Aquatic Sciences最新文献

{"title":"The impact of drought duration on two Potamogeton species with different growth forms","authors":"Maya M. Daumal,&nbsp;Dian Oosterhuis,&nbsp;Michiel J. J. M. Verhofstad,&nbsp;Roy H. J. Erkens,&nbsp;Edwin T. H. M. Peeters","doi":"10.1007/s00027-024-01089-4","DOIUrl":"10.1007/s00027-024-01089-4","url":null,"abstract":"<div><p>When facing new climate extremes, aquatic plant communities may experience more frequent or increasing durations of water shortages. Aquatic macrophytes of permanently inundated habitats (true hydrophytes) may lack the physiological or morphological characteristics that protect terrestrial plants from drying out. Aquatic hydrophytes with floating or emergent leaves are expected to be more resilient to droughts than completely submerged plants, as they have morphological characteristics adapted to air-exposed conditions. Therefore, we expected the latter to survive longer periods of air exposure and perform better with increasing drought than a completely submerged growing species. Here, we conducted a microcosm experiment and exposed two <i>Potamogeton</i> species—the completely submerged growing <i>Potamogeton perfoliatus</i> and the areal leaf producing <i>Potamogeton nodosus</i>—to different drought conditions (1, 5, and 15 days). We aimed to detect how two species with different growth strategies cope with and respond to increasing air exposures with waterlogged sediment. Both species showed a resistance to 1–5 days of drought but showed high mortality after 15 days. They displayed significant differences in all measured morphological responses (shoot length, side shoot, and leaf counts), plant chemistry (carbon, nitrogen, and phosphate), and the produced biomass (shoot, root, leaves), and reacted significantly to increasing drought durations. Differences in their resistance were observed based on the mortality rate and morphological responses. To prevent long-term droughts and keep mortality low, we recommend to the water managers to identify areas of risk and increase water levels during dry periods.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"86 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00027-024-01089-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141193623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of rarity and ecological preferences of the non-marine ostracods (Crustacea) in Çanakkale Province (Türkiye)","authors":"Mehmet Yavuzatmaca,&nbsp;Okan Külköylüoğlu,&nbsp;Alper Ataman,&nbsp;Ahmet Ayteğin,&nbsp;İsmail Ömer Yılmaz","doi":"10.1007/s00027-024-01088-5","DOIUrl":"10.1007/s00027-024-01088-5","url":null,"abstract":"<div><p>Rarity as a multidimensional concept has not been discussed for the ostracods along with the effects of physicochemical factors and sedimentation rates of waters on their distribution. We randomly sampled 91 aquatic sites including eight habitat types in the Çanakkale Province to study ostracod species rarity, commonness, and ecological preferences, and to test the relationships between the rarity index (average of geographic range, habitat specificity, and population size indices) and environmental factors. A total of 44 ostracod taxa (25 living) were reported from 75 sites. Among the species, <i>Candonocypris caledonica</i> was recorded for the first time in Türkiye. Sixty percent of 25 living species exhibited cosmopolitan characteristics, making significant contributions to the diversity of ostracods. The well-known cosmopolitan species, <i>Heterocypris salina</i> (rr = 0.268), <i>Cypridopsis vidua</i> (rr = 0.289), <i>Limnocythere inopinata</i> (rr = 0.330), <i>Ilyocypris bradyi</i> (rr = 0.370), and <i>Psychrodromus olivaceus</i> (rr = 0.390), were identified as common species based on the rarity index (rr) values. Of the environmental variables, only sediment grain sizes (×2000, ×500, and ×63 μm) were found to be effective on the distribution of ostracod species. The Shannon index exhibited a positively significant association with ×2000, while the population size index displayed a linear relationship with ×63 μm grain size, indicating a small population size and rarity. Associations among index values, sediment grain size, and water quality variables showed that comprehensive studies on ostracods, analyzing both water and sediment, can provide a clearer and more precise information for evaluating the rarity and ecological preferences of species.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"86 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00027-024-01088-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141193625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial contamination in a large drinking water reservoir in north Vietnam","authors":"Nhu Da Le,&nbsp;Thi Mai Huong Nguyen,&nbsp;Thi Thu Ha Hoang,&nbsp;Emma Rochelle-Newall,&nbsp;Thi Xuan Binh Phung,&nbsp;Thi Minh Hanh Pham,&nbsp;Thi Thuy Duong,&nbsp;Tien Dat Nguyen,&nbsp;Thi Phuong Quynh Le","doi":"10.1007/s00027-024-01086-7","DOIUrl":"10.1007/s00027-024-01086-7","url":null,"abstract":"<div><p>Surface water is used by 50% of the global population as a source of drinking water. It is therefore important to have an understanding of the quality of surface water used for this purpose, given its potential risk to human health. We studied fecal indicator bacteria [FIB; comprising total coliforms (TC), <i>Escherichia coli</i> (EC) and fecal streptococci] numbers along with 28 other water quality variables in Hoa Binh reservoir, Vietnam during six sampling campaigns undertaken from July 2023 to January 2024. Hoa Binh is a multi-purpose reservoir used for aquaculture, drinking water for local cities and Hanoi, the capital, which is downstream of the reservoir, and irrigation. Of the measured FIB, the mean value of TC exceeded that permitted by the Vietnam technical regulation for surface freshwater, QCVN 08-MT:2023/BTNMT. The mean values of the other variables, except for total nitrogen, were within the limits, although the maximal values of total organic carbon and total phosphorus exceeded them. Different point sources, including those originating from the local human population, tourists, livestock farming and fish cage farming, and diffuse sources from agriculture, comprise the major sources of contamination of the reservoir. Due to the importance of Hoa Binh reservoir for the provision of drinking water for Hanoi, the largest city of Vietnam, our results indicate the need to regularly monitor the quality of the water in the reservoir to provide a scientific basis for the implementation of timely measures to protect it. Our results also contribute to filling the knowledge gap on the microbial quality of water in developing countries.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"86 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141193662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phytoplankton composition in Mediterranean confined coastal lagoons: testing the use of ecosystem metabolism for the quantification of community-related variables","authors":"Maria Bas-Silvestre,&nbsp;Maria Antón-Pardo,&nbsp;Dani Boix,&nbsp;Stéphanie Gascón,&nbsp;Jordi Compte,&nbsp;Jordi Bou,&nbsp;Biel Obrador,&nbsp;Xavier D. Quintana","doi":"10.1007/s00027-024-01084-9","DOIUrl":"10.1007/s00027-024-01084-9","url":null,"abstract":"<div><p>Estimations of ecosystem metabolism have rarely been used to quantify productivity in structural reductionist approaches for the description of phytoplankton composition. However, estimations of ecosystem metabolism could contribute to a better understanding of the relationship between phytoplankton composition and ecosystem functioning. To examine this, we investigated the community structure of phytoplankton in a set of Mediterranean coastal lagoons (natural and artificial) during a hydrological cycle to identify the most important environmental variables determining phytoplankton species composition. The focus of the study was on the quantification of productivity-related variables using estimations of ecosystem metabolism, such as different proxies for the estimation of the production-to-biomass ratio and of the relative importance of <i>K-</i> and <i>r</i>-strategies, which are commonly used conceptually but not quantified. Our results demonstrated differences in phytoplankton composition between seasons, due to the dominant hydrological pattern of flooding confinement in the salt marsh, and between lagoons that were caused by different levels of nutrient availability. Moreover, there was a notable decrease in the production/biomass ratio and a prevalence of <i>K</i>-strategists with seasonal succession, as predicted by Margalef’s mandala. Thus, the results showed that estimations of ecosystem metabolism are useful for the higher frequency quantification of important ecological variables, and contribute to a better understanding of planktonic assemblages, and physical and chemical changes, in these fluctuating ecosystems.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"86 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00027-024-01084-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141173153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plankton assemblages in a tropical West African estuary","authors":"Rael Adhiambo,&nbsp;Paul Kojo Mensah,&nbsp;Emmanuel Acheampong,&nbsp;Eric Appiah Krampah","doi":"10.1007/s00027-024-01085-8","DOIUrl":"10.1007/s00027-024-01085-8","url":null,"abstract":"<div><p>The taxonomic composition, abundance, diversity and spatial distribution of phytoplankton and zooplankton, as well as the prevailing hydrographic conditions, were examined in the Whin Estuary, which is considered one of the most pristine and productive coastal ecosystems of Ghana, which is located on the Gulf of Guinea. Hydrographic and plankton variables were determined along the gradient of the estuary between March and July 2022 across two seasons and tidal periods. A total of 50 genera of phytoplankton and 27 genera of zooplankton were recorded across the two seasons and sampling periods. Diatoms and copepods dominated the plankton communities across the estuary. Plankton genera such as <i>Navicula</i>, <i>Nitzschia</i>, <i>Thalassiosira</i>, <i>Cyclops</i>, <i>Paracalanus</i> and <i>Temora</i> were recorded across all the seasons and tidal periods, despite the varying hydrographic conditions. The environmental variables varied across the seasons, tidal periods and sampling stations in the estuary. For instance, temperature, DO, transparency, and chlorophyll <i>a</i> varied significantly (<i>p</i> &lt; 0.05) across both the seasons and tidal periods. pH values were significantly (<i>p</i> &lt; 0.05) lower in the rainy season compared to the dry season. There was a strong salinity gradient across the estuary, with the upper reaches dominated by freshwater organisms, such as cladocerans and cyanobacteria, and the lower reaches by marine organisms, primarily diatoms and copepods. In sum, the results reported here are important as they highlight the distribution of plankton communities in a tropical estuarine ecosystem and can serve as a reference for the management of tropical brackish ecosystems.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"86 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141059532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structure of plankton and waterbird communities under water level fluctuations: two case studies in shallow lakes of the Patagonian steppe","authors":"Sol Porcel,&nbsp;Juan Francisco Saad,&nbsp;Carmen Alejandra Sabio y García,&nbsp;Martín Saraceno,&nbsp;María Cristina Marinone,&nbsp;Laura Fasola,&nbsp;Ignacio Roesler,&nbsp;Julio Lancelotti,&nbsp;Irina Izaguirre","doi":"10.1007/s00027-024-01083-w","DOIUrl":"10.1007/s00027-024-01083-w","url":null,"abstract":"<div><p>The Buenos Aires Lake Plateau, a unique semi-arid environment and priority area for waterbird conservation in Argentina, has recently shown reductions in lake sizes due to scarce rainfall. This study assessed the impact of contrasting hydrological conditions on the abiotic variables of lakes Chapu and Cervecero, as well as on the structure of plankton and how this affected the use of the lakes by waterbirds. We show that hydrological conditions shape the abiotic and biological features of these lakes. In 2015, both lakes were vegetated, but by 2016, their water level had dropped, causing decreased macrophyte coverage. In 2017, the lakes dried up completely, but were refilled the following year. The partial drought of 2015-2016 led to reduced concentrations of nutrients and food that support a high density and richness of birds, which are mostly aquatic and terrestrial feeders. After the extreme drought in 2017 and refilling phase in 2018, there was an improvement in the water quality of lake Chapu, as indicated by its increased clarity compared to that in 2015, while Cervecero remained turbid. Increased homogenization in plankton and waterbird species composition became evident in both lakes. There was a cyanobacteria bloom in Cervecero, while in Chapu Gammaproteobacteria were dominant. Both lakes supported few waterbirds, of which aquatic-terrestrial feeders and terrestrial herbivores were dominant. The abundance of the endemic and endangered hooded grebe (<i>Podiceps gallardoi</i> Rumboll 1974) declined with the cover of macrophytes, which these birds use when establishing their colonies. In sum, this study revealed changes in the conditions of lakes Chapu and Cervecero and their plankton communities in response to hydrological shifts, with implications for waterbird assemblages and, thus, biodiversity conservation.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"86 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140972325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An inexpensive method for the measurement of photosynthetically active radiation profiles in waterbodies","authors":"Facundo Scordo,&nbsp;Carina Seitz,&nbsp;Erin K. Suenaga,&nbsp;M. Cintia Piccolo,&nbsp;Sudeep Chandra,&nbsp;Martín Amodeo,&nbsp;Gerardo M. E. Perillo","doi":"10.1007/s00027-024-01082-x","DOIUrl":"10.1007/s00027-024-01082-x","url":null,"abstract":"<div><p>We developed an inexpensive light instrument (ILI) and protocol for the measurement of photosynthetically active radiation (PAR) at discrete depths underwater. We tested the accuracy of the ILI against a submersible radiometer (RAD) and a Secchi disk method. The ILI consists of a PAR sensor (HOBO MX2202; Onset) attached to a flat disk that ensures that the sensor faces upwards when lowered through the water column. The flat disk is attached to a rope marked at 1-m increments (to 20 m) that allows for the measurement of PAR at discrete depths. A weight is attached to the bottom of the flat disk to prevent it from drifting. The ILI is much cheaper (US $130), less bulky, and lighter (1.1 kg) than the RAD (US $40,000, weight 9 kg). We tested our method in a mesotrophic lake and in an oligotrophic lake in summer and fall 2023. The correlations between the RAD and ILI measurements of irradiance at depth (as a percentage of surface irradiance), and the depth to which 1% of the PAR at the surface penetrated the water (<i>Z</i>_1%PAR), were high and did not significantly differ. There was a difference of 8% in the <i>Z</i>_1%PAR determined by the ILI compared with that determined by the RAD. However, the estimated Z_1%PAR based on the Secchi disk data was 37% deeper than that calculated with the RAD data. Our method should enable the study of underwater PAR in remote regions where transporting bulky and expensive equipment is impossible due to logistic and/or financial constraints. Moreover, our method can be used for the direct measurement of PAR at discrete depths.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"86 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140885000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Land-use effects on leaf-litter breakdown in streams in a tropical lowland catchment","authors":"Oscar Alberto Rojas-Castillo,&nbsp;Sebastian Kepfer-Rojas,&nbsp;Dean Jacobsen","doi":"10.1007/s00027-024-01079-6","DOIUrl":"10.1007/s00027-024-01079-6","url":null,"abstract":"<div><p>The expansion of oil palm and cattle grazing in the tropics continues to alter numerous ecosystem functions. The generated land-use change is potentially impacting stream leaf-litter breakdown, a fundamental process for freshwater ecosystems. To assess the effect of land-use change, we studied breakdown rates of forest (<i>Pachira aquatica</i>, <i>Pouroma aspera</i>, <i>Sloanea ampla</i>, and <i>Hippocratea volubilis</i>) and oil palm (<i>Elaeis guineensis</i>) leaves after a 26-day immersion in streams surrounded by rainforests, grazing lands, or oil palm plantations with and without riparian buffers. In addition, we assessed breakdown drivers by deploying litter bags (248) of two mesh sizes (15 mm and 0.5 mm) allowing or restricting macroinvertebrates’ access (134 coarse-mesh bags and 114 fine-mesh bags). Forest leaf breakdown by microbes (fine-mesh) was lower by 55% in the plantations compared to forests; while microbial oil palm-leaf breakdown was lower by 32% in the unbuffered plantations compared to forests (<i>p</i> &lt; 0.05). Total litter breakdown was lower (<i>p</i> &gt; 0.05) in the plantations but not when these preserved riparian buffers. Litter breakdown was driven primarily by microbes in all land uses except in the buffered plantations, possibly due to increased shredder biomass. These results suggest that oil palm agriculture may decrease microbial stream leaf-litter breakdown, especially in streams with no riparian buffers.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"86 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00027-024-01079-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140835401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysing the contribution of intermittent rivers to beta diversity can improve freshwater conservation in Mediterranean rivers","authors":"Maria Soria,&nbsp;Núria Cid,&nbsp;Jean Ortega,&nbsp;Luis Mauricio Bini,&nbsp;Raúl Acosta,&nbsp;Cayetano Gutiérrez-Cánovas,&nbsp;Pablo Rodríguez-Lozano,&nbsp;Pau Fortuño,&nbsp;Dolors Vinyoles,&nbsp;Francesc Gallart,&nbsp;Narcís Prat,&nbsp;Núria Bonada","doi":"10.1007/s00027-024-01074-x","DOIUrl":"10.1007/s00027-024-01074-x","url":null,"abstract":"<div><p>In Mediterranean climate regions, intermittent rivers (IRs) harbor highly dynamic communities with species and trait composition changing over time and space. Simultaneously considering multiple biodiversity facets and a spatiotemporal perspective is, therefore, key to developing effective conservation strategies for these ecosystems. We studied the spatiotemporal dynamics of aquatic macroinvertebrates in rivers of the western Mediterranean Basin by analysing (1) the taxonomic and functional richness and the local contribution to beta diversity (LCBD; measured considering taxonomic and functional facets) of perennial rivers and IRs over five sampling times, and (2) their relation with flow intermittence, local environmental uniqueness, and the number of anthropogenic impacts. Both analyses were also conducted for the subset of data including only IRs to compare values between their flowing and disconnected pool phases. According to our results, taxonomic and functional richness tended to be higher in perennial rivers than in IRs, while taxonomic and functional LCBD tended to be higher in IRs than in perennial rivers. When comparing IR sites over time, higher values of taxonomic and functional LCBD corresponded mostly to their disconnected pool phase. Flow intermittence, the number of anthropogenic impacts and the environmental uniqueness were significant predictors of taxonomic and functional richness, but only flow intermittence was an important predictor of taxonomic LCBD. For the IR-only data subset, disconnected pool permanence was the main predictor explaining spatiotemporal patterns. Our results highlight the importance of IRs to biodiversity conservation of Mediterranean climate rivers, especially during the disconnected pool phase, suggesting that these ecosystems cannot be ignored in conservation planning strategies.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"86 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00027-024-01074-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140654666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of environmental conditions and the fragmented landscape on the co-occurrence patterns of the ichthyofauna of a stream in southwestern Brazilian Amazon","authors":"Lucas Pires de Oliveira,&nbsp;Fabiano Corrêa,&nbsp;Jean Carlo Gonçalves Ortega,&nbsp;Ronaldo Souza da Silva,&nbsp;Edson Fontes de Oliveira,&nbsp;Lisandro Juno Soares Vieira","doi":"10.1007/s00027-024-01080-z","DOIUrl":"10.1007/s00027-024-01080-z","url":null,"abstract":"<div><p>We assessed the spatiotemporal co-occurrence patterns of a fish assemblage in the watershed of a stream in the western Amazon basin, and verified the influence of abiotic factors (physicochemical variables and the hydrological phase) on these patterns. We also examined whether species that were more similar in their tolerance of physicochemical variables tended to co-occur more frequently. The structure of the assemblage was evaluated using the standardized effect size (SES) of the C-score index and null models, with the SES being used as an indicator of the organization of the assemblage. We employed linear regression models to investigate the influence of precipitation levels and physicochemical variables on the SES. We calculated the outlying mean index and ran a Mantel test on the checkerboard unit matrix of the C-score and tolerance values to assess the influence of species tolerance on co-occurrence patterns. Finally, we examined the correlations between species pairs and both physicochemical variables and adjacent land use. We observed patterns of aggregation or randomness in varying degrees at different scales. Increased precipitation influenced the establishment of random patterns, while species pairs correlated primarily with the degree of preservation of the local habitat at each study site. During the dry season, species that were more similar to each other in their environmental tolerance tended to co-occur more systematically. If the current levels of change in land use in the study area continue, the fish assemblage investigated here may suffer a significant loss of diversity, as well as destabilization of its structure, with a high possibility of local extinction of the most sensitive species.</p></div>","PeriodicalId":55489,"journal":{"name":"Aquatic Sciences","volume":"86 3","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140655945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}