scholarly journals Effects of flooding regime on the feeding activity and body condition of piscivorous fish in the Upper Paraná River floodplain

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 481-490 ◽  
Author(s):  
KDG. Luz-Agostinho ◽  
AA. Agostinho ◽  
LC. Gomes ◽  
HF. Júlio-Jr. ◽  
R. Fugi
Keyword(s):  
Water Level ◽  
Body Condition ◽  
Feeding Activity ◽  
Flood Pulse ◽  
Paraná River ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Piscivorous Fish ◽  
Flooding Regime ◽  
Parana River

Flood pulses affect floodplain enrichment via the incorporation of nutrients and terrestrial biomass. As a result, they positively affect the body condition of aquatic organisms. This paper evaluates whether the absence of floods (resulting from dam control) affects the feeding activity and body condition of piscivorous fish. In addition, whether piscivores respond similarly to alterations in the flooding regime was assessed. Five piscivorous species were selected (Acestrorhynchus lacustris, Hoplias aff. malabaricus, Plagioscion squamosissimus, Rhaphiodon vulpinus, and Salminus brasiliensis). The fish were captured in four distinct years and in three river subsystems with differentiated water level fluctuations (Ivinheira = not regulated; Baía = regulated by the Paraná River level; Paraná = regulated by dams). Feeding activity and body condition were evaluated using the mean values of the standard residuals generated by regression models between body and stomach weights and standard length and body weight (all log-transformed). Differences among years and subsystems were evaluated via two-way analysis of variance. Pearson and Spearman correlations were performed between flooding attributes (duration, amplitude, timing, and daily variability) and feeding activity and body condition. Feeding activity differed across subsystems, whereas body condition varied across years, depending on the subsystem. Hoplias aff malabaricus (an ambusher adapted to starvation) presented feeding activity independent of the flooding regime and also presented better body condition in times of high water levels. Rhaphidon vulpinus exhibited variations in feeding activity but did not present alterations in body condition. The other species presented poorer body condition in years or subsystems with regular floods. Correlations identified that the duration and timing of floods had negative effects on body condition, whereas amplitude and mean annual water level improved feeding activity. Therefore, regular floods affect the feeding activity and body condition of piscivorous fish, and the response of each species depends on the existence or absence of pre-adaptation to long periods of starvation. Consequently, considering the role of the flood pulse in determining the availability of feeding resources for early life stages of piscivores, control of the flood pulse by dams is also disadvantageous for piscivorous fish.

scholarly journals Annual Cycle Dampening and the Decrease Predictability of Water Level Fluctuations in a Dam-Regulated Neotropical Floodplain

2019 ◽  
Author(s):  
Jaques Everton Zanon
Keyword(s):  
Water Level ◽  
Annual Cycle ◽  
Flood Pulse ◽  
Paraná River ◽  
Transitional Period ◽  
Dynamical Analysis ◽  
Water Level Fluctuations ◽  
River Floodplain ◽  
Parana River ◽  
Upper Paraná River

AbstractThe flood pulse concept refers to seasonal variations in river water level and is the driving force in river-floodplain systems that ‘responsible for the existence, productivity and interactions’ of these system’s biota. This seasonal variation is inherent to river-floodplain systems and establishes a natural pattern of these ecosystems that has frequently been observed in nature. One particular river-floodplain system of interest is the Upper Parana River and its floodplain, whose upstream contains a reservoir cascade that caused profound alterations on its flooding regime by having diminished flood magnitude, but increased its frequency. In this study, I sought to explore the flood pulse condition in the Upper Paraná River Floodplain by using a set of state-of-the-art spectral and non-linear analyses and a time series of water level fluctuations (1968-2017) from this system. I divided the data into four periods: i) natural regime period, ii) transitional period, iii) dam cascade period, and iv) Primavera’s dam period. Spectral analysis demonstrated a decrease in the annual cycle amplitude, reflected in its power spectrum, which means a weakening in the difference between flood and drought events. Additionally, nonlinear dynamical analysis revealed a less deterministic and predicable behavior leading to more erratic fluctuations jeopardizing the temporal heterogeneity of that system.

Habitat-mediated influence of water-level fluctuations on waterbird occurrence in floodplain wetlands of the Parana River, Argentina

2017 ◽  
Vol 33 (9) ◽  
pp. 1494-1505 ◽  
Author(s):  
R.E. Lorenzón ◽  
A.H. Beltzer ◽  
P.M. Peltzer ◽  
P.F. Olguin ◽  
E.J. León ◽  
...  
Keyword(s):  
Water Level ◽  
Paraná River ◽  
Water Level Fluctuations ◽  
Floodplain Wetlands ◽  
Parana River ◽  
Influence Of Water

scholarly journals Effects of hydrological regime and connectivity on the interannual variation in taxonomic similarity of periphytic algae

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 609-616 ◽  
Author(s):  
VM. Algarte ◽  
NS. Siqueira ◽  
EA. Murakami ◽  
L. Rodrigues
Keyword(s):  
Aquatic Macrophytes ◽  
Hydrological Regime ◽  
High Water ◽  
Flood Pulse ◽  
Paraná River ◽  
Water Levels ◽  
Periphytic Algae ◽  
Parana River ◽  
Eichhornia Azurea ◽  
Flood Pulses

The aim of this study was to analyze the effects of flood pulses (intensity) on the richness and composition of periphytic algae in lentic environments of the Upper Paraná River floodplain, over a six-year period. Other factors, such as connectivity of the environments with the main channel of the river and the availability of substrate for the periphyton, were also evaluated. For qualitative analyses, periphyton community was sampled from adult petioles of Eichhornia azurea Kunth taken from the littoral regions of the lakes studied. A total of 457 taxa of periphytic algae, distributed within 141 genera and 10 classes, were registered in the four environments. The greatest richness of periphytic algae was observed in connected floodplain lakes, especially in 2007 and during high water periods. In both connected and disconnected lakes, richness correlated positively with water levels of the Paraná River. Richness was also positively correlated with the number of taxa of aquatic macrophytes. The specific composition of periphytic algae differed between high and low water periods, and between connected and disconnected lakes. Therefore, among the considered variables, it is evident that flood pulse constitutes the principal force acting on periphytic algae communities of the floodplain, followed by the degree of connectivity and the presence of aquatic macrophytes.

scholarly journals Water level influences on body condition of Geophagus brasiliensis (Perciformes: Cichlidae) in a Brazilian oligotrophic reservoir

2004 ◽  
Vol 2 (3) ◽  
pp. 151-156 ◽  
Author(s):  
Alejandra Filippo Gonzalez Neves dos Santos ◽  
Luciano Neves dos Santos ◽  
Francisco Gerson Araújo
Keyword(s):  
Water Level ◽  
Body Condition ◽  
Gonadosomatic Index ◽  
Gonad Development ◽  
Reproductive Investment ◽  
High Water ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Somatic Development ◽  
Geophagus Brasiliensis

Effects of water level fluctuations on body condition of Geophagus brasiliensis were studied in a 30 km² Brazilian oligotrophic reservoir. Physiological condition (K) and gonadosomatic index (GSI) were compared according to water level (low and high). Females' best conditions were associated to higher resources availability during high water, since gonad development did not change between low and high water. Males' condition did not change between water levels, while the highest gonad development occurred in low water. Females presented higher reproductive investment than males, which allocated most of energy for somatic development. This strategy could be a mechanism to undergo the stress caused by oligotrophic characteristics of the reservoir enhanced during low water level.

AUTOMATIC WATER LEVEL MONITORING WITH IOT AND LPWAN

2019 ◽  
pp. 95-103
Author(s):  
Krum Videnov ◽  
Vanya Stoykova
Keyword(s):  
Water Level ◽  
Real Time ◽  
Early Warning ◽  
Water Sources ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Level Monitoring ◽  
Water Level Monitoring

Monitoring water levels of lakes, streams, rivers and other water basins is of essential importance and is a popular measurement for a number of different industries and organisations. Remote water level monitoring helps to provide an early warning feature by sending advance alerts when the water level is increased (reaches a certain threshold). The purpose of this report is to present an affordable solution for measuring water levels in water sources using IoT and LPWAN. The assembled system enables recording of water level fluctuations in real time and storing the collected data on a remote database through LoRaWAN for further processing and analysis.

scholarly journals The effect of water level on lateral movements of fish between river and off-channel habitats and implications for management

2010 ◽  
Vol 61 (3) ◽  
pp. 271 ◽  
Author(s):  
Jarod Lyon ◽  
Ivor Stuart ◽  
David Ramsey ◽  
Justin O'Mahony
Keyword(s):  
Water Level ◽  
Fish Community ◽  
Life History Strategy ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Main River Channel ◽  
Murray River ◽  
Wetland Biodiversity ◽  
Eastern Australia ◽  
Riverine Wetland

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.

scholarly journals Regulation of Vegetation and Evapotranspiration by Water Level Fluctuation in Shallow Lakes

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2651
Author(s):  
Qiang Liu ◽  
Liqiao Liang ◽  
Xiaomin Yuan ◽  
Sirui Yan ◽  
Miao Li ◽  
...  
Keyword(s):  
Water Level ◽  
Open Water ◽  
Water Area ◽  
Water Level Fluctuation ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Water Evaporation ◽  
Level Fluctuation ◽  
Open Water Area ◽  
Annual Scale

Water level fluctuations play a critical role in regulating vegetation distribution, composition, cover and richness, which ultimately affect evapotranspiration. In this study, we first explore water level fluctuations and associated impacts on vegetation, after which we assess evapotranspiration (ET) under different water levels. The normalized difference vegetation index (NDVI) was used to estimate the fractional vegetation cover (Fv), while topography- and vegetation-based surface-energy partitioning algorithms (TVET model) and potential evaporation (Ev) were used to calculate ET and water evaporation (Ep). Results show that: (1) water levels were dramatically affected by the combined effect of ecological water transfer and climate change and exhibited significant decreasing trends with a slope of −0.011 m a−2; and (2) as predicted, there was a correlation between water level fluctuation at an annual scale with Phragmites australis (P. australis) cover and open-water area. Water levels also had a controlling effect on Fv values, an increase in annual water levels first increasing and then decreasing Fv. However, a negative correlation was found between Fv values and water levels during initial plant growth stages. (iii) ET, which varied under different water levels at an annual scale, showed different partition into transpiration from P. australis and evaporation from open-water area and soil with alterations between vegetation and open water. All findings indicated that water level fluctuations controlled biological and ecological processes, and their structural and functional characteristics. This study consequently recommends that specifically-focused ecological water regulations (e.g., duration, timing, frequency) should be enacted to maintain the integrity of wetland ecosystems for wetland restoration.

scholarly journals Determination of diurnal water level fluctuations in headwaters

2016 ◽  
Vol 47 (4) ◽  
pp. 888-901 ◽  
Author(s):  
Marek Marciniak ◽  
Anna Szczucińska
Keyword(s):  
Water Temperature ◽  
Water Level ◽  
Air Temperature ◽  
Hyporheic Zone ◽  
Water Pressure ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Diurnal Changes ◽  
Atmospheric Conditions ◽  
Diurnal Fluctuations

The aim of this paper is to study diurnal fluctuations of the water level in streams draining headwaters and to identify the controlling factors. The fieldwork was carried out in the Gryżynka River catchment, western Poland. The water levels of three streams draining into the headwaters via a group of springs were monitored in the years 2011–2014. Changes in the water pressure and water temperature were recorded by automatic sensors – Schlumberger MiniDiver type. Simultaneously, Barodiver type sensors were used to record air temperature and atmospheric pressure, as it was necessary to adjust the data collected by the MiniDivers calculate the water level. The results showed that diurnal fluctuations in water level of the streams ranged from 2 to 4 cm (approximately 10% of total water depth) and were well correlated with the changes in evapotranspiration as well as air temperature. The observed water level fluctuations likely have resulted from processes occurring in the headwaters. Good correlation with atmospheric conditions indicates control by daily variations of the local climate. However, the relationship with water temperature suggests that fluctuations are also caused by changes in the temperature-dependent water viscosity and, consequently, by diurnal changes in the hydraulic conductivity of the hyporheic zone.

Lake water level response to drought in a lake-rich region explained by lake and landscape characteristics

2020 ◽  
Vol 77 (11) ◽  
pp. 1836-1845
Author(s):  
K. Martin Perales ◽  
Catherine L. Hein ◽  
Noah R. Lottig ◽  
M. Jake Vander Zanden
Keyword(s):  
Climate Change ◽  
Water Level ◽  
Lake Water ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Lake Area ◽  
Lake Water Level ◽  
Landscape Characteristics ◽  
Lake Ecology ◽  
Coarse Woody Habitat

Climate change is altering hydrologic regimes, with implications for lake water levels. While lakes within lake districts experience the same climate, lakes may exhibit differential climate vulnerability regarding water level response to drought. We took advantage of a recent drought (∼2005–2010) and estimated changes in lake area, water level, and shoreline position on 47 lakes in northern Wisconsin using high-resolution orthoimagery and hypsographic curves. We developed a model predicting water level response to drought to identify characteristics of the most vulnerable lakes in the region, which indicated that low-conductivity seepage lakes found high in the landscape, with little surrounding wetland and highly permeable soils, showed the greatest water level declines. To explore potential changes in the littoral zone, we estimated coarse woody habitat (CWH) loss during the drought and found that drainage lakes lost 0.8% CWH while seepage lakes were disproportionately impacted, with a mean loss of 40% CWH. Characterizing how lakes and lake districts respond to drought will further our understanding of how climate change may alter lake ecology via water level fluctuations.

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