No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Limnoecology: The Ecology of Lakes and Streams
... However, SRP was the main variable to explain the higher density of bacteria, the main phytoplankton taxonomic groups, and ciliates at S1, as well as carbon biomass of both BAC and PHY (especially CHL) at the station. Since macrophytes in subtropical shallow lakes are strong competitors for nutrients (Finkler Ferreira et al., 2018), bacterial metabolism may be uncoupled from phytoplankton carbon sources, and they probably compete when phosphorus is limiting (Lampert and Sommer, 2007). CILI carbon content, otherwise, promoted a negative effect on TP at S1. ...
... POC, the second most related variable to the density of S1 communities selected in the RDA, negatively affected MTZ:BAC at S2. POC consumption by BAC could increase their biomass and enhance MTZ predation. Most of POC is usually bound up in detritus, and the remainder in living organisms (Lampert and Sommer, 2007). Bacteria use excretory products and dead matter (detritus), making this a circular component in the food web through the microbial loop (Azam et al., 1983). ...
... Responses of MTZ to WT related to ORP could indicate an indirect relationship with nutrient availability and system production, since biologically important elements, such as nitrogen, undergo redox changes. Photosynthesis and respiration can also be described in terms of redox reactions (Lampert and Sommer, 2007). ...
... Gamboa et al. (12) affirm the negative impact of agricultural activities on benthic macroinvertebrate communities and water quality, which is noted in the results obtained in this study by the ETP index; which could be the result of multiple factors such as the pouring of waste and substances into the channel of crops near the river system, or the domestic activities constantly developed in the body of water, which impede the processes purifying and deteriorate the organisms present in the ecosystem. Physicochemical variables exposed environmental conditions that are relatively normal; for example, the conductivity of most freshwater bodies ranges from 10 to 1 000 μS/cm; (13) however, in contaminated water, their values may exceed these values, although this condition was not observed for this study, as they had a maximum of 292,5 S/cm in the highest part of the river, even though there is an influence of crops near the river You're a marque. Overall, water quality according to the variables studied is good, both because of the conductivity values presented, as well as the high levels of oxygen saturation (around 100 %), and the temperatures that had a range that does not exceed 30 oC; however, the pH values in the system for the start of the study period are considered low, and negative for the ecological condition of the ecosystem. ...
... Overall, water quality according to the variables studied is good, both because of the conductivity values presented, as well as the high levels of oxygen saturation (around 100 %), and the temperatures that had a range that does not exceed 30 oC; however, the pH values in the system for the start of the study period are considered low, and negative for the ecological condition of the ecosystem. (13) As established by Huerto et al. (14) the application of biotic indexes has a great advantage over so-called diversity indexes, because they base their results on characteristics inherent to the ecological community, such as the structure of the community, and to sensitivity or tolerance that each group presents against system changes or alterations; or, by contamination processes, the ETP index (Ephemeroptera, Trichoptera and Plecoptera) which have been established by the individuals belonging to this order were applied in this study are sensitive to system variations, for which they are sensitive to system variations, for which they are truthful indicators of water quality. (15) However, different behavior was observed for the diversity indexes employed, where the lower dominance was observed at Station 1 (D-0,154) coinciding with greater diversity according to Shannon-Wienner (H-2,077); in terms of this type of results, the Shannon exponential was used, which transforms the values of the H index to equivalent numbers of taxa, resulting in a range between 7,16 and 7,98, which is a very small variation that highlights that the stations have a similar diversity between them (number of taxa and abundanceratios ratio), so this type of transformation is most useful when comparing sampling sites using indexes. ...
... (15) However, different behavior was observed for the diversity indexes employed, where the lower dominance was observed at Station 1 (D-0,154) coinciding with greater diversity according to Shannon-Wienner (H-2,077); in terms of this type of results, the Shannon exponential was used, which transforms the values of the H index to equivalent numbers of taxa, resulting in a range between 7,16 and 7,98, which is a very small variation that highlights that the stations have a similar diversity between them (number of taxa and abundanceratios ratio), so this type of transformation is most useful when comparing sampling sites using indexes. (16) Low pH values were observed in the initial two months of study (July and August), which is consistent with the low precipitation time, and could partly explain these values, by low photosynthesis rates and a high breathing rate resulting from the decomposition of leaf litter in these areas, which is little favoured by low current speeds, (13) highlighting the lowest oxygen saturation values in these months. For the above, it was remarkable that pH was one of the most variability factors in the Marquesote River, which is a phenomenon that must be studied more carefully in the future, to understand which processes are the cause of variability, mainly temporary in the system. ...
Different biotic indices have been used for the integral analysis of hydrographic basins in Colombia, using benthic microinverters and physicochemical parameters. A comprehensive analysis of water quality was performed in the low Marquesote river basin, using benthic macroinvertebrates and the ETP index (Ephemeroptera-Trichoptera-Plecoptera) as a biological indicator and some physicochemical parameters. Work was worked on the middle and lower basin on the Marquesote River at two times of the year (dry and rainy); standardized methods for water physicochemical variables were applied, for benthic fauna collected using a Surber network, and identifying them up to the taxonomic level of family. The study observed 22 families and 1388 individuals, where 49% represent PTSD, indicating regular water quality; however, physicochemical variables had wide variation, noting that pH showed the greatest variability based on an analysis of major components. Environmental quality in the Marquesote river basin is compromised according to the indicators used, a more detailed study of the sources of pollution and dynamics of macroinvertebrates could provide a greater ecological knowledge of the basin.
... While supplies of C, N, and P vary naturally in aquatic ecosystems in space and time (Lampert & Sommer, 2007), anthropogenic impacts increasingly intensify or differentially (i.e., in different directions or degrees) alter resource availability. The C:N:P ratios of algae reflect their macromolecular composition (e.g., protein, carbohydrate, lipid, nucleic acids, and pigments) and can respond strongly to environmental variation (Geider & La Roche, 2002;Sterner & Elser, 2002). ...
... N:P ratios ranged from 6:1 (low N supply) to 16:1 (Redfield ratio, can be thought of as a "control" or "reference" treatment under saturating light conditions) to 80:1 (low P supply). Although most lake ecosystems are P-limited, seasonal variation in nutrient fluxes often leads to Nlimitation or a co-limitation of both nutrients (Elser et al., 1990;Lampert & Sommer, 2007). The chosen ratios are within the range of N:P that occurs in natural systems around the world (Sterner & Elser, 2002). ...
With the ongoing differential disruption of the biogeochemical cycles of major elements that are essential for all life (carbon, nitrogen, and phosphorus), organisms are increasingly faced with a heterogenous supply of these elements in nature. Given that photosynthetic primary producers form the base of aquatic food webs, impacts of changed elemental supply on these organisms are particularly important. One way that phytoplankton cope with the differential availability of nutrients is through physiological changes, resulting in plasticity in macromolecular and elemental biomass composition. Here, we assessed how the green alga Chlamydomonas reinhardtii adjusts its macromolecular (e.g., carbohydrates, lipids, and proteins) and elemental (C, N, and P) biomass pools in response to changes in growth rate and the modification of resources (nutrients and light). We observed that Chlamydomonas exhibits considerable plasticity in elemental composition (e.g., molar ratios ranging from 124 to 971 for C:P, 4.5 to 25.9 for C:N, and 15.1 to 61.2 for N:P) under all tested conditions, pointing to the adaptive potential of Chlamydomonas in a changing environment. Exposure to low light modified the elemental and macromolecular composition of cells differently than limitation by nutrients. These observed differences, with potential consequences for higher trophic levels, included smaller cells, shifts in C:N and C:P ratios (due to proportionally greater N and P contents), and differential allocation of C among macromolecular pools (proportionally more lipids than carbohydrates) with different energetic value. However, substantial pools of N and P remained unaccounted for, especially at fast growth, indicating accumulation of N and P in forms we did not measure.
... The combined effect of saltwater intrusion and river discharge produces significant changes in nutrient loads, since the extent to which nutrients are retained in rivers and then made available during the biomass development (Lancelot and Muylaert, 2011;Lichter et al., 2011;Newman et al., 2005;Pinckney et al., 1999;). Many authors state that changes in river water regime from lotic to lentic are accompanied by an increase in allogenic phytoplankton biomass (Lampert and Sommer, 1997;Reynolds, 1984Reynolds, , 1999Reynolds, , 2003Reynolds and Descy, 1996;Waylett et al., 2013) generating blooms under optimal environmental conditions dominated by species able to grow at intermediate salinity as well as tolerant to large salinity fluctuations in brackish waters of terminal stretches (Jackson et al., 1987;Muylaert et al., 2009;Roubeix and Lancelot, 2008). Being passively transported by currents, phytoplankton at the source of the river would require a very rapid replication time so that they can generate blooms. ...
... This is the reason why rivers are considered highly selective environments, where flow rate and turbidity, along with temperature, are the most critical factors lim-iting the development and structuring the phytoplankton community composition (Rojo et al., 1994;Reynolds, 1994, Tavernini et al., 2011. The higher the flow rate and turbidity, the lower the amount of phytoplankton can be expected: where the water retention time is longer than the generation time of the phytoplankton, large blooms can occur (Ibeling et al.,1998;Lampert and Sommer, 1997;Newman et al., 2005). Nevertheless, the extent to which nutrient loads trigger phytoplankton blooms in micro-and macrotidal estuaries is different, with small nutrient enrichment producing larger effects in the microtidal ones (Warwick et al., 2018). ...
Mediterranean coastal systems, particularly those characterized by river mouths, have played an important role in the history of human civilization, thanks to unique species assemblages, a high biodiversity, and complex ecological interactions. The overlapping of multiple cross-scale effects, triggered by the ongoing climate change, makes these systems particularly important sites for ecological studies. Here, we have investigated the phytoplankton community structure in the terminal stretch of the Sele River (Tyrrhenian Sea) under two different hydrological regimes: i) with river mouth occluded by sediments preventing water exchange with the sea; ii) with river mouth completely opened, which allowed the maximum water mass exchanges between the river and the sea. The strong variations in physical-chemical properties of the water column, the point-distribution of total phytoplankton biomass, and the dominance of cryptophytes and cyanophytes under occluded and opened river mouth, respectively, indicate the presence of strong allogenic pressures acting on the system. Our data suggest that the monitoring of phytoplankton communities in the terminal stretch of micro-tidal estuaries, could be a useful tool for studying the extent of climate change underway in Mediterranean coastal marine areas.
... Streams are well known for offering several ecosystem services, such as climate regulation, drinking water, food, and recreation [1]. These systems are characterized by hydrologic, geomorphic, and biological processes [2], support great species diversity, and provide species to the regional pool [3,4]. In some sub-basins of the Amazon territory, streams can represent up to 90% of the total channel length [5], draining large areas inside forests, cities, crops, mining, and others [6][7][8]. ...
... By draining these areas under intense land use, the biodiversity of Amazon streams and their ecosystem services are threatened [9]. That is because stream systems act as a sink catching the changes in the landscape [2,10]. Deforestation, the input of nutrients, agrochemicals, and mining residuals are examples of threats to the species diversity in Amazon streams [7,8]. ...
Amazon streams present great biodiversity and offer several ecosystem services, but these systems are threatened by multiple land uses. The changes created by land use are expected to drive the composition of species, ultimately changing the trophic relationships of several biological groups, including zooplankton. We investigated if land use changes the composition of zooplankton functional guilds in Amazon streams and which are the local (physical-chemical) variables driving the zooplankton functional guilds in the land-use gradient. Zooplankton and physical-chemical variables were sampled in 17 water bodies in the municipality of Barcarena, Pará, Brazil in 2018 and 2019, five sampling sites were in the Pará River and 12 in streams. Forest cover (a proxy for land use) was determined through digital image processing and converted in percentage. Zooplankton species were classified into five functional guilds (filter, raptorial, scraper, suctor, and predator feeders). We recorded 98 zooplankton taxa and filters were the most abundant functional guild. The composition of zooplankton functional guilds did not change in the land use gradient. However, the distribution of zooplankton functional guilds in Amazon streams was determined by local environmental variables related to the feeding strategies. Scraper-feeders (cladocerans) were positively related to greater canopy cover, suctor-feeders and predator-feeders (both rotifers) were related to greater total phosphorus, whereas filter-feeders (rotifers, cladocerans, and copepods) and raptorial (copepods) were related to total suspended solids. This study brings new information about zooplankton in Amazon streams that are under-studied. The functional approach clarifies the patterns observed and reflects the trophic relationships in which the zooplankton community is involved in streams under a degree of land use, i.e., scraper-cladocerans can represent more preserved streams under greater canopy cover, whereas the other functional guilds were related to variables that can represent more altered streams.
... His work was important for limnology but has far reaching consequences, as his study systems also served to test general ecologi-cal concepts. His belief that limnological experiments can be also useful and fruitful test systems for general ecological concepts resulted in the famous textbook "Limnoecology" (written together with Ulrich Sommer - Lampert & Sommer 1997;Lampert & Sommer 2007), which has been translated into several languages. ...
... He was one of the leading protagonists in this "battle". Now the issue is more-or-less settled, and most agree that the prevalence of top-down vs. bottom-up effects is a question of scale (see Lampert & Sommer 1997;Lampert & Sommer 2007). Large-scale comparisons between ecosystems of widely different nutrient levels have to be interpreted from a bottom-up perspective, while seasonal events or differences between lakes of similar nutrient richness, but different fish stocks, call for a top-down explanation. ...
... Phytoplankton are not overriding other food sources in the floodplain ecosystem, and algae are a major food item for many aquatic organisms 11) . It is well documented phytoplankton is as one important energy source for some zooplankton groups 14,15,16,17,18,19) . As one of the top trophic level organism in the freshwater ecosystems, fish interact with various trophic level of the food chains, including plankton 15,16,17) . ...
... It is well documented phytoplankton is as one important energy source for some zooplankton groups 14,15,16,17,18,19) . As one of the top trophic level organism in the freshwater ecosystems, fish interact with various trophic level of the food chains, including plankton 15,16,17) . ...
A total of 74 species of phytoplankton were found in Lake Lutan where beneath the floating macrophyte mat, IR was higher than at open water zone, OW. Euglenoids, Diatoms and Chlorophytes predominantly occurred. Density and biomass were higher at IR than OW, and chlorophyll-a was the opposite. Statistically, it was, however, no significantly different between OW and IR, even if the presence of macrophytes slightly attributed high diversity and abundance of phytoplankton in IR. Chlorophyll-a was detected higher in low than in high water period on both sites by 2-ways ANOVA. Chlorella sp1. was significant in density among abundant phytoplankton species by 3-ways ANOVA and MCA. CCA revealed water level fluctuation greatly influenced other physico-chemical factors, and by constraining physico-chemical parameters, dissolved oxygen, water level and temperature were significantly correlated with some abundant species of phytoplankton at OW and IR sites of Lake Lutan.
... Zooplankton are heterotrophic organisms that drift in the water and constitute an essential food source for other aquatic organisms (Mandal and Mukherjee 2011). Being the essential component of the food web in aquatic ecosystems, they are the primary source of food for nearly all fish species at some point (Lampert and Sommer 2007). Zooplankton are essential for maintaining biodiversity and serve as indicators in different water masses (Wang et al. 2022(Wang et al. , 2023, in freshwater, and marine ecosystems (Ratnarajah et al. 2023). ...
Sagartaal is located in Budaun with geographical coordinates 28.0512°N and 79.1305°E in Nawada region, Uttar Pradesh, Uttar Pradesh, India. Understanding the composition, diversity, and abundance of the zooplankton is vital for better utilization of such waterbodies. The present study was carried out from October 2022 to September 2023. A total of 24 species belonging to 16 species of Rotifera, 4 species of Cladocera, 2 species of Copepoda, and 2 species of Ostracoda were recorded. The prominent species were Brachionus forficula, B. calyciflourus, Keratella cochlearis, Simocephalus sp., Cyclops sp., and Mesocyclops sp. Zooplankton showed seasonal variations in their species composition, abundance, and diversity concerning water temperature, pH, total alkalinity, dissolved oxygen, and hardness. The zooplankton density was recorded as maximum in winter and minimum in monsoon. Statistically, zooplankton shows significant correlations as Rotifera with EC, BOD (r =− 0.50; − 0.58, respectively); while with total hardness (r = 0.75); Cladocera with DO (r = 0.53), alkalinity (r = 0.57), nitrate (r = 0.56), and phosphate (r = − 0.49). The highest Shannon index (2.83) was obtained for summer, due to the lowest value of the dominance index (0.07) for this season. More studies are warranted on Monitoring such ecosystems as Sagartaal to understand the effects of anthropogenic pressure on zooplankton's community structure, can help in identifying the indicator species to formulate effective conservation planning.
... Zooplanktonic communities play an essential role in the regulation of the biological balance in aquatic ecosystems (Lampert & Sommer, 2007). In particular, the structure and dynamics of zooplankton communities are of interest because this group of small invertebrates plays a central role in the pelagic food chain (Jeppesen et al., 2011), transferring energy from lower trophic levels to higher ones (Li et al., 2019;Shayestehfar et al., 2010) as well as representing an essential food source for upper trophic levels such as fish (Chase, 2003). ...
Reservoirs play a crucial role in providing essential social and economic services at different scales. However, in recent years, anthropogenic impacts such as climate change and pollution have increased, affecting this type of ecosystem. Zooplankton communities are fundamental for regulating the biological balance in these environments, so it is essential to understand the processes that affect their dynamics. This study investigated the seasonal and spatial variation in species abundance of the zooplankton community of the Zahara- El Gastor Reservoir, Cádiz, Spain. This reservoir it is located in the Guadalete-Barbate River basin and is included in the Sierra de Grazalema Natural Park, the area with the highest rainfall in the Iberian Peninsula. Water and zooplankton samples were collected monthly over a year at four sampling sites located along the reservoir’s long-axis to determine its physicochemical characteristics and zooplankton species composition. The reservoir presented a mesotrophic state and a monomictic thermal cycle, with the mixing period occurring in winter. Temperature, water depth and volume, phosphates, carbonates, pH, and conductivity were the main environmental variables that affected the seasonal and spatial patterns of the zooplankton community. Rotifers presented the highest number of species and were predominant at the tail of the reservoir, especially in autumn, where Polyarthra spp. reached high densities. Relatively low densities of copepods were found throughout the year. Small branchiopods and cyclopoids were predominant in summer, while Daphnia longispina was linked to the colder seasons. The zooplankton community of the Zahara-El Gastor Reservoir reflected changes in the trophic state of the reservoir both in space and time.
... En los embalses se presentan fuertes interacciones entre el fitoplancton y el zooplancton que son determinantes de los patrones espaciales y temporales de su composición taxonómica, densidad y estructura (Lampert & Sommer, 2007). El pastoreo selectivo del zooplancton afecta la estructura del fitoplancton. ...
Introduction: Reservoirs are conceived as a set of interactions in which physical, chemical, and biological insta- bility determines changes in the density of planktonic communities.
Objective: To evaluate the instability of phytoplankton and zooplankton, and their interactions with environ- mental factors in four tropical Andean reservoirs with different trophic status.
Methods: Physical and chemical variables and phytoplankton and zooplankton densities were measured between 2010-2018 in the oligotrophic reservoirs Punchiná and San Lorenzo and between 2013 and 2015 in the hypereutrophic reservoir Porce II and in the eutrophic Porce III reservoir (total N = 248). The Factor Shaping Community Assemblages (FCA) was used to calculate environmental and biotic instability as well as their interaction.
Results: High environmental and biological instability was observed in the studied reservoirs. Oxygen saturation, pH, total nitrogen, water temperature, nitrites, total phosphorus (only for zooplankton), and total solids were the abiotic variables with the greatest contribution to planktonic instability, regardless of trophic state. Particularly, Cryptomonas sp., Aulacoseira sp., Cyclotella sp., Dinobryon sp., Nephrocytium sp., Tetraëdron caudatum and Oscillatoria sp. had the greatest influence on the instability of various rotifer taxa and some copepods. Conclusions: Regardless of trophic state, pH dynamics, nutrients availability, amount of suspended solids and the availability of gases, such as dissolved oxygen, mainly determined the instability of phytoplankton and to a lesser extent that of zooplankton. In the oligotrophic reservoirs, zooplankton instability was mainly influenced by highly palatable algae with no toxicity, and in reservoirs highly enriched, the instability was influenced by algae with low nutritional quality and difficult to ingest and manipulate.
... Burrowing activity of mussels further plays a crucial role in substrate mixing and aeration, contributing to improved nutrient cycling and antimicrobial activity. The combined outcomes of decreased algal blooms, increased oxygen availability, and enhanced habitat conditions create a more balanced ecosystem (Lampert and Sommer 2007). ...
The study extended over 60 days to assess the impact of extractive species on improving water quality and enhancing GIFT fish production performance within the FIMTA system. Prior to initiating the experiment, the extraction capacities of both organic and inorganic extractives were assessed. Subsequently, based on these evaluations, GIFT fish were co-cultured with freshwater mussels and aquatic macrophytes as organic and inorganic extractive agents, respectively, within 1000 L FRP tanks. Three treatment combinations were established: GIFT fish with Lemna minor (T1), GIFT fish with Lamellidens marginalis (T2), and GIFT fish with both L. minor and L. marginalis (T3). The control treatment (C) consisted solely of GIFT fish. GIFT fish were stocked at a density of 40 m⁻², while L. marginalis at 250 g per tank and L. minor covering 25% of the tank surface. GIFT fish were fed with floating commercial pelleted feed at 4% of body weight (30% CP). The results indicated that among the water quality parameters, chlorophyll a, dissolved solids, and suspended solids showed a reduction in T3. The control group exhibited elevated levels of BOD and COD, whereas the treatment groups showed significantly lower levels. Furthermore, the control group demonstrated increased conductivity levels, while T3 exhibited the lowest levels. In T3, a significant reduction was observed in both POM and POC. Growth variables like SGR and PWG were found to be highest in T3. Regarding enzyme activity, the control group exhibited lower levels of protease, lipase, and amylase, while the highest levels were observed in T3. Physiological enzyme activities such as LDH, MDH, ALP, and ACP were significantly increased (p < 0.05) in the control system, indicating elevated water pollution levels. Meanwhile, bacterial load was found to be very low in the FIMTA system (T3). These findings suggest that the integration of GIFT with L. minor and L. marginalis in the FIMTA system has the potential to enhance water quality and physiological responses, ultimately contributing to higher yields.
... There has been extensive research on the impact of cyanobacteria secondary metabolites on aquatic grazers-particularly on Daphnia, which are the dominant grazers in many lakes and ponds, with large impacts on ecosystem functioning, including water clarity, nutrient cycling, and energy flow (Lampert & Sommer, 2007). In nature, Daphnia are exposed to a diverse range of phytoplankton that vary both in nutrient quality and secondary metabolites, including Microcystis aeruginosa. ...
Secondary metabolites produced by primary producers have a wide range of functions as well as indirect effects outside the scope of their direct target. Research suggests that protease inhibitors produced by cyanobacteria influence grazing by herbivores and may also protect against parasites of cyanobacteria. In this study, we asked whether those same protease inhibitors produced by cyanobacteria could also influence the interactions of herbivores with their parasites. We used the Daphnia ‐ Metschnikowia zooplankton host‐fungal parasite system to address this question because it is well documented that cyanobacteria protease inhibitors suppress trypsin and chymotrypsin in the gut of Daphnia , and because it is known that Metschnikowia infects via the gut. We tested the hypothesis that Daphnia gut proteases are necessary for Metschnikowia spores to be released from their asci. We then also tested whether diets that decrease trypsin and chymotrypsin activity in the guts of Daphnia lead to lower levels of infection. Our results show that chymotrypsin promotes the release of the fungal spores from their asci. Moreover, a diet that strongly inhibited chymotrypsin activity in Daphnia decreased infection levels, particularly in the most susceptible Daphnia clones. Our results support the growing literature that cyanobacterial diets can be beneficial to zooplankton hosts when challenged by parasites and uncover a mechanism that contributes to the protective effect of cyanobacterial diets. Specifically, we demonstrate that host chymotrypsin enzymes promote the dehiscence of Metschnikowia spores; when cyanobacteria inhibit the activity of chymotrypsin in hosts, this most likely traps the spore inside the ascus, preventing the parasite from puncturing the gut and beginning the infection process. This study illustrates how secondary metabolites of phytoplankton can protect herbivores against their own enemies.
... It also aligns with Ekinadose et al. (2021) [16] who worked at East coast of North America from Cape Breton, St John's River in Florida and reported that plankton, small fishes, shrimp were the main food items of A. aestivalis. Zooplankton play an important role in nutrient cycling in aquatic ecosystems and support healthy fish population (Lampart and Sommer, 2007) [30] . The presence of sand particles and detritus in the gut content is an indication that the species is a bottom feeder. ...
... Strengthened stratification and oligotrophic conditions prevail in the mixed layer under global warming, favoring small phytoplankton dominance (Falkowski and Oliver, 2007;Winder et al., 2009;Zohary et al., 2021). Given that key herbivorous zooplankton, such as Daphnia and copepods, feed preferably on nanoplankton, i.e., the <20-50 μm size category (Lampert and Sommer, 2007), downsizing PP affects trophic structure (Kazama et al., 2021c) and material cycling (Ray et al., 2001;Law et al., 2009). Therefore, considering long-term PP changes necessitates examining the qualitative aspect of size structure. ...
... Daphnia undergo aging, eventually reaching a stage of senescence characterized by reduced reproduction and increased mortality. 21 ...
Daphnia magna, a small freshwater crustacean, has emerged as a
crucial model organism in toxicological research due to its sensitivity
to various environmental stressors and its ecological relevance. Its
biological characteristics, such as short life cycles, rapid reproduction,
and transparent exoskeleton, make it an ideal subject for studying
toxicological effects. These features allow for efficient observation
and measurement of toxic responses, facilitating the assessment of
acute and chronic toxicity of various substances. The immobilization,
feeding, and reproductive behaviors of Daphnia magna can be sensitive
indicators of toxic effects, providing valuable insights into lethal and
sub-lethal impacts on survival, growth, and reproduction. Toxicity tests
utilizing Daphnia magna play a crucial role in evaluating the potential
hazards of chemicals, pharmaceuticals, pesticides, heavy metals, and
nanoparticles in aquatic environments. The standardized protocols,
like OECD guidelines, ensure consistent and reliable toxicological
assessments, aiding in risk assessment and regulatory decision-making.
Additionally, Daphnia magna’s responses can be used to elucidate
mechanisms of toxicity, allowing a deeper understanding of how
contaminants affect biological processes at the organismal and molecular
levels. Furthermore, the ecological relevance of Daphnia magna as a
keystone species in freshwater ecosystems emphasizes the importance
of studying its responses to pollutants. Insights gained from Daphnia
magna studies can contribute to the protection and preservation of
aquatic biodiversity and the sustainable management of freshwater
resources. In short, Daphnia magna’s application as a model organism
in toxicological research is instrumental in advancing our understanding
of environmental toxicity and promoting effective environmental risk
assessment and management strategies.
... Other factors, such as biological activity, contribute significantly to the diversity of each of these systems, as the activities of the organisms in aquatic systems add a dynamic character to the transformation of energy and matter, and consequently have a significant impact on the environmental quality of the biota (Lampert and Sommer, 2007). However, when lakes are disturbed by anthropogenic actions, the biological production of these systems is usually altered due to eutrophication. ...
... However, the most common water quality problem, which attracted much public attention worldwide, is the excessive growth of phytoplankton-algal bloom-in water supply reservoirs (Lampert and Sommer, 1997) due to eutrophication. Algal blooms are naturally occurring and their occurrence has been documented for thousands of years (Shillo, 1965). ...
Phytoplankton and physico-chemical water quality dynamics were investigated at nearly biweekly intervals at three stations in Legedadi Reservoir from November, 2004 to August, 2005. All physico-chemical water quality parameters including inorganic nutrients varied spatially and temporally being associated with dry and wet periods. This nutrient-rich and moderately turbulent reservoir was characterized by unusually high turbidity (with most values > 400 NŤU) and low Secchi disc transparency, ZSD (<12 cm).
The relative importance of the different taxonomic groups to the abundance of total phytoplankton varied temporally, with the cyanobacteria accounting for over 60% of the total Phytoplankton abundance throughout the study period. Phytoplankton biomass varied between 8.69 and 72, 2.61 and 57.33 and 3.48 and 126.8 mg m-3 with mean values of 29.92, 22.19 and 39.45 mg m-3 at stations 1, 2 and 3 respectively.
The depth-distribution of gross photosynthesis was of the typical pattern for phytoplankton, with surface-inhibition on all days of productivity measurement and with light-saturated rates (Amax) always at 0.25 m depth Amax varied ≈ from 167 mg O2 (≈ 52.1 mg C) m-3 h-1 to 952 mg O2 (≈ 297 mg C) m-3h-1 with strong and positive correlation with chlorophyll a concentration (r2 = 0.77, P=0.00).Biomass-specific rates at light saturation, phtotosynthetic capacity [Pmax, mg O2(mg chl a)-1h-1)] varied from a minimum of 10 corresponding to the maximum phytoplankton biomass, to a maximum of 32 associated with the lowest phytoplankton biomass, with most values above 20.The hourly integral rate of photosynthesis (∑A) ranged from 0.067 to 0.58 g O2 (≈ 0.021 to 0.181 g C) m-2 h-1 at the, with peak values coinciding with peaks of phytoplankton biomass and Amax. The daily integral rate of photosynthesis (∑∑A) ranged from 0.67 to 5.8 g O2m-2 d-1.
The year-round importance of cyanobacteria, the temporal variations in phytoplankton biomass and production in relation to physico-chemical water quality parameters and PhAR surface irradiance are discussed.
... Energy flow at the primary producer and herbivore interface is influenced by both the quality and quantity of food available for zooplankton [3, 19, and 36]. Algal size, secondary metabolites, digestibility, elemental and biochemical composition have previously been used to explain food quality for zooplankton [16,19]. Zooplankton growth in nature may depend on the quality of the food available as the phytoplankton community changes. ...
Feeding management plays a critical role in the success of fish culture. The current trend in fish culture is towards increased intensification whereby, provision of feeds becomes necessary and success depends significantly on the availability of well balanced nutritionally complete and cost effective compounded feeds. Micro algae and zooplankton play a vital role in the hatchery phase of many aquacultures as feed for larval and juvenile crustaceans and fish. Several algae are being investigated as potential source of protein for both livestock and human consumption. The food value of live food organisms for a particular fish species was primarily determined by its size and form. Nutrients are often the limiting resources in ecosystems and an environmental template of geological and climatic and ecological features ultimately delimits their availability. Nutritional quality of live food in aquaculture is important for survival and growth of larvae. A 5-d laboratory trial was conducted to evaluate live feed organisms on growth and survival of Catla catla. Chroococcus turgidus and Mesocyclops aspericornis were fed to fish throughout the study. Biochemical analysis was carried out on the live feed organisms and fish. The protein, lipid, carbohydrate and amino acids content of fish were quite variable when live food was consumed. The present study confirmed that alga and copepod could be suitable live food for Catla catla rearing because it meets their nutritive requirements.
... biotic communities, and maintaining soil fertility 8,9 and being at the core of the chain of aquatic food webs which serve as a substantial source of nutrition directly or indirectly for nearly all freshwater fishes. 10 The biotic and abiotic aspects of aquatic ecosystems can be reflected by zooplankton diversity patterns and community structure, which can help in tracking ecological changes. 11,12 Local and regional environmental factors that alter the variety, abundance, and composition of zooplankton populations cause changes in their spatial patterns. ...
The transfer of energy from producers to consumers, such as fish, fish larvae, and invertebrates, is facilitated by zooplankton.
... Daphnia undergo aging, eventually reaching a stage of senescence characterized by reduced reproduction and increased mortality. 21 ...
Daphnia magna, a small freshwater crustacean, has emerged as a crucial model organism in toxicological research due to its sensitivity to various environmental stressors and its ecological relevance. Its biological characteristics, such as short life cycles, rapid reproduction, and transparent exoskeleton, make it an ideal subject for studying toxicological effects. These features allow for efficient observation and measurement of toxic responses, facilitating the assessment of acute and chronic toxicity of various substances. The immobilization, feeding, and reproductive behaviors of Daphnia magna can be sensitive
indicators of toxic effects, providing valuable insights into lethal and sub-lethal impacts on survival, growth, and reproduction. Toxicity tests utilizing Daphnia magna play a crucial role in evaluating the potential hazards of chemicals, pharmaceuticals, pesticides, heavy metals, and nanoparticles in aquatic environments. The standardized protocols, like OECD guidelines, ensure consistent and reliable toxicological assessments, aiding in risk assessment and regulatory decision-making. Additionally, Daphnia magna’s responses can be used to elucidate mechanisms of toxicity, allowing a deeper understanding of how contaminants affect biological processes at the organismal and molecular levels. Furthermore, the ecological relevance of Daphnia magna as a keystone species in freshwater ecosystems emphasizes the importance
of studying its responses to pollutants. Insights gained from Daphnia magna studies can contribute to the protection and preservation of aquatic biodiversity and the sustainable management of freshwater resources. In short, Daphnia magna’s application as a model organism in toxicological research is instrumental in advancing our understanding of environmental toxicity and promoting effective environmental risk
assessment and management strategies.
... Additionally, some cladoceran species may even change their morphology in response to predator chemical signals (kairomones) (Lagergren and Stenson 2000). This is interpreted as an adaptive strategy that may favour prey survivorship (Chang and Hanazato 2003;Lampert and Sommer 2007). Thus, some paleolimnologists have recently investigated relations between morphological attributes of cladoceran subfossils and the predation intensity in a lake (Labaj et al. 2013). ...
In a natural lake of southeastern Brazil (Lake Carioca), the current scarcity of limnetic cladocerans is attributed to the predatory activity of the dipteran Chaoborus larvae. The Inverted Trophic Cascade Hypothesis (ITCH) predicted that such predation pressure intensified after the decrease in native planktivorous fish populations, due to non-native piscivorous fish introductions. However, the ITCH is mainly based on recent data obtained when the non-native piscivorous fish have already disturbed the community of this Neotropical lake. In the present study, we used a paleolimnological approach aiming to provide evidence in support of ITCH. Specifically, we evaluated: (1) whether a great numerical increase of Chaoborus larvae and a sharp decline in the number of small cladocerans (Bosminidae) occurred in the recent past of Lake Carioca, and (2) whether the Bosmina tubicen size structure changed temporally in response to the dominant predator (from planktivorous fish to Chaoborus larvae). Samples from one sediment core collected in the deepest zone of the lake were concurrently used for radiometric dating, quantification of invertebrate subfossils, and measurement of B. tubicen size attributes. The radiometric dating was based on the analysis of ²¹⁰Pb. Although we recorded an evident decline of Bosmina subfossils after the introduction of non-native piscivorous fish, we did not observe an increase of Chaoborus subfossils. Significant increases in the mean lengths of carapaces and mucros of B. tubicen were detected in Lake Carioca after the dominant predation regime changed from planktivorous fish to Chaoborus larvae. Despite the statistical significance, the differences for both attributes exhibited a small effect size and likely had limited ecological implications on the dynamics of local food web. Our results support one of the assumptions of the ITCH; showing that the negative effects of non-native piscivorous fish were not restricted to their prey (native planktivorous fish), but cascaded down, reaching the lower trophic levels (small limnetic cladocerans). This finding has relevant implications for the conservation and management of biodiversity in Neotropical lakes. It reinforces the need to better plan and control activities that historically have contributed to the spread of piscivorous fish outside their original areas such as aquaculture and sport fishing.
... Orthophosphate reacts with several different cations (A1, Fe, Ca) to generate very insoluble products and rapidly binds to clay. It is significantly less mobile than nitrogen in the sediments and precipitates more easily (Lampert and Sommer 1997). The minimum month mean value was July 2022, which was significantly different from December, January, April, and October and was not significantly different from other studied months. ...
The physical, chemical, and biological parameters have been studied at six selected sampling sites in the Duhok Drinking water plant within Duhok city. Algal and water samples were collected monthly from October 2021 to September 2022. The water temperature ranged from 8.1 to 22.5 0C. The pH values varied from 7.31 to 8.93. Specific electrical conductivity ranged from 328.1 to 472.6 µs cm-1. Alkalinity values ranged from 120 to 195 mg/L CaCO3. Total hardness varied from 184 to 250 mg/L CaCO3. Silicate values ranged from 67.89 to 120.01 mg/L. Phosphate concentrations ranged from 0.01 to 0.73 mg/L. Values of nitrate varied from 2.3 to 5.8 mg/L. A total of 58 algal taxa were identified during this study, which belong to four divisions: 25 taxa belong to Bacillariophyta, making up 43% from the all; 21 taxa belong to Chlorophyta, making up 36% from the all; 7 taxa belong to Cyanophyta, making up 12% from the all; and 2 taxa belong to Euglenophyta, making up 3.5%. 2 taxa belong to Dinoflagellata, making up 3.5% from the all; 1 taxa belong to Xanthophyta, making up 2% from the all
... Indeed, studies have shown that Daphnia species plastically reduce their maturation size in response to chemical cues released by fish that feed on the species (Gu et al., 2020(Gu et al., , 2023. However, reducing the maturing size could have an adverse effect on food intake because of the limited space available for feeding (Lampert & Sommer, 2007). To compensate for the reduced food intake caused by the smaller body size, they may increase the digestive enzyme activities. ...
Evolutionary theory suggests the hypothesis that among genetically isolated populations, phenotypic variation should be smaller in populations with smaller ratios of nonsynonymous to synonymous substitutions (dN/ dS) because smaller dN/dS ratios occur under greater purification selections. Two distinct lineages (JPN1 and JPN2) of panarctic Daphnia cf. pulex sensu Hebert (1995), invaded independently into Japan from North America, provide an excellent opportunity to test this hypothesis because the earlier invader JPN1 has a lower dN/dS ratio than JPN2. Therefore, we examined phenotypic variations in fitness-related traits, including digestive, life-history, and morphological traits, among several genotypes within these two lineages. We found that phenotypic variations were smaller within the JPN1 lineage than within the JPN2 lineage. Furthermore, within-lineage variation of the phenotypic plasticity to changing food levels was smaller in the JPN1 lineage than in the JPN2 lineage. These results support the hypothesis that the JPN1 lineage has been more efficiently subjected to negative selection. However, the magnitude of the phenotypic plasticity of these traits was, on average, at the same level between the JPN1 and JPN2 lineages and its direction differed among genotypes of these lineages, suggesting that the JPN2 genotypes might have exploited niches that were different from those of the JPN1 genotypes.
... This is particularly relevant for the taxonomic groups that are crucial to the food web of lakes ( Hintz and Relyea, 2019 ). One such group is the zooplankton, which act as energy transmitters from primary producers to higherorder consumers in freshwater ecosystems ( Lampert and Sommer, 1997 ). Herbivorous zooplankton can exert pressure via top-down control and determine phytoplankton composition and abundance. ...
... Zooplankton occupy a fundamental position in aquatic food webs, contributing significantly to nutrient recycling [14]. At the ecoregional level, local environmental factors, such as lake morphology, water chemistry and watershed characteristics, as well as anthropogenic factors, act together to influence zooplankton community composition and structure (e.g. ...
Understanding the patterns and mechanisms underlying community structure and composition along altitudinal gradients is key for modern ecology and biogeography; indeed, this research agenda can provide a useful toolbox to forecast the consequences of climate change on present-day ecosystems. However, spatial variation of zooplankton communities at different elevations has rarely been addressed, and most available research on aquatic systems has focused on species richness only. Here, we aim to study the effect of elevation on zooplankton communities, both in terms of species composition and abundance. NMDS analysis was performed to examine community-level patterns in the ordination space between plateau and mountain ponds. In addition, we used SIMPER to assess whether these ponds differed in the composition of zooplankton communities and identify species groups that contributed to biotic dissimilarities between mountain and lowland regions. Mann–Whitney’s tests were run to verify the existence of statistical differences in the total abundance and relative abundances of constant, rare and accessory species between plateau and mountain ponds. Our findings illustrate a clear patterning in zooplankton community composition and abundance between mountain and lowland ponds in a geographically extensive area of the Iberian Peninsula. These contrasting patterns were correlated with a set of environmental features that vary concomitantly along altitudinal gradients (e.g., mean annual temperature, ionic content, nutrient concentration and the development of dense aquatic plant stands). Accessory species contributed most to total abundance at increasingly lower elevations, although small-sized rotifers were the dominant component of zooplankton communities in both pond types. These results should bring certainty to predictions about the effects of future climate on freshwaters, especially in the context of the potential consequences of altitudinal migrations on the spatial variation of community composition and abundance of these small planktonic animals.KeywordsElevationPondsZooplankton
... Rotifers, cladocerans, and copepods, as members of an intermediate trophic level, are at the same time predators and prey. As predators (sensu Lampert and Sommer, 2007), they exert selective pressures on algae, bacteria, and other zooplankters; as prey, they react to the direct and indirect effects of vertebrates and other invertebrate predators. ...
The varied physiography and climate of the Mexican territory have produced a large mosaic of inland aquatic ecosystems. However, zooplankton ecology has been studied mainly from the water bodies of Central (Trans Mexican Volcanic Belt), eastern (the Yucatán Peninsula), and southern Mexico. In contrast, the zooplankton from the Mesa Central water bodies has been insufficiently investigated. After a long history of zooplankton taxonomic studies, the first contributions to the zooplankton ecology dated to the 90's, rapidly increasing afterward. Most ecological information arises from field investigations and experiments under laboratory conditions, lacking mesocosms and whole-lake experiments. In the same way, the studies have been carried out in lentic, natural, and artificial water bodies, primarily eutrophic. Differently, the zooplankton ecology of lotic ecosystems is largely unknown. Here we summarized the progress made in the study of the zooplankton ecology of Mexican inland waters, revealing the most important research topics developed so far.
... Urban stressors from diffuse origins ultimately reach and have an impact on the myriad of micro-and macroorganisms inhabiting urban streams. Since flow direction is the stream driv- ing force (Reynolds et al., 1991), the growth and development of planktonic communities is slow, while benthic (i.e., attached) communities are dominant (Lampert & Sommer, 2007). Benthic macro-and microorganisms colonize multiple streambed surfaces worldwide. ...
Catchment urbanisation results in urban streams being exposed to a multitude of stressors. Notably, stressors originating from
diffuse sources have received less attention than stressors originating from point sources. Here, advances related to diffuse
urban stressors and their consequences for stream benthic communities are summarised by reviewing 92 articles. Based on
the search criteria, the number of articles dealing with diffuse urban stressors in streams has been increasing, and most of
them focused on North America, Europe, and China. Land use was the most common measure used to characterize diffuse stressor sources in urban streams (70.7 % of the articles characterised land use), and chemical stressors (inorganic nutrients, xenobiotics, metals, and water properties, including pH and conductivity) were more frequently reported than physical or biological stressors. A total of 53.3 % of the articles addressed the impact of urban stressors on macroinvertebrates, while 35.9 % focused on bacteria, 9.8 % on fungi, and 8.7 % on algae. Regarding ecosystem functions, almost half of the articles (43.5 %) addressed changes in community dynamics, 40.3 % addressed organic matter decomposition, and 33.9 % addressed nutrient cycling. When comparing urban and non-urban streams, the reviewed studies suggest that urbanisation negatively impacts the diversity of benthic organisms, leading to shifts in community composition. These changes imply functional degradation of streams. The results of the present review summarise the knowledge gained to date and identify its main gaps to help improve
our understanding of urban streams.
... An ecosystem, like any system, is a set of different elements that interact with each other and behave as a unit. This close interaction between the elements of the ecosystem allows one element to be used as an indicator of the properties of another element (Brönmark and Hansson 2005;Lampert and Sommer 2007). In this study, macrophytes were used as bioindicators of the properties of the aquatic environment, specifically, as bioindicators of the ecological state of a group of small lakes in the Valaam archipelago. ...
The article evaluates the ecological status of five small lakes on Valaam Island (Igumenskoe, Chernoe, Ossievo, Nikonovskoe, Krestovoe) using macrophytes as bioindicators. The methods proposed by Finland, Sweden, and Norway were used, to assess the state of eutrophication, the change in the composition of specific species, the change in the water level, and the state of acidification, according to different indexes (Reference index (RI), Trophic Macrophyte Index (TMI), Trophic Index (TIc), the Proportion of Type–Specific Taxa (PTST), the Percent Model Affinity (PMA), Water level Index (WIc), and Acidification Index (SIc)). An analysis of the floristic composition for the period 2011–2020 was realized, including taxonomic analysis, ecogroup, and macrophyte diversity. The dominant taxon was Elodea canadensis Michx. in Igumenskoe, Chernoe, Ossievo lakes and Calla palustris L. in Nikonovskoe and Krestovoe lakes. The ecogroup hygrohelophyte was the most diverse in all lakes studied. The ecological status of the lakes according to each assessed parameter reflects that all lakes are characterized by a mesotrophic to eutrophic state, there is a variation in species composition of macrophyte and no water level change or acidification processes are presumed to occur in any of the lakes. In general, each method has its limitations, but it is suggested to continue studies for the RI, TMI, PTST, and PMA indices, and to integrate them with other
national physicochemical or biological indices.
... As the lake is shallow and subject to frequent winds, we assumed the z m is equal to the water depth. K d is the vertical attenuation coefficient, which is calculated by the following equation (Lampert and Sommer, 2007): ...
Land-water transition areas play a significant role in the functioning of aquatic ecosystems. However, anthropogenic pressures are posing severe threats on land-water transition areas, which leads to degradation of the ecological integrity of many lakes worldwide. Enhancing habitat complexity and heterogeneity by restoring land-water transition areas in lake systems is deemed a suitable method to restore lakes bottom-up by stimulating lower trophic levels. Stimulating productivity of lower trophic levels (phytoplankton, zooplankton) generates important food sources for declining higher trophic levels (fish, birds). Here, we study ecosystem restoration project Marker Wadden in Lake Markermeer, The Netherlands. This project involved the construction of a 700-ha archipelago of five islands in a degrading shallow lake, aiming to create additional sheltered land-water transition areas to stimulate food web development from its base by improving phytoplankton quantity and quality. We found that phytoplankton quantity (chlorophyll-a concentration) and quality (inversed carbon:nutrient ratio) in the shallow waters inside the Marker Wadden archipelago were significantly improved, likely due to higher nutrient availabilities, while light availability remained sufficient, compared to the surrounding lake. Higher phytoplankton quantity and quality was positively correlated with zooplankton biomass, which was higher inside the archipelago than in the surrounding lake due to improved trophic transfer efficiency between phytoplankton and zooplankton. We conclude that creating new land-water transition areas can be used to increase light and nutrient availabilities and thereby enhancing primary productivity, which in turn can stimulate higher trophic levels in degrading aquatic ecosystems.
... Para comprender la estructura y el funcionamiento de un ecosistema, se deben considerar tanto los procesos biológicos (individuos o poblaciones) como la manera en la que interactúan con los parámetros abióticos (como los fisicoquímicos) (Lambert y Sommer, 1997). Las alteraciones físicas y químicas del agua repercuten en las respuestas individuales, poblacionales, comunitarias y ecosistémicas de los organismos acuáticos (Vélez-Azañero et al., 2016). ...
Las comunidades biológicas están conformadas por grupos taxonómicos, donde el fitoplancton, como productor primario, tiene una relevancia ecológica: sirve para comprender la estructura y el funcionamiento de un ecosistema y la manera en la que los organismos interactúan con los parámetros fisicoquímicos. Con el fin de evaluar la riqueza y la abundancia del fitoplancton de la zona litoral del departamento del Atlántico y su asociación con las variables fisicoquímicas para conocer sus cambios espaciales y temporales, se realizaron monitoreos durante el año 2013. Se ubicaron cinco zonas a lo largo de la zona litoral como Astilleros, Santa Verónica, Puerto Velero, Puerto Colombia y Mallorquín. En cada una se establecieron tres estaciones, distribuidas en línea recta, con distancia entre ellas de 5 km. Para la recolecta de las muestras de fitoplancton y clorofila a (Cl-a), en cada una de las estaciones se filtraron 24 L de agua superficial, con un tambor cónico con malla de diámetro de poro de 24 µm y con botellas ámbar de 500 mL, respectivamente, las cuales se mantuvieron en oscuridad. Adicionalmente, se registraron in situ variables fisicoquímicas. Se identificaron un total de 560 cél.mL-1 de fitoplancton, agrupadas en 47 especies y cinco clases. Las Bacillariophyceae presentaron las mayores densidad y riqueza, seguidas de las Dinophyceae, Cyanophyceae, Euglenophyceae y Chlorophyceae. Chaetoceros sp. (83 cél.mL-1) y Chaetoceros lorenzianus (64 cél.mL-1) fueron las especies más abundantes y más representativas, precisamente por su abundancia. El análisis de Jaccard mostró una disimilitud de un 80 % entre las estaciones 5A, 5B y 5C, lo que indica una composición diferente. En general, las estaciones de monitoreo se comportaron como sitios contaminados con alta influencia de las aguas del río Magdalena.
... La acidificación, de la que ya se han comentado sus causas en este y otros apartados (aumento del CO2, deposición de contaminantes ácidos en polvo o lluvia), tiene un efecto inmediato sobre la biota. Por ejemplo, una disminución del pH hasta valores de 6 reduce a la mitad las especies de fitoplancton y de invertebrados (comida para los peces) de los lagos (Lampert y Sommer 1997), y malformaciones y muerte de todos aquellos organismos que necesitan formaciones calcáreas (p.e. erizos, Byrne y Hernández 2020). ...
... mg/L), though leveling off at high TP. This concurs with the results of numerous other studies revealing that zooplankton abundance is generally lowest in oligotrophic lakes (May and O'Hare, 2005;Lampert and Sommer, 2007;García-Chicote et al., 2018). Some studies have reported a lower or a decreasing trend in species richness at high nutrient status. ...
Both eutrophication and salinization are growing global environmental problems in freshwater ecosystems, threatening the water quality and various aquatic organisms. However, little is known about their interactive effects on theses stressors and the role of lake depth on these interactions. We used field surveys to compared zooplankton assemblages over four seasons in eight Yunnan Plateau lakes with different trophic states, salinization levels, and water depths. The results showed that: 1) the species number (S), density (DZoop), and biomass (BZoop) of zooplankton exhibited strong seasonal dynamics, being overall higher in the warm seasons. 2) Data collected over four seasons and summer data both revealed highly significant positive relationships of S, DZoop, and BZoop with total nitrogen (TN), total phosphorus (TP), and phytoplankton chlorophyll a (Chl a). 3) S, DZoop, and BZoop displayed a unimodal relationship with salinity, peaking at 400–1000 μS/cm (conductivity, to reflect salinity). 4) The two large-sized taxa (cladocerans and copepods) generally increased at low-moderate levels of TN, TP, Chl a, and Cond and was constant or decreased at high levels. The average body mass (biomass/density) of crustaceans decreased with increasing TN, TP, Chl a, and conductivity. Our findings indicate that zooplankton may be more vulnerable in deep lakes than in shallow lakes when exposed to conductivity stress even under mesotrophic conditions, and the overall decrease in size in zooplankton assemblages under the combined stress of eutrophication and salinization may result in a lowered grazing effect on phytoplankton.
... In natural populations, the hatching of the resting stages could be related to biotic factors, for example changes in limiting factors (Gyllström and Hansson, 2004;Ko stál, 2006). In tropical systems environmental factors such as temperature and photoperiod show a not so marked variation throughout the year (Lampert and Sommer, 2007), the hatching of the resting stages could be stimulated by other signals, such as the concentration of food in the medium or any other allelochemical-mediated signal (Ko stál, 2006). Particularly in tropical countries where cyanobacterial blooms are common and potentially harmful (Mowe et al., 2015), they could be associated as a signal of hatching, because the blooms, for example of Microcystis, have been related to a specific season of the year (dry season) or even because of their potential toxicity (Mowe et al., 2015), could negatively affect the egg bank. ...
Many zooplankton organisms facing harsh environmental conditions producing resting eggs. Resting eggs accumulate in the sediment and create a resting egg bank. Knowledge on the egg bank structure, morphology and morphometry of the eggs as well as the effect of cues on hatching, contributes to the understanding zooplankton dynamics in lakes. Here we described the composition and structure of zooplankton egg bank from a shallow tropical lake and analyzed the effect of some biotic factors on hatching rates. In order to describe the structure and composition of the resting egg bank, we determined the richness, density, morphology and morphometry of the resting eggs isolated by the sugar flotation method. Diapausing eggs were measured and their external features studied by microphotography under optical microscope and SEM. To analyze the effect of biotic factors on hatching rates, we exposed the resting structures and the entire sediment to three biotic factors: a chlorophyte ( Scenedesmus acutus ), a cyanobacteria ( Microcystis sp.) and a predatory rotifer ( Asplanchna girodi ). A total of 25 zooplankton species hatched from the sediments. Our results show that the medium density of the healthy-looking diapausing eggs was of 7.6 ± 2 diapausing eggs · cm ⁻³ and that rotifers are the predominant group in the egg bank. Medium conditioned with the chlorophyte and the cyanobacteria resulted in a higher hatching rate. The ornamentations of rotifer diapausing eggs present different features, such as wrinkles and spines, which can help to taxonomic identification without the need of promoting hatching.
... In the pelagic interaction network, zooplankton have a key role by concentrating and transferring carbon and essential biomolecules from primary producers to upper trophic levels and by shaping the phytoplanktonic community structure (Humes, 1994;Lampert and Sommer, 1997;Ohman and Hirche, 2001;Varpe et al., 2005;Winder et al., 2017). Zooplankton use various dietary resources of both autotrophic and heterotrophic origin (Kleppel, 1993). ...
The plankton community consists of diverse interacting species. The estimation of species interactions in nature is challenging. There is limited knowledge on how plankton interactions are influenced by environmental conditions because of limited understanding of zooplankton feeding strategies and factors affecting trophic interactions. In this study, we used DNA-metabarcoding to investigate trophic interactions in mesozooplankton predators and the influence of prey availability on their feeding behavior. We found that mesozooplankton feeding strategies vary within species across an environmental gradient. Some species, such as Temora longicornis consistently used a selective strategy, while diets of Centropages hamatus and Acartia spp. varied between stations, showing a trophic plasticity with the prey community. We found a dominance of Synechococcales reads in Temora's gut content and a high prey diversity for the cladoceran Evadne nordmanni. Our study shows the wide range of prey species that supports mesozooplankton community and helps to understand the spatial and temporal complexity of plankton species interactions and discriminate the selectivity ability of four zooplankton key species. Due to the central role of plankton in marine waters, a better comprehension of the spatiotemporal variability in species interactions helps to estimate fluxes to benthic and pelagic predators.
... It is one of the most abundant fish found in Lake Mainit (de Guzman et al., 2008). Lake Mainit is one of the most valuable freshwater resources in the Caraga Region that are wide open (Lampert & Sommer, 1997). People living nearby or surrounding the lake rely mainly on fishing and farming as their food source and finances. ...
Channa striata Bloch is a type of indigenous freshwater fish abundant in Lake Mainit and it serves as a source of foods and finances of the people. This species was reported as an intermediate host of many helminth parasites. This research aimed to determine the association of endo-parasites, diet composition, and length and weight in snakehead fish C. striata Bloch in three selected municipalities along Lake Mainit, Caraga Region, Philippines. The results revealed that food items found in the stomach of the fish were mostly composed of shrimps, plant debris, fish, crab, detritus (dry & wet seasons), aquatic insects and snail (wet season). Among the seven food items, highest index of relative importance (IRI) value observed are shrimps in both wet and dry seasons. A nematode parasite was recovered in the gut of the fish samples. Out of 180 fish samples, 133 were infected with Procamallanus sp. The prevalence was higher in the dry season compared to the wet season. However, parasite intensity and diet count of C. striata Bloch. showed no significant variations between sampling sites and seasons. On the other hand, there were no significant differences between the intensity of the parasite count to the length and weight of the fish; the association between parasite count and diet count during dry and wet seasons showed a strong positive correlation. The results indicated that C. striata Bloch is susceptible to Procamallanus sp. nematode infection because of its carnivorous diet and serves as the vector or intermediate host in freshwater. Thus, more fish samples, the host’s age, host’s sex, the study gap, infection rate of the fish organs, and assessment of the physico-chemical parameters in future studies must be used.
... Generally, the physical and chemical characteristics of water are key factor influencing the composition of benthic macroinvertebrate assemblages, with each species associated with particular habitat types (Baptista et al. 2001). The habitat preferences are defined here as substratum type, velocity, width and depth, riparian vegetation, pH, conductivity (Gordon et al., 1992;Lampert & Sommer, 1997;Milisa et al., 2006). ...
Thirty years after the first Ephemeroptera checklist (excluding Baetidae) of the Tafna basin (North-west Algeria) involved in an ecological study, new sampling investigations in 12 of the 48 sites prospected allowed us to record 12 taxa including six Baetidae taxa. The aim of the present study is to analyze and discuss the current diversity and distribution of Ephemeroptera. The results highlighted that more than half of the Ephemeroptera fauna previously mentioned has been depleted, with the loss of filtering and burrowing species. The mayfly fauna was mostly dominated by the family Baetidae (83%). Baetis (Rhodobaetis) sp. and Baetis pavidus were the most common taxa, with a large spatiotemporal distribution; other baetid species include Acentrella sinaica and Baetis maurus, two rheophilic species with strict ecological requirements and a distinct seasonality, as well as two limnophilic species Cloeon cf. dipterum and Procloeon stagnicola. Conductivity and habitat integrity seem the most influencing parameters to explain the current distribution and abundance of Ephemeroptera, especially Baetidae. Moreover, specific richness variability is related to conductivity and altitude.
Lake temperature plays a pivotal role in the physical and chemical processes in the water. It has a significant impact on the distribution of lake organisms. In lake temperature modelling, the physics-based models have the shortcomings of parameter calibration and generalization difficulties. The data-driven models are highly data dependent. This makes hybrid models an effective solution at present. In this paper, we explore the spatial and temporal co-evolution process for multi-depth lake temperature and propose a Physics-Informed Deep learning model for Lake multi-depth Temperature prediction, PID4LaTe. It consists of three sub-models, two of which are long short-term memory (LSTM) models for spatial and temporal prediction respectively, and the other is a physical model, the General Lake Model. The physical model offers simulation data based on its rich knowledge for data-driven model learning, while guaranteeing consistency between model results and physical mechanisms. We compared PID4LaTe with the Process-Based model (PB), the Deep Learning model (DL) and the Physics-Guided Recurrent Neural Networks model (PGRNN), and used Root Mean Square Error (RMSE), Mean Square Error (MSE), Mean Absolute Error (MAE) and Mean Absolute Percentage Error (MAPE) to assess the effectiveness of the models. Extensive experiments show the superiority of our hybrid model for lake multi-depth prediction over PB, DL and PGRNN with RMSE of 0.798, MSE of 0.644, MAE of 0.567 and MAPE of 4.367% in Mendota Lake and RMSE of 1.099, MSE of 1.261, MAE of 0.783 and MAPE of 7.936% in Sparkling Lake. The two-cases study indicates that the hybrid model combining the physics-based model with the data-driven model is a promising technique for multi-depth lake temperature predicting. This study provides a reference method for accurate prediction of temperature at multiple depths in lakes.
Macrophytes and cladocerans represent the main antagonistic groups that regulate phytoplankton biomass; however, the mechanism behind this interaction is unclear. In laboratory conditions, we separately evaluated the effects of three submerged macrophytes (Ceratophyllum demersum, Myriophyllum aquaticum, and Stuckenia pectinata), as well as their exudates, and plant-associated microbiota (POM < 25 µm) + exudates on the population growth of Daphnia cf. pulex and Simocephalus cf. mixtus. Living Ceratophyllum, exudates, and POM < 25 µm + exudates exhibited the most robust positive effects on Simocephalus density and the rate of population increase (r). Subsequently, we examined the effects of Ceratophyllum on the filtration and feeding rates of Simocephalus and Daphnia, revealing significant (p < 0.001) promotion of filtration and feeding in Simocephalus but not in Daphnia. To elucidate the specific effects of this macrophyte on Simocephalus demography, we assessed selected life table variables across the same treatments. The treatments involving exudates and living Ceratophyllum resulted in approximately 40% longer survivorship and significantly (p < 0.01) enhanced fecundity. Our findings indicate that exudates from submerged macrophytes positively influence Simocephalus demography by increasing filtration rates, survivorship, and fecundity. This synergy suggests a substantial impact on phytoplankton abundance.
The current state of aquatic ecosystems was assessed for lakes in two river-lake systems: Swięta Struga (Święte and Ocypelek) and Kałębnica (Czarne Południowe and Kałębie). Trophic states were determined using the Vollenweider, Nürnberg, and Carlson methods. Additionally, shoreline changes were analyzed for all lakes concerning their natural character, and physicochemical parameters were utilized as auxiliary elements in the assessment of the ecological state following the guidelines of Directive 2000/60/EC. Supplementary to these methods, the ecological evaluation of the littoral zone utilized meiobenthic organism grouping as an indicator. The results indicate significant differences among the studied reservoirs. LakeŚwięte is a reservoir bordering mesotrophy and eutrophy, with the ecological state of the littoral zone showing ongoing trophic development. Lake Ocypelek exemplifies a eutrophic reservoir undergoing progressive degradation. The lakes in the Kałębnica system also exhibit advanced trophic conditions, with Lake Kałębie being a eutrophic reservoir. Its shoreline has been significantly altered due to the development of the direct catchment area. In contrast, Lake Czarne Południowe serves as an example of a mesotrophic reservoir, with a substantially changed shoreline. Considering physicochemical elements and chlorophyll a concentration , the water quality for all examined lakes was found to be below the good category. The diagnosis of the condition of lake aquatic ecosystems requires an individualized approach to each of them. Therefore, employing various methods for their assessment, encompassing physico-chemical, biological, and morphological parameters, provides the opportunity to initiate potential remedial actions that will effectively contribute to their improvement. Conducting low-cost research involving a multidisciplinary approach to diagnose the state of aquatic ecosystems is becoming a crucial element in lake monitoring.
Thermal stratification is an important driver shaping phytoplankton community and their habitat condition in freshwater ecosystems. However, studies on river stratification have been restricted to rivers below dams or reservoirs affected by their water release and lacked examination of diel stratification and its impact on phytoplankton, in particular. Therefore, this study aimed to determine the degree of thermal stratification, its environmental drivers, and the response of water quality and phytoplankton community against stratification in the mid-lower reach of the Nakdong River, whose morphology has been highly modified, including the construction of eight weirs. We implemented vertical temperature profiling at three study sites, both seasonally and diurnally. From this data, we calculated three stratification indices: relative water column stability (RWCS), Schmidt stability (S), and maximum temperature gradient (Max). These indices showed that most sites experienced diel stratification during summer (mean = RWCS 74.3, S 41.5 J m−2, Max 0.9 °C m−1). Principal component analysis showed that stratification significantly led to seasonal and diel variations in the water environment. Solar radiation and air temperature were positive controllers, while a negative controller (in this case, the river flow rate) existed only for diel variation in the stratification. The seasonal shifts in phytoplankton community structure were either insensitive or showed a limited response to the stratification indices. In summer, Microcystis cell abundance and accumulation into the surface water was positively affected by the diel variations in the stratification indices and thermocline instead of with other temperature and nutrient variables. Overall, the results suggest that the river has summer stratification, which is involved in amplifying cyanobacterial bloom intensity. Without a suppressing factor, summer stratification is expected to be recurrent in the river, and thus mitigating the developed stratification is needed by promptly regulating the river flow.
This work presents a case study accompanied by an analysis of potential reasons for fish mortality in the lower Oder River during an ecological disaster in August 2022. Changes in physicochemical water quality indicators indicate that fish and benthic organism death was likely due to the creation of hypoxia. The research also highlighted the trophic threats to the studied Oder River section linked to the disaster. The disaster occurred in the upper and middle Oder River, extending to the lower stretch. A physicochemical analysis of water samples revealed that the fish and organism death in the estuarine section was mainly due to reduced dissolved oxygen, caused by the decomposition of organic matter from the upper river sections. This was reinforced by high temperatures and low water levels. The negative trophic consequences of the described ecological disaster for the lower section of the Oder River may be long-term. Over thirty years of monitoring showed threats of excess biogenic compounds, organic matter, and bacterial contamination. Despite decreasing nitrogen and phosphorus, significant phytoplankton blooms implied internal nutrient sources. Considering climate change and the poor trophic status, recurrent disasters and deteriorating conditions are anticipated. Mitigation requires continuous monitoring, limiting the nutrient input (especially phosphorus), and preparing for extreme events. Geotechnical methods in the lower river can improve oxygen levels and fish survival.
We have used Daphnia cucullata (Crustacea: Cladocera) as a model organism for the first time in the four deepest Latvian lakes from the Boreal biogeographical region in order to find the genetic diversity of these populations. During the research, we detected the most appropriate microsatellite markers for future genetic studies of Daphnia cucullata populations of lakes Svente, Riča, Dridzis and Geran , imovas-Ilzas in the Boreal biogeographical region. Based on these microsatellite markers, we determined the genetic diversity of these populations. The loci Dgm105 and Dgm101 had the maximum number of alleles and the maximum number of private alleles. The specific locus Dgm105 had five private alleles (62% of all detected alleles), and locus Dgm101 had four private alleles (57% of all detected alleles) in these loci. We determined the observed heterozygosity (H obs) and the expected heterozygosity (H exp) level (via Hardy-Weinberg equilibrium), the number of polymorphic loci, the number of detected alleles in each analyzed microsatellite locus, the average number of alleles at the locus (N a), the average effective number of alleles at the locus (N e), the F ST of the population's genetic differentiation, the genetic distance (D) (following Nei) and the significance (χ 2-test) of differences between the levels of observed and expected heterozygosity. It was shown that Daphnia cucullata populations from lakes with a low number of zooplankton taxa (Riča and Geran , imovas-Ilzas) have a higher genetic diversity compared to lakes with a high number of zooplankton taxa (Dridzis and Svente). It was found that Daphnia cucullata populations from lakes Dridzis and Svente have the least genetic distance, and these populations form a single genetic group, as confirmed via clustering.
Salinization of freshwater ecosystems is one of the major challenges imposed largely by climate change and excessive water abstraction for irrigated crop farming. Understanding how aquatic ecosystems respond to salinization is essential for mitigation and adaptation to the changing climate, especially in arid landscapes. Field observations provide invaluable data for this purpose, but they rarely include sufficient spatial and temporal domains; however, experimental approaches are the key to elucidating complex ecosystem responses to salinization. We established similar experimental mesocosm facilities in two different climate zones in Turkey, specifically designed to simulate the effects of salinization and climate change on shallow lake ecosystems. These facilities were used for two case-study experiments: (1) a salinity gradient experiment consisting of 16 salinity levels (range: 0–50 g/L); and (2) a heatwave experiment where two different temperature regimes (no heatwave and +6 °C for two weeks) were crossed with two salinity levels (4 and 40 g/L) with four replicates in each treatment. The experiments lasted 8 and 2 months, respectively, and the experimental mesocosms were monitored frequently. Both experiments demonstrated a significant role of salinization modulated by climate on the structure and function of lake ecosystems. Here, we present the design of the mesocosm facilities, show the basic results for both experiments and provide recommendations for the best practices for mesocosm experiments conducted under saline/hypersaline conditions.
For the sustainable use of lake ecosystem services—water resources, aquatic habitats for biodiversity conservation, and aesthetic values as waterfront space—ecosystem health assessments using biota are implemented as important national environmental monitoring projects. Zooplankton play a key role as an important linkage in the material circulation as secondary producers in lake ecosystems. At the same time, they influence the composition and biomass of other communities through biological interactions. In this review, we summarize useful zooplankton indices for ecosystem health assessment and suggest considerations for their use. Suggestions are provided for the practical application of indirectly measured zooplankton biomass, as well as the potential and limitations of eDNA application, which has recently been actively utilized in biological monitoring.
Este libro se compone de tres partes: UNA MIRADA DE ACTUALIDAD EN EL TEMA, CONSIDERACIONES A LOS ESTUDIOS AMBIENTALES EN LIMNOECOLOGÍA, y ESTUDIOS ECOLÓGICOS ACTUALES Y FUTUROS, donde se analizan las principales amenazas y los principales estudios a realizar. Se entrega como un aporte al debate y desarrollo de la ecología aplicada en las aguas continentales de Chile
Forests provide many services to society but climate change, biotic, and abiotic forest disturbances are altering ecological systems. Among these, Mediterranean pine forests, distinctive environmental elements of the Italian coastal area for both natural and historical reasons, are particularly susceptible. As evidenced by numerous wind damages, drought stress, and more recently Toumeyella parvicornis infestation in central Italy. On the other hand, there is a lack of reliable and spatialized data on the spread of infestations and stress states. In this context, their monitoring using all available sources of information is essential. In this study, we used Sentinel-2 optical data to monitor the health status and damage that occurred to Mediterranean pine forests in Italy in recent years (2018–2022). In terms of damaged area, we identified a growing trend over the years (4.5% of Italian Mediterranean pine forests in 2018, 4.0% in 2019, 6.4% in 2020, and 14.6% in 2021), with an abrupt increase in 2022 (24.2%). While our model was calibrated using reference data available for a Mediterranean pine forest study area of about 1000 ha in central Italy and 80% accuracy was reported, more exhaustive reference data should be used for providing solid estimates. On the other hand, Sentinel-2 data proved to be a relevant source of information, pointing to a very serious situation for Mediterranean pine forests.KeywordsGoogle Earth EngineInfestationsMediterranean basinPine forestsSentinel-2
This study assessed the residual contaminant load of three groups of artisanal gold mining (ASM) impacted lands, thereafter, phytoremediation techniques using Jatropha curcas, Manihot esculenta and organic amendments were used for mitigation. A total of 110 soil samples from 30 ASM sites were investigated for their total contents of Cd, As, Pb, Hg, Zn, Fe and Al. After sample digestion, ICP-MS was used for content determinations. Using activated neem seed extracts (NE) and poultry manure (PM) at different application rates, the phytoremediation potentials of Jatropha curcas and Manihot esculenta were assessed for 270 days after planting. The obtained data were analyzed with SPSS statistics 28 for the ANOVA. The results indicated mining spoils were suppliers of toxic elements in the soil however, their distributions per contaminant varied based on the properties of the ore materials mined. As a result, mine spoils created the processing of oxide and underground rock ores supplied contents of As, Fe, Al, Cd and Zn much more than alluvial mining sites and above tolerable threshold levels. Both J. curcas and M. esculenta exhibited phytostabilizing potentials as larger portions of absorbed elements were stored in their root organs. However, the application of a 25% mixture of neem seed extract and poultry manure or 25% poultry manure only (w/w) to soils reduced the uptake capacity of potentially toxic elements by J. curcas and M. esculenta by 19-38% and 10.4-45% respectively.KeywordsMine spoilPotentially toxic elementsPhytoremediation
Thermal stratification in lotic systems has occurred globally and more frequently in recent decades due to global warming and artificial river modification, often with negative ecological effects. However, studies on river stratification have been restricted to rivers below dams or reservoirs affected by their water release and lacked examination of diel stratification and its impact on phytoplankton, in particular. In the present study, we assessed the degree of thermal stratification, its environmental drivers, and the response of water quality and phytoplankton community against stratification in the mid-lower reach of the Nakdong River, whose morphology has been highly modified, including the construction of eight weirs. We implemented vertical temperature profiling at three study sites, both seasonally and diurnally. Then, we calculated three stratification indices: relative water column stability, Schmidt stability, and maximum temperature gradient. Three indices for assessing the degree of stratification showed that most sites experienced diel stratification during summer. Principal component analysis showed that stratification significantly led to seasonal and diel variations in the water environment. Solar radiation and air temperature were positive controllers, while a negative controller (in this case, the river flow rate) existed only for diel variation in the stratification. Higher abundance and surface cell accumulation of cyanobacteria Microcystis were observed at the stratified sites, and the diel variations in its biomass (chlorophyll a) in the surface water were primarily associated with the stratification indices instead of with other temperature and nutrient variables. Overall, the results suggest that the river has summer stratification, which is involved in amplifying cyanobacterial bloom intensity. Without a suppressing factor, summer stratification is expected to be recurrent in the river, and thus mitigating the developed stratification is needed by promptly regulating the river flow.
Lake turbidity, representing a general indicator of water ‘cloudiness’, is a key parameter in many monitoring programs. It is not possible to cover all lakes with frequent in situ monitoring. Sentinel-2 MultiSpectral Imager (MSI) can help to fill the gaps if a robust turbidity retrieval methodology is developed. Previously published results demonstrated the usefulness of MSI at a limited regional scale, while our aim was to develop methodology that allows monitoring turbidity over the whole of China. We proposed methodology with a reflectance that can be classified into optical water types (OWTs), and then a back propagation neural network model (BP-TURB) is used to estimate turbidity. The reflectance of in situ lake samples extracted from MSI imagery was clustered as three OWTs, and validation performance was satisfactory: R2 > 0.81, RMSE < 17.54, and MAE < 11.20. This allowed us to map turbidity in all Chinese lakes, of which the area is larger than 1 km2. A larger percentage of clear lakes (53.26%) with low turbidity levels (<10 NTU) was found in 2020 than in 2015 (37.43%). Lakes in the plateau regions generally exhibited lower turbidity than those situated in the plains regions, for which the turbidity patterns were determined by lake volume, averaged depth, and elevation. We demonstrated that the Sentinel-2 MSI data with the novel approach proposed by us allows for mapping lake turbidity over a large variety of lakes and extensive geographic conditions, as well as for revealing temporal changes in these lakes and their links to lake abiotic characteristics.
The gradients of hydrological, hydrophysical, and hydrochemical conditions form the transition zones in river mouth areas. These areas are considered ecotones in the presence of the edge effect. Our research aimed to identify the main patterns in the structural organization of zooplankton communities in different types of river mouth areas in lowland reservoir tributaries within the Middle Volga basin. A cluster analysis was performed to structure and determine the zooplankton communities. The identified zooplankton communities were characterized by the noticeable heterogeneity in the species structure. We analyzed the spatial distribution of the structural indicators of zooplankton communities and, on the basis of RDA, determined the factors that significantly affect the organization of the ecotone community. An ecotone was found in all types of river mouth areas where the highest density, biomass, diversity, species, and functional richness of zooplankton were noted, as compared to bordering zooplankton communities. As the morphological structure of the mouth areas became more complex, the values of the main structural parameters of zooplankton communities increased. It was demonstrated that conditions in the ecotones are favorable to the development of zooplankton alien species. The major factors determining the species structure of the ecotone zooplankton community were water electrical conductivity (R2 = 21.07%, p-value = 0.001), dissolved oxygen content (R2 = 10.33%, p-value = 0.003), and water transparency (R2 = 9.77 %, p-value = 0.001).
ResearchGate has not been able to resolve any references for this publication.