Flow modification of lotic ecosystems is one of the main threats to global freshwater biodiversity. Commonly, and in the river studied here, modification results from hydroelectric dam installation. We evaluated the impacts of damming on zooplankton communities in the Amazonian floodplain of the Madeira River (Porto Velho, Rondônia, Brazil) following construction in 2012 of the run‐of‐river dam of Jirau Hydroelectric Power Plant. Using data sampled between 2009 and 2015, we tested for discontinuities in zooplankton community composition attributable to damming and the naturally occurring flood pulse. The flood pulse remained the main predictor explaining variation in zooplankton community structure even with the installation of the dam on the Madeira River. Despite this, discontinuities for the entire zooplankton community and for the main compositional groups (testate amoebae, rotifers, cladocerans, and copepods) were detected in relation to the dam (pre‐/post‐dam periods), mainly in ebb and low water, and with weaker evidence of dam effects during flood and highwater hydrological periods. A multivariate regression tree explained 9.6% of the variation in zooplankton communities and identified four groups: (1) flood and high‐water periods; (2) low water post‐dam; (3) low water pre‐dam; and (4) ebb hydrological periods. The deviance in each multivariate regression tree node was attributable to variation in eight rotifer, three testate amoeba, and three copepod taxa. Our study demonstrates that the flood pulse, dam construction, and interaction between both of these factors affect zooplankton community structure in the Madeira River. While for many zooplankton community variables, effects occurred mainly during ebb and low‐water periods, some effects were also observed during high water and flood periods. We thus recommend the establishment of a permanent environmental monitoring programme during all hydrological periods in tropical floodplain rivers and the addition of sampling sites downstream from dams. Many rivers in the world are increasingly disrupted by multiple dams, yet little is known of their effects, especially for run‐of‐river dams. Our study identified short‐term impacts of only one run‐of‐river dam on zooplankton communities. More research is needed on the effects of multiple run‐of‐river dams on zooplankton and other biota, especially in tropical floodplain rivers, so that negative effects can be understood and ameliorated.
O tráfico de animais é uma ameaça à biodiversidade. Aproximadamente 82% dos animais contrabandeados são aves. Objetivou-se elaborar uma lista das espécies de aves traficadas no Brasil, evidenciando espécies ameaçadas. Para a busca de artigos foram utilizadas as bases de dados Web of Science e Google Scholar. Foram encontradas 45 publicações e 343 espécies oriundas do tráfico de animais. A ordem com maior riqueza é a dos Passeriformes, seguida pelos Psittaciformes. A família Thraupidae apresentou-se expressiva. 29 espécies possuem algum nível de ameaça: seis criticamente em perigo, cinco em perigo e 18 vulneráveis. Ações prioritárias para reduzir o impacto da atividade ilegal sobre essas espécies devem ser priorizadas. A identificação das espécies deve ser feita de modo criterioso, devem ser criados programas específicos para destinação das espécies ameaçadas e utilizadas metodologias genéticas e isótopos estáveis como ferramenta no combate ao tráfico. Educação ambiental e penas mais severas também são recomendadas.
Aim This study aimed to answer: (i) can phytoplankton communities be used as surrogate of zooplankton communities?; (ii) can we use ecological approaches like functional groups (FG) or morphofunctional classification (MBFG) as surrogate for phytoplankton species?; (iii) can we use substitute groups (cladocera, copepod, rotifer or testate amoebae) as surrogate for zooplankton species?; (iv) are the environmental variables’ ordination standards concordant with the ordering patterns of phytoplankton and zooplankton species?; and (v) for both communities, is the spatial pattern of ordination maintained using density data or presence/absence of individuals or lower taxonomic resolutions? Methods The study was conducted in 25 water bodies that supply central-pivot irrigation in the Federal District - Brazil (Rio Preto Basin), in October 2012. We evaluated some physical and chemical variables as well as phytoplankton and zooplankton samples. To evaluate correlation among biological groups, numerical and higher taxonomic resolutions, we performed some Mantel and Procrustes analyses. Results Evaluating the use of substitute groups, comparisons between phytoplankton and zooplankton, FG and MBFG classifications and almost all the comparisons between zooplankton groups suggested concordant patterns. However, the values of r were low, all below 0.70. Biological analyses with phytoplankton and zooplankton can be performed using presence/absence of individuals without significant loss of information, except for MBFG classification and copepods. Data may also be used at genus or family level for copepods and testate amoebae and only data at genus level for cladocerans and rotifers. Different results were found concerning taxonomic resolution for phytoplankton considering that, while being significant, the r value was less than 0.70. Conclusions For environmental monitoring purposes, it is important to sample both phytoplankton and zooplankton communities because one is not surrogate of the other one, in the same way as phytoplankton density and their functional and morphofunctional approaches. On the other hand, to simplify the environmental monitoring, it is possible to adopt presence/absence species data instead of abundance data for both zooplankton and phytoplankton communities, except for copepods and morphofunctional approach. It is also possible to adopt genera level for zooplankton community and family level for copepods and testate amoebae.
Zooplankton plays a key role in aquatic food chains. In the present study we aimed to evaluate the trends of zooplankton studies in the scientific literature published between 1991 and 2015 and also to answer the following questions: (i) Has the number of studies increased? (ii) Which are the main countries and journals that publish papers about zooplankton? (iii) Is it possible to identify temporal trends? We used the ISI Web of Science database to find articles that had the word "zooplankton" or its groups ("copepods", "cladocerans", "rotifers", "testate amoebae") in their title, abstract or keywords. The number of zooplankton publications increased over the years, but, when we removed the effect of total publications, the number of publications on copepods decreased, while publications on testate amoebae increased. The country with the most published studies was the USA and the journal was the Hydrobiologia. The keywords formed four groups, evidencing a temporal change in the main interest of the studies on zooplankton community. The oldest articles showed the interest of researches in zooplankton species description. In subsequent years, the main concern was still species description, but also ecology and other aspects. Recently, studies concerned to environmental issues, preservation and sustainability became more frequent.
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