Jaguaribe River Basin Research Articles

Diversity and ecology of parasitic fauna of the endemic Serrasalmus brandtii Lütken, 1875 from the Caatinga Domain, Brazil

ABSTRACT The genus Serrasalmus, popularly known as ‘pirambebas’, includes 87 valid species of endemic freshwater fish from the Neotropical region. Amidst this diversity, the parasitic fauna of Serrasalmus brandtii, the unique endemic species in the Caatinga domain, was investigated in the Lima Campos dam, municipality of Icó, Ceará, Brazil. Our objectives were to survey the parasite composition and to analyse the component community of this host. Of the total of 50 hosts examined, 48 (96%) were parasitised by at least one species of parasite. A total of 682 parasite specimens were recovered, representing a mean intensity of 14.20 parasites per fish. Seven parasitic taxa were recorded: two monogeneans, three digeneans and two nematodes. The most prevalent taxa were the monogeneans Anacanthorus serrasalmi (82%) and Amphithecium falcatum (76%), also showing the highest abundance (n = 317 and n = 177, respectively). Metacercariae of Clinostomum sp. revealed the highest mean intensity of infection (7.8). This survey reveals new host records for Serrasalmus brandtii, and new parasitic records for the Jaguaribe river basin. Two of the recovered species, Clinostomum sp. and Contracaecum sp., present a zoonotic potential: to raise awareness regarding the proper handling and preparation of fish for human consumption.

Diversity and community ecology of metazoan parasites in Tetragonopterus argenteus Cuvier, 1816 (Characiformes, Characidae) from Jaguaribe River basin in Brazil.

The present study aims to inventory the metazoan parasites of Tetragonopterus argenteus from the Lima Campos weir, municipality of Icó, Ceará, Brazil and to analyze the influence of the host size and sex on the prevalence and parasitic abundance. A total of 359 metazoan parasites specimens were collected from 54 specimens of T. argenteus, presenting a mean intensity of 7.04 parasites/fish and prevalence of 94%. A richness of 10 parasite taxa were recorded, taxonomically classified into the following groups: Monogenea (n=1), Digenea (n=2) and Nematoda (n=7). The parasite community of T. argenteus was composed of helminth species with low prevalence, low mean intensity, low mean abundance, low dominance and low diversity, predominance of endoparasites of the phylum Nematoda. As for the importance value, six species were considered secondary and showed an aggregated dispersion pattern. The host size influenced significantly the abundance of Creptrotrema sp. and the prevalence of Procamallanus (Spirocamallanus) hilarii. The results present new reports of parasites have been recorded for this host, thus expanding the ecological interactions between parasites and Characiformes fish and contributing to the knowledge of the freshwater biodiversity from Brazilian Caatinga domain.

Leptodactylus macrosternum (Anura: Leptodactylidae) as a bioindicator of potentially toxic chemical elements in irrigated perimeters in northeastern Brazil

Biomonitoring programs have developed in the last decades, including the toxicity evaluation of endemic organisms in populations from polluted areas. Environmental bioindicators respond to contaminants as predictors of future damage to their population, ecosystem and human. Amphibian are considered very sensitive contamination bioindicators. Researchers in several continents have conducted ecological studies on the accumulation of potentially toxic elements in anuran tissues, especially in mining and agriculture areas. The Jaguaribe River is an important water source in northeastern Brazil, home of agriculture irrigated perimeters; but it also concerns users for increasing the risks of environmental contamination. The objective of this work was to quantify potentially toxic elements in Leptodactylus macrosternum carcasses, evaluating its potential as a contamination bioindicator of agrosystem areas in the Lower Jaguaribe River basin, Ceará, northeastern Brazil. The elements As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were detected in the L. macrosternum carcasses' samples. There was no significant difference in the concentrations of detected metals by area status; however, analysis of variance suggested that individuals had more constant exposure to Cu, Ni, Cd and Pb in cultivated area status. The cluster analysis of chemicals indicated two optimal element groups, which proposed different compounds from diverse origins. Body index significantly influenced Mn and Pb, while sex influenced Fe and Pb accumulation. The results suggested that the L. macrosternum species is a conceivable local bioindicator for environmental potentially toxic elements. However, other tissues will be tested to improve their sensitivity and validate their capacity to be employed as a biomonitoring tool.

Spatio-temporal dynamics of land use changes of an intense anthropized basin in the Brazilian semi-arid region

The temporal dynamics of land use and land cover (LULC) changes affect natural resources and biodiversity on a local and global scale. The negative impacts of LULC changes can be enhanced in arid and semi-arid areas, where vegetations are more sensitive to changes due to limited water availability. The present study aimed to explore the detailed spatio-temporal LULC changes in the Jaguaribe River basin, Ceará state, Brazil. Specifically, we aimed to identify the dynamics of LULC changes from 1985 to 2018, including the main LULC conversations and the sub-basins that presented the most intense dynamics. For this, we used annual LULC maps generated by the national Mapbiomas project. The LULC conversions were determined through cross-tabulation analysis and pixel comparison analysis. Our results indicate that in the last three decades there was a significant conversion of the natural vegetation Caatinga (Arboreal and Herbaceous) to agricultural and livestock areas, showing that the anthropic activities are the main factors behind the historical landscape changes in the Jaguaribe River basin. The Middle Jaguaribe and the Lower Jaguaribe sub-basins were the most affected by LULC changes during the study period. While the LULC changes in Middle Jaguaribe sub-basin reveal that this area has been impacted by anthropic interference with similar areas of pasture and the caatinga class since 1985, the Lower Jaguaribe sub-basin was continuously impacted mainly by the expansion of the annual and perennial culture and reduction of natural vegetation areas. The Lower Jaguaribe sub-basin had a higher percentage of altered areas, LULC classes per pixel and LULC changes during the study period. The spatio-temporal analysis presented can orient planning actions to conserve natural resources and preserve the biodiversity in this semi-arid region of Brazil.

Socio-Economic Indexes for Water Use in Irrigation in a Representative Basin of the Tropical Semiarid Region

Performance evaluation of irrigated agriculture is an important tool that assists in decision-making on water management in the river basin, particularly in tropical semiarid regions. This study was carried out using information from the Jaguaribe River basin, located in the Northeast region of Brazil, which has an important restriction in the availability of water resources and high competition for water use. From a set of indicators (production, water, economic, and social), the overall performance index of irrigated agriculture was estimated (ranging from zero to 1.0) for two scenarios: high water scarcity and low water scarcity. The performance index used was based on the mean value of these security criteria normalized with respect to the maximum value of the indicator for the crop obtained in the sub-basin. A low performance index of irrigated agriculture (less than 0.3) has always been associated with inadequacy of more than one security indicator. Crops with significant cultivated areas and, therefore, requiring a high volume of irrigation, such as rice, sugar cane, banana, and green coconut, require technical interventions related to the management of the soil–water–plant system aiming at improving yield with less water. Under conditions of water restrictions, crops with performance indexes higher than 0.3 should be prioritized. The study presented here for Jaguaribe River basin may support public policies related to irrigation and agronomic techniques necessary to improve the performance of agricultural under tropical dry lands.

“Network” socio-hydrology: a case study of causal factors that shape the Jaguaribe River Basin, Ceará-Brazil

ABSTRACT Socio-hydrology has recently garnered attention as a promising research paradigm among hydrologists. In this paper, we argue that viewing the socio-hydrological systems as a network of causal factors can assist in these efforts by revealing emergent properties of socio-hydrological systems. These factors, which are neither actors nor affiliations but symbolic representations of miscellaneous phenomena, represent the key variables affecting socio-hydrological system behaviour. Despite being crucial for understanding system dynamics, these factors are not captured by most equations of coupled human–water coevolutionary models. To demonstrate our method, we use qualitative case study research to analyse the Jaguaribe Basin in Ceará State-Brazil as a network of factors, i.e. mental conceptions, and representations of water resource management experts. We show that most results are unsurprising, exhibiting expected causal relationships. However, there was at least one unexpected result, which showed that the variable “conflict” was the single most sensitive variable to systemic evolution.

First record of non-native platyfish, Xiphophorus maculatus (Günther, 1866) (Cyprinodontiformes, Poeciliidae), in the Jaguaribe River basin, northeastern Brazil

We provide the first record of Xiphophorus maculatus (Günther, 1866) in a river basin in the northeastern Brazil. Specimens were collected in the Jaguaribe River basin, João Pessoa, Paraíba state, Brazil. Two hundred eighty-one specimens, corresponding to 143 males and 138 females of X. maculatus, were collected at nine sites along the basin, from 2017 to 2019. Specimens total length ranged from 17.5 to 26.6 mm in males and from 11.7 to 32.7 mm in females. Introduction of non-native species greatly threatens the biological diversity worldwide. When introduced into a new habitat, X. maculatus usually decreases microcrustacean, macroinvertebrate and native fish populations.

Indicators and criteria to define the priority for irrigation water use in the Baixo Jaguaribe basin, Brazil

The Baixo Jaguaribe basin has the smallest area of that Watershed (upper, middle and lower Jaguaribe river), but it has enormous importance in terms of water resources. The amount of water for crops irrigation is quite representative in relation to the total volume of water demanded in the entire Jaguaribe river basin. The research presents a methodology of indicators and criteria to define the priority of use of irrigation water in conditions of water scarcity. The analysis of four requirements of socioeconomic security (productive, economic, water and social) indicated a recommendation to cultivate tomato, forage palm, melon, cassava and papaya, that required the smallest water cuts for irrigation at the River Basin (less than 21%). However, crops as orange, rice, soursop, coconut, lemon, custard apple, guava, mango, banana and sugarcane must present the highest water cuts (more than 37%), mainly orange, rice, soursop, coconut, lemon and custard apple which may present values higher than 46% due to their low profitability and yield, and high water consumption.

Trends in Crop Reference Evapotranspiration and Climatological Variables Across Ceará State – Brazil

Abstract Irrigation has a substantial share in total world water demand. At the global level, the withdrawal ratio for agriculture is 69 percent. Irrigation is necessary to compensate evapotranspiration (ET) deficit due to insufficient precipitation. Knowing the impacts of climatic changes on meteorological variables that directly affect the ET is important for successful climate adaptation. This paper analyzes annual trends in measured meteorological variables and in the crop reference evapotranspiration (ET0), at eight climatological stations in Ceará State, Brazil. Two statistical tests for trend analysis were used - Mann-Kendall and linear regression. The results indicate positive trend, statistically significant, in the maximum air temperature in five of eight stations. Minimum air temperature showed positive trend in three stations. Wind speed, sunshine hours and relative humidity presented positive and negative trends. These irregular patterns directly impacted ET0 in three stations. It seems that the increasing trend in ET0 was probably due to a significant increase detected in maximum temperature and minimum air temperature, not fully offset by the decrease in wind speed and relative humidity. The warning from these results is that water demand for irrigation is expected to significantly increase over the next decades on in Jaguaribe River Basin.

Análise da Suscetibilidade à Ocorrência de Enchentes e Inundações na Bacia do Rio Jaguaribe - João Pessoa/PB (Analysis of the susceptibility to the occurrence of floods and inundations in the Jaguaribe river basin - João Pessoa / PB)

Enchentes e inundações constituem um fenômeno geomorfológico que decorre do aumento da vazão das águas pluviais que escoam numa bacia hidrográfica. A suscetibilidade de ocorrência desses fenômenos na bacia do rio Jaguaribe foi analisada com base nos seguintes índices morfométricos: índice de circularidade, densidade de drenagem, fator forma e o coeficiente de compacidade. Os valores encontrados para os índices adotados nessa pesquisa indicaram uma bacia com baixa suscetibilidade à ocorrência de enchentes. Tal proposição foi reforçada pelas características físicas da área, a qual apresenta um relevo esculpido sobre rochas sedimentares, de aspecto semiplano e tabular, pouco dissecado, havendo poucas áreas de declives acentuados, a não ser em determinadas porções dos vales fluviais. Os canais fluviais apresentam poucas variações altimétricas, o que garante um fluxo laminar, de baixo poder erosivo. Essa relativa estabilidade encontrada na caracterização física da referida bacia, é perturbada pelo processo de urbanização observado nos últimos 35 anos, que tem se refletido na formação de acentuados processos erosivos que se desenvolvem na porção interfluvial da bacia, causando o assoreamento dos canais fluviais. Além disso, o aumento do escoamento superficial causado pela impermeabilização do solo e a construção de residências dentro da planície e do canal fluvial, constitui-se como outro fator preponderante. A conjugação desses fatores resulta na formação de áreas de risco de enchentes e inundação, além do risco de movimentos de massa, que por sua vez, surgem como produto do modo como ocorre o uso e ocupação das terras. abstract Floods and inundations constitute a geomorphological phenomenon that results from the increase in the water flow in a river basin. The susceptibility of occurrence of these phenomena in the Jaguaribe river basin was analyzed based on the following morphometric indices: circularity index, drainage density, form factor and the coefficient of compactness. The values found for the indices adopted in the research indicated a basin with low susceptibility to the occurrence of floods. This proposition was reinforced by the physical characteristics of the area, which presents a carved relief on sedimentary rocks, of semiplaning and tabular aspect, little dissected, with few areas of steep slopes, except in certain portions of the river valleys. The river channels have a few altimetry variations, which guarantees a laminar flow, with low erosive power. This relative stability found in the physical characterization of this basin is disturbed by the process of urbanization observed in the last 35 years, which has been reflected in the formation of marked erosive processes that develop in the interfluvial portion of the basin, causing the sedimentation of the fluvial channels. Moreover, the increase in surface runoff caused by soil sealing and the construction of residences within the plain and fluvial channel constitutes another preponderant factor. The combination of these factors results in the formation of inundation and flood risk areas, and the risk of mass movements, which in turn, arise as a product of the way the use and occupation of land occurs Keyboards: Morphometric; Floods; Inundations; Jaguaribe River Basin.

DISTRIBUIÇÃO DE MERCÚRIO NA FAUNA ESTUARINA DO RIO JAGUARIBE - CE

Modificações na paisagem natural aliadas às mudanças climáticas globais, alteram a hidrodinâmica da Bacia Inferior do rio Jaguaribe, possibilitando maior biodisponibilidade de contaminantes, entre eles o mercúrio (Hg). Análise das concentrações de Hg na fauna estuarina (13 espécies de peixes e 5 de invertebrados) mostraram variações nas concentrações de Hg relacionadas aos hábitos alimentares das espécies. Tanto entre invertebrados quanto nos peixes, as maiores concentrações foram encontradas nas espécies carnívoras. Entretanto, não foram encontradas diferenças significativas entre as concentrações médias entre peixes carnívoros e onívoros, e entre invertebrados carnívoros e filtradores, o que pode estar relacionado as características biológicas específicas, como tamanho, estado de maturação e composição da dieta.

Climate change impacts on water demand and availability using CMIP5 models in the Jaguaribe basin, semi-arid Brazil

The objective of this study was to analyze climate change impacts on irrigation water demand and availability in the Jaguaribe River basin, Brazil. For northeastern Brazil, five global circulation models were selected using a rainfall seasonal evaluation screening technique from the Intergovernmental Panel on Climate Change named Coupled Model Intercomparison Project Phase 5. The climate variables were generated for the base period of 1971–2000, as were projections for the 2025–2055 future time slice. Removal of maximum and minimum temperature and rainfall output bias was used to estimate reference evapotranspiration, irrigation water needs, and river flow using the rainfall—river flow hydrological model Soil Moisture Accounting Procedure for the baseline and future climate (Representative Concentration Pathways 4.5 and 8.5 scenarios). In addition, by applying improved irrigation efficiency, a scenario was evaluated in comparison with field observed performance. The water-deficit index was used as a water availability performance indicator. Future climate projections by all five models resulted in increases in future reference evapotranspiration (2.3–6.3%) and irrigation water needs (2.8–16.7%) for all scenarios. Regarding rainfall projections, both positive (4.8–12.5%) and negative (− 2.3 to − 15.2%) signals were observed. Most models and scenarios project that annual river flow will decrease. Lower future water availability was detected by the less positive water-deficit index. Improved irrigation efficiency is a key measure for the adaptation to higher future levels of water demand, as climate change impacts could be compensated by gains in irrigation efficiency (water demand changes varying from − 1.7 to − 35.2%).

Contrasting Mercury Bioavailability in the Marine and Fluvial Dominated Areas of the Jaguaribe River Basin, Ceará, Brazil.

This study evaluates the influence of environmental and biological factors upon the mercury (Hg) concentrations in the aquatic fauna in the Lower Jaguaribe River Basin (LJRB) - NE, Brazil. Two campaigns conducted in 2015 in the fluvial (FDA) and in the marine-dominated (MDA) areas resulted in 830 organisms from 16 species collected (nine of finfish and seven of invertebrates). Among the invertebrates, the highest Hg concentration occurred in the crab Callinectes bocourti (201ngg-1), while among the finfish the highest concentration was found in the ladyfish Elops saurus (109ngg-1), both carnivorous and of high trophic level (TL). Intra-specific comparison showed significant higher Hg concentrations in individuals captured in the MDA. Also, Hg bioaccumulation rate in the shrimp Litopenaeus vannamei was much higher in the MDA. These results, point to a concomitant control of Hg bioavailability by physical-chemical variables along the estuarine gradient of the LJRB.

Wind power potential for irrigation of rice and maize using geoprocessing in the Baixo Jaguaribe river basin, Ceará State - Brazil

Realizing that there is currently a larger search for renewable energy sources and that the coastal region of Ceará has a strong wind potential, this work proposes to demonstrate, through geoprocessing techniques, the feasibility of using wind energy systems in the irrigation of corn and rice crops in the Baixo Jaguaribe sub-basin. The production map of these crops and the Atlas of Wind Potential in Ceará State were overlaid with the help of ArcGIS software. After the processing, it was verified that only 4.15% of the territory of the basin studied has winds capable to install wind energy systems, with predominance of winds between 6.0 and 7.0 m.s-1. The use of other sources of renewable energy for irrigation purposes is suggested for this region.

SCIENTOMETRIC STUDY OF SCIENTIFIC LITERATURE ON THE ESTUARIES OF CEARÁ STATE

Os estuários são ambientes costeiros de grande importância econômica, social e ambiental ao redor do Mundo. Muitos estudos têm sido realizados sobre dinâmica estuarina, principalmente relacionado com circulação e processo de mistura para melhor compreensão dos princípios da oceanografia física estuarina. A distribuição dos estudos realizados nos estuários do Estado do Ceará relacionado com a área de hidrodinâmica estuarina apresenta uma desigualdade e/ou um maior interesse pelo principal sistema estuarino da região, o rio Jaguaribe, o que reflete em quantidades distintas de estudos entre os três setores da costa cearense. Ao todo foram selecionados 100 estudos publicados para realizar uma distribuição dos estudos em relação o setor da costa e classificação em Literatura Cinza e Literatura Branca. Os resultados mostram que 77% das publicações são classificadas como Literatura Cinza e 23% como Literatura Branca. 52% dos estudos foram realizados em estuários localizados no litoral leste (setor 3), sendo 42 estudos no estuário do rio Jaguaribe, 22% nos estuários do litoral oeste e extremo oeste (setor 1), 21% nos estuários da região metropolitana de Fortaleza (setor 2), e, 5% são estudos realizados em mais de um estuário e/ou setor do litoral.

Reservoir yield intercomparison of large dams in Jaguaribe Basin-CE in climate change scenarios

ABSTRACT Climate changes can have different impacts on water resources. Strategies to adapt to climate changes depend on impact studies. In this context, this study aimed to estimate the impact that changes in precipitation, projected by Global Circulation Models (GCMs) in the fifth report by the Intergovernmental Panel on Climate Change (IPCC-AR5) may cause on reservoir yield (Q90) of large reservoirs (Castanhão and Banabuiú), located in the Jaguaribe River Basin, Ceará. The rainfall data are from 20 GCMs using two greenhouse gas scenarios (RCP4.5 and RCP8.5). The precipitation projections were used as input data for the rainfall-runoff model (SMAP) and, after the reservoirs’ inflow generation, the reservoir yields were simulated in the AcquaNet model, for the time periods of 2040-2069 and 2070-2099. The results were analyzed and presented a great divergence, in sign (increase or decrease) and in the magnitude of change of Q90. However, most Q90 projections indicated reduction in both reservoirs, for the two periods, especially at the end of the 21th century.

A method to assess hydrological drought in semi-arid environments and its application to the Jaguaribe River basin, Brazil

ABSTRACTThis manuscript proposes a method to assess hydrological drought in semi-arid environments under high impoundment rate and applies it to the semi-arid Jaguaribe River basin in Brazil. It analyzes droughts (1) in the largest reservoir systems; (2) in the Upper Basin, considering 4744 reservoirs, 800 wells and almost 18,000 cisterns; and (3) in reservoirs of different sizes during multiyear droughts. Results show that the water demand is constrained in the basin; hydrological and meteorological droughts are often out of phase; there is a negative correlation between storage level and drought severity; and the small systems cannot cope with long-term droughts.

Mercury in Indigenous, Introduced and Farmed Fish from the Semiarid Region of the Jaguaribe River Basin, NE Brazil

Indigenous, introduced and farmed fish species were collected from the Jaguaribe Basin, NE Brazil to assess total and methyl mercury concentrations in muscle tissue and to determine its relationship with fish origin. The results obtained from introduced species were compared to the Hg content of their original area of occurrence, which is located in the Amazon region. Farmed and wild individuals of Oreochromis niloticus (tilapia) were also compared. Introduced species presented lower Hg contents compared to their Amazonian counterparts. Wild individuals of O. niloticus also presented higher Hg contents than farmed individuals with similar sizes. However, methyl Hg concentrations were not significantly different between the two groups. Total Hg and methyl Hg concentrations were higher in carnivorous species, especially those from the Amazon region, and surpassed the Brazilian guidelines for fish consumption. Based on their Hg content, Jaguaribe basin fish do not pose a significant threat to human consumption.

The influence of castanhão reservoir on nutrient and suspended matter transport during rainy season in the ephemeral Jaguaribe river (CE, Brazil)

Measurements of nutrient and suspended matter concentrations and loads entering and leaving the Castanhão reservoir during the rainy season were carried out to assess the influence of this large reservoir on land-sea fluvial transport in the ephemeral Jaguaribe river basin. Spatial variation indicated statistically significant attenuation of concentrations only for total phosphorous and suspended matter across the reservoir. Strong retention of nutrients and suspended matter loads by the reservoir was observed with average trapping efficiency of 89% for dissolved silicon, 98% of soluble reactive phosphorus, 71% for ammonium, 87% for total nitrogen, 98% for total phosphorus and 97% for suspended matter compared to the reservoir inflow. The dam operational procedure defined by the ephemeral conditions of the river reduced water releases compared to reservoir inflow and induced strong retention of nutrient and suspended matter loads within the reservoir when fluvial transfer occurs in this semiarid watershed.

Reservoir Management Using Coupled Atmospheric and Hydrological Models: The Brazilian Semi-Arid Case

This study investigated the sensitivity of a dynamic downscaling atmospheric model system coupled with a rainfall-runoff model to hindcast an example of reservoir water management in the semi-arid region of Northeast Brazil (NEB). A regional atmospheric spectral model (RSM) is driven by the outputs of an atmospheric general circulation model (AGCM), itself forced by the observed sea surface temperature over the World Ocean. Daily precipitation simulated by the RSM was then used as the input to a hydrological rainfall-runoff model for the Upper Jaguaribe River Basin to estimate inflows at the Oros Reservoir in the state of Ceara. A hindcast analysis of precipitation was performed during the rainy season over NEB (January to June) from 1971 to 2000. The RSM captured the precipitation variability relatively well when a probability density function (PDF) was used to correct the numerical bias. Three hindcast series of inflow using (i) the observed rainfall, (ii) the simulated rainfall before the PDF correction, and (iii) the simulated rainfall after the PDF correction were performed during the study period and then compared to the series of observed inflow. The atmospheric-rainfall-runoff “cascade” model efficiency was evaluated by comparing the Oros Reservoir release decisions from different scenarios based on observed, simulated (RSM, RSM-PDF), and mean historical reservoir inflows. The cascade model has the potential, relatively well balanced during dry, normal or wet years, to be a useful tool to correctly forecast the decision managements of reservoirs in the semi-arid region of NEB. Additional progress in the numerical simulation is however necessary to improve the performance.