Additional Food Source Research Articles

The influence of freshwater inflow and seascape context on occurrence of juvenile spotted seatrout Cynoscion nebulosus across a temperate estuary.

Spotted seatrout, a popular recreational sport fish in the southeastern United States, are affected by freshwater flow conditions and the availability of estuarine habitat. However, the relative influence of these factors, particularly on early life stages of seatrout, remains uncertain. We used generalized linear models to quantify relationships between the probability of encountering juvenile spotted seatrout during seine surveys and various factors, including freshwater inflow conditions, the availability and richness of estuarine habitats (seagrass, salt marsh, oyster beds) around (400-m radius) fish collection sites (seascape-scale context), as well as distance to the nearest inlet to the Gulf of Mexico (estuary-scale context) across shallow waters (< 1.5 m depth) of Apalachicola Bay, Florida. Modelling results showed a consistent positive correlation between seagrass area and the probability of encountering juvenile seatrout (all four size classes from 15mm-200mm Standard Length (SL)). The probability of encountering the two smallest juvenile seatrout size classes (15-50mm and 51-100mm SL) was also related to freshwater inflow conditions, particularly within a 3-month period prior to and including peak recruitment. Freshwater inflow may affect early life stages by influencing passive transport of eggs and larvae, planktonic food availability, and predation pressure through increases in turbidity. In contrast, encounter probabilities of the two larger size classes (101-150mm and 151-200mm) were unrelated to freshwater inflow. Inflow-related processes may be less important to the larger juveniles as they have typically settled out of the plankton into benthic habitats which provide refuge from predation and abundant benthic food sources which are not as closely tied to freshwater inflow effects. In addition, models revealed that occurrence of the larger juveniles was related to the availability of nearby habitat types such as oyster beds and salt marshes, suggesting that increased mobility as seatrout grow may allow them to use nearby habitat types as additional sources of food and refuge. These results add to a growing body of literature aimed at understanding the influence of freshwater inflow as well as seascape context on vulnerable juvenile life stages of fishery species to provide more informed strategies for freshwater inflow management and habitat conservation.

Improving green sea urchin (Strongylocentrotus droebachiensis) hatchery production by determining effective settlement cues and post-settlement conditions

Hatchery production methodologies of Northeastern U.S. green sea urchins (Strongylocentrotus droebachiensis) have yielded low settlement success and post-settlement survival (approximately 1–5%) contributing towards high costs for producing juveniles for this emerging aquaculture species. These are likely attributed to hatchery operations needing to optimize settlement cues and post-settlement food supplies. This study examined a range of potential settlement cues using adult conspecifics or a benthic diatom biofilm (Cylindrotheca closterium or Nitzschia sp.) alone, or in combination with seawater conditioned with conspecifics or macroalga (Saccharina latissima or Ulva lactuca). This study also examined whether sea urchin post-settlement survival and growth would improve using a benthic diatom food source (C. closterium or Nitzschia sp.) alone or in combination with an additional macroalga food source (S. latissima or U. lactuca). Both trials were conducted under hatchery ambient (control 12 °C) or elevated (14 °C) temperatures to determine whether temperature elevation could enhance S. droebachiensis settlement success and post-settlement growth. This study also examined what influence biofilm age (1, 4 and 8 weeks) and seawater salinity (26, 30, 33 and 36) had on settlement success to help towards optimizing hatchery methods. This study did not improve post-settlement survival causing it to remain a significant barrier in mass producing juveniles, but it did increase juvenile growth by 30–40% and reduce growth variability when fed the benthic diatom C. closterium in combination with U. lactuca. This combination also served as an adequate settlement cue for this species. The use of a conspecific influenced biofilm substantially improved settlement success from 1 to 5% to 50–80%. Seasonal timing and age (4 weeks) of this biofilm indicated importance in yielding this success which will be location specific. The use of conspecific biofilms for improving post-settlement survival requires further investigation and is worth examining in combination with C. closterium and U. lactuca towards enhancing S. droebachiensis production in the Northeastern U.S. Elevating seawater temperature by 2 °C had no significant effect on settlement, growth, or survival in this study. Salinities of 30–33 were optimal yielding 3–7 times more settlement compared to salinities 27 and 36. This study highlights that settlement trials need to incorporate post-settlement survival measurements for at least 1–2 months to truly reflect the effectiveness of method interventions and consider extending the time before turning seawater flow back on into settlement tanks from 24 to 48 h by up to 72–96 h to facilitate greater settlement success if seawater quality parameters permit it.

A coral-associated actinobacterium mitigates coral bleaching under heat stress

BackgroundThe positive effects of exposing corals to microorganisms have been reported though how the benefits are conferred are poorly understood. Here, we isolated an actinobacterial strain (SCSIO 13291) from Pocillopora damicornis with capabilities to synthesize antioxidants, vitamins, and antibacterial and antiviral compounds supported with phenotypic and/or genomic evidence. Strain SCSIO 13291 was labeled with 5 (and − 6)-carboxytetramethylrhodamine, succinimidyl ester and the labeled cell suspension directly inoculated onto the coral polyp tissues when nubbins were under thermal stress in a mesocosm experiment. We then visualized the labelled bacterial cells and analyzed the coral physiological, transcriptome and microbiome to elucidate the effect this strain conferred on the coral holobiont under thermal stress.ResultsSubsequent microscopic observations confirmed the presence of the bacterium attached to the coral polyps. Addition of the SCSIO 13291 strain reduced signs of bleaching in the corals subjected to heat stress. At the same time, alterations in gene expression, which were involved in reactive oxygen species and light damage mitigation, attenuated apoptosis and exocytosis in addition to metabolite utilization, were observed in the coral host and Symbiodiniaceae populations. In addition, the coral associated bacterial community altered with a more stable ecological network for samples inoculated with the bacterial strain.ConclusionsOur results provide insights into the benefits of a putative actinobacterial probiotic strain that mitigate coral bleaching signs. This study suggests that the inoculation of bacteria can potentially directly benefit the coral holobiont through conferring metabolic activities or through indirect mechanisms of suppling additional nutrient sources.

Among the trees: shade promotes the growth and higher survival of juvenile toads

getation, including trees, significantly shapes microhabitats for amphibians due to the leaf litter input, providing stable shelter, creating a microclimate or indirectly through trophic interactions. It is known that some species can survive in a highly modified urban environment. Species associated with open space can find stable habitats in urban and human-transformed areas, but is the impact of shading (presence of canopy cover) significant in their case? We focus on the effect of solar exposure on the growth rate of juvenile green toads Bufotes viridis in fruit and canopy manipulation treatments. The main aim of the study was to examine the selected habitat traits promoting post-metamorphic growth of the green toad in semi-open enclosures. We investigated differences between exposure/land cover variants, i.e., sunny site (open area with direct solar exposure) and shadow site (shady site with a tree canopy cover). Using imitation fruits and real cherry plum Prunus cerasifera fruits (non-native tree species), we checked wheth­er amphibian growth is related to the additional structure that fruit lying on the ground created (a more heterogeneous surface structure) or to a trophic character (additional food source due to attracting inver­tebrates). We conducted a 40-day rearing experiment in three variants with two replications in semi-open enclosures with 20 juvenile toads each. We found differences in snout-vent length and body mass index in­vestigated due to site exposure during post-metamorphic growth. The survival rate of juvenile toads in the shaded site was higher than in sunny sites. We demonstrated a positive effect of the tree’s shade, regardless of the fleshy fruit’s presence on the ground. Toads benefit from developing at sites with reduced solar ex­posure (i.e., with a tree canopy), resulting in intensive growth and higher survival rate. Thus, there is an opportunity for planners and urban authorities to manage habitats for amphibian conservation purposes by creating a shaded zone, even for open habitat species, especially in transformed areas such as cities. Our results indicate that the beneficial effect of the lying fruit on the growth of juveniles is limited to specific conditions, and understanding this requires further research.

CePP2C19 confers tolerance to drought by regulating the ABA sensitivity in Cyperus esculentus

BackgroundTiger nut (Cyperus esculentus) is widely known as an additional source of food, oil and feed worldwide. The agricultural production of tiger nut has been greatly hindered by drought stress, reducing both yield and quality. Protein phosphatase 2 C (PP2Cs) plays an important role in plant responses to drought stress however, the molecular mechanism of PP2Cs in tiger nuts still unclear.ResultsIn this study, we identified a putative group A PP2C-encoding gene (CePP2C19) from tiger nut using transcriptome analysis, which is highly induced by drought stress. The transient expression assay suggested that CePP2C19 was localized to nucleus. Furthermore, the interaction between CePP2C19 and CePYR1, a coreceptor for ABA signaling, was first detected using a yeast two-hybrid assay and then verified using a bimolecular fluorescence complementation (BiFC) analysis. In addition, the transgenic Arabidopsis lines overexpressing CePP2C19 exhibited extreme tolerance to ABA and mannitol stresses during seed germination and root growth. At the mature stage, overexpression of CePP2C19 resulted in a higher tolerance to drought stress in transgenic Arabidopsis, as confirmed by a visible phenotype and several physiological parameters. Noticeably, the silencing of CePP2C19 by virus-induced gene silencing (VIGS) showed obvious reduction in drought tolerance in tiger nut plants.ConclusionsThe CePP2C19 emerges as a pivotal gene involved in the ABA signaling pathway, which likely reduce ABA sensitivity and thus enhances drought tolerance in Cyperus esculentus.

A generalist predator–prey system with the effects of fear and refuge in deterministic and stochastic environments

In the present study, we investigate the dynamics of a generalist predator–prey system by considering that the fear of predators suppresses the birth rate and enhances the intraspecies competition of the prey species. Also, we assume that a constant proportion of the prey population is taking refuge, which results in a reduction in the predation pressure. We consider Cosner functional response to describe the interactions between prey and predator species. We rigorously analyze the proposed model analytically as well as numerically. We see that the system exhibits multi-stable configurations under identical ecological conditions by allowing different bifurcation scenarios, including saddle–node, Hopf and transcritical bifurcations with varying degrees of fear, on the prey’s reproduction and intraspecies competition, induced by the predator species. The emergence of multistability scenarios in the system is also stimulated by the birth rate of prey species and the growth in predator species due to the additional food sources. We modify our proposed model to its stochastic counterpart by considering the impact of environmental white noises on the natural death rates of both prey and predator species. The simulation results for the stochastic system demonstrate that the fluctuations in the densities of prey and predator populations due to stochastic perturbations are highly sensitive to the intensities of the environmental noises. Additionally, we find that the stochastic system showcases noise-induced transitions whenever the deterministic system exhibits bistability.

Mercury concentrations in Antarctic zooplankton with a focus on the krill species, Euphausia superba

The Antarctic is the most isolated region in the world; nevertheless, it has not avoided the negative impact of human activity, including the inflow of toxic mercury (Hg). Hg deposited in the Antarctic marine environment can be bioavailable and accumulate in the food web, reaching elevated concentrations in high-trophic-level biota, especially if methylated. Zooplankton, together with phytoplankton, are critical for the transport of pollutants, including Hg to higher trophic levels. For the Southern Ocean ecosystem, one of the key zooplankton components is the Antarctic krill Euphausia superba, the smaller euphausiid Thysanoessa macrura, and the amphipod Themisto gaudichaudii – a crucial food source for most predatory fish, birds, and mammals. The main goal of this study was to determine the Hg burden, as well as the distribution of different Hg forms, in these dominant Antarctic planktonic crustaceans. The results showed that the highest concentrations of Hg were found in T. gaudichaudii, a typically predatory taxon. Most of the Hg in the tested crustaceans was labile and potentially bioavailable for planktivorous organisms, with the most dangerous methylmercury (MeHg) accounting for an average of 16 % of the total mercury. Elevated Hg concentrations were observed close to the land, which is influenced by the proximity to penguin and pinniped colonies. In areas near the shore, volcanic activity might be a possible cause of the increase in mercury sulfide (HgS) content. The total Hg concentration increased with the trophic position and ontogenetic stage of predation, specific to adult organisms. In contrast, the proportion of MeHg decreased with age, indicating more efficient demethylation or elimination. The Hg magnification kinetics in the study area were relatively high, which may be related to climate-change induced alterations of the Antarctic ecosystem: additional food sources and reshaped trophic structure.

Ecological Assessment of Drilling Sludge and Development of a Method for their Bioremediation in Western Siberia

The article considers the issue of bioremediation of drilling sludge. The aim of the research is studying of the microbiological processes occurring in soils based on drilling sludge, with their subsequent application for the biological stage of reclamation of disturbed lands. Microbiological characteristics of drilling sludge and four samples of soils based on it with the addition of diatomite, dolomite flour, peat, gypsum, glauconite, humic preparation Rostock in different proportions were studied. Crops were shown on agarized medium: meat-peptone agar (MPA), starch-ammonia agar (SAA), Munz medium, Chapek medium, depending on the determined group of microorganisms. The total number of microflora, the number of saprophytes, microorganisms growing on starch-ammonia agar (SAA), hydrocarbon-oxidizing bacteria (PSB), micromycetes and actinomycetes were estimated. The mineralization coefficient is calculated. The total number of microflora in the samples ranged from 51 to 271 million CFU/g. The share of saprophytes was 16.724.8% of the total amount of microflora. The proportion of microorganisms growing on SAA was 15.6-36.6%. The minimum number of PSB was 2.0 million CFU/g of soil; the maximum was 22.0 million CFU/g. The mineralization coefficient varies from 0.81 to 1.63, which indicates different rates of mineralization processes. The number of micromycetes determined on the Chapek medium ranged from 0.01 to 3.33 million CFU/g, on SAA from 0.03 to 10.4 million CFU/g. At the same time, the number of micromycetes is much lower than the number of bacteria, which is normal for soils. The number of actinomycetes varied from 0.2 to 7.3 million CFU/g. The largest number of actinomycetes was noted when peat and humic preparation Rostock were introduced. The share of actinomycetes in the total number of microflora on the SAA ranged from 0.6 to 14%. There is a development of the total number of microflora, an increase in the diversity of microbocenosis, which indicates a decrease in the concentrations of water-soluble salts, petroleum products and the presence of an additional food source in the form of peat. Based on the data obtained, a conclusion was made about the possibility of using soils based on drilling sludge with the addition of peat and humic preparation Rostock for the reclamation of disturbed lands.

Sugar and pollen supply enhances aphid control by hoverflies in strawberry

Larvae of many hoverfly species (Diptera: Syrphidae) are efficient aphid predators, while the adults feed on pollen and nectar. Strawberry crops can be infested by several aphid species, such as the strawberry aphid Chaetosiphon fragaefolii (Cockerell) and the potato aphid Macrosiphum euphorbiae (Thomas), both of which can cause economic damage. Protected cultivation of strawberry seems to be ideal for introducing biological control agents that depend on flower resources, but the nectar and pollen provided by the crop may not be the most suitable for all flower-dependent insects. In this study, we evaluated the biocontrol potential of hoverflies released preventively or curatively against the potato aphid in strawberry in two separate greenhouse experiments and the effect of adding sugars and pollen on their control efficacy.In the curative experiment, Eupeodes corollae (Fabricius) and Sphaerophoria rueppellii (Wiedemann) were released and supported with flowering plants of Fagopyrum esculentum Moench (buckwheat). Both species reduced the aphid numbers significantly compared to the control treatment.In the preventive experiment, we tested three syrphid species, Episyrphus balteatus (De Geer), S. rueppellii, and E. corollae, in the presence and absence of additional food sources (sugar solution and pollen). All three syrphid species reduced the aphid population to a similar extent, but only in the presence of additional food sources. This study shows that hoverflies perform better in strawberry crops when adults have access to different supplementary food sources.

Vertical distributions of organic matter components in sea ice near Cambridge Bay, Dease Strait, Canadian Archipelago

Ice algae thriving within sea ice play a crucial role in transferring energy to higher trophic levels and influencing biogeochemical processes in polar oceans; however, the distribution of organic matter within the ice interior is not well understood. This study aimed to investigate the vertical distribution of organic matter, including chlorophyll a (Chl-a), particulate organic carbon and nitrogen (POC and PON), carbohydrates (CHO), proteins (PRT), lipids (LIP), and food material (FM), within the sea ice. Samples were collected from the bottom, middle, and top sections of the sea ice column near Cambridge Bay during the spring of 2018. Based on the δ13C signature, biochemical composition, and POC contribution of biopolymeric carbon (BPC), the organic substances within the sea ice were predominantly attributed to marine autotrophs. While the highest concentrations of each parameter were observed at the sea ice bottom, notable concentrations were also found in the upper sections. The average sea ice column-integrated Chl-a concentration was 5.05 ± 2.26 mg m−2, with the bottom ice section contributing 59% (S.D. = ± 10%) to the total integration. The column-integrated concentrations of FM, BPC, POC, and PON were 2.05 ± 0.39, 1.10 ± 0.20, 1.47 ± 0.25, and 0.09 ± 0.03 g m−2, respectively. Contributions of the bottom ice section to these column-integrated concentrations varied for each parameter, with values of 20 ± 6, 21 ± 7, 19 ± 5, and 28 ± 7%, respectively. While the bottom ice section exhibited a substantial Chl-a contribution in line with previous studies, significantly higher contributions of the other parameters were observed in the upper sea ice sections. This suggests that the particulate matter within the interior of the sea ice could potentially serve as an additional food source for higher trophic grazers or act as a seeding material for a phytoplankton bloom during the ice melting season. Our findings highlight the importance of comprehensive field measurements encompassing the entire sea ice section to better understand the distribution of organic carbon pools within the sea ice in the Arctic Ocean.

ROLE OF SPACE IN AN ECO-EPIDEMIC PREDATOR-PREY SYSTEM WITH THE EFFECT OF FEAR AND SELECTIVE PREDATION

In ecological systems, the fear of predation risk asserts a privilege to the prey species by restricting their exposure to the potential predators. It also imposes costs by constraining the exploration of optimal resources. Additional foods for predators play a pivotal role in the biological conservation programs. The predators have ability to distinguish between the susceptible and infected prey items, and they avoid the latter ones to reduce their fitness cost. A predator-prey model with disease in prey is investigated in this study with an aim to explore the effects of fear factor, additional foods and selective predation on the ecological systems. We also investigate the spatio-temporal model to incorporate the facts that the prey and predator populations perform active movements in the spatial directions for their biological relevance. Both the temporal and spatio-temporal models are analyzed through noteworthy mathematical as well as numerical techniques. Our simulation results show that the level of fear responsible for the reduction in the birth rate of susceptible prey, rate of disease transmission and the selective feeding behavior of predators have potentials to create instability in the ecosystem. In contrast, the level of fear responsible for reduction in the disease prevalence can restore stability in the ecosystem by killing the persistent oscillations. Our eco-epidemic system exhibits chaotic nature if the growth of predators due to additional food sources is very low. We find that the spatio-temporal model demonstrates different spatial patterns of the prey and predator populations in the ecosystem.

Biofloc technology as part of a sustainable aquaculture system: A review on the status and innovations for its expansion

AbstractIncreased food demand, reflecting a rising global human population, attaining 8 billion in 2022, has furthered the intensification of farmed aquatic animal production. Intensification practices can be resource demanding for micro and macronutrients, dedicated feeds, fossil fuels, chemotherapeutics, and water. Water replaces evaporative losses and may be used to dilute nutrient‐rich wastewater. As an alternative to wastewater discharge, biofloc technology (BFT) uses microbes to manage nutrient levels in production systems. A microbial community grown at high densities can assimilate waste metabolites for growth. This is promoted by increasing the carbon–nitrogen (C:N) ratio using a combination of aquafeed fed to the fish and an additional carbohydrate source, for example, starch, molasses, or bran. The microbial biomass offers a continuous and additional food source to the farmed animal, thus reducing the need for finished aquafeeds and lowering the feed conversion ratio. Although the approach relies on multiple interacting species, BFT can be deployed in relatively low technology settings. This review considers the basis of BFT and identifies areas for innovation and expansion. For example, control of light quantity and quality can influence the biofloc and hence the growth of cultured species. Research on biofloc aquaculture is dominated by studies using tilapia and shrimp, but the technology could be applied to other species, particularly species that are tolerant of biofloc conditions and not highly carnivorous. Biofloc may be a useful biosecurity tool for all or part of the life cycle, and meals made from dried biofloc may enhance the production of cultured species. The key benefits of BFT can potentially be seen in reduced water consumption, lower feed requirements, and improved fish health. This review differs from current review papers in proposing the use of a life cycle assessment in conjunction with BFT, which may be a useful tool for describing and communicating the relative benefits of biofloc systems and their wider environmental impact. This study will serve as a useful knowledge base of BFT information for students, researchers, and stakeholders alike, offering a central source of the main aspects around the culturing of biofloc, key parameters, common species used, areas of potential improvement, and a discussion on where the future of BFT may lie.

Ecoinformatic Analysis of the Gut Ecological Diversity of Wild and Captive Long-Tailed Gorals Using Improved ITS2 Region Primers to Support Their Conservation.

Ex situ conservation is used to protect endangered wildlife. As captive and wild long-tailed gorals are known to be similar, individuals under ex situ conservation can be reintroduced into nature. However, there is no appropriate indicator to evaluate them. Here, we amplified the internal transcribed spacer 2 (ITS2) region and compared the gut ecological information (eco-information) of captive and wild long-tailed gorals. We validated the existing ITS86F and ITS4 universal primers using reference sequences of the National Center for Biotechnology Information (NCBI) and improved their matching rates. We compared the gut eco-information of captive and wild long-tailed gorals obtained through experiments using the improved primer pair and found that the gut ecological diversity of captive gorals was low. Based on this, we suggested that the gut eco-information can be used as an evaluation index before reintroducing captive long-tailed gorals. Furthermore, we identified four plant types from the gut eco-information of wild long-tailed gorals, which can be the additional food sources to enhance the reduced intestinal ecological diversity of the captive animals.

Effect of deposit chemistry on microbial community structure and activity: Implications for under-deposit microbial corrosion.

The deposition of solid particles carried by production fluids from oil and gas companies in horizontal surfaces of different assets has shown to cause severe localised corrosion. Sand, one of the most common deposits in the energy sector pipelines, is frequently mixed with crude, oil, asphaltenes, corrosion inhibitors, and other organic compounds. For this reason, they might favour the metabolic activity of native microbial communities. This study aimed to determine the impact of sand-deposit chemical composition on the microbial community structure and functional attributes of a multispecies consortium recovered from an oilfield and the resulting risk of under-deposit microbial corrosion of carbon steel. Sand deposits recovered from an oil pipeline were used in their raw form and compared against the same deposits exposed to heat treatment to remove organic compounds. A four-week immersion test in a bioreactor filled with synthetic produced water and a two-centimeter layer of sand was set up to assess corrosion and microbial community changes. The raw untreated deposit from the field containing hydrocarbons and treatment chemicals resulted in a more diverse microbial community than its treated counterpart. Moreover, biofilms developed in the raw sand deposit exhibited higher metabolic rates, with functional profile analysis indicating a predominance of genes associated with xenobiotics degradation. Uniform and localized corrosion were more severe in the raw sand deposit compared to the treated sand. The complex chemical composition of the untreated sand might have represented an additional source of energy and nutrients to the microbial consortium, favoring the development of different microbial genera and species. The higher corrosion rate obtained under the untreated sand suggests that MIC occurred due to syntrophic relationships between sulphate reducers or thiosulphate reducers and fermenters identified in the consortium.

Groundnut production performance based on chemical fertilizer practices and its profitability conditions

From the mid of the 19th-century chemical fertilizers were introduced into Bangladesh as an additional source of plant nutrients. After that the use of fertilizer in crop production increases. However, the extreme use of chemical fertilizers can create hazardous environmental degradation, which in turn can lower yields. So, the optimum level should maintain that can help in turn increase production. In this current study, 150 groundnut farmers in the research areas were taken based on their fertilizer application methods. It shows that the number of chemical fertilizer users constituted a major share of the total almost 44.67%. Among all the farmers, chemical fertilizer users incurred the highest return on investment by 1.48. Land area, cost of irrigation and chemical fertilizer affect the adoption of chemical fertilizer usage positively. The higher cost of production due to the application cost of inorganic fertilizer also increases the yield simultaneously. The study shows that farmers who avoid using fertilizer result in lower production compare to others. In that case, age and education were identified as factors that pushed the farmers towards chemical fertilizer and enjoying higher production. Int. J. Agril. Res. Innov. Tech. 12(2): 126-133, December 2022

Effects of additional food availability and pulse control on the dynamics of a Holling-($ p $+1) type pest-natural enemy model

&lt;abstract&gt;&lt;p&gt;In this paper, a novel pest-natural enemy model with additional food source and Holling-($ p $+1) type functional response is put forward for plant pest management by considering multiple food sources for predators. The dynamical properties of the model are investigated, including existence and local asymptotic stability of equilibria, as well as the existence of limit cycles. The inhibition of natural enemy on pest dispersal and the impact of additional food sources on system dynamics are elucidated. In view of the fact that the inhibitory effect of the natural enemy on pest dispersal is slow and in general deviated from the expected target, an integrated pest management model is established by regularly releasing natural enemies and spraying insecticide to improve the control effect. The influence of the control period on the global stability and system persistence of the pest extinction periodic solution is discussed. It is shown that there exists a time threshold, and as long as the control period does not exceed that threshold, pests can be completely eliminated. When the control period exceeds that threshold, the system can bifurcate the supercritical coexistence periodic solution from the pest extinction one. To illustrate the main results and verify the effectiveness of the control method, numerical simulations are implemented in MATLAB programs. This study not only enriched the related content of population dynamics, but also provided certain reference for the management of plant pest.&lt;/p&gt;&lt;/abstract&gt;

Fear and its carry-over effects in a delay-induced predator-prey model with additional food to predator

Interaction between prey and predator is a natural phenomenon in ecology that significantly contributes to the structure of ecological variety. Recent studies indicate that the presence of predator can influence the physiological behaviour of prey species to such an extent that it can be more efficient than direct predation in decreasing the prey biomass. Moreover, such non-lethal effects can be carried over through seasons or generations. In this present article, we analyze the impact of predator-induced fear and its carry-over effect in a predator-prey model in which the predator species can access some alternative or additional food sources. Well-posedness of the system and some basic dynamical properties such as extinction criteria, stability analysis with global stability, uniform persistence etc. are discussed thoroughly. From the bifurcation analyzes, we can observe that fear and its carry-over effect can not switch the stability from one equilibrium state to other equilibrium state. However once the coexistence equilibrium state occurs in the system, a higher level of fear can stabilize it. On the other hand, higher level of carry-over effect promote the oscillatory dynamics around the coexistence state. Therefore, fear and its carry-over effects have two opposite roles in the stability of the coexistence equilibrium. Predator species may go extinct if the effective quantity of additional food is sufficiently low. Next we study the model system in presence of gestation delay and observe some interesting dynamics by taking the delay parameter as a bifurcation parameter. Our study demonstrates how non-lethal effects alter the dynamics of a prey-predator model and provides valuable biological insights, particularly into the dynamics of small food web.

Raptors benefit from biosolids applications on rangelands

Globally, many grasslands have been lost or degraded via settlement, conversion to agriculture, or use as pasture. These losses have damaged the ability of migratory and nomadic birds of prey to find suitable breeding territories. Habitat restoration of degraded grasslands via the application of biosolids, the treated and sterilized remains from sewage treatment plants, improves soil water retention and nutrient profile, leading to substantial gains in plant growth and nutritive quality. Gains to wild and domestic herbivores have been documented, but impacts to predators are poorly known. Here, we test the hypothesis that biosolids-applied pastures are attractive to and support migratory and nomadic avian predators in central British Columbia, Canada. We obtained habitat records from sightings and prey remains from pellets for three vole-specialists, Long-eared Owls (<em>Asio otus</em>), Short-eared Owls (<em>A. flammeus</em>), and Northern Harriers (<em>Circus hudsonius</em>), as well as the generalist American Kestrels (<em>Falco sparverius</em>). During 5 years, the three diurnal species preferentially used biosolids-applied pastures, and kestrels and owls nested in biosolids-applied pastures or in forest patches adjacent to these pastures. Grasshoppers were more abundant on pastures with biosolids and were common prey for American Kestrels. The owls and harriers preferentially consumed voles, although Short-eared Owls consumed deermice (<em>Peromyscus maniculatus</em>) as a major additional food source during years when voles were scarce. Long-eared Owls were documented only in the 2 years when voles were common. Collectively, these results suggest that biosolids-amended landscapes may attract raptors, even when vole densities are low.

Reuse of brine from inland desalination plants with duckweed, fish and halophytes toward increased food production and improved environmental control

Desalination as means for solving water shortage suffers from three major drawbacks: (i) high energy demand; (ii) fouling, related membrane clogging and time dependent flow reduction, and; (iii) issues related to brine disposal. Reuse of the brine/concentrate is an environmental matter however, also and economic issue and a key factor hindering further adaptation of advanced desalination treatment technologies primarily in inland areas. A novel solution that is based on reuse of the brine for fish growth and utilization of the wastes generated in the fish ponds to culture duckweed plants as feed for the fish; the remaining saline water will be used to cultivate nutritious halophytes green plants. The novelty of the approach lies in the conversion of brine produced in inland industrial desalination plants into a valuable food and water resource. This process will allow saline water application for the production of nutritionary meat (fish), an additional food source (duckweed) and halophytes (Salicornia plants) and serve as a vehicle for better environmental control. A brine-management model, including economic considerations of most system components of the brine produced from inland desalination plants, is presented. The model allows to assess the benefits of food production and improved environment control.

Zooarchaeology of the Late Bronze Age Fortified Settlements in Lithuania

The economic model of the Lithuanian Late Bronze Age (1100–500 cal BC) has long been based on zooarchaeological collections from unstratified, multi-period settlements, which have provided an unreliable understanding of animal husbandry and the role of fishing and hunting. The opportunity to re-evaluate the previously proposed dietary and subsistence patterns arose after zooarcheological assemblages of Garniai 1 and Mineikiškės fortified settlements, dating only to the Late Bronze Age, were collected in 2016–2017 and 2020–2021. The new analysis revealed that the communities in these sites were mainly engaged in animal husbandry of small ungulates such as pigs, sheep/goats, which differed from western Lithuania and the rest of the Eastern Baltic. Moreover, it has been observed that hunting and fishing significantly declined after the Early Bronze Age (1700–1100 cal BC). Lastly, unusual traits for the Baltic region were identified including exceptionally highly fragmented bones and the consumption of molluscs, which could be attributed to the exploration of additional food sources in times of deprivation.