Journal articles: 'Lentic system'

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Thakuria, Dipti, and Jatin Kalita. "Diversity and distribution of odonates in Rani Reserve Forest, Assam, India." Journal of Threatened Taxa 13, no. 1 (January 26, 2021): 17487–503. http://dx.doi.org/10.11609/jott.5964.13.1.17487-17503.

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Odonata are the bioindicators of freshwater ecosystem health and is recognised as an excellent ‘flagship’ group among insects. Baseline knowledge on the diversity and distribution of odonates over spatiotemporal scale is the key to biodiversity conservation. Rani Reserve Forest of Assam is a mosaic of all the habitat types suitable for odonates. The present work aims at studying the diversity and distribution of Odonates in Rani Reserve Forest. The study was carried out from December 2014 to November 2017 by categorising the study area into three major habitat types: 1. lentic system, 2. lotic system and 3. terrestrial woodland. A total of 67 species belonging to 44 genera, representing 11 families were recorded. First published records of three species, Onychothemis testacea (Libellulidae), Philoganga montana (Philogangidae) and Indocnemis orang (Platycnemididae) from the state are also provided herewith. Species richness was the highest in lentic system whereas recorded the lowest in running waters of larger forested streams. Shannon diversity index also indicated that the lentic system is relatively diverse (2.95) and smaller streams of the lotic system showed the highest species evenness (0.87). Libellulidae (43%) was found to be the most dominant family belonging to suborder Anisoptera followed by Coenagrionidae (22%) of suborder Zygoptera. Philogangidae (1%) recorded the lowest number of species. Taxonomically related species showed distinct ecological segregation within these different habitat types occupying different microhabitats therein.

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Resh, Vincent H., and David M. Rosenberg. "SPATIAL–TEMPORAL VARIABILITY AND THE STUDY OF AQUATIC INSECTS,." Canadian Entomologist 121, no. 11 (November 1989): 941–63. http://dx.doi.org/10.4039/ent121941-11.

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AbstractSpatial and temporal variability are essential considerations in the study of aquatic insects. Traditionally, these two sources of variability are treated separately; however, they should be considered together because they occur concurrently in natural systems. To illustrate this interaction, we constructed two-way variability tables in which spatial (habitat, reach or zone, system, intersystem) and temporal (within a day, within a season, within a year, year to year) scales were ordered on separate axes, and examples of concurrent spatial and temporal variability were entered at the intersects of the scales. We examined three aspects of aquatic insect life histories in lotic and lentic waters using such tables: emergence, feeding and growth, and movements and migrations. It proved easier to find examples for the stream tables than for the lake tables, perhaps because of greater spatial and temporal variability in lotic than lentic waters. Also, more papers have been published on stream than on lake insects over the last decade or so. Spatial and temporal scales at which lotic and lentic research is done were determined by examining the recent contents of five key aquatic journals (≈ 500 articles). Research on aquatic insects appears generally to be done at relatively long temporal scales, but at smaller spatial and shorter temporal scales in lotic than lentic systems. Perusal of the literature to find examples of concurrent spatial and temporal variability revealed the prevalence of a “mean-values” appproach to data analysis, in which investigators “homogenize” data to reduce spatial and temporal variability. However, it is this spatial and temporal variability that often provides an explanation of factors causing the patterns observed. A “variance” approach, in which data are disaggregated and fluctuations or extremes are considered, may be far more informative and may elucidate underlying mechanisms.

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Makrakis, Sérgio, Luiz Carlos Gomes, Maristela Cavicchioli Makrakis, Domingo Rodriguez Fernandez, and Carla Simone Pavanelli. "The Canal da Piracema at Itaipu Dam as a fish pass system." Neotropical Ichthyology 5, no. 2 (2007): 185–95. http://dx.doi.org/10.1590/s1679-62252007000200013.

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The Canal da Piracema is the longest (nearly 10 km) fish pass system in the world. The construction of this fish pass was somehow controversial, because it connected two distinct ichthyofaunistic provinces. This study evaluated the ichthyofauna present in the Canal da Piracema and the abundance and distribution of long-distance migratory fish species along this fish pass system (evaluated possible selectivity). The Canal da Piracema was shown to be difficult to sample because of its environmental heterogeneity: artificial ponds, ladders and nature-like fish pass. To solve this problem, we used several fishing gears, adequate for the several biotopes present (unstructured and structured littoral were sampled with seining nets and electrofishing; lentic were sampled with gillnets and longlines (deeper areas); and rapid water areas were sampled with cast nets). The ichthyofauna of the Canal da Piracema followed the pattern for South America and the Paraná River, with a predominance of Characiformes and Siluriformes. The most representative families were Characidae, Anostomidae, Pimelodidae and Loricariidae. We captured 116 species (17 were long-distance migratory) during the period studied. Small-sized species were predominant in unstructured and structured littoral areas, especially Bryconamericus exodon and Apareiodon affinis.The most abundant species was Hypostomus spp. in lentic areas, followed by Iheringichthys labrosus. Hoplias aff. malabaricus predominated in deeper lentic areas. Long-distance migratory species were abundant in rapid waters; they were Prochilodus lineatus and Leporinus elongatus. The sharp reduction in the number of species, including migratory ones, is an indication that the Canal da Piracema is selecting the species that ascend it. Therefore, the search for information on the efficiency of the various fish passes present in the Canal da Piracema is fundamental, to facilitate upward movements of fish. If this is reached, this polemic fish pass has the potential to contribute to the conservation of fish stocks in Itaipu Reservoir and upstream stretches, because of the presence of spawning and development (nurseries) areas for migratory species.

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Russell, J. E., F. W. H. Beamish, and R. J. Beamish. "Lentic Spawning by the Pacific Lamprey, Lampetra tridentata." Canadian Journal of Fisheries and Aquatic Sciences 44, no. 2 (February 1, 1987): 476–78. http://dx.doi.org/10.1139/f87-057.

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Anadromous Pacific lamprey, Lampetra tridentata, typically construct nests and reproduce in lotic environments. In the summer of 1984, Pacific lamprey were observed spawning in shallow lentic water in two regions of the Babine Lake system, British Columbia. Nests were subject to wave action but an obvious unidirectional flow was not observed.

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Chicaiza Veloz, David, and Héctor Flores. "Biological parameters of Pseudocurimata boulengeri (Characiformes: Curimatidae) inhabiting the Chongón dam, Ecuador." Revista de Biología Tropical 64, no. 1 (June 28, 2016): 131. http://dx.doi.org/10.15517/rbt.v64i1.17853.

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Pseudocurimata boulengeri is an endemic species of Ecuador, which sustains a large group of fisher families. The biological data of this species correspond to reports from lotic systems of Los Ríos province; nevertheless, their trend in a lentic system is not yet known. This paper describes the sex ratio, length-weight relationship, gonad development, spawning season and size at reproductive maturity of P. boulengeri, inhabiting the lentic system of Chongón dam, Ecuador. Fish were caught between 2003 and 2009 using gill nets (2.5"). The total length (Lt) of caught specimens ranged from 10.5 to 35.5 cm, spawning occurred between the months of October and March, and size at first maturity for females was estimated at 17.9 cm (Lt) and 20.0 cm (Lt) for males. Between May and October male and female ratios were as expected (1:1), whereas for May, November and April, females ratios were higher than males, situation that coincided with the spawning season. The limnetic conditions and high production characteristics of Chongón dam, have promoted the availability of a great amount of food for this species, which may have allowed P. boulengeri to have a more extended reproductive season in this favorable environment.

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Udotong, Justina Ime R., Ime R. Udotong, and Unyime P. Udoudo. "Microbial, Hydrobiological Indicators and Physicochemical Characteristics of a Remote Aviation Fuel-Contaminated Lentic System in Ibeno, Nigeria." International Journal of Life-Sciences Scientific Research 4, no. 4 (July 2018): 1940–45. http://dx.doi.org/10.21276/ijlssr.2018.4.4.12.

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Paterson, R. A., R. Knudsen, I. Blasco-Costa, A. M. Dunn, S. Hytterød, and H. Hansen. "Determinants of parasite distribution in Arctic charr populations: catchment structure versus dispersal potential." Journal of Helminthology 93, no. 05 (June 18, 2018): 559–66. http://dx.doi.org/10.1017/s0022149x18000482.

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AbstractParasite distribution patterns in lotic catchments are driven by the combined influences of unidirectional water flow and the mobility of the most mobile host. However, the importance of such drivers in catchments dominated by lentic habitats are poorly understood. We examined parasite populations of Arctic charr Salvelinus alpinus from a series of linear-connected lakes in northern Norway to assess the generality of lotic-derived catchment-scale parasite assemblage patterns. Our results demonstrated that the abundance of most parasite taxa increased from the upper to lower catchment. Allogenic taxa (piscivorous birds as final host) were present throughout the entire catchment, whereas their autogenic counterparts (charr as final hosts) demonstrated restricted distributions, thus supporting the theory that the mobility of the most mobile host determines taxa-specific parasite distribution patterns. Overall, catchment-wide parasite abundance and distribution patterns in this lentic-dominated system were in accordance with those reported for lotic systems. Additionally, our study highlighted that upper catchment regions may be inadequate reservoirs to facilitate recolonization of parasite communities in the event of downstream environmental perturbations.

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Higuti, J., FA Lansac-Tôha, LFM Velho, and K. Martens. "Biodiversity of non-marine ostracods (Crustacea, Ostracoda) in the alluvial valley of the upper Paraná River, Brazil." Brazilian Journal of Biology 69, no. 2 suppl (June 2009): 661–68. http://dx.doi.org/10.1590/s1519-69842009000300020.

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In the present study, we test the relevance of a number of environmental factors on alpha and beta ostracod diversities, at species and family level. Ostracods were sampled from several substrates, including sediment and root systems of various floating aquatic macrophytes, from 48 environments (both lentic and lotic habitats, ranging from the river itself, over connecting channels linking with open lakes, and, finally closed lakes), belonging to four different systems (Paraná, Ivinheima, Baía and Taquaruçu), in the alluvial valley of the Upper Paraná River. The faunistic survey recorded the presence of 54 species of Ostracoda, belonging to the families Cyprididae, Candonidae, Limnocytheridae and Darwinulidae. Various diversity estimators indicated that these recorded levels of specific diversity should be close to true values. Higher values of ostracods species richness (alpha diversity) were observed in the Baía and Ivinheima systems, while lotic habitats were richer than lentic ones. In addition, open lakes appeared to be more affected by the variable 'system' than closed ones, which can to some extend be explained by the putative effects of flood pulse on benthic communities. The two investigated factors have different effects on the four ostracod families. The present study also indicated that there is a large homogeneity within and between systems, as exemplified by the low beta-diversity levels.

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Serafim Jr., M., F. A. Lansac-Tôha, J. C. Paggi, L. F. M. Velho, and B. Robertson. "Cladocera fauna composition in a river-lagoon system of the upper Paraná River floodplain, with a new record for Brazil." Brazilian Journal of Biology 63, no. 2 (May 2003): 349–56. http://dx.doi.org/10.1590/s1519-69842003000200020.

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Cladocera communities were studied in lotic and lentic environments of the Upper Paraná River floodplain, State of Mato Grosso do Sul, Brazil. A total of 63 species of Cladocera were identified in 108 samples. Of these, 24 species are considered new records for that floodplain, and one is a new record for Brazil. Chydoridae was the most representative family with 19 genera and 39 species.

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Dirisu, Abdul-Rahman, John Ovie Olomukoro, and Ifeanyi Maxwell Ezenwa. "Physico-chemical trends in the sediments of Agbede Wetlands, Nigeria." Materials and Geoenvironment 64, no. 2 (July 1, 2017): 111–26. http://dx.doi.org/10.1515/rmzmag-2017-0009.

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AbstractThis study assessed the physico-chemical status of sediments in the Agbede Wetlands with the aim to create a reference archive for the Edo North catchment and to further identify the characteristics mostly influenced by the natural and anthropogenic activities going on at the watershed. Nutrients, zinc, nickel and lead were identified to be mostly of anthropogenic origin, while alkali metals and alkaline earth metals were from both anthropogenic and natural sources. The clustering of stations 1 and 4 indicates that the sediment quality in the lentic systems was not completely excluded from the lotic system, suggesting that principal component analysis (PCA) and cluster analysis (CA) techniques are invaluable tools for identifying factors influencing the sediment quality. The mean values of the particle size distribution were in the following order across the ecosystems: sand (61.86–80.53%) > silt (9.75–30.34%) > clay (7.83–13.89%). The contamination of the water bodies was primarily derived from agricultural run-offs and through geochemical weathering of the top soils. Therefore, our analysis indicates that the concentrations of cations, anions and nutrients in the sediments of the lotic and lentic ecosystems in Agbede Wetlands are not at an alarming level.

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Moutopoulos, Dimitrios K., Maria Th Stoumboudi, Alexis Ramfos, Konstantinos Tsagarakis, Konstantinos C. Gritzalis, Olga Petriki, Athina Patsia, et al. "Food web modelling on the structure and functioning of a Mediterranean lentic system." Hydrobiologia 822, no. 1 (June 29, 2018): 259–83. http://dx.doi.org/10.1007/s10750-018-3685-x.

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Lorencová, Erika, and Michal Horsák. "Environmental drivers of mollusc assemblage diversity in a system of lowland lentic habitats." Hydrobiologia 836, no. 1 (March 30, 2019): 49–64. http://dx.doi.org/10.1007/s10750-019-3940-9.

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Pahari, Priti Ranjan, Prabir Pusti, Tapan Kr. Dutta, Biplab Mandal, and Tanmay Bhattacharya. "Diversity and Community Structure of Aquatic Insects in a Fresh Water Lentic System of Purba Medinipur District, W.B., India." Indian Journal of Biology 3, no. 2 (2016): 145–50. http://dx.doi.org/10.21088/ijb.2394.1391.3216.9.

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Silveira, Lidimara Souza da, Renato Tavares Martins, Guilherme Augusto da Silveira, Richard Michael Grazul, Danielle Pinheiro Lobo, and Roberto da Gama Alves. "Colonization by Chironomidae Larvae in Decomposition Leaves ofEichhornia azureain a Lentic System in Southeastern Brazil." Journal of Insect Science 13, no. 20 (March 2013): 1–13. http://dx.doi.org/10.1673/031.013.2001.

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Utete, Beaven, and Joshua Tsamba. "Assessing the relevance of littoral pedestals to chlorophyll a levels in a shallow lentic freshwater system." Water and Environment Journal 30, no. 3-4 (August 23, 2016): 278–83. http://dx.doi.org/10.1111/wej.12179.

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Brauer, Tucker A., Michael C. Quist, Darren T. Rhea, Troy W. Laughlin, and John D. Walrath. "Population Characteristics and Management of Lentic Populations of Nonnative Burbot in the Green River System, Wyoming." North American Journal of Fisheries Management 39, no. 1 (December 18, 2018): 45–57. http://dx.doi.org/10.1002/nafm.10247.

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Vegas-Vilarrúbia, Teresa, and Rafael Herrera. "Seasonal alternation of lentic/lotic conditions in the Mapire system, a tropical floodplain lake in Venezuela." Hydrobiologia 262, no. 1 (June 1993): 43–55. http://dx.doi.org/10.1007/bf00010988.

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Kumari, Dr Rashmi, and Dr Manoj Kumar Upadhyay. "Energy Transformation Through Primary Productivity and Nutrient Dynamics of Lentic Water." International Journal for Research in Applied Sciences and Biotechnology 9, no. 1 (February 22, 2022): 171–73. http://dx.doi.org/10.31033/ijrasb.9.1.20.

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Some societies can cope, at least temporarily, with pollution and availability constraints. In most of the world, however, population increases continue without significant reduction rates. Growth will continue to impose increasing demands upon freshwater supplies. Control and reversal of degradation requires a proper economic and social valuation of fresh water. Human impact on freshwater ecosystems will increase until industrial growth is stabilized. Emotionalism and alarmist reactions to the momentum of exploitation by the technological system accomplish little. Understanding the metabolic responses of aquatic ecosystems is essential in order to confront and offset the effects of human alterations. Many small ponds in different parts of the world have been drained or reclaimed to extend arable land. This has caused unusual fluctuations in water land, the impact of which is tremendous. The biodiversity and dynamics of different phytoplankton population are one of the least explored areas in aquatic biology. Ecological studies give humans a deep insight into principles of life, its forms and levels of existence. F.A forel may be considered as the founder of modern limnology for his original work on Swiss Lakes. The primary social need of every sustainable society is to protect and utilize all their natural resources wisely. In India, such studies on the pattern of energy flow in aquatic ecosystem by various organisms at different trophic levels are very few. Odum suggested to bring out a comparative picture by investigating the physical, chemical and biological characteristic of lentic water bodies. It is clear that no detailed bioecological investigations have been done so far in this area.

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Morant, Daniel, Christian Perennou, and Antonio Camacho. "Assessment of the Pressure Level over Lentic Waterbodies through the Estimation of Land Uses in the Catchment and Hydro-Morphological Alterations: The LUPLES Method." Applied Sciences 11, no. 4 (February 11, 2021): 1633. http://dx.doi.org/10.3390/app11041633.

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The features of lentic waterbodies largely depend on the surrounding environment. Mediterranean coastal lagoons have been historically altered, with their catchment being highly modified for agricultural, livestock, or urban uses. Changes in land uses induce pressures that impact the waterbodies and alter their ecological status. The objectives of this paper were: to develop a methodological approach (LUPLES: Land Uses for estimating Pressure Levels to approach the Ecological Status), to quantify the main pressures on the waterbodies and to forecast the possible impacts of these pressures on their ecological status. Corine-Land Cover maps and Geographic Information System technics were used to delineate and identify land uses in the catchments. Specific algorithms were created to quantify the main pressures from land uses in the catchment and hydro-morphological alterations in the immediate basin. The values of the estimated pressure levels were correlated with ecological status indicators using metrics developed for the European Water Framework Directive. Data were obtained from European and River Basin Authorities databases. Results showed statistically significant correlations between the pressure levels quantified by the LUPLES method and the impact level detected by biological, physical and chemical metrics. This method provides a useful approach to estimate the pressure levels affecting lentic waterbodies and could be applied to approach how they could affect their ecological status.

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Mendes, Yanne A., James T. Lee, Ivana K. S. Viana, Rossineide M. Rocha, and Maria A. P. Ferreira. "Reproductive biology of the tiger pleco Panaqolus tankei (Loricariidae) in a lentic system of the Amazon Basin." Journal of Fish Biology 93, no. 4 (October 2018): 711–14. http://dx.doi.org/10.1111/jfb.13735.

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Pedroza-Ramos, Adriana, Cesar E. Tamaris-Turizo, and Nelson Aranguren-Riaño. "Feeding preferences in aquatic invertebrates associated to Egeria densa in a tropical high-mountain lake." Revista de Biología Tropical 68, S2 (October 22, 2020): S92—S103. http://dx.doi.org/10.15517/rbt.v68is2.44341.

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Introduction: The benthic fauna of the littoral zone in lakes is important in transferring energy to other trophic levels, habitat coupling, and helping to keep habitat stability. The study of this type of interactions in lentic systems is priority, since functional aspects about biological communities are unknown. Objective: Describing the trophic relations of aquatic invertebrates of the littoral zone in a tropical high mountain lake by characterizing gut content and stable isotope analysis of δ13C and δ15N. Methods: Samples of benthic invertebrates were collected in the littoral zone of the Lago de Tota where Egeria densa was present using a handheld net method. Samples were processed in the laboratory, organisms were identified, counted and weighed. Gut contents and δ13C and δ15N stable isotopes analysis were performed as well. Results: Records of the trophic relations of aquatic invertebrates, which live in the littoral in high mountain lentic ecosystem in the Neotropics are shown. The analysis of gut contents distinguished seven food items, microphytes and MOPF were the most frequent, and through the stable isotopes analysis (δ15N) we identified four trophic levels, among resources (macrophytes and POM), and consumers (detritivores, herbivores, and predators). The two upper trophic levels concentrated greater diversity and biomass. Conclusion: Most of the organisms studied were linked to omnivorous habits, evidenced in a wide spectrum of food items in their diet. The δ15N values show an enrichment, which occurs due to the effects of the tendency towards eutrophication of the system or due to unknown values of protozoa and bacteria that plays a fundamental role in the diet of these organisms, besides the δ13C values reported in organisms consumes, allows us to suggest an affinity with native resources of the littoral zone.

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Hansen, Adam G., Erik T. Cristan, Miranda M. Moll, Michael W. Miller, Eric I. Gardunio, and Jesse M. Lepak. "Factors Influencing Early Growth of Juvenile Tiger Trout Stocked into Subalpine Lakes as Biocontrol and to Enhance Recreational Angling." Fishes 7, no. 6 (November 23, 2022): 342. http://dx.doi.org/10.3390/fishes7060342.

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Tiger trout (Salmo trutta × Salvelinus fontinalis) are sterile hybrids often stocked as a biocontrol agent for undesirable fishes and to enhance recreational angling. Yet, how different ecological processes affect their post-stocking performance remain poorly understood. Rapid growth early in life can foster rapid transitions to piscivory, and improve survival. Identifying factors that benefit early growth can help managers optimize tiger trout stocking for meeting multiple fisheries management objectives. Here, we characterized the trophic ecology and growth of tiger trout stocked at varying densities into seven lentic subalpine systems in Colorado, USA. Study systems supported different species of undesirable fish (e.g., minnows or suckers). We used stable isotopes of carbon and nitrogen to quantify trophic relationships among tiger trout and other fishes in each system. We then evaluated several system-specific attributes as predictors for the size of tiger trout at age-1 using a Random Forest model. Stable isotopes demonstrated the potential for resource competition among tiger trout and other fishes, but potential varied by system. Indices of resource competition ranked highest in the Random Forest model, but the stocking density of tiger trout was most important, suggesting that intraspecific competition outweighed interspecific competition in driving early growth. These processes were mediated by system productivity. Thus, stocking density in combination with the realized carrying capacities of systems should be considered when making management decisions for tiger trout.

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Barrientos, Christian, Diego Elías, and Yasmín Quintana. "Fishes from Lake Yaxhá, Mayan Biosphere Reserve, Petén, Guatemala." Check List 11, no. 5 (September 25, 2015): 1751. http://dx.doi.org/10.15560/11.5.1751.

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The Mayan Biosphere Reserve is the largest protected area in Guatemala. Lake Yaxhá is located inside the core zone. Using electrofishing, seines and gillnets we assessed the fish richness and community in 2011. We collected 18 species distributed in seven families, with Cichlidae (seven species) and Poecilidae (five species) the most specious. We evaluated the effectiveness of electrofishing to sample the most important fish in the artisanal fishery in Petén, Petenia splendida, with September being the month with the highest capture per unit of effort. Lake Yaxhá assemblage was similar to the Usumacinta through a hierarchical cluster analysis, despite being located in the Mopan-Hondo basin. Lake Yaxhá is the only system in the area that does not have non-native fish species, emphasizing the importance of conservation of this lentic system in the Mayan Biosphere Reserve.

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Martins, R. T., L. S. Silveira, and R. G. Alves. "Colonization by oligochaetes (Annelida: Clitellata) in decomposing leaves ofEichhornia azurea(SW.) Kunth (Pontederiaceae) in a neotropical lentic system." Annales de Limnologie - International Journal of Limnology 47, no. 4 (2011): 339–46. http://dx.doi.org/10.1051/limn/2011053.

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Blankson, Emmanuel R., Patricia Nakie Tetteh, Prince Oppong, and Francis Gbogbo. "Microplastics prevalence in water, sediment and two economically important species of fish in an urban riverine system in Ghana." PLOS ONE 17, no. 2 (February 3, 2022): e0263196. http://dx.doi.org/10.1371/journal.pone.0263196.

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Urban riverine systems serve as conduits for the transport of plastic waste from the terrestrial dumpsites to marine repositories. This study presented data on the occurrence of microplastics in water, sediment, Bagrid Catfish (Chrysichthys nigrodigitatus) and Black-chinned Tilapia (Sarotherodon melanotheron) from the Densu River, an urban riverine system in Ghana. Microplastics were extracted from the samples collected from both the lentic and lotic sections of the river. The results indicated widespread pollution of the Densu River with microplastics in all the compartments studied. The average numbers of microplastic particles deposited in the Dam (2.0 ± 0.58) and Delta (2.50 ± 0.48) sections of the river were not affected by the differences in their hydrology. However, the stagnant water system of the Dam promoted the floating of larger-sized microplastics while the flowing waters of the Delta did not show any selectivity in the deposition of microplastics between sediment and the water column. The number of microplastics ingestions by the Bagrid Catfish (2.88 ± 2.11) was similar to the Black-chinned Tilapia (2.38 ± 1.66) but both species ingested lower numbers of microplastics than reported for marine fish species in coastal Ghana.

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Latinopoulos, Dionissis, Chrysoula Ntislidou, and Ifigenia Kagalou. "Relationships of environmental conditions and phytoplankton functional groups in a new re-constructed shallow lentic system in draught conditions." Ecohydrology & Hydrobiology 20, no. 3 (July 2020): 369–81. http://dx.doi.org/10.1016/j.ecohyd.2020.04.003.

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von Sperling, E., and C. A. P. Grandchamp. "Changes in water quality during the formation of Brazil's deepest lentic system: a case study of Aguas Claras pit lake." SIL Proceedings, 1922-2010 29, no. 3 (March 2006): 1617–20. http://dx.doi.org/10.1080/03680770.2005.11902957.

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Dunck, Bárbara, Ina de Souza Nogueira, and Maria das Graças Machado. "Planktonic diatoms in lotic and lentic environments in the Lago dos Tigres hydrologic system (Britânia, Goiás, Brazil): Coscinodiscophyceae and Fragilariophyceae." Brazilian Journal of Botany 35, no. 2 (2012): 181–93. http://dx.doi.org/10.1590/s1806-99592012000200007.

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Davies, Ronald W., and T. E. Gates. "Intra- and Interspecific Differences in the Response of Two Lentic Species of Leeches to Seasonal Hyperoxia." Canadian Journal of Fisheries and Aquatic Sciences 48, no. 6 (June 1, 1991): 1124–27. http://dx.doi.org/10.1139/f91-134.

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Intra- and interspecific differences in survivorship of Nephelopsis obscura and Erpobdella punctata exposed to hyperoxia (200 or 300%) at spring (5 °C) and summer (20 °C) water temperatures were examined in a flow-through system. In general, percent survival and time of 50% survival increased with leech size and decreased with higher temperature for both species. All size classes could survive the maximum recorded duration of hyperoxia in the spring, and we conclude that spring hyperoxia probably does not directly affect the ecological success or microhabitat distribution of either species. At 20 °C, medium and large E. punctata had much higher survivorship than N. obscura. As summer hyperoxia can last for 30 d, these differences could contribute to changes in numerical dominance. Intra- and interspecific differences in response to hyperoxia may also influence seasonal movements between different microhabitats of different size classes of N. obscura and E. punctata. We suggest that seasonal and annual variability in littoral hyperoxia regimes can differentially influence the survivorship, reproductive success, and microhabitat distribution of many macroinvertebrates.

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Abd Hamid, Muzzalifah, Siti Norasikin Ismail, and Mashhor Mansor. "Overview of Macrophytes in The Tropical Wetland Ecosystem." Indonesian Journal of Limnology 2, no. 1 (June 30, 2021): 25–34. http://dx.doi.org/10.51264/inajl.v2i1.12.

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Macrophytes are plants that adapted to wet environment and easily be found all over the world. Macrophytes have structures that are more complex, interdependent and physically substantial; make them one of the important components of rivers, lakes and any other wetland ecosystems. Macrophytes can be categorized into four different types; emergent, floating-leaved, submerged and free-floating plants based on their structure and life form. Light, water current and wind flow are among the most important limiting factors of macrophytes occurrence in the water system. Environmental conditions such as lotic and lentic environment influence the limiting factors and would be the key for successful macrophytes distribution. Each macrophyte species could respond differently to different environmental circumstances. It also has been widely used as subject for biological indicator of ecosystem health. This paper aimed to describe the general environmental condition for macrophytes distribution, discuss their role and impact of excessive growth.

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Arostegui, M. C., and T. P. Quinn. "Trophic ecology of nonanadromous rainbow trout in a post-glacial lake system: partial convergence of adfluvial and fluvial forms." Canadian Journal of Zoology 96, no. 8 (August 2018): 818–27. http://dx.doi.org/10.1139/cjz-2017-0201.

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The rainbow trout (Oncorhynchus mykiss (Walbaum, 1792)) is one of many salmonid species exhibiting a gradient of life histories including fluvial (stream-resident), anadromous (ocean-migrant), and adfluvial (lake-migrant) forms, the last of which is less extensively studied than the other two. Our goal was to determine the extent of diet segregation between fluvial and adfluvial rainbow trout. We collected stomach content and stable isotope data on rainbow trout sampled in stream and lake habitats in a southwestern Alaska watershed during summer and compared them with data on sympatric stream- and lake-specialist char species, Dolly Varden (Salvelinus malma (Walbaum in Artedi, 1792)) and Arctic char (Salvelinus alpinus (Linnaeus, 1758)), respectively. Rainbow trout in streams fed largely on aquatic insects, while those in the lake ate primarily benthic snails and amphipods. The trophic segregation of stream-resident and lake-migrant rainbow trout mirrored but was less extreme than the divergence of lotic Dolly Varden and lentic Arctic char in the same system. Spawning sockeye salmon (Oncorhynchus nerka (Walbaum in Artedi, 1792)) provided a nutrient subsidy in the form of eggs that supported rainbow trout in both stream and lake (littoral) habitats, causing their isotopic signatures to converge. This study augments knowledge of partial migration and trophic divergence within populations.

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Musarra, M. L., A. J. Monteiro, Z. Beyruth, S. Sendacz, J. L. Novelli, and N. C. Viana. "Limnological characterization of lentic and lotie habitats of the Upper Paraná River system prior to the inundation of Porto Primavera Reservoir." SIL Proceedings, 1922-2010 26, no. 3 (March 1998): 1072–79. http://dx.doi.org/10.1080/03680770.1995.11900886.

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Reang, Demsai, Aparajita De, and Ashesh Kumar Das. "Water Resources of Barak Valley, India: Spatial Assessment of Lentic and Lotic System Using Remote Sensing and GIS at 5.8 m Resolution." International Journal of Advanced Remote Sensing and GIS 7, no. 1 (May 31, 2018): 2633–42. http://dx.doi.org/10.23953/cloud.ijarsg.358.

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Da Silveira, Lidimara Souza, Renato Tavares Martins, and Roberto da Gama Alves. "Invertebrate Colonization During Leaf Decomposition of Eichhornia azurea (Swartz) Kunth (Commelinales: Pontoderiaceae) and Salvinia auriculata Aubl. (Salvinales: Salvinaceae) in a Neotropical Lentic System." EntomoBrasilis 9, no. 1 (April 29, 2016): 10–17. http://dx.doi.org/10.12741/ebrasilis.v9i1.548.

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Abstract. The decomposition of macrophytes is an essential process for cycling of carbon and nutrients, and it is source of organic matter for invertebrates in lakes. We evaluated the colonization by aquatic invertebrates in decomposing leaves of two species of macrophytes in a Neotropical lentic system. The experiment was conducted from November 2007 to February 2008, with the use of 54 litter bags (Eichhornia azurea (Swartz): n = 27 and Salvinia auriculata Aubl.: n= 27), each containing 10 g of dry leaves. Three bags of each species were retrieved after 2, 4, 8, 12, 24, 36, 48, 60 and 72 days of incubation. The remaining leaf mass of the two macrophytes species tended to decrease with time, although at different rates. The decomposition of E. azurea and S. auriculata leaves were classified as rapid and intermediate, respectively. In general, during the experiment carbon: nitrogen ratio declined in E. azurea and increased in S. auriculata, and presented difference among the days of the experiment and between the macrophyte species. In E. azurea mass loss was negatively correlated with carbon: nitrogen ratio of the leaves, but the same pattern was not observed for the S. auriculata leaves. The composition and richness of invertebrates differed among days, but not between macrophytes species. We concluded that the succession process along the detritus chain was more important in structuring the invertebrate community than the variation in the nutritional quality of the leaf litter for these two species of macrophytes.Colonização por Invertebrados Durante a Decomposição foliar de Eichhornia azurea (Swartz) Kunth (Commelinales: Pontoderiaceae) e Salvinia auriculata Aubl. (Salvinales: Salvinaceae) em um Sistema Lêntico NeotropicalResumo. A decomposição de macrófitas é um processo essencial para ciclagem de carbono e nutrientes, e é fonte de matéria orgânica para invertebrados em lagos. Avaliamos a colonização por invertebrados aquáticos em folhas em decomposição de duas espécies de macrófitas em um sistema lêntico Neotropical. O experimento foi conduzido entre novembro de 2007 e fevereiro de 2008, com a utilização de 54 sacos de detrito (Eichhornia azurea (Swartz): n = 27 e Salvinia auriculata Aubl.: n = 27), cada um contendo 10 g de folhas secas. Três sacos de cada espécie foram recuperados após 2, 4, 8, 12, 24, 36, 48, 60 e 72 dias de incubação. A massa remanescente de folha das duas espécies de macrófitas tendeu a diminuir com o tempo, embora a velocidades diferentes. A decomposição de folhas de E. azurea e S. auriculata foram classificadas como rápida e intermédia, respectivamente. Em geral, durante o experimento a razão carbono: nitrogênio diminuiu em E. azurea e aumentou em S. auriculata, e apresentou diferença entre os dias de experimento e entre as espécies de macrófitas. Em E. azurea perda de massa foi negativamente correlacionada com a razão de carbono: nitrogênio das folhas, mas o mesmo padrão não foi observado para as folhas de S. auriculata. A composição e riqueza de invertebrados diferiram entre os dias, mas não entre espécies de macrófitas. Concluímos que o processo de sucessão ao longo da cadeia de detritos foi mais importante na estruturação da comunidade de invertebrados do que a variação na qualidade nutricional do detrito de folha para estas duas espécies de macrófitas.

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Satish, N. S., C. G. Shruthi, and Kiran B. M. "Applications of GIS & RS for Wetland Management in Mudigere Taluk, Chikkamagalur District, Karnataka." International Journal of Emerging Research in Management and Technology 6, no. 9 (June 24, 2018): 54. http://dx.doi.org/10.23956/ijermt.v6i9.85.

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'Wetland' denotes a large body of water surrounded by land, whether natural or artificial,permanent or temporary with water that is lentic or lotic. Wetlands perform some useful functions in the maintenance of overall balance of nature. Due to economic growth,urbanization,population increase and industrialization, more and more waste materials were discharged in to it, make it unfit for any uses. Hence to maintain the ecological balance,it is imperative to preserve these wetlands to make it fit for various purposes. Study is being undertaken in Mudigere taluk of Chikkamagaluru District, to identify the number of wetlands in the taluk and to assess the status of wetlands), Geographic Information System(GIS) is used to develop a system for the functional analysis of wetlands and to estimate the rainfall and runoff pattern using land-use/land-cover on wetlands and associated ecosystems .The study involves a detailed investigation of physical and chemical water quality parameters of 7 lake, carried out for a period of three months from March to May, the result reveals that the water is not polluted only turbidity exceeds the permissible limit due storm water runoff and 2 lakes have attended the Eutrophic condition due to agriculture run-off, sewage pollution and anthropogenic activities. A System for the Functional Analysis of Wetland using GIS,remote sensing data, topographical maps. Rainfall and Runoff pattern is estimated using land-use/land-cover, Soil using GIS and Remote Sensing Technique.

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Weyl, Olaf L. F., Timo Stadtlander, and Anthony J. Booth. "Establishment of Translocated Populations of Smallmouth Yellowfish,Labeobarbus aeneus(Pisces: Cyprinidae), in Lentic and Lotic Habitats in the Great Fish River System, South Africa." African Zoology 44, no. 1 (April 2009): 93–105. http://dx.doi.org/10.3377/004.044.0109.

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VARELA-SOTO, DONALD, JUAN G. ABARCA, ESTEBAN BRENES-MORA, VALERIA ASPINALL, TWAN LEENDERS, and ALEX SHEPACK. "A new species of brilliant green frog of the genus Tlalocohyla (Anura, Hylidae) hiding between two volcanoes of northern Costa Rica." Zootaxa 5178, no. 6 (August 31, 2022): 501–31. http://dx.doi.org/10.11646/zootaxa.5178.6.1.

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A new species of hylid frog is described from Tapir Valley Nature Reserve, located on the Caribbean slope of Tenorio Volcano in Bijagua, Alajuela Province, Costa Rica. A molecular phylogenetic analysis supports its inclusion in the genus Tlalocohyla. Morphological, morphometric, larval, and acoustic characteristics further distinguish it from other species in the genus and support its uniqueness. The new species is closely related to T. picta and T. smithii, and is separated by at least 500 kilometers from the nearest known occurrence of a population of T. picta in southern Honduras. The new species is readily distinguished from all other Tlalocohyla by its brilliant green coloration marked with a pronounced, incomplete light dorsolateral stripe that is bordered above by a diffuse reddish-brown stripe. Its dorsum is marked with bold reddish brown spots and its ventral skin is fully transparent. This new Tlalocohyla is currently only known from the type locality, where it inhabits a lentic wetland system with an emergent herbaceous vegetation-dominated benthic zone, surrounded by tropical rainforest. A description of its bioacoustic repertoire and information on natural history, reproduction and habitat preference of this new species are provided.

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GBAGUIDI, Jean, Nikita TOPANOU, Jacques FATOMBI, Essegbemon Moyo, Daouda MAMA, and Taofiki AMINOU. "Contributions to the protection of a lentic system in the tropical region against chemical pollutions: A case study of “Toho Lake” in Southeastern Benin, West Africa." Journal of Bioscience and Applied Research 6, no. 1 (March 1, 2020): 8–19. http://dx.doi.org/10.21608/jbaar.2020.115763.

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Wrona, Frederick J., Peter Calow, Ian Ford, Donald J. Baird, and Lorraine Maltby. "Estimating the Abundance of Stone-dwelling Organisms: A New Method." Canadian Journal of Fisheries and Aquatic Sciences 43, no. 10 (October 1, 1986): 2025–35. http://dx.doi.org/10.1139/f86-248.

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A system of stratified sampling has been developed which allows the estimation of population densities of organisms which adhere to, or are associated with, stones in both lentic and lotic habitats, using the stones themselves as the primary sampling units. Knowing the stone profile of the habitat (i.e. the mean count, relative frequency, or mean surface area of the stones occurring within a size class), and using the appropriate statistical equations, an estimate of the mean number of individuals occurring within a predefined stone size class can be obtained along with its associated error estimates. Densities of the organisms can be expressed in terms of either a standardized unit area of substratum, average stone size in the habitat, or unit area of stone surface. The statistical theory and computational equations for each sampling method are presented, together with worked examples of the application of the methods in the field. The new sampling protocols are superior to conventional quadrat techniques in population size estimation because (1) the derived density and error estimates account for sources of variation arising from both the heterogeneity of the habitat and the spatial dispersion of the organisms; (2) physical disturbance to the habitat during the sampling program is minimal, and (3) the procedures allow simultaneous quantitative measures of both the density and spatial dispersion of a population.

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Lonergan, Erin, Julie Pasche, Linnea Skoglund, and Mary Burrows. "Sensitivity of Ascochyta Species Infecting Pea, Lentil, and Chickpea to Boscalid, Fluxapyroxad, and Prothioconazole." Plant Disease 99, no. 9 (September 2015): 1254–60. http://dx.doi.org/10.1094/pdis-06-14-0620-re.

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Management of Ascochyta blight in pea, lentil, and chickpea relies on repeated fungicide applications, which has led to development of fungicide resistance and disease control failures in some systems. In vitro assays were conducted to determine baseline fungicide sensitivity in Mycosphaerella pinodes (Ascochyta pinodes), A. lentis, and A. rabiei populations to the demethylation-inhibiting fungicide prothioconazole and the succinate dehydrogenase-inhibiting fungicides boscalid and fluxapyroxad by determining the effective concentration at which 50% of germination or fungal growth was inhibited (EC50). Mean boscalid EC50 values from conidial germination assays were 0.669, 0.639, and 0.171 μg/ml and from mycelial growth assays were 0.258, 0.791, and 0.443 μg/ml for M. pinodes, A. lentis, and A. rabiei, respectively. Mean fluxapyroxad EC50 values were 0.050, 0.763, and 0.057 μg/ml for M. pinodes, A. lentis, and A. rabiei, respectively. Mean baseline EC50 values for prothioconazole with mycelial growth were 0.541, 0.604, and 0.283 μg/ml for M. pinodes, A. lentis, and A. rabiei, respectively. A single discriminatory fungicide concentration of 1 μg/ml was selected for all species. Established sensitivity profiles and discriminatory concentrations will be used to monitor sensitivity shifts in populations of Ascochyta spp. and to make effective disease management recommendations.

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Alvarez, MF, HH Benítez, LC Solari, JC Villegas Cortés, NA Gabellone, and MC Claps. "Effects of polyphenols on plankton assemblages and bacterial abundance representative of a pampean shallow lake: an experimental study." Aquatic Microbial Ecology 85 (October 8, 2020): 85–100. http://dx.doi.org/10.3354/ame01943.

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Shallow lakes are complex environments that play an important role in ecology. Their relationships with the surrounding areas make these lentic water bodies susceptible to alterations in response to human activity. For example, the input of polyphenols could be critical in altering species interactions. The shallow lakes located in the pampean plain of Argentina are major reservoirs of diversity, with the environmental habitats of the Salado River basin in particular having become impacted by human activities. The aim of this work was to evaluate the effects of different polyphenol concentrations (i.e. tannins) on changes in the plankton assemblages and on the abundance of bacteria in San Miguel del Monte Lake. Factorial experiments under laboratory conditions (4 tannin concentration levels and 4 response times) revealed that high tannin concentrations affected neither the phyto- and zooplankton assemblages nor bacterial abundances. Major changes both in assemblages and in the bacterioplankton abundances were dependent on exposure time. We found that the initial food web of grazers shifted to detritivorous feeding, thus producing a simplification of the community toward early succession. Although no effects of polyphenols were registered here, what proved striking was the resilience of the system and the capability to support high tannin concentrations throughout the experiment. Therefore, future investigations are necessary to elucidate the key role of such humic substances in the structuring of plankton assemblages of shallow lakes from strongly impacted areas, such as those found in the pampean region.

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Rodríguez, Rafael, Marcos Pastorini, Lorena Etcheverry, Christian Chreties, Mónica Fossati, Alberto Castro, and Angela Gorgoglione. "Water-Quality Data Imputation with a High Percentage of Missing Values: A Machine Learning Approach." Sustainability 13, no. 11 (June 2, 2021): 6318. http://dx.doi.org/10.3390/su13116318.

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The monitoring of surface-water quality followed by water-quality modeling and analysis are essential for generating effective strategies in surface-water-resource management. However, worldwide, particularly in developing countries, water-quality studies are limited due to the lack of a complete and reliable dataset of surface-water-quality variables. In this context, several statistical and machine-learning models were assessed for imputing water-quality data at six monitoring stations located in the Santa Lucía Chico river (Uruguay), a mixed lotic and lentic river system. The challenge of this study is represented by the high percentage of missing data (between 50% and 70%) and the high temporal and spatial variability that characterizes the water-quality variables. The competing algorithms implement univariate and multivariate imputation methods (inverse distance weighting (IDW), Random Forest Regressor (RFR), Ridge (R), Bayesian Ridge (BR), AdaBoost (AB), Hubber Regressor (HR), Support Vector Regressor (SVR) and K-nearest neighbors Regressor (KNNR)). According to the results, more than 76% of the imputation outcomes are considered “satisfactory” (NSE > 0.45). The imputation performance shows better results at the monitoring stations located inside the reservoir than those positioned along the mainstream. IDW was the model with the best imputation results, followed by RFR, HR and SVR. The approach proposed in this study is expected to aid water-resource researchers and managers in augmenting water-quality datasets and overcoming the missing data issue to increase the number of future studies related to the water-quality matter.

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Baković, Najla, Renata Matoničkin Kepčija, and Ferry J. Siemensma. "Transitional and small aquatic cave habitats diversification based on protist assemblages in the Veternica cave (Medvednica Mt., Croatia)." Subterranean Biology 42 (January 25, 2022): 43–60. http://dx.doi.org/10.3897/subtbiol.42.78037.

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Protists in caves are scarcely researched. Most cave studies address the diversity of protists, but very little is known about their habitats and spatio-temporal dynamics. The aim of this study was to investigate the diversity and abundance of protists in the Veternica cave in the Medvednica mountain in Croatia on hygropetric and sinter and clay pools during six months. During this study, 47 protists taxa were distinguished belonging to the groups of heterotrophic flagellates, ciliates, heliozoans, stramenopiles and testate and naked amoebae. The highest taxon richness was found at the sinter pool site richest in bats guano (36 taxa). Most diverse were testate amoebae and ciliates. The number of taxa and their abundance differed significantly between the sampling sites. The prospected habitats supported different protist assemblages, proved by ordination analysis. The most distinctive habitat was the hygropetric. Habitat heterogeneity could be attributed to the presence of inorganic and organic sediments at the sites and habitat microhydrology (lotic or lentic system). Kendall’s concordance coefficient showed a good synchronicity between the habitats in the Veternica cave, based on taxon richness and abundance of protists indicating similar seasonal trends. Seasonality in the studied habitats is attributed to the hydro-meteorological conditions in the Veternica cave drainage area. This study is one of the few studies of spatio-temporal diversity and abundance of protists in caves. Despite the similar appearance of small transitional and aquatic habitats in caves, an example of this study showed specific habitat diversification.

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Tosi, L., and C. Cappelli. "First Report of Fusarium oxysporum f. sp. lentis of Lentil in Italy." Plant Disease 85, no. 5 (May 2001): 562. http://dx.doi.org/10.1094/pdis.2001.85.5.562a.

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During June and July 1999-2000, a disease causing severe losses of seedlings of a local ecotype of lentil (Lens culinaria Medik, syn. Lens esculenta Moench.) was observed in four commercial fields in central Italy (Umbria and Latium regions). Disease symptoms, observed in both years, included stunting, wilting, marked reduction of root system, and internal vascular discoloration of the lower stem. Twenty-five samples for each field, consisting of lentil roots and stems, were collected. Seven to eight tissue pieces per sample, derived from the lower stem and a variety of root sizes, were sampled, surface-treated in 1 or 0.1% HgCl2 for 30 s, rinsed in sterile deionized water, placed on petri dishes containing potato dextrose agar (PDA, pH 5.5) and then incubated for 7 days at 25°C. F. oxysporum (2) (identification confirmed by R. A. Samson, Centraalbureau Voor Schimmelcultures of Baarn, Netherlands) was consistently recovered from affected tissues. Monoconidial cultures of four isolates were prepared and evaluated for pathogenicity. Seventy 4-week-old lentil seedlings (local ecotype) were inoculated by dipping the root system of each seedling in a spore suspension of each isolate of F. oxysporum (106 conidia/ml) for 30 min and transplanted into a pot containing a sterilized sandy-loam soil mix. In a second experiment, 100 seeds for each isolate were sown in the same soil mix amended with rice kernels colonized with four isolates of F. oxysporum (10% wt/wt). Seedlings dipped in sterile deionized water and seeds sown in soil amended with noncolonized rice kernels served as controls in the first and second experiments, respectively. Three replications of both pathogenicity tests were carried out in a controlled growth chamber at day/night 22/20 ± 2°C, 60/70% RH, 12 h day (180 μE•m2•s-1). Both experiments were repeated. Two to three weeks after inoculation, all plants inoculated with each F. oxysporum isolate showed the same symptoms observed in the field and caused wilting and death of 80 to 100% of the inoculated plants. F. oxysporum was consistently reisolated from the symptomatic test plants, whereas the fungus was never isolated from all control plants which remained symptomless and healthy. F. oxysporum was not observed in seed health tests (blotter and agar plate methods) carried out on 100 seeds per sample harvested from infected crops. Management practices include long-term crop rotation with nonsusceptible hosts and removal and destruction of infected crop debris. Seed treatment with fungicides (benzimidazoles, thiram) (3) can reduce incidence of the disease but host resistance is the best mean of controlling Fusarium wilt. Most resistant lentil accessions come from Chile, Egypt, India, Iran, and Romania (1). This is the first report of F. oxysporum f. sp. lentis on lentil in Italy. Without adequate control, this seedling disease may become a major factor limiting production of high quality lentils in Umbria and Latium. References: (1) B. Baya et al. Euphytica 98:69, 1997. (2) C. Booth. C.M.I. Description of Fungi and Bacteria. No. 271, 1971. (3) J. Kannayan and Y. L. Nene. Indian J. Plant Prot. 2:80, 1974.

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Curtis, Amanda N., and Eric R. Larson. "No evidence that crayfish carcasses produce detectable environmental DNA (eDNA) in a stream enclosure experiment." PeerJ 8 (June 11, 2020): e9333. http://dx.doi.org/10.7717/peerj.9333.

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Environmental DNA (eDNA) is an emerging tool for monitoring invasive and imperiled species, particularly at low densities. However, the factors that control eDNA production, transport, and persistence in aquatic systems remain poorly understood. For example, the extent to which carcasses produce detectable eDNA is unknown. If positive detections are associated with dead organisms, this could confound monitoring for imperiled or invasive species. Here, we present results from one of the first studies to examine carcass eDNA in situ by deploying carcasses of the invasive red swamp crayfish (Procambarus clarkii) in a stream enclosure experiment for 28 days. We predicted that carcasses would initially produce eDNA that would decline over time as carcasses decayed. Unsurprisingly, crayfish carcasses lost biomass over time, but at the conclusion of our experiment much of the carapace and chelae remained. However, no eDNA of P. clarkii was detected in any of our samples at the crayfish density (15 P. clarkii carcasses at ∼615 g of biomass initially), stream flow (520–20,319 L/s), or temperature (∼14–25 °C) at our site. Subsequent analyses demonstrated that these results were not the consequence of PCR inhibition in our field samples, poor performance of the eDNA assay for intraspecific genetic diversity within P. clarkii, or due to the preservation and extraction procedure used. Therefore, our results suggest that when crayfish are relatively rare, such as in cases of new invasive populations or endangered species, carcasses may not produce detectable eDNA. In such scenarios, positive detections from field studies may be more confidently attributed to the presence of live organisms. We recommend that future studies should explore how biomass, flow, and differences in system (lentic vs. lotic) influence the ability to detect eDNA from carcasses.

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Mancini, Francesco, Raffaele De Giorgi, Alessandro Ludovisi, Salvatrice Vizzini, and Giorgio Mancinelli. "Ontogenetic shift in the trophic role of the invasive killer shrimp Dikerogammarus villosus: a stable isotope study." Biological Invasions 23, no. 6 (February 19, 2021): 1803–17. http://dx.doi.org/10.1007/s10530-021-02472-0.

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AbstractThe introduction of the amphipod Dikerogammarus villosus in European fresh waters is to date recognized as a threat to the integrity of invaded communities. Predation by D. villosus on native benthic invertebrates is assumed as the key determinant of its ecological impact, yet available information describe the species as a primary consumer as well as a carnivore depending on local conditions. Here, we assessed the trophic position (TP) of D. villosus in Lake Trasimeno, a recently invaded lentic system in central Italy, using the CN isotopic signatures of individuals captured in winter spanning two orders of magnitude in body size. TP estimations were compared with those characterizing the native amphipod Echinogammarus veneris and other representative invertebrate predators. On average, D. villosus showed a trophic position higher than E. veneris, and comparable with that of odonate nymphs. An in-depth analysis revealed that large-sized individuals had a trophic position of 3.07, higher than odonates and close to that of the hirudinean predator Erpobdella octoculata, while small-sized specimens had a trophic position of 2.57, similar to that of E. veneris (2.41). These findings indicate that size-related ontogenetic shifts in dietary habits may per se vary the nature of the interaction between Dikerogammarus villosus and native invertebrates from competition to predation. Information collated from published isotopic studies corroborated the generality of our results. We conclude that intra-specific trophic flexibility may potentially amplify and make more multifaceted the impact of the species on other invertebrate species in invaded food webs.

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Lewis, Dustin F., Robert J. Richardson, Fred H. Yelverton, and Thomas R. Wentworth. "Bioavailability of Aminocyclopyrachlor and Triclopyr plus Clopyralid from Turfgrass Clippings in Aquatic and Riparian Plants." Weed Science 61, no. 4 (December 2013): 594–600. http://dx.doi.org/10.1614/ws-d-13-00013.1.

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Synthetic auxin herbicides are widely utilized in golf course settings for selective broadleaf weed control. Aminocyclopyrachlor (AMCP) is a newly registered pyrimidine carboxylic acid with similar chemical mode-of-action and structure to triclopyr (TRIC) and clopyralid (CLPY). Off-target injury on terrestrial plants has been documented following exposure to turfgrass clippings previously treated with TRIC and CLPY. Management practices on golf courses can distribute turfgrass clippings into water bodies; however, research has not evaluated the bioavailability of synthetic auxin residues from turfgrass clippings to aquatic and riparian plants within these environments. A bioassay study was conducted to determine the response of alligatorweed and parrotfeather to tall fescue clippings previously treated with synthetic auxin herbicides. Previously treated AMCP and TRIC + CLPY clippings were placed into growth containers mimicking a lentic system containing both alligatorweed and parrotfeather. Results indicated all herbicide treated clippings induced significant growth responses to alligatorweed and parrotfeather growth compared to a nontreated mulch and nontreated control. Alligatorweed control was greater from AMCP clippings treated 14, 7, 3, and 1 DBCC (49, 60, 90, and 80%, respectively) than comparative TRIC + CLPY clippings (33, 25, 37, and 64%, respectively) at 10 weeks after treatment (WAT). Parrotfeather control was greater from AMCP clippings (57 to 87%) than TRIC + CLPY clippings (9 to 63%) collected from all days before clipping collection (DBCC) timings when evaluated 6 WAT. At 10 WAT, greater parrotfeather control and shoot reduction was observed from AMCP than TRIC + CLPY clippings when treated 14, 7, and 3 DBCC. Based on these data, synthetic auxin residues can become bioavailable to aquatic and riparian plants within aqueous environments.

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Liu, Yang, and Mei-Po Kwan. "Structuralization of Complicated Lotic Habitats Using Sentinel-2 Imagery and Weighted Focal Statistic Convolution." Hydrology 9, no. 11 (October 31, 2022): 195. http://dx.doi.org/10.3390/hydrology9110195.

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Deriving the proper structure of lotic habitats, namely the structuralization of lotic habitats, is crucial to monitoring and modeling water quality on a large scale. How to structuralize complicated lotic habitats for practical use remains challenging. This study novelly integrates remote sensing, geographic information system (GIS), and computer vision techniques to structuralize complicated lotic habitats. A method based on Sentinel-2 imagery and weighted focal statistic convolution (WFSC) is developed to structuralize the complicated lotic habitats into discrete river links. First, aquatic habitat image objects are delineated from Sentinel-2 imagery using geographic object-based image analysis (GEOBIA). These lotic habitat image objects are then separated from lentic habitat image objects using a hydrologically derived river network as a reference. Second, the binary image of the lotic habitat image objects is converted to a fuzzy magnitude surface using WFSC. The ridgelines on the magnitude surface are traced as the centerlines of river links. Finally, the centerlines of river links are used to split the complicated lotic habitats into discrete river links. Essential planar geometric attributes are then numerically derived from each river link. The proposed method was successfully applied to the braided river network in the Mobile River Basin in the U.S. The results indicate that the proposed method can properly structuralize lotic habitats with high spatial accuracy and correct topological consistency. The proposed method can also derive essential attributes that are difficult to obtain from conventional methods on a large scale. With sufficient measurements, a striking width–abundance pattern has been observed in our study area, indicating a promising logarithmic law in lotic habitat abundance.

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49

Mamun, Md, Ji Yoon Kim, and Kwang-Guk An. "Trophic Responses of the Asian Reservoir to Long-Term Seasonal and Interannual Dynamic Monsoon." Water 12, no. 7 (July 21, 2020): 2066. http://dx.doi.org/10.3390/w12072066.

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The main objectives of the study were to determine the trophic response of the temperate reservoir to seasonal and interannual variabilities of monsoon inorganic solids and nutrients along the gradients of the morphologically complex Asian reservoir using long-term datasets between 2000–2018. Nutrient regime (total nitrogen—TN, total phosphorus—TP), total suspended solids (TSS), and chlorophyll-a (CHL-a) were primarily affected by an intensity of summer monsoon and the longitudinal structure of riverine (Rz), transitional (Tz), and lacustrine (Lz) zone. The reservoir is a nitrogen-rich system and the phosphorus content of the water was relatively low, and it had low mean N:P ratios (<40), implying a P-limiting system. The Lz was a highly P-limited zone in comparison to Rz and Tz zone during both drought (2015) and flood year (2011). The TP content was higher in the mainstem (S3) than the embankment (S4 and S6) of the reservoir due to the monsoon river inputs of the nutrients. Nonparametric Mann–Kendall tests indicated that TP decreased over the long-term years in the Rz, while it did not show any trend in Tz, Lz, IT1, and IT2. TN showed an increasing trend in Rz, Tz, Lz, and IT2 except for IT1. The empirical regression model for chlorophyll nutrients showed that CHL-a had a strong positive relationship with TP (R2 = 0.67, p < 0.01) than TN (R2 = 0.06, p < 0.01), supporting the view that algal growth in lentic systems responds to TP enrichment and TP may provide a reliable basis for predicting algal biomass. The seasonality of CHL-a and TP showed a monomodal pattern and indicates that summer TP influences summer algal growth in Tz, Lz, and IT2. The water clarity (SD) of the reservoir was significantly (p < 0.01) influenced by TP (R2 = 0.62), TSS (R2 = 0.67), and CHL-a (R2 = 0.68) rather than TN (R2 = 0.10). The non-algal light attenuation coefficient (Kna) was determined mainly by suspended solids and the monsoon hydrology. The trophic state was much higher when assessments were based on TSI (CHL-a) than on TSI (TP) and TSI (SD). TSI (CHL-a) indicated the eutrophic state of the reservoirs except for the zone of Lz during the premonsoon season. Analysis of trophic state index deviation (TSID) suggested that the blue-green algae dominated the algal community, and the effects of non-algal turbidity and zooplankton grazing were minor in the reservoir.

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50

Chemagin, Andrey Aleksandrovich. "Fish distribution in riverbed depression and conjugated reservoirs (effects of lighting and turbulence)." Vestnik of Astrakhan State Technical University. Series: Fishing industry 2019, no. 4 (December 13, 2019): 42–54. http://dx.doi.org/10.24143/2073-5529-2019-4-42-54.

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The paper describes the studies carried out by the hydroacoustic method in the open water period (spring) in the water area of the riverbed depression of the Irtysh River and its conju-gated water bodies (Western Siberia, the Russian Federation) in 2017. Collectively investigated reservoirs form a laminar-turbulent system, as they vary in intensity and direction of currents which form a certain turbulence and turbidity. It has been stated that in the dark time the fish population density increases in the waters of the reservoir with the maximal turbulence and turbidity rates - 166 NTU (the Irtysh river), and decreases in other water bodies (in the Konda river - 20.75 NTU and in the lentic section of the riverbed depression - 25 NTU). In the waters of conjugate reservoirs an increasing share of cyprinids is accompanying by a decrease in the proportion of predatory fish, while with an increase in predatory fish, on the contrary, the proportion of cyprinids decreases. A significant difference (P < 0.001) in terms of fish density was noted in the dark time. It was found that of the two factors (time of the day and turbulence) the second factor has a significant reliable effect (F = 18.518; P < 0.001) on the variable of fish population average density, both factors reliably interacting (F = 3.982; P = 0.037). There has been shown a transition of non-predatory fish to the site that is visually and hydrodynamically the most difficult for finding prey, which seems to be an element of reducing the risk of predation. Thus, there was found a significant influence of an abiotic factor of turbulence and, consequently, arising turbidity when interacting with the illumination factor on forming the increased fish concentration in the waters of the riverbed depression during the open water period.

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Journal articles on the topic 'Lentic system'

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