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.

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 Spatial and temporal distribution of ''curvina'' larvae (Plagioscion squamosissimus HECKEL, 1840) and its relationship to some environmental variables in the upper Paraná River floodplain, Brazil

2003 ◽  
Vol 63 (3) ◽  
pp. 381-391 ◽  
Author(s):  
M. S. T. Baumgartner ◽  
K. Nakatini ◽  
G. Baumgartner ◽  
M. C. Makrakis
Keyword(s):  
Water Level ◽  
Temporal Distribution ◽  
Paraná River ◽  
Spatial And Temporal Distribution ◽  
River Floodplain ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain ◽  
Spawning Sites

With the objective of studying the spatial and temporal distribution of ''curvina'' Plagioscion squamosissimus larvae and verifying respective spawning sites, monthly sampling was carried out from March 1993 to February 1994 on the Upper Paraná River floodplain. Using a conical-cylindrical plankton net (0.5 mm mesh), samples were taken from the surface of the water bodies, and in the marginal vegetation a strainer and a dragnet (''picaré'') were used. Water samples were collected for environmental variable analysis (temperature, dissolved oxygen, water pH, and electrical conductivity). Water level data were obtained from hydrometric stations. High average density of larvae was found from December 1993 to February 1994 due to high temperature and water level. The Baía sub-area was shown to be the most important in the larvae catch, probably due to its semi-lotic characteristics. Larvae size distribution was shown to be more frequent in the 4.0 mm standard length class, indicating that the sampling stations were next to the spawning sites.

scholarly journals Periphytic and planktonic algae records from the upper Paraná river floodplain, Brazil: an update

Hoehnea ◽  
2018 ◽  
Vol 45 (4) ◽  
pp. 560-590 ◽  
Author(s):  
Bárbara Dunck ◽  
Maria Gabriela Junqueira ◽  
Andressa Bichoff ◽  
Matheus Vieira da Silva ◽  
Alfonso Pineda ◽  
...  
Keyword(s):  
Geographic Distribution ◽  
Paraná River ◽  
State University ◽  
Conservation Units ◽  
River Floodplain ◽  
Planktonic Algae ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain

ABSTRACT The upper Paraná river floodplain is a strategic area for the Brazilian biological and environmental patrimony and contains several conservation units. We aimed to record the occurrence and the geographic distribution of microalgae in this floodplain during 30 years of research carried out by the Center for Research in Limnology, Ichthyology and Aquaculture - State University of Maringá. We consulted 80 publications (national and international journals and books published from 1986 to 2016). We considered only published works that referenced algae at the generic and infrageneric levels. The results indicated 938 species of algae (562 periphytic, 482 planktonic), which 103 co-occur in the two habitats. Cosmarium was the richest genera for periphyton and Traquelomonas for phytoplankton. This study increased the knowledge of microalgae biodiversity in Brazil and provided data for future ecological and biogeographic studies.

scholarly journals Vascular flora of the Upper Paraná River floodplain

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 735-745 ◽  
Author(s):  
MC. Souza ◽  
K. Kawakita ◽  
SR. Slusarski ◽  
GF. Pereira
Keyword(s):  
Ricinus Communis ◽  
Paraná River ◽  
Pennisetum Purpureum ◽  
Panicum Maximum ◽  
River Floodplain ◽  
Parana River ◽  
Number Of Species ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Paraná River Floodplain

The purpose of this study was to update the floristic inventory found in the Upper Paraná River floodplain. Floristic surveys were performed from February 2000 through March 2008, as part of the Brazilian Long-Term Ecological Research Program (PELD/CNPq -Site 6). The material collected was identified from 774 species, 442 genera, and 116 families. The ten families with high species richness were Leguminosae, Poaceae, Rubiaceae, Asteraceae, Euphorbiaceae, Myrtaceae, Cyperaceae, Solanaceae, Sapindaceae, and Orchidaceae, which contributed to 46.1% of the total number of species. Genera with high richness were Solanum, Cyperus, Panicum, Eugenia, Tillandsia, Serjania, Casearia, and Polygonum, which together contributed to 10.2% of the total number of species. These data, combined with information published in 1997, recorded 955 species, 575 genera, and 128 families. These organisms were from several riparian environments and were distributed as herbs, shrubs, trees, climbers and epiphytes. Panicum maximum, Pennisetum purpureum, Ricinus communis, and Urochloa decumbens are considered weeds due to the wide distributions determined for these species. The results presented herein suggest the need to further investigate the control of these potential weed species.

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