Search the Database

Biodiversity (General)

• Assessing the ecological impact of pesticides/herbicides on algal communities: A comprehensive review
  The escalating use of pesticides in agriculture for enhanced crop productivity threatens aquatic ecosystems, jeopardizing environmental integrity and human well-being. Pesticides infiltrate water bodies through runoff, chemical spills, and leachate, adversely affecting algae, vital primary producers in marine ecosystems. The repercussions cascade through higher trophic levels, underscoring the need for a comprehensive understanding of the interplay between pesticides, algae, and the broader ecosystem. Algae, susceptible to pesticides via spillage, runoff, and drift, experience disruptions in community structure and function, with certain species metabolizing and bioaccumulating these contaminants. The toxicological mechanisms vary based on the specific pesticide and algal species involved, particularly evident in herbicides' interference with photosynthetic activity in algae. Despite advancements, gaps persist in comprehending the precise toxic effects and mechanisms affecting algae and non-target species. This review consolidates information on the exposure and toxicity of diverse pesticides and herbicides to aquatic algae, elucidating underlying mechanisms. An emphasis is placed on the complex interactions between pesticides/herbicides, nutrient content, and their toxic effects on algae and microbial species. The variability in the harmful impact of a single pesticide across different algae species underscores the necessity for further research. A holistic approach considering these interactions is imperative to enhance predictions of pesticide effects in marine ecosystems. Continued research in this realm is crucial for a nuanced understanding of the repercussions of pesticides and herbicides on aquatic ecosystems, mainly algae.
  [Narayanan, N. et al. (2024) Assessing the ecological impact of pesticides/herbicides on algal communities: A comprehensive review, Aquatic Toxicology. Available at: https://www.sciencedirect.com/science/article/abs/pii/S0166445X24000225?via%3Dihub.]
• Comparing the effects of three neonicotinoids on embryogenesis of the South African clawed frog Xenopus laevis
  Neonicotinoids (NEOs) are widely used insecticides that are ubiquitous in agricultural use. Since NEOs are found in natural waters as well as in tap water and human urine in regions where NEOs are widely used, NEOs pose a potential hazard to non-target organisms such as animals and humans. Some of the commonly detected NEOs are imidacloprid (IMD), thiamethoxam (TMX), and its metabolite clothianidin (CLO). Although previously published scientific information, including an assessment of the environmental risks, particularly for bees, had resulted in a ban on the outdoor use of these three NEOs in the EU – their use is now only permitted in closed greenhouses – these NEOs continue to be used in agriculture in many other parts of the world. Therefore, a detailed study and comparison of the effects of NEOs on the embryonic development of non-target organisms is needed to further define the risk profiles.

  Embryos of the South African clawed frog Xenopus laevis, a well-established aquatic model, were exposed to different concentrations of IMD, TMX, or CLO (0.1–100 mg/L) to study and compare the possible effects of a single contaminant in natural water bodies on early embryogenesis. The results included a reduced body length, a smaller orbital space, impaired cranial cartilage and nerves, and an altered heart structure and function. At the molecular level, NEO exposure partially resulted in an altered expression of tissue-specific factors, which are involved in eye, cranial placode, and heart development.

  Our results suggest that the NEOs studied negatively affect the embryonic development of the non-target organism X. laevis. Since pesticides, especially NEOs, pollute the environment worldwide, it is suggested that they are strictly controlled and monitored in the areas where they are used. In addition, the question arises as to whether pesticide metabolites also pose a risk to the environment and need to be investigated further so that they can be taken into account when registering ingredients.
  [Flach, H. et al. (2024) Comparing the effects of three neonicotinoids on embryogenesis of the South African clawed frog xenopus laevis, Current Research in Toxicology. Available at: https://www.sciencedirect.com/science/article/pii/S2666027X24000227?via%3Dihub. ]

• Identification of DDT+ in Deep Ocean Sediment and Biota in the Southern California Bight
  The recent rediscovery of offshore DDT waste dumping in the Southern California Bight (SCB) has led to questions about the extent and type of pollution in deep ocean environments. We used a nontargeted analysis to identify halogenated organic compounds (HOCs), including DDT+, in sediment in the San Pedro Basin. Additionally, we examined the chemical profiles of deep ocean biota inhabiting the SCB to assess the bioavailability of DDT+ and HOCs to the deep ocean food web. We detected 49 HOCs across all samples, including 15 DDT+ compounds in the sediment and 10 DDT+ compounds in the biota. Compounds included tris(4-chlorophenyl)methane (TCPM) and its isomers and three unknown DDT-related compounds previously identified in marine mammals. No clear trends were identified regarding DDT+ distribution in sediments. High DDT+ body burdens were found in biota irrespective of collection location, indicating widespread DDT+ contamination in the deep ocean of the SCB. TCPMs were detected in all biota samples except a single surface species, indicating that deep ocean sediment may be a source of DDT+ to the marine food web. This study demonstrates that the analysis of the larger suite of DDT+ is critical to trace deep ocean pollution of DDT in the SCB.
  [Stack, M.E. et al. (2024) ‘Identification of DDT+ in deep ocean sediment and biota in the Southern California bight’, Environmental Science & Technology Letters, 11(5), pp. 479–484. Available at: https://pubs.acs.org/doi/full/10.1021/acs.estlett.4c00115.]
• Insecticides, more than herbicides, land use, and climate, are associated with declines in butterfly species richness and abundance in the American Midwest
  Mounting evidence shows overall insect abundances are in decline globally. Habitat loss, climate change, and pesticides have all been implicated, but their relative effects have never been evaluated in a comprehensive large-scale study. We harmonized 17 years of land use, climate, multiple classes of pesticides, and butterfly survey data across 81 counties in five states in the US Midwest. We find community-wide declines in total butterfly abundance and species richness to be most strongly associated with insecticides in general, and for butterfly species richness the use of neonicotinoid-treated seeds in particular. This included the abundance of the migratory monarch (Danaus plexippus), whose decline is the focus of intensive debate and public concern. Insect declines cannot be understood without comprehensive data on all putative drivers, and the 2015 cessation of neonicotinoid data releases in the US will impede future research.
  [Deynze, B.V. et al. (2024) Insecticides, more than herbicides, land use, and climate, are associated with declines in butterfly species richness and abundance in the American Midwest, PLoS ONE. Available at: https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0304319. ]
• Organic farming reduces pesticide load in a bird of prey
  Human activities have led to the contamination of all environmental compartments worldwide, including bird species. In birds, both the environment and maternal transfer lead to high inter-brood variability in contamination levels of pollutants, whereas intra-brood variability is generally low. However, most existing studies focused on heavy metals or persistent compounds and none, to our knowledge, addressed the variability in contamination levels of multiple pesticides and the factors influencing it. In this study, the number of pesticides detected (of 104 compounds searched) and the sum of their concentrations in the blood of 55 Montagu's harrier (Circus pygargus) nestlings from 22 nests sampled in 2021 were used as metrics of contamination levels. We investigated the effect of organic farming at the size of male's home range (i.e., 14 km2) and chicks' sex and hatching order on contamination levels. We did not find a difference between inter-brood and intra-brood variability in pesticide contamination levels, suggesting a different exposure of siblings through food items. While chicks' sex or rank did not affect their contamination level, we found that the percentage of organic farming around the nests significantly decreased the number of pesticides detected, although it did not decrease the total concentrations. This finding highlights the potential role of organic farming in reducing the exposure of birds to a pesticide cocktail.
  [Fuentes, E. et al. (2024) Organic farming reduces pesticide load in a bird of prey, Science of The Total Environment. Available at: https://www.sciencedirect.com/science/article/pii/S0048969724029255.]
• Organic food has lower environmental impacts per area unit and similar climate impacts per mass unit compared to conventional
  In recent years, interest in studying the climate and environmental impact of organic food has grown. Here, we compared the environmental impacts of organic and conventional food using data from 100 life cycle assessment studies. Most studies focused on climate impacts, with fewer addressing biodiversity loss and ecotoxicity. Findings revealed no significant differences in global warming, eutrophication potential, and energy use per mass unit. However, organic food showed lower global warming, eutrophication potential, and energy use per area unit, with higher land use. Additionally, organic farming showed lower potential for biodiversity loss and ecotoxicity. Challenges in life cycle assessment include evaluating biodiversity, toxicity, soil quality, and carbon changes. The choice of functional units influences results, highlighting the importance of considering multiple units in assessing organic food’s environmental footprint. This study emphasizes the necessity for comprehensive assessments at both product and diet levels to support informed decisions.
  [Hashemi, F. et al. (2024) Organic food has lower environmental impacts per area unit and similar climate impacts per mass unit compared to conventional, Communications Earth & Environment. Available at: https://www.nature.com/articles/s43247-024-01415-6. ]
• Risk assessments underestimate threat of pesticides to wild bees
  Ecological risk assessments (ERAs) are crucial when developing national strategies to manage adverse effects from pesticide exposure to natural populations. Yet, estimating risk with surrogate species in controlled laboratory studies jeopardizes the ERA process because natural populations exhibit intraspecific variation within and across species. Here, we investigate the extent to which the ERA process underestimates the risk from pesticides on different species by conducting a meta-analysis of all records in the ECOTOX Knowledgebase for honey bees and wild bees exposed to neonicotinoids. We found the knowledgebase is largely populated by acute lethality data on the Western honey bee and exhibits within and across species variation in LD50 up to 6 orders of magnitude from neonicotinoid exposure. We challenge the reliability of surrogate species as predictors when extrapolating pesticide toxicity data to wild pollinators and recommend solutions to address the (a)biotic interactions occurring in nature that make such extrapolations unreliable in the ERA process.
  [Shahmohamadloo, R., Guzman, L. and Tissier, M. (2024) Risk assessments underestimate threat of pesticides to wild bees, Conservation Letters. Available at: https://conbio.onlinelibrary.wiley.com/doi/full/10.1111/conl.13022. ]
• The molecular determinants of pesticide sensitivity in bee pollinators
  Bees carry out vital ecosystem services by pollinating both wild and economically important crop plants. However, while performing this function, bee pollinators may encounter potentially harmful xenobiotics in the environment such as pesticides (fungicides, herbicides and insecticides). Understanding the key factors that influence the toxicological outcomes of bee exposure to these chemicals, in isolation or combination, is essential to safeguard their health and the ecosystem services they provide. In this regard, recent work using toxicogenomic and phylogenetic approaches has begun to identify, at the molecular level, key determinants of pesticide sensitivity in bee pollinators. These include detoxification systems that convert pesticides to less toxic forms and key residues in insecticide target-sites that underlie species-specific insecticide selectivity. Here we review this emerging body of research and summarise the state of knowledge of the molecular determinants of pesticide sensitivity in bee pollinators. We identify gaps in our knowledge for future research and examine how an understanding of the genetic basis of bee sensitivity to pesticides can be leveraged to, a) predict and avoid negative bee-pesticide interactions and facilitate the future development of pest-selective bee-safe insecticides, and b) inform traditional effect assessment approaches in bee pesticide risk assessment and address issues of ecotoxicological concern.
  [Bass, C. et al (2024) The molecular determinants of pesticide sensitivity in bee pollinators, Science of The Total Environment. Available at: https://www.sciencedirect.com/science/article/pii/S0048969724003097.]
• Cetaceans as bio-indicators revealed the increased risks of triclosan exposure and associated thyroid hormone disruption during the COVID-19 pandemic.
  The global surge in disinfection practices from the COVID-19 response has raised concerns about the marine exposure to the hazardous ingredients in disinfectant products, including triclosan (TCS) and triclocarban (TCC). However, there are very limited studies on the response of marine TCS and TCC (TCs) loading to the COVID-19 pandemic. Here we used cetaceans as bio-indicators for a long-term retrospective analysis of TCs loading to the South China Sea (SCS) between 2004 and 2022. Hepatic TCs was 100% detected in all nine cetacean species (n = 120). Interestingly, TCS concentrations decreased in Indo-Pacific humpback dolphins (IPHD) before the pandemic from 2010 to 2017. However, after 2019, TCS concentrations in IPHD significantly increased several-fold. Similarly, post-pandemic TCS concentrations in Indo-Pacific finless porpoises (IPFP) and two fish species were significantly higher than pre-pandemic levels. There were significant relationships between thyroid hormones (THs) and TCs in IPHD and IPFP, suggesting that increased TCs may worsen the interference of THs homeostasis and nutritional conditions in cetaceans. These findings demonstrate the profound impact of the surging use of TCs-containing products from the COVID-19 response on marine ecosystems.
  [Guo, Y., Shi, W., Liu, Z., Sun, X. and Wu, Y., 2023. Journal of Hazardous Materials, 459, p.132289.]
• Characterization of Sulfoxaflor and Its Metabolites on Survival, Growth, Reproduction, Biochemical Markers, and Transcription of Genes of Daphnia magna
  Sulfoxaflor is a promising neonicotinoid. However, the negative implications of sulfoxaflor on nontarget aquatic organisms have been rarely studied. In this study, the risks of sulfoxaflor and its main metabolites X11719474 and X11519540 on Daphnia magna were characterized, including acute toxicity, reproduction, swimming behavior, biochemical markers, and gene transcription. Acute toxicity measurements indicated that X11719474 and X11519540 have high toxicity than the parent compound sulfoxaflor. Chronic exposure reduced reproduction and delayed the birth of the firstborn D. magna. Swimming behavior monitoring showed that exposure to three compounds stimulated swimming behavior. The induction of catalase, superoxide dismutase, and acetylcholinesterase activities was observed with oxidative stress, whereas malondialdehyde content was remarkably increased with exposure to sulfoxaflor, X11719474, and X11519540. Moreover, transcriptomics profiles showed that sulfoxaflor, X11719474, and X11519540 induced KEGG pathways related to cellular processes, organismal systems, and metabolisms. The findings present valuable insights into the prospective hazards of these pesticides and emphasize the critical importance of conducting a systematic evaluation of combining antecedents and their metabolites.
  [Yuan, T., Jiao, H., Ai, L., Chen, Y., Hu, D. and Lu, P., 2023. Journal of Agricultural and Food Chemistry, 71(16), pp.6424-6433.]
• Glyphosate-based formulation affects Tetragonisca angustula worker’s locomotion, behavior and biology
  Declining bee populations diminish pollination services, damaging plant and agricultural biodiversity. One of the causes of this decline is the use of pesticides. Pesticides with glyphosate as the main active ingredient are among the most used pesticides worldwide, being the most used in Brazil. This study determined the 24 and 48 h LD50 (median lethal dose) of the herbicide’s glyphosate-based formulation by ingestion, identified sublethal doses, and investigated its effects on the locomotion and behavior of Tetragonisca angustula workers. The LD50 found indicates that a glyphosate-based formulation is highly toxic to T. angustula. The doses applied, including concentrations found in nature, caused death, motor changes (decreased speed and tremors), excessive self-cleaning, and disorientation (return to light and stop). Although we did not test for pollination effects, we can infer from our results that this formulation can negatively affect the pollination activity of T. angustula. Evaluation of the toxicity and sublethal effects of pesticides on bees contributes to a better understanding of their harmful effects on hives and allows for the development of strategies to reduce these impacts.
  [Prado, I.S., da Rocha, A.A., Silva, L.A. and Gonzalez, V.C., 2023. Ecotoxicology, 32(4), pp.513-524.]
• Haematological and biochemical toxicity in freshwater fish Clarias gariepinus and Oreochromis niloticus following pulse exposure to atrazine, mancozeb, chlorpyrifos, lambda-cyhalothrin, and their combination
  Transient exposures to high or low concentrations of a single or mixture of pesticides are common in aquatic organisms. Routine toxicity tests disregard transient exposures and the influence of time when examining the toxicity of contaminants. This study investigated the haematological and biochemical responses of juvenile C. gariepinus and O. niloticus to pesticide pulse exposure using three exposure patterns. The patterns include 4-hour pulse exposure to a high pesticide concentration, then 28 days of depuration, continuous exposure to a low pesticide concentration for 28 days, and 4-hour pulse exposure to a high concentration followed by continuous exposure to a low pesticide concentration for 28 days. On days 1, 14, and 28, fish samples were collected for haematological and biochemical analysis. Results showed that red blood cell count, packed cell volume, haemoglobin, platelet count, total protein, and sodium ion decreased, while white blood cell count, total cholesterol, bilirubin, urea, and potassium ion increased in both fish species after pulse, continuous and pulse & continuous exposure to the pesticides (p < 0.05). However, pulse exposure to the pesticides did not significantly affect alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase activity, and creatinine levels. The changes in these biomarkers indicate that 4-hour pulse exposure to high concentration was as hazardous as 24-hour continuous exposure to low pesticide concentration (p > 0.05). The toxic effects of pulse exposure were largely reversible by day 14. Using C. gariepinus and O. niloticus, this study shows that brief exposure to high pesticide pesticides was as hazardous as continuous pesticide exposure.
  [Kanu, K.C., Okoboshi, A.C. and Otitoloju, A.A., 2023. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology, 270, p.109643.]
• Mixture effects of thiamethoxam and seven pesticides with different modes of action on honey bees (Aplis mellifera)
  Even though honey bees in the field are routinely exposed to a complex mixture of many different agrochemicals, few studies have surveyed toxic effects of pesticide mixtures on bees. To elucidate the interactive actions of pesticides on crop pollinators, we determined the individual and joint toxicities of thiamethoxam (THI) and other seven pesticides [dimethoate (DIM), methomyl (MET), zeta-cypermethrin (ZCY), cyfluthrin (CYF), permethrin (PER), esfenvalerate (ESF) and tetraconazole (TET)] to honey bees (Aplis mellifera) with feeding toxicity test. Results from the 7-days toxicity test implied that THI elicited the highest toxicity with a LC50 data of 0.25 (0.20–0.29) μg mL−1, followed by MET and DIM with LC50 data of 4.19 (3.58–4.88) and 5.30 (4.65–6.03) μg mL−1, respectively. By comparison, pyrethroids and TET possessed relatively low toxicities with their LC50 data from the range of 33.78 (29.12–38.39) to 1125 (922.4–1,442) μg mL−1. Among 98 evaluated THI-containing binary to octonary mixtures, 29.59% of combinations exhibited synergistic effects. In contrast, 18.37% of combinations exhibited antagonistic effects on A. mellifera. Moreover, 54.8% pesticide combinations incorporating THI and TET displayed synergistic toxicities to the insects. Our findings emphasized that the coexistence of several pesticides might induce enhanced toxicity to honey bees. Overall, our results afforded worthful toxicological information on the combined actions of neonicotinoids and current-use pesticides on honey bees, which could accelerate farther comprehend on the possible detriments of other pesticide mixtures in agro-environment.
  [Li, W. et al. (2023) Mixture effects of thiamethoxam and seven pesticides with different modes of action on honey bees (Aplis mellifera), Scientific Reports. Available at: https://www.nature.com/articles/s41598-023-29837-w#ref-CR30. ]
• Neonicotinoids: Still present in farmland birds despite their ban
  Neonicotinoids (neonics) are the most widely used insecticides worldwide and are considered to be of low risk to non-target organisms such as vertebrates. Further, they are reported to be rapidly excreted and metabolized, reducing their potential toxicity. Nevertheless, growing evidence of adverse effects of neonics on farmland bird species raise questions about the purported harmless nature of these pesticides. We attempted to search for pesticide residues in species of different trophic levels and at different life stages, by using multiple bird monitoring programs on a Long-Term Socio-Ecological Research (LTSER) platform. Three passerine birds-the blackbird (Turdus merula), cirl bunting (Emberiza cirlus), and common nightingale (Luscinia megarhynchos)-that feed on seeds and invertebrates were monitored during their reproductive period, and the grey partridge (Perdix perdix) that feeds on seeds was monitored during its wintering period. We also monitored chicks of an apex predator-the Montagu's harrier (Circus pygargus)-that preys mostly upon common voles but also upon insects. We found that the birds' blood samples showed presence of residues of five neonics: three banned since 2018 in France-clothianidin, thiacloprid, and thiamethoxam-and two-dinotefuran and nitenpyram-used for veterinary purposes only. While none of these neonics was detected in blackbirds, all were present in grey partridges. Clothianidin was detected in all species, except blackbirds. Concentrations of the three banned neonics were similar or higher than concentrations found in birds monitored elsewhere before the ban. These findings raise questions about the persistence of neonics within the environment and the mode of exposure to wild fauna. Future investigations on the sublethal effects of these neonics on life-history traits of these farmland birds may help in providing a better understanding of the effects of exposure of bird populations to these insecticides, and also to the consequent effect on human health.
  [Fuentes, E., Gaffard, A., Rodrigues, A., Millet, M., Bretagnolle, V., Moreau, J. and Monceau, K., 2023. Chemosphere, 321, p.138091.]
• Pesticide contamination of bird species from Doñana National Park (southwestern Spain): Temporal trends (1999-2021) and reproductive impacts
  Doñana National Park (DNP) is a protected area renowned for hosting a wide variety of birds. However, the agricultural practices in its surroundings might cause pesticide contamination of the park biota. This work aimed to assess temporal trends of a wide variety of pesticides, including organochlorine (OCPs), organophosphate (OPPs) and pyrethroid (PYRs) pesticides, in bird eggs collected for more than twenty years (1999-2021) in DNP. Twenty-six pesticides were detected, being 4,4'-DDE the most frequently detected and also the one with the highest concentrations (up to 2.55 μg g-1 ww), exceeding in some cases the values usually reported to cause detrimental health and reproductive effects in avian species. An overall decreasing trend of OCPs was observed. In contrast, an apparent increase in PYRs was detected from 2013 onwards, especially for fenvalerate, whose median concentration was 3-5 orders of magnitude higher in the most recent samples. Moreover, other pesticides such as oxadiazon, oxyfluorfen and fenitrothion were first detected in 2021 samples. Finally, two variables estimating the cumulative impact of pesticides significantly decreased the breeding performance of a top predator such as the booted eagle. Therefore, it is essential to control the use of pesticides in the agricultural practices surrounding DNP and to study their potential negative impact on the bird populations breeding in this protected area.
  [Peris, A., Baos, R., Martínez, A., Sergio, F., Hiraldo, F. and Eljarrat, E., Available at SSRN 4312955.]
• Pesticides and Parabens Contaminating Aquatic Environment: Acute and Sub-Chronic Toxicity towards Early-Life Stages of Freshwater Fish and Amphibians
  Pesticides and personal care products are two very important groups of contaminants posing a threat to the aquatic environment and the organisms living in it.. Therefore, this study aimed to describe the effects of widely used pesticides and parabens on aquatic non-target biota such as fish (using model organisms Danio rerio and Cyprinus carpio) and amphibians (using model organism Xenopus laevis) using a wide range of endpoints. The first part of the experiment was focused on the embryonal toxicity of three widely used pesticides (metazachlor, prochloraz, and 4-chloro-2-methyl phenoxy acetic acid) and three parabens (methylparaben, propylparaben, and butylparaben) with D. rerio, C. carpio, and X. laevis embryos. An emphasis was placed on using mostly sub-lethal concentrations that are partially relevant to the environmental concentrations of the substances studied. In the second part of the study, an embryo-larval toxicity test with C. carpio was carried out with prochloraz using concentrations 0.1, 1, 10, 100, and 1000 µg/L. The results of both parts of the study show that even the low, environmentally relevant concentrations of the chemicals tested are often able to affect the expression of genes that play either a prominent role in detoxification and sex hormone production or indicate cell stress or, in case of prochloraz, to induce genotoxicity.
  [Medkova, D., Hollerova, A., Riesova, B., Blahova, J., Hodkovicova, N., Marsalek, P., Doubkova, V., Weiserova, Z., Mares, J., Faldyna, M. and Tichy, F., 2023. Toxics, 11(4), p.333.]
• Predicting the environmental fates of emerging contaminants: Synergistic effects in ozone reactions of nitrogen-containing alkenes
  While nitro and amino alkenes are common in pharmaceuticals, pesticides, and munitions, their environmental fates are not well known. Ozone is a ubiquitous atmospheric oxidant for alkenes, but the synergistic effects of nitrogen-containing groups on the reactions have not been measured. The kinetics and products of ozonolysis of a series of model compounds with different combinations of these functional groups have been measured in the condensed phase using stopped-flow and mass spectrometry methods. Rate constants span about six orders of magnitude with activation energies ranging from 4.3 to 28.2 kJ mol-1. Vinyl nitro groups substantially decrease the reactivity, while amino groups have the opposite effect. The site of the initial ozone attack is highly structure dependent, consistent with local ionization energy calculations. The reaction of the neonicotinoid pesticide nitenpyram, which forms toxic N-nitroso compounds, was consistent with model compounds, confirming the utility of model compounds for assessing environmental fates of these emerging contaminants.
  [Wang, X., Wang, W., Wingen, L.M., Perraud, V., Ezell, M.J., Gable, J., Poulos, T.L. and Finlayson-Pitts, B.J., 2023. Science Advances, 9(9), p.eade9609.]
• The effects of glyphosate, pure or in herbicide formulation, on bumble bees and their gut microbial communities
  The widespread use of glyphosate-based formulations to eliminate unwanted vegetation has increased concerns regarding their effects on non-target organisms, such as honey bees and their gut microbial communities. These effects have been associated with both glyphosate and co-formulants, but it is still unknown whether they translate to other bee species. In this study, we tested whether glyphosate, pure or in herbicide formulation, can affect the gut microbiota and survival rates of the eastern bumble bee, Bombus impatiens. We performed mark-recapture experiments with bumble bee workers from four different commercial colonies, which were exposed to field relevant concentrations of glyphosate or a glyphosate-based formulation (0.01 mM to 1 mM). After a 5-day period of exposure, we returned the bees to their original colonies, and they were sampled at days 0, 3 and 7 post-exposure to investigate changes in microbial community and microbiota resilience by 16S rRNA amplicon sequencing and quantitative PCR. We found that exposure to glyphosate, pure or in herbicide formulation, reduced the relative abundance of a beneficial bee gut bacterium, Snodgrassella, in bees from two of four colonies when compared to control bees at day 0 post-exposure, but this reduction became non-significant at days 3 and 7 post-exposure, suggesting microbiota resilience. We did not find significant changes in total bacteria between control and exposed bees. Moreover, we observed an overall trend in decreased survival rates in bumble bees exposed to 1 mM herbicide formulation during the 7-day post-exposure period, suggesting a potential negative effect of this formulation on bumble bees.
  [Motta, E.V. and Moran, N.A., 2023. Science of The Total Environment, 872, p.162102.]
• Trophodynamics of halogenated organic pollutants (HOPs) in aquatic food webs
  Halogenated organic pollutants (HOPs) represent hazardous and persistent compounds characterized by their capacity to accumulate within organisms and endure in the environment. These substances are frequently transmitted through aquatic food webs, engendering potential hazards to ecosystems and human well-being. The trophodynamics of HOPs in aquatic food webs has garnered worldwide attention within the scientific community. Despite comprehensive research endeavors, the prevailing trajectory of HOPs, whether inclined toward biomagnification or biodilution within global aquatic food webs, remains unresolved. Furthermore, while numerous studies have probed the variables influencing the trophic magnification factor (TMF), the paramount determinant remains elusive. Collating a compendium of pertinent literature encompassing TMFs from the Web of Science between 1994 and 2023, our analysis underscores the disparities in attention accorded to legacy HOPs compared to emerging counterparts. A discernible pattern of biomagnification characterizes the behavior of HOPs within aquatic food webs. Geographically, the northern hemisphere, including Asia, Europe, and North America, has demonstrated greater biomagnification than its southern hemisphere counterparts. Utilizing a boosted regression tree (BRT) approach, we reveal that the food web length and type emerge as pivotal determinants influencing TMFs. This review provides a valuable basis for gauging ecological and health risks, thereby facilitating the formulation of robust standards for managing aquatic environments.
  [Xie, J. et al. (2023) Trophodynamics of halogenated organic pollutants (HOPs) in aquatic food webs, Science of The Total Environment. Available at: https://www.sciencedirect.com/science/article/abs/pii/S0048969723050519. ]
• Vegans, vegetarians, fish-eaters and meat-eaters in the UK show discrepant environmental impacts
  Modelled dietary scenarios often fail to reflect true dietary practice and do not account for variation in the environmental burden of food due to sourcing and production methods. Here we link dietary data from a sample of 55,504 vegans, vegetarians, fish-eaters and meat-eaters with food-level data on greenhouse gas emissions, land use, water use, eutrophication risk and potential biodiversity loss from a review of 570 life-cycle assessments covering more than 38,000 farms in 119 countries. Our results include the variation in food production and sourcing that is observed in the review of life-cycle assessments. All environmental indicators showed a positive association with amounts of animal-based food consumed. Dietary impacts of vegans were 25.1% (95% uncertainty interval, 15.1–37.0%) of high meat-eaters (≥100 g total meat consumed per day) for greenhouse gas emissions, 25.1% (7.1–44.5%) for land use, 46.4% (21.0–81.0%) for water use, 27.0% (19.4–40.4%) for eutrophication and 34.3% (12.0–65.3%) for biodiversity. At least 30% differences were found between low and high meat-eaters for most indicators. Despite substantial variation due to where and how food is produced, the relationship between environmental impact and animal-based food consumption is clear and should prompt the reduction of the latter.
  [Scarborough, P. et al. (2023) Vegans, vegetarians, fish-eaters and meat-eaters in the UK show Discrepant Environmental impacts, Nature Food. Available at: https://www.nature.com/articles/s43016-023-00795-w?fromPaywallRec=false. ]
• Effects of Pesticides on Biodiversity and Climate Change
  Pesticides are the biological pollutants, which are being used by the man to kill the pests for increasing the yield of many crops and insect vectors to control the spread of disease. The tremendous use of pesticides has caused severe health hazards to organisms including human beings due to climate change. Excessive use of pesticides may lead to the destruction of biodiversity. Many birds, aquatic organisms and animals are under the threat of harmful pesticides for their survival. The pesticides effects can be lessen by organizing awareness program among the farmers, special training to them regarding consequences of pesticides, their screening and monitoring methods.
  [Chaudhary, V., Arya, S. and Singh, P. (2021) Effects of Pesticides on Biodiversity and Climate Change, International Journal on Environmental Sciences. Available at: https://doi.org/10.53390/ijes.v12i2.1. ]
• Food system impacts on biodiversity loss
  — Biodiversity loss is accelerating around the world. The global rate of species extinction today is orders of magnitude higher than the average rate over the past 10 million years. — The global food system is the primary driver of this trend. Over the past 50 years, the conversion of natural ecosystems for crop production or pasture has been the principal cause of habitat loss, in turn reducing biodiversity. — Our food system has been shaped over past decades by the ‘cheaper food’ paradigm. Policies and economic structures have aimed to produce ever more food at ever lower cost. Intensified agricultural production degrades soils and ecosystems, driving down the productive capacity of land and necessitating even more intensive food production to keep pace with demand. Growing global consumption of cheaper calories and resource-intensive foods aggravates these pressures. — Current food production depends heavily on the use of inputs such as fertilizer, pesticides, energy, land and water, and on unsustainable practices such as monocropping and heavy tilling. This has reduced the variety of landscapes and habitats, threatening or destroying the breeding, feeding and/or nesting of birds, mammals, insects and microbial organisms, and crowding out many native plant species. — As a major contributor to global greenhouse gas emissions, our food system is also driving climate change, which further degrades habitats and causes species to disperse to new locations. In turn, this brings new species into contact and competition with each other, and creates new opportunities for the emergence of infectious disease. — Without reform of our food system, biodiversity loss will continue to accelerate. Further destruction of ecosystems and habitats will threaten our ability to sustain human populations.
  [Benton, T. et al. (2021) Food system impacts on Biodiversity loss, Energy, Environment and Resources Programme. Available at: https://www.chathamhouse.org/sites/default/files/2021-02/2021-02-03-food-system-biodiversity-loss-benton-et-al_0.pdf. ]
• Greater stability of carbon capture in species-rich natural forests compared to species-poor plantations
  Tree plantations and forest restoration are leading strategies for enhancing terrestrial carbon (C) sequestration and mitigating climate change. While it is well established that species-rich natural forests offer superior C sequestering benefits relative to short-rotation commercial monoculture plantations, differences in rates of C capture and storage between longer-lived plantations (commercial or non-commercial) and natural forests remain unclear. Using a natural experiment in the Western Ghats of India, where late-20th century conservation laws prohibited timber extraction from monodominant plantations and natural forests within nature reserves, we assessed forests and plantations for aboveground C storage and the magnitude and temporal stability of rates of photosynthetic C capture (gross primary production). Specifically, we tested the hypothesis that species-rich forests show greater temporal stability of C capture, and are more resistant to drought, than monodominant plantations. Carbon stocks in monodominant teak (Tectona grandis) and Eucalyptus (Eucalyptus spp.) plantations were 30%–50% lower than in natural evergreen forests, but differed little from moist-deciduous forests. Plantations had 4%–9% higher average C capture rates (estimated using the Enhanced Vegetation Index–EVI) than natural forests during wet seasons, but up to 29% lower C capture during dry seasons across the 2000–18 period. In both seasons, the rate of C capture by plantations was less stable across years, and decreased more during drought years (i.e. lower resistance to drought), compared to forests. Thus, even as certain monodominant plantations could match natural forests for C capture and storage potential, plantations are unlikely to match the stability–and hence reliability–of C capture exhibited by forests, particularly in the face of increasing droughts and other climatic perturbations. Promoting natural forest regeneration and/or multi-species native tree plantations instead of plantation monocultures could therefore benefit climate change mitigation efforts, while offering valuable co-benefits for biodiversity conservation and other ecosystem services.
  [Osuri, A. et al. (2020) Greater stability of carbon capture in species-rich natural forests compared to species-poor plantations, Environmental Research Letters. Available at: https://iopscience.iop.org/article/10.1088/1748-9326/ab5f75. ]
• Neonicotinoids pose undocumented threats to food webs
  
  One of the main lessons that emerged from Silent Spring (1) is that we overuse pesticides at our own peril because human and natural environments are unquestionably linked. It is time to revisit these lessons given current use patterns of neonicotinoid insecticides.
   
  Neonicotinoids pose broader risks to biodiversity and food webs than previously recognized. Serious efforts must be made to decrease the scale of their use. 
   
  Since their introduction in the early 1990s, neonicotinoids have become the most widely used insecticides in the world. Their toxicity allows less active ingredients to be used and, compared with older classes of insecticides, they appear to have relatively low toxicity to vertebrates, particularly mammals (2). Neonicotinoids have been repeatedly called “perfect” for use in crop protection (2).
   
  Yet recent research calls this perfection into doubt as neonicotinoids have become widespread environmental contaminants causing unexpected nontarget effects. In particular, researchers have found that neonicotinoids can move from treated plants to pollinators and from plants to pests to natural enemies. Worse, transmission through simple food chains portends widespread, undocumented transmission into entire food webs. We believe that neonicotinoids pose broader risks to biodiversity and food webs than previously recognized. Although further research is needed to document the ecosystem-wide transmission and consequences of neonicotinoids to establish their true costs and benefits, serious efforts must be made to decrease the scale of their use.
  
  [Frank, S.D. and Tooker, J.F. (2020) ‘Neonicotinoids pose undocumented threats to food webs’, Proceedings of the National Academy of Sciences, 117(37), pp. 22609–22613. doi:10.1073/pnas.2017221117. ]