Journal articles: 'River-lake connectivity'

1

Liang, Li, Zuoqin Guo, Huixia Yang, Hexi Zhang, and Wei Huang. "Ecological Response Characteristics of Interconnected River System Network in Karst Area: A Case Study of Dabang River Basin Connecting Engineering in Guizhou Province." E3S Web of Conferences 165 (2020): 01015. http://dx.doi.org/10.1051/e3sconf/202016501015.

Full text

Abstract:

As an important water control strategy in the 21st century, interconnected river system network has been widely implemented in all parts of China. However, the possible ecological response mechanism which can be decided by the structure of rivers and the river-lake connectivity is still in the exploratory stage at present, especially in karst areas where the ecosystem is particularly fragile. Taking the Huangguoshu Waterfall-Wangerhe reservoir connection engineering in Dabang River Basin of Guizhou Province as an example, this paper collects the basic data of hydrometeorology, vegetation coverage and river water quality in the Dabang River Basin in the past 20 years, and study and analysis the connectivity of water system and the ecological factors based on GIS which include meteorological, terrestrial habitat and water environment before and after the completion of the Link Project. The results show that the implementation of the project not only changes the connectivity pattern of river and lake systems, but also has a significant impact on the hydrometeorology, terrestrial habitat and water environment. The increase of connectivity leads to the decrease of regional rainfall, evaporation and temperature year by year, while the vegetation coverage and water temperature show an annual upward trend. In addition, the water quality of the receiving area is better after the implementation of the river-lake link project, which does not bring water pollution risk to the receiving area.

APA, Harvard, Vancouver, ISO, and other styles

2

Chen, Jing, Chenguang Xiao, and Dan Chen. "Connectivity Evaluation and Planning of a River-Lake System in East China Based on Graph Theory." Mathematical Problems in Engineering 2018 (July 18, 2018): 1–12. http://dx.doi.org/10.1155/2018/1361867.

Full text

Abstract:

The connectivity of the stream network plays an important role in water-mediated transport and river environments, which are threatened by the rugged development process in China. In this study, based on graph theory, a connectivity evaluation index system was built, which includes the Edge Connectivity, Edge-Node rate, Connectivity Reliability, and Edge Weight. The new evaluation standard and calculation method of each index is presented. The river-lake system of Fenhu industrial park in Jiangsu China is simplified to an Edge-Node graph and evaluated by the index system as a case study. The results indicate that the river-lake system of the research area has low Edge Connectivity, a high Edge-Node rate, and high reliability in the current connectivity level. In addition, the Edge Weight index of several channels does not satisfy the standard of the Basic Edge Weight. To solve the connectivity problems, specific project plans include broadening the unqualified channel and building canals linked with the low-connectivity lakes. The results show that, after the planning, the connectivity of the stream network in Fenhu industrial park will increase, and the connectivity evaluation index system is useful in the study area.

APA, Harvard, Vancouver, ISO, and other styles

3

Tretkoff, Ernie. "Research Spotlight: River‐to‐lake connectivity and habitat diversity." Eos, Transactions American Geophysical Union 92, no. 8 (February 22, 2011): 72. http://dx.doi.org/10.1029/2011eo080024.

Full text

APA, Harvard, Vancouver, ISO, and other styles

4

Liu, Ying, and Anming Bao. "Exploring the Effects of Hydraulic Connectivity Scenarios on the Spatial-Temporal Salinity Changes in Bosten Lake through a Model." Water 12, no. 1 (December 20, 2019): 40. http://dx.doi.org/10.3390/w12010040.

Full text

Abstract:

Lake water salinization in arid areas is a common problem and should be controlled for the better use of freshwater of lakes and for the protection of the environment around lakes. It is well known that the increasing of hydraulic connectivity improves water quality, but for a lake, understanding how hydraulic connectivity changes its water quality in terms of spatial aspects is of great significance for the protection and utilization of different regions of the lake water body. In this paper, the impacts of three connectivity scenarios on the spatial-temporal salinity changes in Bosten Lake were modeled through the three-dimensional (3D) hydrodynamic model, Environmental Fluid Dynamics Code (EFDC). The constructed Bosten Lake EFDC model was calibrated for water level, temperature, and salinity with acceptable results. As for the Bosten Lake, three connectivity scenarios were selected: (1) the increasing of the discharge water amount into the lake from the Kaidu River, (2) the transferring of 1 million cubic meter freshwater to the southwestern part of the lake (the Huangshuigou region of the lake), and (3) the changing of the outflow position from the southwestern part of the lake (the Kongque river) to the southeastern of the lake (the Caohu region). Through the simulations, we found that the region of the lake mainly influenced by the three scenarios presented here were different, and of the three scenarios, scenario 3 was the best means of controlling the overall lake salinity. On the basis of the salinity distribution results gained from the simulations, decision-makers can choose the ways to mitigate the salinity of the lake according to which region they want to improve the most in terms of economic efficiency and preserve in terms of ecological balance.

APA, Harvard, Vancouver, ISO, and other styles

5

Lazartigues, Angélique, Chantale Girard, Philippe Brodeur, Frédéric Lecomte, Marc Mingelbier, and Pascal Sirois. "Otolith microchemistry to identify sources of larval yellow perch in a fluvial lake: an approach towards freshwater fish management." Canadian Journal of Fisheries and Aquatic Sciences 75, no. 3 (March 2018): 474–87. http://dx.doi.org/10.1139/cjfas-2016-0289.

Full text

Abstract:

The study aims at determining which spawning sites are contributing to yellow perch (Perca flavescens) juveniles’ recruitment in Lake Saint-Pierre (St. Lawrence River, Canada). We expect to highlight new management perspectives. Thus, we investigated both natal origin and connectivity processes for young of the year prior to their first winter. Otolith chemical composition was measured at larval and juvenile stages using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Five spawning sites were sampled and discriminated using a three-elemental model (manganese, barium, strontium). Results showed that (i) all within-lake sites contributed similarly to juvenile production and (ii) production results from both local recruitment and lake-wide connectivity processes. The study suggests fish management should include an overall evaluation of the lake-wide recruitment. Both local and widespread actions are required, depending on the level of connectivity in the lake, which plays a central role in shaping the spatial pattern of recruitment. Finally, otolith microchemistry proves to be an efficient tool for freshwater fish managers to evaluate both natal origin and connectivity in heterogeneous aquatic ecosystems.

APA, Harvard, Vancouver, ISO, and other styles

6

Strange, Rex Meade, and Carol A. Stepien. "Genetic divergence and connectivity among river and reef spawning groups of walleye (Sander vitreus vitreus) in Lake Erie." Canadian Journal of Fisheries and Aquatic Sciences 64, no. 3 (March 1, 2007): 437–48. http://dx.doi.org/10.1139/f07-022.

Full text

Abstract:

Discerning population genetic structure is challenging for highly vagile open water animals, as contemporary gene flow may obscure historic phylogeographic patterns. We examined genetic variation among all 10 major river and reef spawning groups of walleye (Sander vitreus vitreus) in Lake Erie for evidence of isolation by distance, segregation by physiographic partitions, and natal site fidelity using 10 nuclear DNA microsatellite loci. Results revealed that although most spawning groups were distinguishable, relationships did not correspond with physiographic basins or distances among localities. Bayesian analyses showed connectivity among some southern shore spawning groups, which included the largest-sized groups. Significant genetic divergence was discerned among walleye spawning in the river systems of eastern Lake Erie, as well as in two sites in western Lake Erie, along with marked isolation from Lake St. Clair. Population structure of Lake Erie walleye thus appears to reflect the interaction of two different intrinsic factors: isolation due to natal site fidelity that maintains patterns of divergence, and connectivity due to individuals that stray from their natal sites to spawn.

APA, Harvard, Vancouver, ISO, and other styles

7

Brodnik, Reed M., Michael E. Fraker, Eric J. Anderson, Lucia Carreon-Martinez, Kristen M. DeVanna, Daniel D. Heath, Julie M. Reichert, Edward F. Roseman, and Stuart A. Ludsin. "Larval dispersal underlies demographically important intersystem connectivity in a Great Lakes yellow perch (Perca flavescens) population." Canadian Journal of Fisheries and Aquatic Sciences 73, no. 3 (March 2016): 416–26. http://dx.doi.org/10.1139/cjfas-2015-0161.

Full text

Abstract:

Ability to quantify connectivity among spawning subpopulations and their relative contribution of recruits to the broader population is a critical fisheries management need. By combining microsatellite and age information from larval yellow perch (Perca flavescens) collected in the Lake St. Clair – Detroit River system (SC-DRS) and western Lake Erie with a hydrodynamic backtracking approach, we quantified subpopulation structure, connectivity, and contributions of recruits to the juvenile stage in western Lake Erie during 2006–2007. After finding weak (yet stable) genetic structure between the SC-DRS and two western Lake Erie subpopulations, microsatellites also revealed measurable recruitment of SC-DRS larvae to the juvenile stage in western Lake Erie (17%–21% during 2006–2007). Consideration of precollection larval dispersal trajectories, using hydrodynamic backtracking, increased estimated contributions to 65% in 2006 and 57% in 2007. Our findings highlight the value of complementing subpopulation discrimination methods with hydrodynamic predictions of larval dispersal by revealing the SC-DRS as a source of recruits to western Lake Erie and also showing that connectivity through larval dispersal can affect the structure and dynamics of large lake fish populations.

APA, Harvard, Vancouver, ISO, and other styles

8

Wang, Hua, Feng Qiang Ji, Yi Yi Zhou, and Kun Xia. "Water Pollutant Control for a River-Lake Region to the Northwest of Lake Taihu." Applied Mechanics and Materials 665 (October 2014): 420–25. http://dx.doi.org/10.4028/www.scientific.net/amm.665.420.

Full text

Abstract:

In this paper, Zhushan Bay watershed to the northwest of Lake Taihu was selected as the research area. Taking the developed river-lake connectivity and frequent exchange of pollutants into consideration, we put forward a calculation method of water environment carrying capacity (WECC) for river network based on multiple objectives of water quality reaching standard in river environment function zones and control sections, concentration profile constraint of sewage outlet. According to the proposed method, we calculated the watershed WECC, assigned to each control unit, and quantitatively analyzed the reductions and reduction rate of pollutants under the condition of total amount of each pollutant of control unit reach water quality standards. The results showed that: The pollution loads of each pollutant in Zhushan Bay watershed were greater than WECC. The reduction of COD, NH3-N, TN and TP is 834.4 tons, 226.1 tons, 724.8 tons and 108.9 tons, and the reduction rate of COD, NH3-N, TN and TP is 13.8%, 36.5%, 55.2% and 73.4%, respectively. This paper plays a guiding role in the research of total amount control of river network in Zhushan Bay watershed, and provides important references for total amount control of similar river-lake region.

APA, Harvard, Vancouver, ISO, and other styles

9

Nadai, R., and R. Henry. "Temporary fragmentation of a marginal lake and its effects on zooplankton community structure and organization." Brazilian Journal of Biology 69, no. 3 (August 2009): 819–35. http://dx.doi.org/10.1590/s1519-69842009000400009.

Full text

Abstract:

A river lateral lake (Coqueiral Lake marginal to Paranapanema River in its mouth zone into Jurumirim Reservoir, São Paulo, Brazil) presented fragmentation into four small isolated bodies of water during a prolonged drought period, disrupting the link with the river. The aim of this work was to compare the temporal modifications on zooplankton community structure (total abundance, species richness, and diversity) in the four water bodies. Zooplankton samplings and abiotic factor measurements were made in two periods - during isolation phase of the lake in relation to river and after re-establishment of hydrologic connectivity. A concentration effect on zooplankton abundance was recorded with drought progression, but without significant modifications in species richness and diversity. When the river inundation pulse occurred, a reduction in total zooplankton density was observed due to the dilution effect and a significant increase in species richness and diversity was recorded. Lateral water influx from the river to the lacustrine environment acts as a temporary disturbance factor on the zooplankton community structure. Zooplankton species composition presented some modifications between the two periods. Zooplankton organism drift in water from the river to the lake, removal of individuals from the aquatic macrophytes, and eclosion of resting eggs from sediment are probable factors that can increase zooplankton species richness immediately after lateral pulse inundation with water by the river.

APA, Harvard, Vancouver, ISO, and other styles

10

Granado-Lorencio, Carlos, Alejandra Gulfo, Frank Alvarez, Luz Fernanda Jiménez-Segura, Juan David Carvajal-Quintero, and Andrés Hernández-Serna. "Fish assemblages in floodplain lakes in a Neotropical river during the wet season (Magdalena River, Colombia)." Journal of Tropical Ecology 28, no. 3 (April 12, 2012): 271–79. http://dx.doi.org/10.1017/s0266467412000181.

Full text

Abstract:

Abstract:A number of studies have pointed out that abiotic factors and recolonization dynamics appear to be more important than biotic interactions in structuring river–fish assemblages. In this paper, we studied the fish assemblages in 27 floodplain lakes, with perennial connection to the river, in the middle section of the Magdalena River (Colombia), to examine spatial pattern in freshwater fish diversity in relation to some environmental parameters. Our objective was to examine relationships between floodplain-lake fish communities and environmental variables associated with lake morphology, water chemistry and river–floodplain connectivity in a large river–floodplain ecosystem. During the study, a total of 18 237 fish were caught from 50 species (regional richness; 17 were migrants and 33 residents). In the present study, the most diverse order was Characiformes with 20 species, followed by Siluriformes, with 19 species. Characidae and Loricaridae were the richest families. The range of species richness (local richness) varied between five and 39 species. Similarity of local assemblages (using the presence–absence data) depends on the distance between lakes. A positive relationship was observed between the Ln of the total abundance of each species and the number of lakes where they were found. Out of all the environmental parameters taken in the lakes, only the size (Log Area) and relative perimeter length are significantly related to local assemblage species richness. It has not been possible to demonstrate that the connectivity (distance) from lakes to the main river can be considered a predictor of the local richness.

APA, Harvard, Vancouver, ISO, and other styles

11

Neuenhoff, Rachel D., Jonah L. Withers, Lori A. Davis, Nicholas D. Markley, Stephanie Dowell, Meredith L. Bartron, Dimitry Gorsky, and John A. Sweka. "Discovery of an Undocumented Lake Sturgeon Spawning Site in the Headwaters of the Niagara River." Journal of Fish and Wildlife Management 9, no. 1 (February 19, 2018): 266–73. http://dx.doi.org/10.3996/102017-jfwm-087.

Full text

Abstract:

Abstract Information about spawning fish is important to stock-assessment data needs (i.e., recruitment and fecundity) and management (i.e., habitat connectivity and protection). In Lake Erie, information about Lake Sturgeon Acipenser fulvescens early-life history is available for the Detroit River and Lake St. Clair system in the western basin, but fisheries biologists know comparatively little about Lake Sturgeon in the eastern basin. Although researchers have summarized historical spawning areas, no known natural Lake Sturgeon spawning site is described in Lake Erie proper. Researchers documented a remnant population of reproductively mature Lake Sturgeon near the headwaters of the Niagara River in eastern Lake Erie in 2011. Researchers hypothesized that a spawning site was likely in the immediate vicinity of the Niagara River headwaters near Buffalo Harbor, New York; however, its exact location was unknown. We attempted to locate spawning sites near the confluence of the Niagara River using egg traps at three potential spawning sites. We identified Lake Sturgeon eggs at one of these sites using morphological and genetic techniques. Lake Sturgeon eggs collected on one sampling trip began to emerge when placed in preservative, confirming that eggs deposited at this site are fertilized and viable, and that the area supports viable embryos. This discovery fills data gaps in the early-life history for this population, which has domestic and international management implications with respect to proposed recovery targets, stock assessment models, habitat remediation efforts, and status determinations of a protected species in a geographic region designated as an Area of Concern by the International Joint Commission.

APA, Harvard, Vancouver, ISO, and other styles

12

Aprile, Fabio, and Assad José Darwich. "Nutrients and water-forest interactions in an Amazon floodplain lake: an ecological approach." Acta Limnologica Brasiliensia 25, no. 2 (June 2013): 169–82. http://dx.doi.org/10.1590/s2179-975x2013000200008.

Full text

Abstract:

AIM: Catalão Lake was surveyed between 2002 and 2011 with the aim of studying seasonality of the flow of nutrients between water, sediment and aquatic macrophytes. The role of the flood pulse and the ecological mechanisms influencing the forest-water interactions in the Amazon floodplain were discussed; METHODS: Catalão Lake is located in the Amazon floodplain (03º 08'-03º 14' S and 59º 53'-59º 58' W), near the confluence of the Solimões and Negro rivers, approximately 3000 m from the port of CEASA, near the city of Manaus. It is considered to be a mixed water lake because it receives white waters rich in sediments from the Solimões River and black waters with humic substances from the Negro River. Physical and chemical parameters including C, N and P levels were studied in the diverse compartments, and a flux model was developed; RESULTS: There is a strong nutritional (C, N and P) and ionic (Na+, K+, Ca2+, Mg2+, Cl-, HCO3-, CO3(2-) and SO4(2-)) flow from the rivers to the lake. The highest C:N:P ratio was found in Paspalum repens which, during periods of drought, played an important role in releaseing nutrients into the water. The connectivity of the lake with the rivers ensured a high variation of transparency and nutrient content, fundamental for biological processes. A model of the nutrient flow, interaction and connectivity between ecosystems, and the influence of the hydrological cycle has been developed.

APA, Harvard, Vancouver, ISO, and other styles

13

MacKinnon, Brett D., Jay Sagin, Helen M. Baulch, Karl-Erich Lindenschmidt, and Timothy D. Jardine. "Influence of hydrological connectivity on winter limnology in floodplain lakes of the Saskatchewan River Delta, Saskatchewan." Canadian Journal of Fisheries and Aquatic Sciences 73, no. 1 (January 2016): 140–52. http://dx.doi.org/10.1139/cjfas-2015-0210.

Full text

Abstract:

Globally, hydrological connectivity between rivers and their floodplains has been reduced by river flow management and land transformation. The Saskatchewan River Delta is North America’s largest inland delta and a hub for fish and fur production. To determine the influence of connectivity on limnology within this northern floodplain, water chemistry and stable isotopes (δ18O and δ2H) were analyzed during the winter of 2014 in 26 shallow lakes along a hydrological gradient. A total of five lake connectivity categories were determined by optical remote sensing imagary of surface water coverage area from years of varying flood intensities. Accuracy of categories was verified by degree of 18O and 2H enrichment within lakes. Both isotopes showed marked successional enrichment between connectivity categories, with more isolated lakes exhibiting greater enrichment. Water chemistry in lakes with greater connectivity to the main channel were characterized by higher pH, dissolved oxygen, nitrates, and sulfates and lower total nitrogen, total phosphorus, and ammonium compared with more isolated lakes. These findings illustrate how connectivity influences water chemistry in northern floodplain lakes and how it might determine the suitability of these lakes as winter refuge for fishes. Additionally, our study provides supporting evidence for the effective use of optical remote sensing imagery, an inexpensive and accessible source of data for researchers, when determining connectivity characteristics of large northern floodplain systems. Additionally, this study provides further evidence that the inundation of floodplain lakes by river water during peak discharge has an impact on the conditions within the lakes long into the winter ice-cover season. Understanding the year-round influence of river–floodplain connection is imperative for assessing potential impacts of climate change and future water regulation on such ecosystems.

APA, Harvard, Vancouver, ISO, and other styles

14

Enders, Eva C., Colin Charles, Douglas A. Watkinson, Colin Kovachik, Douglas R. Leroux, Henry Hansen, and Mark A. Pegg. "Analysing Habitat Connectivity and Home Ranges of Bigmouth Buffalo and Channel Catfish Using a Large-Scale Acoustic Receiver Network." Sustainability 11, no. 11 (May 30, 2019): 3051. http://dx.doi.org/10.3390/su11113051.

Full text

Abstract:

The determination if fish movement of potadromous species is impeded in a river system is often difficult, particularly when timing and extent of movements are unknown. Furthermore, evaluating river connectivity poses additional challenges. Here, we used large-scale, long-term fish movement to study and identify anthropogenic barriers to movements in the Lake Winnipeg basin including the Red, Winnipeg, and Assiniboine rivers. In the frame of the project, 80 Bigmouth Buffalo (Ictiobus cyprinellus) and 161 Channel Catfish (Ictalurus punctatus) were tagged with acoustic transmitters. Individual fish were detected with an acoustic telemetry network. Movements were subsequently analyzed using a continuous-time Markov model (CTMM). The study demonstrated large home ranges in the Lake Winnipeg basin and evidence of frequent transborder movements between Canada and the United States. The study also highlighted successful downstream fish passage at some barriers, whereas some barriers limited or completely blocked upstream movement. This biological knowledge on fish movements in the Lake Winnipeg basin highlights the need for fish passage solutions at different obstructions.

APA, Harvard, Vancouver, ISO, and other styles

15

Napiórkowski, Bąkowska, Mrozińska, Szymańska, Kolarova, and Obolewski. "The Effect of Hydrological Connectivity on the Zooplankton Structure in Floodplain Lakes of a Regulated Large River (the Lower Vistula, Poland)." Water 11, no. 9 (September 14, 2019): 1924. http://dx.doi.org/10.3390/w11091924.

Full text

Abstract:

The zooplankton community structure and diversity were analysed against the gradient of floodplain lakes connectivity and water level under different flood-pulse dynamics in the Vistula River. The lakes differed in terms of hydrology, among others in the degree/type of their connection with the river (permanent, temporary and no connection). The study was conducted during the growing seasons in the years 2006–2013 and involved the lower Vistula River and three floodplain lakes: isolated, transitional and connected. Water samples were collected biweekly from April to September. Zooplankton was the most diverse and abundant in the transitional lake (the highest Shannon α-diversity index H’ and Pielou’s evenness index J’). The gentle washing of the lakes might have stimulated the development of zooplankton in accordance with the Intermediate Disturbance Hypothesis. The diversity and density of zooplankton were higher in the connected lake compared to the isolated one. We confirmed the hypothesis that zooplankton should be more abundant and diverse in floodplain lakes connected with the river (or transitional) than in isolated ones. Zooplankton analyses indicated that hydrological conditions (flood-pulse regime) contributed most substantially to zooplankton diversity and density in the floodplain lakes of the lower Vistula valley.

APA, Harvard, Vancouver, ISO, and other styles

16

Daga, Vanessa Salete, Tatiane Mary Gogola, Paulo Vanderlei Sanches, Gilmar Baumgartner, Dirceu Baumgartner, Pitágoras Augusto Piana, Éder André Gubiani, and Rosilene Luciana Delariva. "Fish larvae assemblages in two floodplain lakes with different degrees of connection to the Paraná River, Brazil." Neotropical Ichthyology 7, no. 3 (September 2009): 429–38. http://dx.doi.org/10.1590/s1679-62252009000300010.

Full text

Abstract:

The objective of this study was to assess the abundance, attributes of assemblages, and spatial and temporal distributions of fish larvae and their relationships with some abiotic variables in two floodplain lakes with different degrees of connection to the Paraná River in Ilha Grande National Park, PR, Brazil. Four sampling sites were chosen, two in each floodplain lake. Night samples were taken with plankton nets during three spawning seasons (monthly, from October to March) from 2001 to 2005. The highest diversity and abundance were recorded at Saraiva Lake, with 25 taxa being identified. In Xambrê Lake, only sedentary species were captured, and the most abundant species were Plagioscion squamosissimus and Hypophthalmus edentatus. The greatest abundance of larvae was found in the second spawning season. In the Saraiva Lake, the most abundant species were Moenkhausia aff. intermedia, Hyphessobrycon sp., and Bryconamericus stramineus, but larvae of known migratory species were also documented. In this lake, the greatest abundance of larvae was found in the third spawning. Larvae abundance was influenced by water temperature and conductivity. The high diversity and abundance recorded in Saraiva Lake may be a result of its connectivity with the Paraná River, and the low diversity and abundance observed at Xambrê Lake are likely due to its isolation from the river. This work shows the importance of these lagoons for fish development, for both sedentary and migratory species. Both lagoons may be considered to have extreme ecological importance and they are also extremely susceptible to impacts, so any careless disturbance may cause irreversible damage.

APA, Harvard, Vancouver, ISO, and other styles

17

Lyon, Jarod, Ivor Stuart, David Ramsey, and Justin O'Mahony. "The effect of water level on lateral movements of fish between river and off-channel habitats and implications for management." Marine and Freshwater Research 61, no. 3 (2010): 271. http://dx.doi.org/10.1071/mf08246.

Full text

Abstract:

Off-channel habitats, such as wetlands and backwaters, are important for the productivity of river systems and for many species of native fish. This study aimed to investigate the fish community, timing and cues that stimulated movement to and from off-channel habitats in the highly regulated Lake Hume to Lake Mulwala reach of the Murray River, south-eastern Australia. In 2004–05, 193 712 fish were collected moving bi-directionally between a 50-km section of the Murray River and several off-channel habitats. Lateral fish movements approximated water level fluctuations. Generally as water levels rose, fish left the main river channel and moved into newly flooded off-channel habitats; there was bi-directional movement as water levels peaked; on falling levels fish moved back to the permanent riverine habitats. Fish previously classified as ‘wetland specialists’, such as carp gudgeons (Hypseleotris spp.), have a more flexible movement and life-history strategy including riverine habitation. The high degree of lateral movement indicates the importance of habitat connectivity for the small-bodied fish community. Wetlands adjacent to the Murray River are becoming increasingly regulated by small weirs and ensuring lateral fish movement will be important in maintaining riverine-wetland biodiversity.

APA, Harvard, Vancouver, ISO, and other styles

18

Yi, Yujun, Zhifeng Yang, and Shanghong Zhang. "Ecological influence of dam construction and river-lake connectivity on migration fish habitat in the Yangtze River basin, China." Procedia Environmental Sciences 2 (2010): 1942–54. http://dx.doi.org/10.1016/j.proenv.2010.10.207.

Full text

APA, Harvard, Vancouver, ISO, and other styles

19

Paula-Bueno, M. C., and A. A. Fonseca-Gessner. "Coleoptera associated with macrophytes of the genus Salvinia in four oxbow lakes in two river basins in southeast Brazil." Brazilian Journal of Biology 75, no. 4 suppl 1 (November 24, 2015): 108–18. http://dx.doi.org/10.1590/1519-6984.06914.

Full text

Abstract:

Abstract Macrophytes in oxbow lakes represent an important substrate for the Coleoptera. Two oxbow lakes the Rio Paranapanema were studied and the other two Rio Mogi-Guaçu, in the State de São Paulo, Brasil. In this study, there is greater similarity between the communities of Coleoptera of lakes greater connectivity with the main river channel or the difference in the species of Salvinia collected in the lakes studied interferes Coleoptera fauna that uses as substrate. A total of 9,222 specimens of Coleoptera were collected and identified in 10 families and 40 genera. The analysis MDS for abundance of Coleoptera showed the grouping of the oxbow lakes the Paranapanema River and a distancing the oxbow lakes the Mogi-Guaçu. The PERMANOVA test did not reveal any difference in the fauna between the wet and dry periods. It was concluded that the connectivity between river and lake is not decisive for the richness and abundance of aquatic fauna of Coleoptera. Therefore, the richness and abundance of aquatic Coleoptera associated vary with the species of Salvinia used as substrate.

APA, Harvard, Vancouver, ISO, and other styles

20

Bortolini, Jascieli Carla, Vânia Mara Bovo-Scomparin, Aline Caroline Magro de Paula, Geovani Arnhold Moresco, Larissa Mozini Reis, Susicley Jati, and Luzia Cleide Rodrigues. "Composition and species richness phytoplankton in a subtropical floodplain lake: a long-term study." Acta Limnologica Brasiliensia 26, no. 3 (September 2014): 296–305. http://dx.doi.org/10.1590/s2179-975x2014000300009.

Full text

Abstract:

AIM: Phytoplankton species diversity in floodplain lakes is influenced by different conditions imposed by the hydrosedimentological regime of the main channel. This study evaluated the predictors of composition and species richness phytoplankton in the long-term scale, in a floodplain lake directly connected to the Paraná River. We hypothesized that species richness of the floodplain lake is directly related to the degree of connectivity with the main channel. METHODS: Quarterly samplings were conducted between February 2000 and March 2013 (except in 2001 and 2003), under the water surface of the pelagic zone of the lake. Data were analyzed with Spearman correlation, PCA, DCA, ANOVA and regression analysis. RESULTS: We identified 397 taxa with high contribution of rare species (72%). Chlorophyceans and diatoms were the most frequent groups. There was a trend of increasing of diatoms and decrease of cyanobacteria. The DCA showed differences in phytoplankton composition. The highest mean richness values were found in years with high number of days under potamophase. Significant differences between years were detected for total species richness and first axis of DCA. Regression analysis indicated that the predictors of species richness were Zeu and Zmax. CONCLUSION: The species richness phytoplankton of the floodplain lake is directly related to the level of connectivity with the main channel.

APA, Harvard, Vancouver, ISO, and other styles

21

Liao, Dawei, Zhonghe Pang, Weiyang Xiao, Yinlei Hao, Jie Du, Xiaobo Yang, and Geng Sun. "Constraining the Water Cycle Model of an Important Karstic Catchment in Southeast Tibetan Plateau Using Isotopic Tracers (2H, 18O, 3H, 222Rn)." Water 12, no. 12 (November 24, 2020): 3306. http://dx.doi.org/10.3390/w12123306.

Full text

Abstract:

Understanding the connectivity between surface water and groundwater is key to sound geo-hazard prevention and mitigation in a waterscape such as the Jiuzhaigou Natural World Heritage Site in the southeast Tibetan Plateau, China. In this study, we used environmental isotope tracers (2H, 18O 3H, and 222Rn) to constrain a water cycle model including confirming hydrological pathways, connectivity, and water source identification in the Jiuzhaigou catchments. We established the local meteoric water line (LMWL) based on the weekly precipitation isotope sampling of a precipitation station. We systematically collected water samples from various water bodies in the study area to design the local water cycle model. The regional water level and discharge changes at one month after the earthquake indicated that there was a hydraulic connection underground across the local water divide between the Rize (RZ) river in the west and Zechawa (ZCW) lake in the east by the δ18O and δ2H measurements. We employed an end-member mixing model to identify and quantify Jiuzhaigou runoff-generating sources and their contributions, and we found that the average contributions of precipitation and groundwater to the surface runoff in the catchments are about 30% and 70%, respectively. The two branches of the Shuzheng (SZ) trunk were recharged by 62 ± 19% from the ZCW lake and 38 ± 19% from the RZ river, which was consistent with the fractions calculated by the actual discharge volume. 222Rn mass balance analyses were employed to estimate the water exchange between groundwater and river, which further confirmed this estimate. 222Rn concentrations and 3H contents showed that the groundwater had a short residence time and it was moderate precipitation, thought the contribution of groundwater to the river was 70%, according to the different tracers. A three-dimensional conceptual model of the water cycle that integrated the regional hydrological and geological conditions was established for the catchments.

APA, Harvard, Vancouver, ISO, and other styles

22

Bonecker, CC, ASM Aoyagui, and RM Santos. "The impact of impoundment on the rotifer communities in two tropical floodplain environments: interannual pulse variations." Brazilian Journal of Biology 69, no. 2 suppl (June 2009): 529–37. http://dx.doi.org/10.1590/s1519-69842009000300008.

Full text

Abstract:

Hydrological pulses are the main factor regulating the structure of biological communities in floodplains. Reservoirs above this ecosystem change the environment's dynamics and the community's biodiversity. This study evaluated the structure and stability of the rotifer community in response to changes in hydrological pulses after the Porto Primavera impoundment in the Upper Paraná River floodplain. The community was studied in a river and in a floodplain lake downstream of the dam over a four-year period before and after the impoundment. A decrease in species richness and abundance was observed soon after the impoundment, followed by an increase in these attributes and in specific diversity when the hydrometric level of the Paraná River rose and, consequently, increased the connectivity between the floodplain environments. Conochilus coenobasis, Filinia longiseta, Keratella cochlearis, Lecane proiecta and Polyarthra dolichoptera persisted throughout the study and contributed to community stability (the maintenance of rank in species abundance over time), which was high in the floodplain lake, mainly after the impoundment. Reductions in the frequency, intensity and amplitude of potamophase pulses after the impoundment led to the decrease in species richness and the increases in abundance, community stability, and species diversity, which determine community resilience.

APA, Harvard, Vancouver, ISO, and other styles

23

Hartz, Sandra Maria, Elise Amador Rocha, Fernanda Thiesen Brum, André Luís Luza, Taís de Fátima Ramos Guimarães, and Fernando Gertum Becker. "Influences of the area, shape and connectivity of coastal lakes on the taxonomic and functional diversity of fish communities in Southern Brazil." Zoologia 36 (June 27, 2019): 1–12. http://dx.doi.org/10.3897/zoologia.36.e23539.

Full text

Abstract:

In this study we investigated the influence of landscape variables on the alpha taxonomic and functional diversity of fish communities in coastal lakes. We built an analytical framework that included possible causal connections among variables, which we analyzed using path analysis. We obtained landscape metrics for the area, shape and connectivity (estuary connectivity and primary connectivity to neighboring lakes) of 37 coastal lakes in the Tramandaí River Basin. We collected fish data from 49 species using standardized sampling with gillnets and obtained a set of traits related to dispersal abilities and food acquisition. The model that best explained the taxonomic diversity and functional richness took into account the shape of the lakes. Functional richness was also explained by estuary connectivity. Functional evenness and dispersion were not predicted by area or connectivity, but they were influenced by the abundant freshwater species. This indicates that all lakes support most of the regional functional diversity. The results highlight the importance of the dispersal process in this lake system and allow the conclusion that considering multiple diversity dimensions can aid the conservation of local and regional fish communities.

APA, Harvard, Vancouver, ISO, and other styles

24

Wang, Danyang, Zhongwu Li, Zhiwei Li, Baozhu Pan, Shimin Tian, and Xiaodong Nie. "Environmental gradient relative to oxbow lake-meandering river connectivity in Zoige Basin of the Tibetan Plateau." Ecological Engineering 156 (September 2020): 105983. http://dx.doi.org/10.1016/j.ecoleng.2020.105983.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Stoffels, R. J., K. R. Clarke, R. A. Rehwinkel, and B. J. McCarthy. "Response of a floodplain fish community to river-floodplain connectivity: natural versus managed reconnection." Canadian Journal of Fisheries and Aquatic Sciences 71, no. 2 (February 2014): 236–45. http://dx.doi.org/10.1139/cjfas-2013-0042.

Full text

Abstract:

To restore lateral connectivity in highly regulated river-floodplain systems, it has become necessary to implement localized, “managed” connection flows, made possible using floodplain irrigation infrastructure. These managed flows contrast with “natural”, large-scale, overbank flood pulses. We compared the effects of a managed and a natural connection event on (i) the composition of the large-bodied fish community and (ii) the structure of an endangered catfish population of a large floodplain lake. The change in community composition following the managed connection was not greater than that exhibited between seasons or years during disconnection. By contrast, the change in fish community structure following the natural connection was much larger than that attributed to background, within- and between-year variability during disconnection. Catfish population structure only changed significantly following the natural flood. While the natural flood increased various population rates of native fishes, it also increased those of non-native carp, a pest species. To have a positive influence on native biodiversity, environmental flows may need to be delivered to floodplains in a way that simulates the properties of natural flood pulses. A challenge, however, will be managing river-floodplain connectivity to benefit native more than non-native species.

APA, Harvard, Vancouver, ISO, and other styles

26

Kalcheva, Hristina, Mária Dinka, Edit Ágoston-Szabó, Árpád Berczik, Roumen Kalchev, Nikolett Tarjanyi, and Anita Kiss. "Bacterioplankton from Two Hungarian Danube River Wetlands (Beda-Karapancsa, Danube-Drava National Park) and its Relations to Environmental Variables." Transylvanian Review of Systematical and Ecological Research 18, no. 1 (April 1, 2016): 1–12. http://dx.doi.org/10.1515/trser-2015-0075.

Full text

Abstract:

AbstractSeasonal and spatial distribution of bacterioplankton from two Hungarian oxbow lake type wetlands, Mocskos-Danube and Riha, was studied. They were both covered by macrophytes and they had different hydrological connectivity to the Danube. The six sampling campaigns from April to October 2014 included parallel samples from the Danube River at Mohács, Hungary. Bacterial abundance was the highest in spring and in Mocskos-Danube, followed by Mohács and Riha. Positive relationships existed between bacterioplankton and temperature on one hand and suspended solids, pH, PO4-P and chl-a on the other. Negative correlations were with DOC, dissolved oxygen and NH4-N.

APA, Harvard, Vancouver, ISO, and other styles

27

Carvalho, Débora A., Verónica Williner, Federico Giri, Carina Vaccari, and Pablo A. Collins. "Quantitative food webs and invertebrate assemblages of a large River: a spatiotemporal approach in floodplain shallow lakes." Marine and Freshwater Research 68, no. 2 (2017): 293. http://dx.doi.org/10.1071/mf15095.

Full text

Abstract:

To test the hypothesis that the hydrological regime of large Rivers affects the structure of invertebrate communities and food webs in floodplain lakes, we studied invertebrate assemblages and stomach contents of fish and decapods in two shallow lakes in the Paraná River floodplain, Argentina, with different connectivity (indirect and permanent, IPC; direct and temporal, DTC) to the fluvial system over three hydroperiods (flooding, transition, drought). Invertebrate assemblages exhibited temporal variation, with higher dissimilarity during the drought phase. However, zooplanktonic and pleustonic attributes varied spatiotemporally, and were better explained by other environmental variables. The food webs in the two lakes differed, with higher connectance and fewer predators in the DTC Lake. In general, the use of trophic resources by fish and decapods reflected the local and abundant resources in the system. The persistence of communities in floodplain lakes with temporary connectivity to the river may relate to the foraging decisions of consumers to buffer environmental fluctuations. The consumption of abundant resources highlighted the importance of autochthonous inputs into floodplain lakes. However, the variation in food supply as a key factor governing food-web structure and stability should be further investigated.

APA, Harvard, Vancouver, ISO, and other styles

28

Napiórkowski, Paweł, and Teresa Napiórkowska. "Limnophase versus potamophase: how hydrological connectivity affects the zooplankton community in an oxbow lake (Vistula River, Poland)." Annales de Limnologie - International Journal of Limnology 53 (2017): 143–51. http://dx.doi.org/10.1051/limn/2017001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Meattey, D. E., S. R. McWilliams, P. W. C. Paton, C. Lepage, S. G. Gilliland, L. Savoy, G. H. Olsen, and J. E. Osenkowski. "Annual cycle of White-winged Scoters (Melanitta fusca) in eastern North America: migratory phenology, population delineation, and connectivity." Canadian Journal of Zoology 96, no. 12 (December 2018): 1353–65. http://dx.doi.org/10.1139/cjz-2018-0121.

Full text

Abstract:

Understanding full annual cycle movements of long-distance migrants is essential for delineating populations, assessing connectivity, evaluating crossover effects between life stages, and informing management strategies for vulnerable or declining species. We used implanted satellite transmitters to track up to 2 years of annual cycle movements of 52 adult female White-winged Scoters (Melanitta fusca (Linnaeus, 1758)) captured in the eastern United States and Canada. We used these data to document annual cycle phenology; delineate migration routes; identify primary areas used during winter, stopover, breeding, and molt; and assess the strength of migratory connectivity and spatial population structure. Most White-winged Scoters wintered along the Atlantic coast from Nova Scotia to southern New England, with some on Lake Ontario. White-winged Scoters followed four migration routes to breeding areas from Quebec to the Northwest Territories. Principal postbreeding molting areas were in James Bay and the St. Lawrence River estuary. Migration phenology was synchronous regardless of winter or breeding origin. Cluster analyses delineated two primary breeding areas: one molting area and one wintering area. White-winged Scoters demonstrated overall weak to moderate connectivity among life stages, with molting to wintering connectivity the strongest. Thus, White-winged Scoters that winter in eastern North America appear to constitute a single continuous population.

APA, Harvard, Vancouver, ISO, and other styles

30

Scott, Ryan W., Suzanne E. Tank, Xiaowa Wang, and Roberto Quinlan. "Are different benthic communities in Arctic delta lakes distinguishable along a hydrological connectivity gradient using a rapid bioassessment approach?" Arctic Science 6, no. 4 (December 1, 2020): 463–87. http://dx.doi.org/10.1139/as-2019-0024.

Full text

Abstract:

Aquatic habitats in the Canadian Arctic are expected to come under increasing stress due to projected effects of climate change. There is a need for community-based biomonitoring programs to observe and understand the effects of these stressors on the environment. Here we present results from a 5 year annual sampling program of benthic invertebrates from lakes in the Mackenzie Delta, Northwest Territories, using a rapid bioassessment protocol. Connectivity between the deltaic lakes and main channels is a major driver of lake function and is expected to be substantially impacted by climate change. Lakes were selected along a gradient of connectivity based on sill elevation above the river. Using multivariate analyses of community structure, we determined that benthic assemblages responded to differences in connection time among lakes. This response was detected using a coarse taxonomic level that could be applied by community groups or volunteers but was stronger when invertebrates were identified to the family and genus levels. A secondary gradient was observed that corresponded to productivity gradients in lakes that are isolated from the river during summer. We show that benthic assemblages have potential use as sensitive indicators of climate-mediated changes to the hydrology of lakes in the Mackenzie Delta.

APA, Harvard, Vancouver, ISO, and other styles

31

Dou, Ming, Lu Yu, Meng Jin, and Yan Zhang. "Correlation analysis and threshold value research on the form and function indexes of an urban interconnected river system network." Water Supply 16, no. 6 (June 20, 2016): 1776–86. http://dx.doi.org/10.2166/ws.2016.103.

Full text

Abstract:

As urbanization has accelerated, the form of river and lake systems has changed greatly in cities, which has caused variations in the functioning of the interconnected river system network (IRSN). To quantitatively evaluate the influence of the urbanization process on IRSN, the form index system and function index system were established in this study. The form index system involved eight indexes, and the function index system included 18 indexes. We also used statistical methods to analyze the correlations between the form indexes and the function indexes of the IRSN. Multiple linear regression equations were established between the variations in the IRSN form indexes and the function indexes. Finally, we determined the threshold values of the IRSN form indexes that can meet Zhengzhou City's future development demands for water function. The threshold value for the drainage network density is between 0.32 and 0.33; the threshold value for the node connection rate is between 1.54 and 2; the threshold value for the degree of connectivity between river systems ranges from 0.55 to 0.77; and the threshold value for circuitry of the river ranges from 0.40 to 0.60. Validation shows that these values are reasonable.

APA, Harvard, Vancouver, ISO, and other styles

32

Ren, Peng, Hu He, Yiqing Song, Fei Cheng, and Songguang Xie. "The spatial pattern of larval fish assemblages in the lower reach of the Yangtze River: potential influences of river–lake connectivity and tidal intrusion." Hydrobiologia 766, no. 1 (September 7, 2015): 365–79. http://dx.doi.org/10.1007/s10750-015-2471-2.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

García, Ivis, and Jeni Crookston. "Connectivity and Usership of Two Types of Multi-Modal Transportation Network: A Regional Trail and a Transit-Oriented Commercial Corridor." Urban Science 3, no. 1 (March 15, 2019): 34. http://dx.doi.org/10.3390/urbansci3010034.

Full text

Abstract:

This article explores concepts related to connectivity and usership of the Jordan River Parkway Trail (JRPT) and the North Temple corridor—two locations or nodes that link together in a larger transportation network along the west side of Salt Lake City, Utah, a low-income, racially and ethnically diverse area. The JRPT is a multi-use trail providing regional connectivity for bicycles and pedestrians. It intersects North Temple, a transit development corridor accommodating automobiles, light rail, buses, bicycles, and pedestrians. Although the purposes of each corridor differ, one being recreational and one being commercial, the modes of transportation for each corridor overlap through active transportation—that is, biking and walking. The questions that drive this paper are: (1) How are these two neighborhood assets are connected and form a larger transportation network? and, (2) How can connectivity and usership be improved? The idea of increasing the utilization of the JRPT through increasing destinations along North Temple and vice versa is explored. Community feedback was gathered through a survey which was distributed to 299 residents who live less than a mile from each subnetwork. Extracted from the responses were key aspects of connectivity, accessibility, and the purposes of each corridor for the community as a whole to understand how they are connected and how they affect each other. More broadly, urban policy recommendations that increase active transportation connectivity and usership of two sets of links—that is, regional trails and transit-oriented corridors such as the JRPT and the North Temple corridor are described.

APA, Harvard, Vancouver, ISO, and other styles

34

Liu, Yeling, Baoshan Cui, Jizeng Du, Qing Wang, Shuling Yu, and Wei Yang. "A method for evaluating the longitudinal functional connectivity of a river–lake–marsh system and its application in China." Hydrological Processes 34, no. 26 (October 30, 2020): 5278–97. http://dx.doi.org/10.1002/hyp.13946.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Huziy, O., and L. Sushama. "Impact of lake–river connectivity and interflow on the Canadian RCM simulated regional climate and hydrology for Northeast Canada." Climate Dynamics 48, no. 3-4 (April 5, 2016): 709–25. http://dx.doi.org/10.1007/s00382-016-3104-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

Jiang, Tao, Hongbo Liu, Mingjie Lu, Tingting Chen, and Jian Yang. "A Possible Connectivity among Estuarine Tapertail Anchovy (Coilia nasus) Populations in the Yangtze River, Yellow Sea, and Poyang Lake." Estuaries and Coasts 39, no. 6 (May 13, 2016): 1762–68. http://dx.doi.org/10.1007/s12237-016-0107-z.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Gresswell, Bob, and Kris Homel. "Evaluating the Movement Patterns of Snake River Finespotted Cutthroat Trout in the Snake River Below Jackson Lake Dam, Grand Teton National Park." UW National Parks Service Research Station Annual Reports 31 (January 1, 2008): 23–28. http://dx.doi.org/10.13001/uwnpsrc.2008.3693.

Full text

Abstract:

The Snake River finespotted cutthroat trout Oncorhynchus clarkii behnkei has been formally recognized as a subspecies of cutthroat trout Oncorhynchus clarkii, but it is more generally perceived as a morphologically divergent ecotype of the more broadly distributed Yellowstone cutthroat trout Oncorhynchus clarkii bouvieri. This large-river cutthroat trout has persisted in the Snake River downstream of Jackson Lake Dam through a century of flow regulation. Although there is a popular sport fishery focused on this native trout, spawning and distribution patterns throughout its range are poorly understood. Consequently, it is difficult to predict how future disturbances (e.g., climate change or an increase in the prevalence of nonnative species) may affect behavior or persistence. In 2008, radio telemetry techniques were used to identify spawning patterns of cutthroat trout. From August-October, 2007, 49 radio telemetry tags were implanted into cutthroat trout in the Snake River, Grand Teton National Park and fish movements were tracked during the spawning season. Significant temporal and spatial variability in spawning behavior was observed (n = 22 fish with distinct spawning migrations). The earliest spawning migration began at the end of April, and the last spawning migration was initiated in mid-July. Spawning was observed in the mainstem and side channels of the Snake River, several tributaries, and three major spring creek complexes. Although the majority of this spawning activity occurred within 40 km of the respective original tagging location, three fish migrated to spawning areas 75-100 river kilometers away. Ultimately, developing a comprehensive understanding of the behavioral variability of Snake River finespotted cutthroat trout and the habitat connectivity required to complete the life cycle will provide new insights into the management of this portion of the Snake River.

APA, Harvard, Vancouver, ISO, and other styles

38

Luo, Mingke, Hui Yu, Qian Liu, Wei Lan, Qiaoru Ye, Yuan Niu, and Yong Niu. "Effect of river-lake connectivity on heavy metal diffusion and source identification of heavy metals in the middle and lower reaches of the Yangtze River." Journal of Hazardous Materials 416 (August 2021): 125818. http://dx.doi.org/10.1016/j.jhazmat.2021.125818.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

Muniz, Claumir Cesar, Ernandes Sobreira Oliveira Junior, Ana Paula Dalbem Barbosa, and Alberto Carvalho Peret. "Gill nets selectivity determine the fish community in connected oxbow lakes of the Pantanal." Revista Ibero-Americana de Ciências Ambientais 10, no. 5 (October 12, 2019): 295–306. http://dx.doi.org/10.6008/cbpc2179-6858.2019.005.0026.

Full text

Abstract:

Pantanal is known because of the amplitude on the water dynamics, with a pronounced flood and dry seasons. The water expansion and retraction reflect in the hydric connectivity between river and bays, resembling the environments and causing distinct characteristics of water quality. In order to capture fish in these environments the gill nets are used. These passive devices allow the capture of a certain length category according to the meshes size, avoiding the capture of fish that are too small or too large, characterizing their selectivity. The present study aims to characterize the ichthyofauna of an oxbow lake system, as well as to establish its relationship with the seasonal, limnology and structural alterations of fish, seeking to understand the spatial and temporal distribution characteristics of the community. Three points of two side lakes were sampled using a set of gill nets with 2, 3, 4 and 5 cm between knots, allocated in parallel columns at every 10 meters in the lakes. The samples were performed during the day and during the night, where the nets were left in the water for 6 hours. Concomitantly to the fish sampling, the limnologic variables were obtained using a portable field equipment and Secchi disk. The results showed that the limnological variables changes according to the hydric seasons. These changes associated to the connectivity between the river and lakes presented an increase in the diversity indices considering the inlet of water in the system, while the disconnected lakes remained about the same during the entire year. This discrepancy may be caused by the selectivity of the gill nets using in the study, where fish may use the flooded area during the high waters, reducing the capture capacity of these devices. In the Pantanal, the connectivity associated to the selectivity of the gill nets determine the fish community.

APA, Harvard, Vancouver, ISO, and other styles

40

VanTassel, N. M., C. E. Beaver, D. A. Watkinson, T. J. Morris, and D. T. Zanatta. "Absence of genetic structure reflects post-glacial history and present-day host use in Mapleleaf (Quadrula quadrula) mussel from Manitoba, Canada." Canadian Journal of Zoology 98, no. 8 (August 2020): 551–56. http://dx.doi.org/10.1139/cjz-2019-0227.

Full text

Abstract:

Our study documents and analyzes the absence of genetic diversity and structure of the Mapleleaf (Quadrula quadrula (Rafinesque, 1820)) (Bivalvia: Unionidae) mussel in the Lake Winnipeg, Assiniboine River, and Red River drainages (Manitoba, Canada). Previous studies have revealed patterns of genetic diversity and structure in the Mississippi and Ohio river drainages, as well as in the Laurentian Great Lakes drainage. Genotypes from six variable microsatellite loci showed that the Q. quadrula population in Manitoba was significantly differentiated from the population in the Great Lakes drainage (Ontario, Canada), supporting the existence of two Designatable Units in Canada. Conversely, there was no evidence of genetic structure within the sampled range of Q. quadrula in Manitoba. The lack of genetic structure in Q. quadrula across its distribution in Manitoba reflected its post-glacial history and use of a vagile host and necessitates that efforts should be made to ensure connectivity and maintain gene flow across the region. Given that the evidence suggests that Manitoba Q. quadrula belong to a single genetic population, movement of hatchery-propagated juvenile Q. quadrula, adult Q. quadrula, or glochidia-carrying host catfish sourced from any location in Manitoba could be used to augment declining populations or at-risk locations in Manitoba.

APA, Harvard, Vancouver, ISO, and other styles

41

Perkins, Jeremy Simon. "Take me to the River along the African drought corridor: Adapting to climate change." Botswana Journal of Agriculture and Applied Sciences 14, no. 1 (April 3, 2020): 60–71. http://dx.doi.org/10.37106/bojaas.2020.77.

Full text

Abstract:

This paper brings together a wide range of concepts from climate change predictions, palaeoecology, wildlife ecology and sustainable livelihoods in order to prioritise adaptive management measures that are necessary for the conservation of the African megafauna. Climate change predictions emphasise the severe aridity that will surge into southern Africa later this century and must be contrasted with the relatively wetter conditions in eastern Africa. The evolution of African mammals and their adaptive responses to past episodes of climate change is explained by reference to range shifts and movements along Balinsky’s (1962) ‘drought corridor’ that extends from SW Africa northeastwards to Somalia and then westwards across the Saharan-Sahelian zone. The drought corridor today could potentially extend from Kenya southwestward through to Botswana/South Africa and Namibia, via connectivity corridors linking existing wildlife areas, forming the Kalahari-Rift Valley Transfrontier Conservation Landscape (KALARIVA TFCL). The most promising route along the drought corridor links the Chobe – Linyanti – Kwando river systems of Botswana/Namibia with Luangwa Valley in Northern Zambia, along the Zambezi River via Lake Kariba (Matsudonna and Mana Pools) in Zimbabwe. Malawi poses an absolute barrier to such connectivity and by the turn of this Century runs the risk of confining the area to the south almost entirely to the SW arid adapted fauna and that to the north to water dependent ungulates such as elephants, buffalo and zebra. The key movement corridors are identified in a bid to extend the spatial and temporal scale of conservation planning in order to adapt effectively to climate change. The importance of ‘co-existence’ between wildlife and people is emphasised together with the need for local communities to benefit from sharing the KALARIVA TFCL with African wildlife, via new models of conservation financing and management that reward rural African communities for being the true custodians of the African megafauna.

APA, Harvard, Vancouver, ISO, and other styles

42

van de Wolfshaar, K. E., H. Middelkoop, E. Addink, H. V. Winter, and L. A. J. Nagelkerke. "Linking Flow Regime, Floodplain Lake Connectivity and Fish Catch in a Large River-Floodplain System, the Volga–Akhtuba Floodplain (Russian Federation)." Ecosystems 14, no. 6 (June 3, 2011): 920–34. http://dx.doi.org/10.1007/s10021-011-9457-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Rodrigues, Luzia Cleide, Sueli Train, Maria do Carmo Roberto, and Thomaz Aurélio Pagioro. "Seasonal fluctuation of some limnological variables on a floodplain lake (Patos lagoon) of the Upper Paraná River, Mato Grosso do Sul State, Brazil." Brazilian Archives of Biology and Technology 45, no. 4 (December 2002): 499–513. http://dx.doi.org/10.1590/s1516-89132002000600014.

Full text

Abstract:

Temporal variations of some limnological variables in limnetic and littoral regions of Patos lagoon, a "várzea" lake on the floodplain of the Upper Paraná River (22(0) 43'12"S e 53(0) 17'37"W), were studied in relation to hydrological and climatological factors. Measurements of water temperature, euphotic zone, suspended material, electrical conductivity, total alkalinity, pH, dissolved oxygen, carbon dioxide, total nitrogen, total Kjeldahl nitrogen, total phosphorus, dissolved phosphorus, reactive soluble phosphorus and chlorophyll a were taken monthly between March 1993 and February 1994. Results lend evidence to the importance of the hydrological regime on the dynamic of limnological variables in floodplain lakes. A dilution of nutrients in the lagoon, especially phosphates, occurred during floods. This was followed by fertilization of the environment by nutrients from the inundated marginal regions. During low connectivity periods, autochthonous, events such as ressuspension of sediment, brought on by wind and rain, governed limnological events in the lagoon.

APA, Harvard, Vancouver, ISO, and other styles

44

Takahashi, Erico L. H., Fabricio R. T. Rosa, Francisco Langeani, and Laura S. O. Nakaghi. "Spatial and seasonal patterns in fish assemblage in Corrego Rico, upper Parana River basin." Neotropical Ichthyology 11, no. 1 (March 2013): 143–52. http://dx.doi.org/10.1590/s1679-62252013000100017.

Full text

Abstract:

The upper Paraná River basin drains areas of intensive industry and agriculture, suffering negative impacts. The Córrego Rico flows through sugar cane fields and receives urban wastewater. The aim of this work is to describe and to compare the fish assemblage structure in Córrego Rico. Six standardized bimonthly samples were collected between August 2008 and June 2009 in seven different stretches of Córrego Rico. Fishes were collected with an experimental seine and sieves, euthanized, fixed in formalin and preserved in ethanol for counting and identification. Data were recorded for water parameters, instream habitat and riparian features within each stretch. Non-metric multidimensional scaling, species richness and diversity analysis were performed to examine spatial and seasonal variation in assemblage structure. Fish assemblage structure was correlated with instream habitat and water parameters. The fish assemblage was divided in three groups: upper, middle and lower reaches. High values of richness and diversity were observed in the upper and lower stretches due to connectivity with a small lake and Mogi Guaçu River, respectively. Middle stretches showed low values of richness and diversity suggesting that a small dam in the middle stretch negatively impacts the fish assemblage. Seasonal differences in fish assemblage structure were observed only in the lower stretches.

APA, Harvard, Vancouver, ISO, and other styles

45

Peacock, Mary M., Evon R. Hekkala, Veronica S. Kirchoff, and Lisa G. Heki. "Return of a giant: DNA from archival museum samples helps to identify a unique cutthroat trout lineage formerly thought to be extinct." Royal Society Open Science 4, no. 11 (November 2017): 171253. http://dx.doi.org/10.1098/rsos.171253.

Full text

Abstract:

Currently one small, native population of the culturally and ecologically important Lahontan cutthroat trout ( Oncorhynchus clarkii henshawi , LCT, Federally listed) remains in the Truckee River watershed of northwestern Nevada and northeastern California. The majority of populations in this watershed were extirpated in the 1940s due to invasive species, overharvest, anthropogenic water consumption and changing precipitation regimes. In 1977, a population of cutthroat trout discovered in the Pilot Peak Mountains in the Bonneville basin of Utah, was putatively identified as the extirpated LCT lacustrine lineage native to Pyramid Lake in the Truckee River basin based on morphological and meristic characters. Our phylogenetic and Bayesian genotype clustering analyses of museum specimens collected from the large lakes (1872–1913) and contemporary samples collected from populations throughout the extant range provide evidence in support of a genetically distinct Truckee River basin origin for this population. Analysis of museum samples alone identified three distinct genotype clusters and historical connectivity among water bodies within the Truckee River basin. Baseline data from museum collections indicate that the extant Pilot Peak strain represents a remnant of the extirpated lacustrine lineage. Given the limitations on high-quality data when working with a sparse number of preserved museum samples, we acknowledge that, in the end, this may be a more complicated story. However, the paucity of remnant populations in the Truckee River watershed, in combination with data on the distribution of morphological, meristic and genetic data for Lahontan cutthroat trout, suggests that recovery strategies, particularly in the large lacustrine habitats should consider this lineage as an important part of the genetic legacy of this species.

APA, Harvard, Vancouver, ISO, and other styles

46

Tang, Xianqiang, Rui Li, Ding Han, and Miklas Scholz. "Response of Eutrophication Development to Variations in Nutrients and Hydrological Regime: A Case Study in the Changjiang River (Yangtze) Basin." Water 12, no. 6 (June 7, 2020): 1634. http://dx.doi.org/10.3390/w12061634.

Full text

Abstract:

Data and literature related to water quality as well as nutrient loads were used to evaluate the Changjiang River (also Yangtze or Yangzi) Basin with respect to its hydrological regime, sediment transport, and eutrophication status. Waterbodies exhibited different eutrophic degrees following the ranking order of river < reservoir < lake. Most of the eutrophic lakes and reservoirs distributed in the upstream Sichuan Basin and Jianghan Plain are located in the middle main stream reaches. During the past decade, the water surface area proportion of moderately eutrophic lakes to total evaluated lakes continually increased from 31.3% in 2009 to 42.7% in 2018, and the trophic level of reservoirs rapidly developed from mesotrophic to slightly eutrophic. Construction and operation of numerous gates and dams changed the natural transportation rhythm of runoff, suspended solids (SS), and nutrients, and reduced flow velocity, resulting in decreased discharge runoff, slow water exchange, and decreased connectivity between rivers and lakes as well as accumulated nutrient and SS, which are the main driving forces of eutrophication. To mitigate eutrophication, jointly controlling and monitoring nutrient concentrations and flux at key sections, strengthening water quality management for irrigation backwater and aquaculture wastewater, and balancing transportation among runoff, SS, and nutrients is recommended.

APA, Harvard, Vancouver, ISO, and other styles

47

Sendrowski, Alicia, Kazi Sadid, Ehab Meselhe, Wayne Wagner, David Mohrig, and Paola Passalacqua. "Transfer Entropy as a Tool for Hydrodynamic Model Validation." Entropy 20, no. 1 (January 12, 2018): 58. http://dx.doi.org/10.3390/e20010058.

Full text

Abstract:

The validation of numerical models is an important component of modeling to ensure reliability of model outputs under prescribed conditions. In river deltas, robust validation of models is paramount given that models are used to forecast land change and to track water, solid, and solute transport through the deltaic network. We propose using transfer entropy (TE) to validate model results. TE quantifies the information transferred between variables in terms of strength, timescale, and direction. Using water level data collected in the distributary channels and inter-channel islands of Wax Lake Delta, Louisiana, USA, along with modeled water level data generated for the same locations using Delft3D, we assess how well couplings between external drivers (river discharge, tides, wind) and modeled water levels reproduce the observed data couplings. We perform this operation through time using ten-day windows. Modeled and observed couplings compare well; their differences reflect the spatial parameterization of wind and roughness in the model, which prevents the model from capturing high frequency fluctuations of water level. The model captures couplings better in channels than on islands, suggesting that mechanisms of channel-island connectivity are not fully represented in the model. Overall, TE serves as an additional validation tool to quantify the couplings of the system of interest at multiple spatial and temporal scales.

APA, Harvard, Vancouver, ISO, and other styles

48

DeHaan, Patrick W., Shana R. Bernall, Joseph M. DosSantos, Lawrence L. Lockard, and William R. Ardren. "Use of genetic markers to aid in re-establishing migratory connectivity in a fragmented metapopulation of bull trout (Salvelinus confluentus)." Canadian Journal of Fisheries and Aquatic Sciences 68, no. 11 (November 2011): 1952–69. http://dx.doi.org/10.1139/f2011-098.

Full text

Abstract:

Dams and other barriers fragment important migratory corridors for bull trout ( Salvelinus confluentus ) across the species range. Three dams constructed without fish passage facilities prevented migratory bull trout in the Lake Pend Oreille and Clark Fork River system in Idaho and Montana, USA, from returning to their natal spawning tributaries for nearly 100 years. We genotyped bull trout from 39 spawning tributaries to assemble a baseline data set that we used to develop a real-time genotyping and analysis protocol to assist with upstream fish transport decisions. Self-assignment tests and analysis of blind samples indicated that unknown individuals could be assigned to their region of origin with a high degree of confidence. From 2004 to 2010, genetic assignments were conducted for 259 adult bull trout collected below mainstem dams. Based on genetic assignments, 203 fish were transported upstream above one or more dams. This protocol has helped re-establish connectivity in a fragmented system, providing increased numbers of spawning adults for numerically depressed populations above the dams. We discuss the utility of genetic data for assisting with upstream passage decisions.

APA, Harvard, Vancouver, ISO, and other styles

49

Meijers, Maud J. M., Gilles Y. Brocard, Donna L. Whitney, and Andreas Mulch. "Paleoenvironmental conditions and drainage evolution of the central Anatolian lake system (Turkey) during late Miocene to Pliocene surface uplift." Geosphere 16, no. 2 (January 10, 2020): 490–509. http://dx.doi.org/10.1130/ges02135.1.

Full text

Abstract:

Abstract Continued Africa-Eurasia convergence resulted in post–11 Ma surface uplift of the Central Anatolian Plateau (CAP) and the westward escape of the Anatolian microplate. Contemporaneously, a central Anatolian fluvio-lacustrine system developed that covered extensive parts of the rising CAP. Today, the semi-arid CAP interior—except for the Konya closed catchment—drains toward the Black Sea, the Mediterranean Sea, and the Persian Gulf. Lake connectivity and drainage patterns of the fluvio-lacustrine system in the evolving plateau region are, however, largely unknown. Here, we present sedimentological and stable isotopic (δ13C and δ18O) data (N = 665) from 13 well-dated lake sections covering the former fluvio-lacustrine depocenters of the southern CAP. Persistently (>1 m.y.) stable paleoenvironmental and hydrological conditions suggest that a low-relief environment characterized the southern CAP during plateau uplift. Throughout the late Miocene, various open and closed lakes of the southern CAP drained into closed, terminal lakes within the plateau interior. Sedimentation east of the Tuz Gölü fault ceased during the early Pliocene (ca. 5.3–3.6 Ma), when the eastern CAP became connected to marine base level as a result of river incision shortly after the switch from regional compression to extension. A final phase of lacustrine carbonate sedimentation characterizes most sampled basins, yet occurred asynchronously over the extent of the CAP. Therefore, the final episode of lacustrine sedimentation is unlikely to have been the result of a climatic event, consistent with the absence of a clear aridification trend in the lacustrine δ18O data. Rather, capping carbonates reflect the interplay of surface uplift and transition from inward- to outward-drained plateau regions and concomitant lake reorganization during the formation of the CAP and its margins.

APA, Harvard, Vancouver, ISO, and other styles

50

Kemp, Joanna Lynn, Andreas Ballot, Jens Petter Nilssen, Ingvar Spikkeland, and Tor Erik Eriksen. "Distribution, identification and range expansion of the common Asellidae in Northern Europe, featuring the first record of Proasellus meridianus in the Nordic countries." Fauna norvegica 40 (August 12, 2020): 93–108. http://dx.doi.org/10.5324/fn.v40i0.3353.

Full text

Abstract:

Two out of the three common Asellidae species in Northern Europe are increasing their ranges, aided by humanactivities. Here we report the discovery of Proasellus coxalis (Dollfuss 1892) in new areas in Norway and thediscovery of Proasellus meridianus (Racovitza 1919) for the first time in the Nordic countries, verified withDNA barcoding. A new, detailed photo-identification guide to Asellus aquaticus Linnaeus 1758, P. coxalis andP. meridianus is presented. In addition to head pattern, attention is drawn to the female pleopods as an easy way to differentiate between the two genera. Then detailed examination of male pleopods 1 and 2 can differentiate between P. coxalis and P. meridianus. The origins, competitive relationships and potential dispersal mechanisms of the two introduced species and the native A. aquaticus are explored. By examining the shipping activity at the small, freshwater port where P. meridianus was found, we highlight the great connectivity between many European brackish and freshwater ports and possible pathways for species transfer. The risk of trans-oceanic freshwater to freshwater (not just brackish and saltwater) species transfer through ballast water needs to be better communicated. Proasellus coxalis may have been introduced to the river system of Lake Stokkalandsvatnet together with fish transported in microaquaria used as live bait for fishing.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'River-lake connectivity'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles