scholarly journals Flood pulse effects on multispecies fishery yields in the Lower Amazon

2015 ◽  
Vol 2 (11) ◽  
pp. 150299 ◽  
Author(s):  
Leandro Castello ◽  
Victoria J. Isaac ◽  
Ram Thapa
Keyword(s):  
Interannual Variability ◽  
Complex Dynamics ◽  
Flood Pulse ◽  
Large River ◽  
Fishing Effort ◽  
Water Levels ◽  
Fish Biomass ◽  
River Floodplain ◽  
River Floodplains ◽  
Flood Pulses

Seasonally fluctuating water levels, known as ‘flood pulses’, control the productivity of large river fisheries, but the extent and mechanisms through which flood pulses affect fishery yields are poorly understood. To quantify and better understand flood pulse effects on fishery yields, this study applied regression techniques to a hydrological and fishery record (years 1993–2004) for 42 species of the Amazon River floodplains. Models based on indices of fishing effort, high waters and low waters explained most of the interannual variability in yields ( R 2 =0.8). The results indicated that high and low waters in any given year affected fishery yields two and three years later through changes in fish biomass available for harvesting, contributing 18% of the explained variability in yields. Fishing effort appeared to amplify high and low water effects by changing in direct proportion to changes in fish biomass available for harvesting, contributing 62% of the explained variability in yields. Although high waters are generally expected to have greater relative influence on fishery yields than low waters, high and low waters exerted equal forcing on these Amazonian river-floodplain fishery yields. These findings highlight the complex dynamics of river-floodplain fisheries in relation to interannual variability in flood pulses.

Population age structure and growth in four syntopic amphibian species inhabiting a large river floodplain

2003 ◽  
Vol 81 (6) ◽  
pp. 1096-1106 ◽  
Author(s):  
Dan Cogalniceanu ◽  
Claude Miaud
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Age Structure ◽  
Environmental Conditions ◽  
Age Distribution ◽  
Large River ◽  
Danube River ◽  
Population Age Structure ◽  
River Floodplain ◽  
River Floodplains

River floodplains are disturbance-dominated landscapes where floods are major regulators of both aquatic and nearby terrestrial communities. Amphibians are common inhabitants of floodplains and their life cycle depends on both aquatic and terrestrial habitats. We focused on how different syntopic species of amphibians reacted to the environmental conditions of a large river floodplain. We examined life-history traits such as population age structure and growth in small- and large-bodied species of anurans and urodeles in the lower Danube River floodplain in Romania. Two newt species, Triturus vulgaris (small-bodied) and Triturus dobrogicus (large-bodied), and two anuran taxa, Bombina bombina (small-bodied) and the Rana esculenta complex (large-bodied), were included in the study. The ages of individuals estimated by skeletochronology varied from 3 to 5–6 years for T. vulgaris and from 2–3 to 4–5 years for T. dobrogicus. In the anurans, ages varied from 2 to 5 years in B. bombina and from 4 to 10 years in the R. esculenta complex. The numbers of breeding opportunities (i.e., the number of years the adults reproduce) are similar in both newt species (3), while growth rates and age at maturity differ between the large- and small-bodied species. In anurans, the number of breeding opportunities for the smallest species, B. bombina (4), is associated with a high growth rate and earlier maturation. In the larger R. esculenta complex, the higher number of breeding opportunities (7) is associated with a low growth rate and delayed maturation. The study of age distribution and associated parameters provides useful information on population life history. We discuss how age structure and growth of amphibian populations in large river floodplains can be used as indicators of environmental conditions.

GRUPOS FUNCIONAIS FITOPLANCTÔNICOS EVIDENCIAM DIFERENÇAS AMBIENTAIS EM UMA PLANÍCIE DE INUNDAÇÃO TEMPERADA

2021 ◽  
Vol 25 (03) ◽  
pp. 648-661
Author(s):  
Felipe Morais Zanon ◽  
◽  
Patrícia Iatskiu ◽  
Michael Joseph Lemke ◽  
Luiz Felipe Machado Velho ◽  
...  
Keyword(s):  
Species Richness ◽  
Primary Productivity ◽  
Hydrological Cycle ◽  
Biogeochemical Cycles ◽  
Water Levels ◽  
Illinois River ◽  
River Floodplain ◽  
Flood Pulses ◽  
High Turbidity

Floodplain environments have high biodiversity and provide many ecosystem services maintained by the flood pulses. The phytoplankton is essential to the functioning of these ecosystems, acting upon primary productivity and biogeochemical cycles. We evaluated phytoplankton in a river-lake flood system (Illinois River floodplain-USA) during a hydrological cycle and compared the taxonomic (species) and functional (morphologic-based functional groups – MBFG) approaches. As expected, greater species richness was registered in the river and higher biovolume in the lake, as well as the predominance of different MBFGs in each environment. Furthermore, seasonality drove richness and biovolume temporal variation due to the higher water levels during spring. The MBFG IV (i. e. without specialized traits), V (phytoflagellates) and VI (diatoms) were more important for richness and biovolume in both environments. We reinforce the fundamental role of the hydrodynamics characteristics, with higher phytoplankton biovolume values in the lake. Using MBFG resulted in a better explanation to the phytoplankton-environment relationship. Constant water column mixture and high turbidity selected species with traits (e.g. small size, presence of silica) specifically adapted to these conditions.

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.

The annual flood pulse mediates crayfish as a major diet constituent of carnivorous fishes in south Louisiana

2020 ◽  
Vol 25 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Christopher P. Bonvillain ◽  
Quenton C. Fontenot
Keyword(s):  
Mississippi River ◽  
Stomach Contents ◽  
Flood Pulse ◽  
Large River ◽  
River Floodplain ◽  
Pulse Dynamics ◽  
Barataria Basin ◽  
Floodplain Inundation ◽  
Atchafalaya River Basin ◽  
Anthropogenic Modifications

Abstract Anthropogenic modifications to river-floodplain systems can decouple floodplains from mainstem inputs, alter flood pulse dynamics, and disrupt population dynamics and trophic web stability of aquatic biota. The Atchafalaya River Basin (ARB) receives an annual flood pulse from the Mississippi River that contributes to high crayfish abundance. Conversely, reduced crayfish abundance in the Barataria Basin (BB) is attributed to the system no longer receiving an annual flood pulse from the Mississippi River. Therefore, the purpose of this research was to determine if the absence of an annual flood pulse and reduced crayfish abundance influenced the diets of carnivorous fishes by examining stomach contents of fishes from both basins. Stomach contents were grouped as crayfish, fish, non-crayfish invertebrate, and herpetological. Although the percent occurrence of crayfish in fish stomachs differed between floodplain inundation and low-water periods in the ARB, crayfish were still the major diet constituent of ARB fishes during both periods. Non-crayfish invertebrate was the major diet constituent in BB fishes, with crayfish ranking as the second fewest diet constituent present. Our results demonstrate how flood pulse dynamics influence crayfish, and ultimately trophic webs, in large river-floodplain systems.

scholarly journals Mollusc fisheries and length–weight relationship in Tonle Sap flood pulse system, Cambodia

2018 ◽  
Vol 54 ◽  
pp. 34 ◽  
Author(s):  
Peng Bun Ngor ◽  
Ratha Sor ◽  
Leang Hour Prak ◽  
Nam So ◽  
Zeb S. Hogan ◽  
...  
Keyword(s):  
Annual Variation ◽  
Flood Pulse ◽  
Growth Patterns ◽  
Water Levels ◽  
Relationship Analysis ◽  
Weight Relationship ◽  
Daily Data ◽  
Tonle Sap ◽  
Mollusc Species ◽  
One Year

Molluscs are important for ecological function, livelihoods and fisheries, but are often forgotten in research and management. Here, we investigated intra-annual variation in the landing and growth patterns of three mollusc species, i.e., Corbicula moreletiana, Pila virescens and Pila ampullacea, using one-year daily data on landing catches and values, recorded in Kampong Chhnang province of Tonle Sap (TS) Lake. Overall, 8330 tonnes with a first sale landing value of US$ 1.4 million for the three species were reported. Also, we found that C. moreletiana was abundant during the dry season with high temperature and less precipitation. By contrast, the two Pila species were abundant from the early rainy to early dry seasons when precipitation and water levels increase. The length–weight relationship analysis indicated that a faster growth in weight of Pila species occurred in the rainy season, and a general negative allometric growth was observed for the three species. This implies that their populations were intensively fished. Our preliminary results suggest that molluscs in the TS Lake (i) are important resources in support of people's livelihoods, (ii) respond differently to intra-annual variation in temperature, precipitation and hydrology and (iii) are being intensively exploited with significant reduction in growth rate. Therefore, it is necessary to conduct further comprehensive research describing status of mollusc stocks and their ecology to support long-term management and conservation of this important aquatic fauna. Our study contributes to establishing the first important baseline data and information on key mollusc species for the TS.

scholarly journals Inter-annual variations in the abundance of young-of-the-year of migratory fishes in the Upper Paraná River floodplain: relations with hydrographic attributes

2009 ◽  
Vol 69 (2 suppl) ◽  
pp. 649-660 ◽  
Author(s):  
HI. Suzuki ◽  
AA. Agostinho ◽  
D. Bailly ◽  
MF. Gimenes ◽  
HF. Júlio-Junior ◽  
...  
Keyword(s):  
Water Levels ◽  
Migratory Species ◽  
River Floodplain ◽  
Annual Variations ◽  
Parana River ◽  
Upper Paraná River Floodplain ◽  
Upper Paraná River ◽  
Young Of The Year ◽  
Paraná River Floodplain ◽  
Migratory Fishes

In this study, we identified and characterized the hydrographic attributes related to the success of recruitment of migratory fishes in the Upper Paraná River floodplain. To achieve our objectives, we analyzed inter-annual variations in the abundance of young-of-the-year (YOY; index of recruitment) of six migratory species and their relations with hydrographic attributes. Recruitment was related to the intensity, duration (in different fluviometrical levels), elasticity, number of pulses, greater uninterrupted overflow and delay of the floods (all obtained using the PULSO software). Collections of fish were conducted in the period between January 1987 and November 2007 in distinct environments (river channels, secondary channels and connected and disconnected floodplain lakes) distributed along three subsystems (Paraná, Baía and Ivinheima). Relations between recruitment and the attributes of interest were determined through analysis of covariance. In the studied period, the highest abundances of YOY were registered in 2007, followed by 1992, 1993, 2005 and 1988. The abundance of YOY was positively correlated with an intensity of high water levels (potamophase) and the duration of potamophase 1 and negatively with the duration of low water levels (limnophase) and a delay of flood. Higher hydrometric levels (540 and 610 cm for Paraná and 325 and 450 cm for Ivinheima) and greatest uninterrupted overflow presented different relations (significant interactions) among subsystems, but all with positive effects on recruitment. Results evidenced that recruitment responded better when floods started in January with potamophase intensities above 610 cm and water levels above 450 cm over a period of 50 days and repeated every two years (or > 610 cm for 38 days and repeated every two or three years). Therefore, artificial control of the floods at intervals of two or three years by manipulating the discharge of dams located upstream from the floodplain in a way that promotes potamophases with the potential to ensure recruitment of migratory species may become an important tool for conservation of migratory fish species in the floodplain.

scholarly journals Quantitative assessment of ecological operation effects based on flood pulses and ecology-economic coupling model: a case study of Three Gorges Reservoir, China

2021 ◽  
Author(s):  
Jiqing Li ◽  
Jing Huang ◽  
Zhiming Xue ◽  
Pengteng Liang ◽  
Yueqiu Wu
Keyword(s):  
Three Gorges Reservoir ◽  
Simulation Method ◽  
Coupling Model ◽  
Flood Pulse ◽  
Ecological Impacts ◽  
Three Gorges ◽  
River Ecosystem ◽  
Random Simulation ◽  
Flood Pulses

Abstract Flood pulses are closely related to river ecosystem health. Reservoirs bring many benefits to flood control, power generation, shipping etc., but their attenuation effects on runoff flood pulses should not be ignored. Ecological operation can effectively reduce some negative ecological impacts brought by the reservoir. However, the inability to quantitatively assess ecological effects hinders the promotion of ecological operation in reservoir management. To solve this problem, we proposed 11 flood pulse indicators (FPI), a random simulation method and an ecology-economy coupling model in this study. In addition, we used four major Chinese carps as indicator species and the Three Gorges Reservoir as a case study to test the role of flood pulses in improving the ecological operation effects of the reservoir from the fish protection perspective. The results show that: (1) FPI can be controlled by the reservoir and reflect the flood pulse characteristics of runoff. (2) Random simulation method guides managers to optimize the discharge and formulate eco-friendly operation schemes. (3) Ecology-economy coupling model helps managers analyze the relationship between ecological operation effects and economic benefits. A comprehensive assessment can improve the acceptance of ecological operation, which is conducive to the sustainable development of river ecosystem.

scholarly journals Changes in composition of aquatic bird assemblages associated with changing in water levels in the Aquatic Terrestrial Transitional Zone of the Pantanal wetland Brazil

2020 ◽  
Vol 9 (10) ◽  
pp. e4479108555
Author(s):  
Josué Ribeiro da Silva Nunes ◽  
Carolina Joana da Silva ◽  
Solange Kimie Ikeda-Castrillon ◽  
Nilo Leal Sander
Keyword(s):  
Aquatic Macrophyte ◽  
Transitional Zone ◽  
High Water ◽  
Flood Pulse ◽  
Water Levels ◽  
Aquatic Birds ◽  
Mato Grosso ◽  
Paraguay River ◽  
The Difference ◽  
Pantanal Wetland

The Pantanal wetland Mato Grosso, Brazil is among the largest floodplains in the world, with a mosaic of different habitats and rich aquatic and terrestrial biota. The habitat mosaics are found in the Chacororé and Sinhá Mariana lake System. These parental lakes of the Cuiabá River, a left tributary of the Upper Paraguay River, are known for their aquatic productivity and scenic beauty. The characteristics of these lakes and their floodplains are showed through the difference between their waters, the diversity of the aquatic macrophytes communities, fish communities and aquatic birds. Our study looked at changes in limnological variables as well as diversity of aquatic birds, during high water or flooded phase; medium water or receding phase; and the low water or dry phase. We used a temporary small lagoon in the floodplain of this system as our study area. The flood pulse is the main ecological factor affecting the Pantanal; it modifies ecological process and species composition. The water depth decreases during the season, decreasing electrical conductivity, dissolved phosphate and nitrate, water transparency, dissolved oxygen and biomass of aquatic macrophyte; and increasing calcium, total phosphorus and total nitrogen. We also observed increase in species richness and abundance of aquatic birds during the receding phase. Results show that the number of species (density) of aquatic birds increased from 10 to 30 species and the numbers of individuals from 40 to 936. The maximum richness and abundance of aquatic birds was registered during the receding phase.

Flood pulses control soil nitrogen cycling in a dynamic river floodplain

Geoderma ◽  
2014 ◽  
Vol 228-229 ◽  
pp. 14-24 ◽  
Author(s):  
J. Shrestha ◽  
P.A. Niklaus ◽  
N. Pasquale ◽  
B. Huber ◽  
R.L. Barnard ◽  
...  
Keyword(s):  
Nitrogen Cycling ◽  
Soil Nitrogen ◽  
Control Soil ◽  
River Floodplain ◽  
Flood Pulses ◽  
Soil Nitrogen Cycling
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