High Nutrient Levels Research Articles

Effects of Cricket Frass Biofertilizer on Growth of Spring Onion (Allium Fistulosum L.) and Physicochemical Properties of Soil

Objective: This study aims to assess the effects of cricket frass biofertilizer on the growth and yield potential of spring onion (Allium fistulosum L.) and its residual effects on physicochemical properties of the soil in greenhouse and field conditions. Methods: 7 treatments namely cricket frass (0t/Ha, 5t/Ha, 10t/Ha, 15t/Ha, and 20t/Ha), poultry manure (15t/Ha) and cattle manure (15t/Ha) were used and replicated 3 and 4 times in field and greenhouse conditions respectively. Plots of 1m2 arranged in a randomized complete block design for field experiment and pots with 5kg of soil laid out in a completely randomized design for the controlled experiment were used. Spring onion transplants were maintained in both trials for 16 weeks with uniform agronomic inputs. Growth and yield were assessed based on plant height, crop growth rate, number of leaves per plant, plant fresh weight, plant dry weight and root to shoot ratio. The effect of frass on soil was scored based on the percentage of organic carbon, nitrogen, phosphorus, and potassium at the start and end of the experiment. The data was assessed for normality (Shapiro-Wilks test) and subjected to analysis of variance at P<0.05 using R-statistical software. Treatment means were separated using fishers-protected least significant different. Results: Frass application increased growth and yield traits in both trials with the exception of the number of leaves per plant, regardless of the dosage. Frass at 15t/ha outperformed all other treatments and competed favorably against conventional manures obtained from poultry and cattle. Frass bio-fertilizer significantly increased the organic carbon, phosphorus, potassium, calcium and magnesium content of the soils. Frass contained adequate nutrients in labile forms that contributed to growth and yields. This significance can also be linked to the presence of growth promoters and stimulation of microbial population in soils, which is characteristic of insect manures. The high levels of nutrients in the soil after planting confirms frass as an amicable soil amendment that buffers and supports soil properties. Conclusion: Cricket frass biofertilizer is a valuable bio-fertilizer that has the potential to improve the quality of soils and support the growth and yields of notable kitchen vegetables such as onions.

Elemental composition of small pelagic fishes in three East African lakes: Implications for nutritional security

Micronutrient deficiencies and food insecurity constitute major threats to human health across Africa. With decreasing availability of large-bodied fishes (>20 cm), strategies have developed to target small pelagic fish (SPF) species (<20 cm total length) to improve the food availability; yet little is known regarding their nutritional content. Three species of SPFs - Engraulicypris bredoi (muziri), Brycinus nurse (ragoogi) and Rastrineobola argentea (mukene) - were collected from lakes Albert, Victoria, and Nabugabo in Uganda, East Africa. The content of essential elements (Ca, Fe, K, Mg, Na, P, Se, and Zn) and non-essential, potentially toxic elements (Cd and Pb) were measured and compared in fishes across landing sites within lakes Victoria (R. argentea) and Albert (B. nurse, E. bredoi) and between lakes (R. argentea). Rastrineobola argentea was the most nutritious of the fishes examined, although some variation was present in their elemental concentration among landing sites. Overall, all three species contain high levels of essential nutrients and fall within a safe range for non-essential, toxic elements based on current consumption habits. These SPFs can play an important role in addressing nutritional deficiencies in Uganda, and effort should be made to increase the availability, accessibility, and consumption of these under-utilized small fishes.

Co-Inoculation with Phosphate-Solubilizing Microorganisms of Rock Phosphate and Phosphogypsum and Their Effect on Growth Promotion and Nutrient Uptake by Ryegrass

In the previous half-century, natural rock phosphates (PN) have been a valuable alternative for phosphorus (P) fertilizer for sustainable agriculture; furthermore, phosphogypsum (PG) has been widely used as a soil amendment fertilizer since it improves some soil properties, increases crop yields, and represents an environmental concern that can make a good economic profit; this research aimed to study the effects of microbial consortia of phosphate-solubilizing microorganisms (PSM) on the solubilization of PN and PG in the soil, and their effects on promoting plant growth and nutrient assimilation using ryegrass as a plant model. Local supply of PG with Pseudomonas fluorescens (MW165744) significantly increases root proliferation and plant biomass dry weight compared to other isolates, as well as improves total P uptake, with a maximum value of 62.31 mg/pot. The opposite occurred in mixing inoculation with Pseudomonas fluorescens, Pantoea agglomerans (MW165752) and Stenotrophomonas maltophilia (MW221274), with a negligible total P assimilation of 5.39 mg/pot. Whereas the addition of Pseudomonas agglomerans with PG gave outstanding total P absorption of 57.05 mg/pot when compared with PN input of 38.06 mg/pot. Finally, the results prove that the co-inoculation of Pseudomonas fluorescens with PG could be a promising and alternative option to use it as a source of P fertilizer for plants and to maintain a high level of nutrients in the soil.

Optimization of Neochetina eichhorniae Warner and Neochetina bruchi Hustache for the management of water hyacinth, Eichhornia crassipes (Mart.) Solms in the Central Rift Valley lakes through the use of different nutrient levels in Ethiopia

Water hyacinth, Eichhornia crassipes (Mart.) Solms, is an alien invasive weed in Ethiopia that has been established in freshwater bodies. Eichhornia crassipes negatively affects water transportation, fishing and biodiversity among others. Hence, implementation of eco-friendly management option such as biological control is a mandatory. The weevils, Neochetina eichhorniae Warner and N. bruchi Hustache, are the principal biocontrol agents against E. crassipes in their native ranges and have been introduced to Ethiopia for the management of the weed. The weevils and their host are affected by the nitrate and phosphate contents of the water body. Thus, this study was conducted to investigate the effect of N. bruchi and N. eichhorniae in relation to water nutrient contents in the management of E. crassipes. The experiment was conducted in a randomized complete block design with three replications in a 4x4x3 factorial arrangement. Eight weeks after the treatments’ application, the population of the weevils and E. crassipes growth parameters were recorded. The larval population was significantly (p &lt; 0.05) affected only by the interaction effect of N. bruchi and the nutrient levels. Among the treatments, the highest mean number of larvae was found on the plants given high and medium nutrient levels. There was also a significant interaction (p &lt; 0.05) between the two weevils adult density. The mean number of emerged adult density of the weevils increased with increasing nutrient levels. The nutrients and weevils exhibited a significant interaction effect on E. crassipes leaf scarring and petiole tunnel. Leaf scarring at the highest weevil density and nutrient level was sixfold greater than that at the lower nutrient level and weevil density. The tunnel length of the weed was threefold higher at the highest nutrient level regardless of the weevil density. The growth parameters of E. crassipes were found to be greater at high nutrient level, except for the mean number of flowers. Conversely, the growth parameters showed a non-uniform trend with the increasing density of the weevils. The current result suggests reduction in E. crassipes could be achieved by lowering the water nutrient levels and use of N. bruchi and N. eichhorniae.&#x0D;

Negative effects of fish cages on coral reefs through nutrient enrichment and eutrophication in Nha Trang Bay, Viet Nam

The potential impact of cage farming activities on nutrient enrichment of the coastal waters of Nha Trang bay, Viet Nam as investigated within a project financed by the Vietnam Academy of Science and Technology (VAST). Results show a very high level of nitrogen (N) in the studied area: the average content of dissolved inorganic nitrogen (DIN) was 177.4 ±6.0μg/l (range from 169.9 to 188.9μg/l), in which NO3-N accounts for the major proportion (average 152.9 ±1.9μg/l). The Redfield ratio (N/P) also showed values larger than 16 in almost all studied sites, indicating that phosphorus may be the limiting nutritional factor in these coastal waters. The TRIX indexes recorded for both the surface and bottom waters are within a range of about 5–6 (at high nutrient level); especially at sites under the cages and near the cage farming area. Cross-transplantation experiments with corals showed significant differences at different sites, particularly in relation to distance to fish cages. In comparison, the zooxanthellae densities of Acopora formosa in coral polyps indicated a rapidly reduced value after 31 days of exposure in the polluted areas. Strong side effects such as increased sedimentation as a result of fish farm activities can be detected on nearby coral reef. It is concluded that fish cage farming is negatively impacting coral reefs by being a point source of surplus nutrients.

Chemical Fruit Profiles of Different Raspberry Cultivars Grown in Specific Norwegian Agroclimatic Conditions

Raspberries are considered valuable fruits due to their high levels of nutrients and phytochemicals, which have many beneficial effects on humans. As many external factors affect the composition of these fruits (the type of cultivation, soil characteristics, ripeness, storage time and post-harvest technologies, cultivar/genotype, and climatic conditions), the goal of this study was to analyze different raspberry cultivars grown in Norway. Considering that Norway is a country with specific climatic conditions, as well as has a limited period of fruit vegetation, another important goal of this study was also to compare raspberries from different Norwegian areas, as well as different grown cultivars. Modern analytical techniques, such as high-performance anion-exchange liquid chromatography with pulsed amperometric detection (HPEAC-PAD), ultra-high-performance liquid chromatography with diode array detector coupled to triple quadrupole mass spectrometry (UHPLC-DAD MS/MS), and inductively coupled plasma–optical emission spectrometry (ICP-OES), provided a detailed examination of the raspberry extract samples. Based on their high levels of minerals (especially N, P, and K), organic acids (predominantly citric and malic acids), sugars (glucose, fructose, sucrose, and galactose), and polyphenols (ellagic acid, syringic acid, quercetin, and rutin), Norwegian raspberries could be considered fruits with increased health-beneficial compounds. The chemical composition of the studied cultivars depended on the locality of growth.

Nutrition, Phytochemicals, Antioxidants, and Cytotoxicity of Sweet Potato Leaf Tea

Due to their nutritional loadings and the value-added aspect, fresh leaves of 5 sweet potato varieties were screened for phytochemicals and used to produce herbal teas. The teas were observed for their proximate components, antioxidants, antioxidative activity, cytotoxicity and colour parameters under brewing at 60, 80 and 100 ºC for 3, 5, 7 and 10 min. Tannins, phenolic compounds, saponins, flavonoids, phytosterols and alkaloids were contained in almost all varieties, whereas cardiac glycosides were dominant only in WP (white skin and purple flesh root) fresh leaves. Results for proximate components found that WP tea was prominent with the enrichment of crude fat (16.71 g/100 g of tea), chlorophyll b (29.41 mg/100 g of tea), cyanidin-3-glucoside (83.59 mg/100 g of tea), pelargonidin-3-glucoside (72.30 mg/100 g of tea) and tannins (1,994.81 mg TAE/100 g of tea). This was followed by RO (red skin and orange flesh root) with more protein content (0.13 g/100 g of tea). In the antioxidant test, OO (orange skin and orange flesh root) had the highest total phenolic content (1,260.92 mg GAE/100 g of tea) and offered the greatest potential of antioxidative activity (12,218.44 mg GAE/100 g of tea). No teas showed any signs of cytotoxicity (LC50 &gt; 1,000 µg/mL). Almost all the tea was green in colour, but a yellow colour indicating lutein or its influence was also detected. In conclusion, WP, RO and OO tea were predominantly served as a low-price healthy beverage with high nutrient levels and antioxidative properties.&#x0D; HIGHLIGHTS&#x0D; &#x0D; Edible sweet potato leaves can be served as a low-cost healthy tea beverage&#x0D; Sweet potato leaf teas enrich of medicinal bioactivities such as cyanidin-3-glucoside, pelargonidin-3-glucoside, tannins, and total phenolic compounds&#x0D; Sweet potato leaf teas have strong antioxidative activity&#x0D; &#x0D; GRAPHICAL ABSTRACT

Linking the network topology of plant traits with community structure, functioning, and adaptive strategies of submerged macrophytes

Plant trait network analysis can calculate the topology of trait correlations and clarify the complex relationships among traits, providing new insights into ecological topics, including trait dimensions and phenotypic integration. However, few studies have focused on the relationships between network topology and community structure, functioning, and adaptive strategies, especially in natural submerged macrophyte communities. In this study, we collected 15 macrophyte community-level traits from 12 shallow lakes in the Yangtze River Basin in the process of eutrophication and analyzed the changes in trait network structure (i.e., total phosphorus, TP) by using a moving window method. Our results showed that water TP significantly changed the topology of trait networks. Specifically, under low or high nutrient levels, the network structure was more dispersed, with lower connectance and higher modularity than that found at moderate nutrient levels. We also found that network connectance was positively correlated with community biomass and homeostasis, while network modularity was negatively correlated with community biomass and homeostasis. In addition, modules and hub traits also changed with the intensity of eutrophication, which can reflect the trait integration and adaptation strategies of plants in a stressful environment. At low or high nutrient levels, more modules were differentiated, and those modules with higher strength were related to community nutrition. Our results clarified the dynamics of community structure and functioning from a new perspective of plant trait networks, which is key to predicting the response of ecosystems to environmental changes.

TOC Standards for Sustainably Managing Refractory Organic Matter in Swine Wastewater Effluent

Swine wastewater effluent is a key source of water contamination since it contains high levels of nutrients, including nitrogen and phosphorus, as well as nitrates and refractory organic matter (ROM). ROM refers to organic compounds that are usually resistant to microbial degradation. When swine wastewater effluent containing high levels of ROM is subsequently discharged into rivers and streams without being adequately treated, purification costs for drinking water increase and there remains a possibility for harmful substances to enter the human body. In this study, we introduce new methods for setting total organic carbon (TOC) water quality standards for discharging swine wastewater effluent containing high levels of ROM after treatment. To set the TOC water quality standards, various analysis methods based on statistics, technology, and experience based on operational data of livestock-manure treatment facilities were applied. In addition, the achievability of the proposed TOC standards in livestock-manure treatment facilities and the financial burden of their implementation on livestock farms were also reviewed. Here, we set tentative values that include all of our results derived from each methodology and set the TOC standards to levels that can be achieved through the normal operation of swine-wastewater treatment facilities (60 mg/L for public treatment facilities and 140 mg/L for treatment facilities operated by individual farms). When setting TOC standards, both single and combined methodologies should be considered and employed after comprehensively assessing livestock management policies, regional conditions, and the burden on stakeholders.

Soil organic carbon stock capacity in karst dolines under different land uses

The soil organic carbon (SOC) was determined in soils of enclosed karst depressions (dolines) (NW Dinaric Mts.) to define their potential for organic carbon sequestration. SOC was measured in the forest, succession (scrubland), and grassland plots at the bottom of dolines at four depths (0–40 cm) and for 40 cm soil layer SOC stock was calculated. We demonstrated that the prevailing fine soil fractions, the C/N ratio and soil thickness play a positive role in the storage capacity of SOC in dolines regardless land use type. Grasslands have the lowest SOC storage capacity (106 t/ha/40 cm), while the highest SOC storage capacity is in succession plots (130 t/ha/40 cm). The last are covered by shrub communities dominated by Prunus spinosa, forming dense communities, and are typical of abandoned croplands or meadows that have been impacted by high levels of nutrients during cultivation phase. At this stage, there is no additional nutrient input in studied plots, which lowers the nutrient content and increases the C/N ratio. C/N ratio is the highest in the forest, where SOC stock capacity is 116 t/ha/40 cm. Given the trend towards the abandonment of agricultural land at Kras Plateau (SW Slovenia), we can expect more overgrowth of dolines, and thus an increase in carbon stocks and stabilization of organic carbon in forest soils. In contrary, we noticed the alarming decrease in grasslands and increase in urban land. The SOC storage in 2020 was for 12,538 t/ha/40 cm lower than in 2002. Although grasslands showed the lowest SOC storage, their contribution to total SOC storage in dolines is very important. Since there is a lack of studies on carbon stocks in doline soils, our research is of great importance and a novelty and gives an important background for further research on SOC stock in karst landscapes worldwide.

Variability of particulate organic carbon and assessment of satellite retrieval algorithms over the eastern Arabian Sea.

Particulate organic carbon (POC) and its variability were studied to assess the accuracy of ocean colour retrieval algorithms over the eastern Arabian Sea (EAS) as it controls the carbon sequestration, oxygen minimum zone and biogeochemical (C, N and P) cycles. The seasonality in the physical and biological processes strongly influenced the distribution of POC along the EAS. Higher POC and chlorophyll a (chl a) during the spring inter monsoon (SIM) in the north EAS were due to detrainment bloom. The lower POC:chl a ratios during the winter monsoon (WM) (299.8 ± 190.8) than the SIM (482.1 ± 438.3) were due to the influence of freshly derived organic matter with high nutrient levels. The moderate coefficient of regression values of POC with chl a (R2 = 0.49, N = 59) suggests the importance of dead organic materials in controlling the POC distribution in the EAS. Validation between satellite and in situ POC using the four ocean colour retrieval algorithms showed that the algorithm based on the ratio of remote sensing reflectance (Rrs) performed better (R2 = 0.6, N = 17). It also showed a linear trend of POC with absorption coefficients suggesting it as an optical proxy for the POC retrieval.

Interactions of treated municipal wastewater with native plant species

Potentially, the restoration of native ecosystems could be combined with the land application of treated municipal wastewater (TMW), reducing TMW discharge into waterbodies. High levels of nutrients, pathogens, and other contaminants from TMW can degrade water quality. The land application of TMW onto native vegetation reduces the nutrient load in water bodies and may create zones of ecological value. However, establishing native plants may be challenging if the species are not adapted to highly fertile environments, such as those resulting from TMW irrigation. There is a critical knowledge gap about the response of native plant species to irrigation with TMW. We aimed to determine the distribution and speciation of nutrients in the soil-plant system following application of TMW onto 11 species of native plants in a long-term field trial on Banks Peninsula, New Zealand (NZ). TMW was irrigated at a rate of 1000 mm per annum, equivalent to N, and P loading rates of 194 and 110 kg ha yr−1, respectively. We determined physicochemical properties from soil profiles (0–65 cm) under selected species as well as the growth and chemical composition of the plants. Despite the site receiving 950 kg ha−1 yr−1 of Na, there was no evidence of impaired soil structure following TMW irrigation. Nitrogen did not accumulate in the soil, and it is likely to have been taken up by plants or lost through denitrification and nitrate leaching. The accumulation rate of P indicated that soil P concentrations will remain within the range found in NZ agricultural soils for at least 50 years. TMW irrigation increased plant height by 10% compared to the control after 3.5 years of growth. Plant species significantly affected the concentrations of total C, total N, nitrate (NO3−), and Na in the soil. TMW application had negligible effects on the elemental composition of plant foliage. NZ native vegetation can facilitate the land application of TMW. Future work should elucidate the maximum rates that can be applied as well as the effect of TMW on the soil microbiota.

Nutrient status of integrated rice-crayfish system impacts the microbial nitrogen-transformation processes in paddy fields and rice yields.

Increasing rice yield is essential for alleviating global food crisis. High soil nutrient level guarantees high rice yields in conventional rice monoculture (RM) systems, but excessive unconsumed nutrients act as pollutants and can even threaten rice growth. The integrated rice-crayfish (IRC) system aims to transfer the excess nutrients from crayfish to paddy fields to improve the comprehensive utilization rate of nutrients and create additional profits, while the responding characteristics of IRC microbial communities in paddy fields and rice yields to the nutrient status remain unclear. Considering the crucial roles of microbiomes in promoting nutrient cycling for crop absorption in rice production progresses, the composition and functional characteristics of soil microbial communities from six IRC farms with variant nutrient statuses in the Yangtze River Delta were surveyed in this study. Compared with RM systems, IRC systems with appropriately improved (p < 0.05) soil quality created favorable nutrient (FN) status accompanied by 15% rice yields increase, while IRC systems with extremely high nutrients (HN) status (p < 0.01) accompanied by 14% rice yields reduction. Soil microbial diversity and network complexity were maintained in FN-IRC systems, but declined in HN-IRC systems, with the Shannon index significantly decreased by 9.2% and network density decreased from 0.135 (in RM) to 0.062. In the FN-IRC systems, the keystone taxa identified by co-occurrence networks displayed inextricably positive correlations with soil nitrification potential (calculated by normalization of amoA gene abundance) and rice yields. While in HN-IRC systems, the large loss of keystone taxa might limit soil nitrogen fixation potential (calculated by normalization of nifH gene abundance), and further rice yields. Our study indicates that soil nutrient management in IRC systems claim attention, and the improvement of nitrogen metabolism is the key to realize agricultural cleaner production.

Pengaruh Konsentrasi Pupuk Kalium Boron dan Mikro terhadap Produksi Kedelai (Glycine max (L.) Merril)

One of the effort to increase soybean production can be done with fertilization. Effect of fertilizer to the land is to create a high level of nutrients and can improve the quality of the crop. Fertilization through leaves intended that nutrients can be absorbed quickly by plants. Macro elements such as potassium (K) and micronutrients such as boron (B) and other micro elements are needed on soybeans. The research objective was to determine the effect of concentration of Boron and Potassium Fertilizer on Soybean Production Micro (Glycine max L. Merrill). This research was conducted in paddy fields in August up to November 2016, in the village Kertonegoro, district Jenggawah Jember district. The study was conducted using a Randomized Block Design (RBD) consisted of two factors with three replications. The first factor is the concentration of potassium boron (KB) consists of 0 ml/l (KB0), 1.5 ml/l (KB1), 3 ml/l (KB2) and the second factor is the concentration of micro fertilizer (M) consisting of 0 g/l (M0), 0.125 g/l (M1), 0.25 g/l (M2). The results showed that fertilizer treatments of Potassium Boron influence on the parameters of a number of branches, number of pods and pod weight, but has no effect on the parameters plant height and number of leaves per plant soybeans. KB2 (3 ml/l) gives the highest production. Micro fertilizer treatment effect on the parameters pod number and weight of pods, but has no effect on the parameters plant height, number of leaves and number of branches. m2 (0,25 g/l) gave the highest soybean production. Potassium fertilizer combination treatment Micro Boron and give effect to the parameter number of pods and pod weight, but the effect on the parameters plant height, number of leaves and number of branches. The highest soybean production in KB2M1 treatment (potassium boron 3 ml/l and micro 0,125 g/l) which is 38.33 grams per plant.

Upper Triassic Carbonate Records: Insights from the Most Complete Panthalassan Platform (Lime Peak, Yukon, Canada)

Upper Triassic carbonate platforms from the Panthalassa Ocean remain less-understood and less-studied than their Tethyan equivalents. This imbalance is largely due to the poorer preservation state of Panthalassan carbonate rock successions in terms of rock quality and depositional geometries, which prevents good appreciation of depositional systems. In this context, carbonate exposures from Lime Peak (Yukon, Canada) represent an outstanding exception. There, the remains of an Upper Norian Panthalassan carbonate platform are well-exposed, show remarkably preserved depositional geometries and overall superior rock preservation. In this work, we analyse the carbonates from the Lime Peak area with particular attention to the vertical and lateral distribution of biotic assemblages and microfacies at the platform scale. Results demonstrate that the Lime Peak platform was surrounded by a basin with an aphotic sea bottom. The carbonate complex developed in warm waters characterized by high carbonate saturation. The area was also defined by moderate to high nutrient levels: this influenced the type of carbonate factory by favouring microbialites and sponges over corals. During its growth, Lime Peak was influenced by tectono-eustatism, which controlled the accommodation space at the platform top, primarily impacting the internal platform environments and the stability of the slope. Gaining better knowledge of the spatial distribution and dynamics of Upper Triassic organisms and sedimentary facies of Panthalassa in relation to tectono-eustatism lays the first foundations for reconstructing more robust platform models and understanding the evolution of other, more dismantled Upper Triassic Panthalassan carbonate systems through time.

Relationship between thermohaline and biochemical patterns in the levantine upper and intermediate water masses, Southeastern Mediterranean Sea (2013–2021)

The relationships between the interannual variations of the Levantine intermediate water (LIW) core properties and the corresponding biochemical variations in the euphotic zone were systematically studied in the Southeastern Mediterranean during 2013–2021 and since 2002 based on a previous study. Salinity and temperature interannual fluctuations in the LIW continue to follow the Adriatic–Ionian Bimodal Oscillating System (BiOS) mechanism, with salinity and temperature peaks in the years 2008–2010, 2014–2015, and 2018–2019 coinciding with periods of anticyclonic circulation of the North Ionian Gyre (NIG). During these anticyclonic periods, the transport of Atlantic Water into the Levant is reduced together with the transport of LIW out of the basin. These interannual fluctuations are superimposed on a long-term warming trend clearly evident from previous studies, showing a maximal temperature in 2018–2019, higher than the previously mentioned temperature peaks by ~0.7°C and ~0.4°C. The enhanced warming in 2018–2019 has caused a decrease in density (sigma) values of the LIW core, which gave way to the shallowest record of this water mass (~110-m depth), bringing it well within the lower photic zone. We suggest that a higher level of nutrients became available, supporting the observed long-term rise of the intergraded chlorophyll a (Chl.a) (0.89 mg m−2 year−1), with a maximum recorded during 2018–2019. The long-term record of the mixed layer depths shows no significant change; thus, the uplift of nutrients during winter mixing cannot support the trend and variations of the integrated Chl.a. Additional biological parameters of specific pico-phytoplankton populations and integrated bacterial production and abundance were measured in 2013–2021, but the measurements were too sparse to follow a clear interannual dynamics. Yet significantly higher average levels for integrated primary production and bacterial abundances were observed during the anticyclonic period (as for Chl.a). The combined impacts of the BiOS mechanism and global warming, and hence the increase in LIW residence time and buoyancy, may impact the primary producers’ biomass at the photic zone. This latter feedback may slightly counter the enhanced oligotrophication due to enhanced stratification.

Aquatic Contamination in Lugano Lake (Lugano Lake Ecological Reserve, Buenos Aires, Argentina) Cause Negative Effects on the Reproduction and Juvenile Survival of the Native Gastropod Biomphalaria straminea.

Lugano Lake is located in an Ecological Reserve of Buenos Aires City. Biomonitoring of its water quality is essential due to its importance as a place for recreation and protection of native species. Biomphalaria straminea is a native hermaphrodite aquatic gastropod that inhabits different freshwater bodies of Argentina and was recently selected as a potential bioindicator. We propose this study as a first approach to assessing specific organisms’ use in biomonitoring of urban wild reserves, and the usefulness of reproduction assays. B. straminea survival, behavior, reproduction success and offspring survival after the exposure to water samples from Lugano Lake (L1, L2, and L3) were evaluated. Temperature, pH, conductivity and dissolved oxygen were registered in situ. Samples were transported to the laboratory and chemical analysis and bioassays were performed using 20 snails per site. A control group with tap water was added. Egg masses were separated, exposed individually and observed daily using a stereoscopic microscope. After hatching, juveniles were placed in tap water and offspring survival was registered at the first, second, third and fourth months after the beginning of the assay. High levels of conductivity, turbidity and nutrients were obtained. Ammonium and nitrite were higher than the guideline level for the protection of aquatic life. During the bioassay 20% of the snails (L2 and L3) showed abnormally protruding of the head-food region. The number of eggs and embryonated eggs per mass did not differ between treatments. Egg masses exposed to water samples from the lake presented overlapping and abnormal eggs and arrested embryos. Besides, low % of hatching (L1: 33%, L2: 42%, and L3: 16%) and juvenile survival after the first (L1:14%; L2:78%) and second month (L1: 60%) were noted. In the control group, 85% of hatching and 100%–90% of survival were observed. Our results suggests the presence of pollutant in the lake. B. straminea seems to be a sensitive local species. Biomphalaria spp. reproduction assays can provide a valuable endpoint for toxicity and risk assessments and a usefulness tool for biomonitoring water quality.

Elevated carbon assimilation and metabolic reprogramming in tomato high pigment mutants support the increased production of pigments.

High pigment mutants in tomato (Solanum lycopersicum L.), a loss of function in the control of photomorphogenesis, with greater pigment production, show altered growth, greater photosynthesis, and a metabolic reprogramming. High pigment mutations cause plants to be extremely responsive to light and produce excessive pigmentation as well as fruits with high levels of health-beneficial nutrients. However, the association of these traits with changes in the physiology and metabolism of leaves remains poorly understood. Here, we performed a detailed morphophysiological and metabolic characterization of high pigment 1 (hp1) and high pigment 2 (hp2) mutants in tomato (Solanum lycopersicum L. 'Micro-Tom') plants under different sunlight conditions (natural light, 50% shading, and 80% shading). These mutants occur in the DDB1 (hp1) and DET1 (hp2) genes, which are related to the regulation of photomorphogenesis and chloroplast development. Our results demonstrate that these mutations delay plant growth and height, by affecting physiological and metabolic parameters at all stages of plant development. Although the mutants were characterized by higher net CO2 assimilation, lower stomatal limitation, and higher carboxylation rates, with anatomical changes that favour photosynthesis, we found that carbohydrate levels did not increase, indicating a change in the energy flow. Shading minimized the differences between mutants and the wild type or fully reversed them in the phenotype at the metabolic level. Our results indicate that the high levels of pigments in hp1 and hp2 mutants represent an additional energy cost for these plants and that extensive physiological and metabolic reprogramming occurs to support increased pigment biosynthesis.

Alive and dead foraminiferal assemblages at sandy beaches of Karachi coast-diversity, ecological distribution and responses to seasonal fluctuations

Foraminifera are eukaryotic protists and play a vital role in marine community structure. However, how physicochemical environment shape meiofaunal community structure at highly dynamic exposed sandy beaches of Arabian sea is inadequately known. This is the first study about spatiotemporal distribution of alive and dead benthic foraminiferal (BF) species from coastal regions of Pakistan based on 48 core samples collected monthly with the help of hand corer (diameter = 3 cm) from four stations at two sandy beaches of Karachi coast i.e., Sandspit and Hawksbay. Sampling was done throughout the year from March 2013 to April 2014 to observe seasonal variability in southwest and northeast monsoon season. Physicochemical parameters (temperature, salinity, pH, dissolved oxygen and nutrients i.e. Ammonia, nitrate and phosphorus) and sediment characteristics (grain size, moisture content, organic content) was analysed using standard methods.The top 0–2 cm sediment slice was analysed for both living and dead foraminiferal assemblages. A sum of 6615 individuals (ind.) cm−2 of BF consisting of 3451 ind. cm−2 empty tests and 3164 ind. cm−2 living specimens belonged to 66 species were recorded, where 47% species are Miliolina, 42% Rotaliida, 9% Textulariina and 2% are Spirillinina. The similarity percentage breakdown analysis (SIMPER) showed 18.51% average dissimilarity between foraminifera abundance at Sandspit and Hawksbay but stations within sites showed similarity (82.83% at Sandspit and 84.65% at Hawksbay). The highest abundance of alive BF was recorded in northeast monsoon season (3232 ind. cm −2) associated with high levels of nutrients. Alive and dead foraminifera assemblages at Karachi coast do not seem to be measured by a single physicochemical and environmental factor but multiple factors are controlling spatiotemporal distribution of BF at these beaches. The most significant and governing factor for benthic abundance and diversity at these beaches is the monsoon season.

Effects of water contamination with heavy metals on pigmented macrophages in spleen of Vardar chub (Squalius vardarensis Karaman) from three rivers in the North-Eastern region of North Macedonia

Background and purpose: Pigmented macrophage aggregates (PMAs) are a part of the immune system of fish and are considered as valuable biomarkers of the impact of water pollution on fish health.Materials and methods: Immunomodulatory effect of water contaminated with high levels of metals on spleen and splenic PMAs of Vardar chub (Squalius vardarensis) (n=129) was examined in two seasons, spring, and autumn 2012. For this purpose, three rivers were chosen: the Zletovska River, heavily contaminated with metals, the Kriva River, moderately contaminated with metals combined with high level of organic matter, and the Bregalnica River, without heavy metal contamination. Spleen masses and splenosomatic indices (SSI) were used for determining the general impact of water contamination on the immune system of Vardar chub. Moreover, volumes and numbers of PMAs within spleen tissue were determined stereologically.Results: The isolated effect of high exposure to metals caused the reduction of spleen mass and/or SSI in the fish from the Zletovska River. The combined effect of exposure to metals and high levels of nutrients in the fish from the Kriva River referred to stimulation of PMAs response, namely increased volumes of splenic PMAs. The existence of seasonally dependent differences was noted since the observed variability in PMAs between rivers occurred only in the autumn.Conclusions: Splenic PMAs in the Vardar chub can be used as an additional biomarker of metal pollution, but with caution, since enhancement of the volumes and numbers of MACs depends on the exposure level of heavy metals, on the presence of the other contaminants, as well as on the physiological condition of the fish.