81 research outputs found
Fish Structure in Channel Networks of a Large Anabranching Floodplain: Effect of Isolation/Connection Processes
Channel networks of floodplain rivers are the main routes for water, sediment, organic matter, and aquatic organisms between main channels and lakes, playing a substantial role in floodplain dynamics. Despite their importance most investigations in large floodplain rivers focus on main channels and lentic water bodies. This research deals with fish assemblage variations in different lotic sites (scour holes and straight reaches) of one of the many channels which shape the wide anabranching floodplain of the middle reach of the ParanĂĄ River. We considered the influence of environmental factors, such as hydro-geomorphological features and water quality of the channel, connections with surrounding lentic water bodies, seasonality, and interannual flow variations. The results showed two main ecological patterns closely related to floodplain connectivity. In-channel habitat heterogeneity has low influence on fish assemblages when minor channels are connected to significant flooded areas (sampling period 2013â2016). Spatial or temporal predictions of fish structure during these stages are not easy due to the interaction of several environmental factors. However, during very low water levels (winter of 2018) most lentic areas become isolated from the nearby channel network, and floodplain fish are forced to move into the numerous scour holes of the floodplain channels where water conditions resemble those in lentic habitats. Our work highlights the importance of in-channel characteristics of floodplain river networks and their crucial role for fish conservation, particularly during very low water stages.Fil: Abrial, Elie. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂa. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂa; ArgentinaFil: EspĂnola, Luis Alberto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂa. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂa; ArgentinaFil: Amsler, Mario Luis. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂa. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂa; ArgentinaFil: Rabuffetti, Ana Pia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂa. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂa; ArgentinaFil: Latosinski, Francisco Guillermo. Universidad Nacional del Litoral. Facultad de IngenierĂa y Ciencias HĂdricas. Departamento de HidrĂĄulica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe; ArgentinaFil: Szupiany, Ricardo Nicolas. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de IngenierĂa y Ciencias HĂdricas. Departamento de HidrĂĄulica; ArgentinaFil: Eurich, MarĂa Florencia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂa. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂa; ArgentinaFil: Blettler, Martin Cesar Maria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂa. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂa; Argentin
Aquatic food webs in mangrove and seagrass habitats of Centla Wetland, a Biosphere Reserve in Southeastern Mexico
SOIL ORGANIC MATTER FRACTIONS IN PRESERVED AND DISTURBED WETLANDS OF THE CERRADO BIOME
Benthic community structure and ecosystem functions in above- and below-waterfall pools in Borneo
Waterfalls are geomorphic features that often partition streams into discrete zones. Our study examined aquatic communities, litter decomposition and periphyton growth rates for above- and below-waterfall pools in Ulu Temburong National Park, Brunei. We observed higher fish densities in below-waterfall pools (0.24 fish mâ2 vs. 0.02 fish mâ2 in above-waterfall pools) and higher shrimp abundance in above-waterfall pools (eight shrimp/pool vs. less than one shrimp/pool in below-waterfall pools). However, macroinvertebrate densities (excluding shrimp) were similar among both pool types. Ambient periphyton was higher in below-waterfall pools in 2013 (4.3 vs. 2.8 g mâ2 in above-waterfall pools) and 2014 (4.8 vs. 3.4 g mâ2 in above-waterfall pools), while periphyton growth rates varied from 0.05 to 0.26 g mâ2 daysâ1 and were significantly higher in below-waterfall pools in 2014. Leaf litter decomposition rates (0.001 to 0.024 daysâ1) did not differ between pool types, suggesting that neither shrimp nor fish densities had consistent impacts on this ecosystem function. Regardless, this research demonstrates the varied effects of biotic and abiotic factors on community structure and ecosystem function. Our results have highlighted the importance of discontinuities, such as waterfalls, in tropical streams.</p
Benthic macroinvertebrate community structure in a stream of the north-west region of ParanĂĄ State, Brazil
Estrutura e composição da comunidade de Trichoptera (Insecta) de rios e ĂĄreas alagadas da bacia do rio SuiĂĄ-MiçĂș, Mato Grosso, Brasil
FIRE MANAGEMENT IN VEREDAS (PALM SWAMPS): NEW PERSPECTIVES ON TRADITIONAL FARMING SYSTEMS IN JALAPĂO, BRAZIL
Consequences of suppressing natural vegetation in drainage areas for freshwater ecosystem conservation: considerations on the new "Brazilian forest code"
Periphytic community structure of Ostracoda (Crustacea) in the river-floodplain system of the Upper ParanĂĄ River
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