific manner. • Exotic species had much higher RGR relative to the native species at all nitrate. Abstract Nutrient status of freshwater ecosystems has a significant influence on biological invasions, species richness and community structure. The role of phosphorus in driving these effects has been widely reported while its co-limitation with nitrogen and other elements has received more recent attention. In a greenhouse experiment, we investigated the growth responses of two invasive exotic (Egeria densa and Salvinia molesta) and one native (Vallisneria spiralis) freshwater plant species to additional low concentrations of nitrate nitrogen (N-NO 3). The species were grown at five nitrate concentrations (0.02, 0.05, 0.1, 0.5, and 0.9 mg N-NO 3 L−1). We found that the growth of E. densa and V. spiralis increased with increasing nitrate concentration. Surprisingly, S. molesta had the fastest growth rate at the midrange nitrate concentration of 0.1 mg N-NO 3 L−1 and its leaf production was not affected by nitrate treatment. Irrespective of nitrate concentration, the invasive exotic species, particularly S. molesta , showed much greater growth responses than the native V. spiralis. We conclude that freshwater plant growth responses to low nitrate concentrations will be species specific but the faster growth rates of S. molesta provide an example of how differences between co-occurring invasive exotic species and native species could have profound effects on the structure and function of freshwater ecosystems under changed environmental conditions. [ABSTRACT FROM AUTHOR]

The aquatic weed Salvinia molesta D.S. Mitch. (Salviniaceae) was first recorded in South Africa in the early 1900s, and by the 1960s was regarded as one of South Africa’s worst aquatic weeds. Following the release of the weevil, Cyrtobagous salviniae Calder and Sands (Coleoptera: Curculionidae) in 1985, the weed is now considered under successful biological control. However, the post-release evaluation of this biological control programme has been ad hoc , therefore, to assess the efficacy of the agent, annual quantitative surveys of South African freshwater systems have been undertaken since 2008. Over the last ten years, of the 57 S. molesta sites visited annually in South Africa, the weevil has established at all of them. Eighteen sites are under successful biological control, where the weed no longer poses a threat to the system and 19 are under substantial biological control, where biological control has reduced the impact of the weed. Since 2008, the average percentage weed cover at sites has declined significantly from 51–100% cover to 0–5% cover in 2017 (R 2  = 0.78; P  < 0.05). Observations of site-specific characteristics suggest that biological control is most effective at small sites and more difficult at larger and shaded sites. Our findings show that S. molesta remains under good biological control in South Africa, however, some sites require intermittent strategic management, such as augmentative releases of C. salviniae. [ABSTRACT FROM AUTHOR]