International audience | Plant protection products (PPP) are extensively used to protect plants against harmful organisms, but they also have unintended effects on non-target organisms, especially terrestrial invertebrates. The impact of PPP on ecosystem functions provided by these non-target invertebrates remains, however, unclear. The objectives of this article were to review PPP impacts on the ecosystem functions provided by pollinators, predators and parasitoids, and soil organisms; and to identify the factors that aggravate or mitigate PPP effects. The literature highlights that PPP alter several ecosystem functions: provision and maintenance of biodiversity, pollination, biotic interactions and habitat completeness in terrestrial ecosystems, and organic matter and soil structure dynamics. However, there are still a few studies dealing with ecosystem functions, with sometimes contradictory results, and consequences on agricultural provisioning services remain unclear. The model organisms used to assess PPP ecotoxicological effects are still limited, and should be expanded to better cover the wide functional diversity of terrestrial invertebrates. Data are lacking on PPP sublethal, transgenerational and “cocktail” effects, and on their multitrophic consequences. In empirical assessments, studies on PPP unintended effects should consider agricultural-pedoclimatic contexts because they influence the responses of non-target organisms and associated ecosystem functions to PPP. Modeling might be a promising way to account for the complex interactions among PPP mixtures, biodiversity and ecosystem functioning.

International audience | Pesticide contamination is often cited as a key factor in the global decline of farmland birds. However, the majority of studies on pesticide exposure in non-target fauna are not representative of what happens in nature because they are limited to artificial conditions. The aim of this study was to define and compare, for the first time, pesticide contamination in grey partridges (Perdix perdix) from two different contexts, i.e., captivity vs. the wild. Blood samples taken from 35 captive and 54 wild partridges in 2021-2022 were analysed for 94 pesticides most commonly used in French agriculture. Captive partridges had 29 molecules detected in their blood (12 herbicides, 14 fungicides, and three insecticides) compared to wild partridges, which had 50 molecules (13 herbicides, 23 fungicides, and 14 insecticides). Of these pesticide compounds found in individuals, 26 were banned. Captive partridges had significantly fewer pesticide molecules than wild partridges, with one to 14 pesticides per captive individual and 8 to 20 pesticides per wild individual. Nineteen molecules were common to both groups, with concentrations up to three times higher in wild partridges than in captive partridges. Our results thus show multiple exposures for most of our individuals, especially in wild partridges, which can lead to cocktail effects, which are never considered. Furthermore, the difference in contamination between the wild and captive partridges reflects the multiple routes of contamination in nature, in particular, due to the use of a wide range of habitats by wild partridges.

Seaweeds hold significant potential for human nutrition due to its high content of essential minerals and trace elements. In Africa, the development of the blue economy promotes their sustainable exploitation. However, harmful elements such as arsenic (As), lead (Pb), and cadmium (Cd) can accumulate in seaweeds, posing potential health risks upon consumption. Meristotheca senegalensis and Hypnea musciformis, two seaweeds of economic interest in Senegal, were collected in various locations, and their concentrations of essential nutrients, heavy metals, and transition metals were analyzed. Notably, cadmium levels in all samples exceeded established toxicity thresholds. A health risk assessment was performed, evaluating non-carcinogenic and carcinogenic risks through estimated daily intakes, target hazard quotients, hazard indexes, and carcinogenic risks. For adults, a low daily intake of seaweed (0.1 g day-1) posed no significant health risk over long-term exposure. High (8 g day-1) and medium (4 g day-1) daily intake levels posed no risk for adults and children, respectively, over 6-month exposure. In addition, seaweed represents a valuable iron source for preventing deficiency in Senegalese populations. Such intake levels could be incorporated into agro-food products for trace element enrichment. Nevertheless, for children, site-specific selection is critical to avoid carcinogenic risks over prolonged exposure. Seaweed offers a valuable opportunity for addressing food and nutrition security as well as promoting economic growth within Africa’s blue economy. However, careful scientific evaluation, particularly regarding site selection, is essential to ensure safe and sustainable uses, especially in countries like those in Africa, where marine pollution monitoring is often limited.

The global accumulation of plastic debris in marine ecosystems is continually increasing. Understanding the interaction between these debris and the bacterial biofilm on their surface is essential, particularly with regard to potential human pathogenic bacteria (PHPB). In this meta-analysis, we re-evaluated 16S rRNA metabarcoding data from 35 plastisphere-related studies, published up to late 2022. We compared the bacteriomes of plastics and other marine substrates, identifying PHPB associated with each type of substrate. PHPB were enriched in the plastisphere compared to the surrounding water but did not appear more abundant nor richer in than in other marine solid substrates. Nevertheless, we described a distinctive PHPB signature associated with plastics, including Vibrionaceae bacteria (5 % of the whole plastisphere) and biomarkers such as Staphylococcus haemolyticus. The contribution of other marine substrates to plastic PHPB was quantified and we found that shell and wood substrates were potential sources of PHPB for plastics. Our results suggest that both plastics and other marine solid substrates could serve as reservoirs for PHPB. However, plastics convey specific PHPB communities, and due to their ubiquity and persistence in marine ecosystems, plastic debris poses a higher risk as fomites compared to other substrates.

A considerable proportion of marine plastic pollution consists of abandoned, lost, or otherwise discarded fishing gear (ALDFG). Whether still intact or break down into fragments, ALDFG is a widespread, enduring problem, and as such, it represents an ideal case for the use of citizen science. The Fish&Click program proposes a mobile application and website to enable non-specialist observers, such as walkers, divers, or sailors, to record their sightings of ALDFG. The simple interface allows the user to characterize found gear without any expert knowledge, and an analysis of these data can shed light on the magnitude and spatio-temporal composition of the ALDFG phenomenon. This report presents the results and feedback from the first two years of Fish&Click, from May 2020 to June 2022, in the north of the Bay of Biscay, Celtic Sea, and English Channel. In addition to a database cleaning procedure, we defined an ad hoc methodology for analyzing these non-standardized data. Using this, we found that the types and quantities of found gear differ between sea and shore locations and were also different from one region to another. We discuss the pros and cons of this citizen-science program, as well as the potential for improvements that might help to mitigate pollution by ALDFG.

The contamination of marine mammals by legacy pollutants has been largely studied in oceans worldwide. However, international regulations have given rise to the replacement of legacy substances by alternative compounds, which represent a potential additional threat to marine mammal health and conservation. In this study, we investigated the occurrence and temporal trends of contaminants of emerging concern (CECs) in the blubber of common dolphins (Delphinus delphis) from the Bay of Biscay, North-East Atlantic, and in their major prey. Alternative brominated flame retardants were below the limits of quantification in all samples, while dechlorane-related compounds were identified as the major CECs, at levels of 4.6 ± 5.9 ng g−1 lw, i.e. similar to or higher than those reported in various marine mammals from other oceanic regions. The concentrations of 3,6-dichlorocarbazole (3,6-CCZ), the major polyhalogenated carbazole, and of methyl-triclosan were one order of magnitude lower. The halogenated natural products, methoxylated polybrominated diphenyl ethers (MeO-BDEs), were also investigated and showed substantially higher concentrations than all CECs, i.e. 322 ± 214 ng g−1 lw. Declorane-602, anti-monohydro dechlorane plus and MeO-BDEs were the only compounds showing biomagnification between small pelagic fish and dolphins. No significant differences in most CEC concentrations were found over the studied time period, indicating that these compounds are still emitted in the environment and/or have long residence times in the dolphins’ blubber. Conversely, methyl-triclosan concentrations significantly decreased over the studied period. An increase in MeO-BDE concentrations in the last two decades might reveal a change in algal production in relation to global warming.

Fishing gears are conventionally made from non-biodegradable materials including polyamide (PA). When lost in the ocean, these gears have long-lasting impacts, including marine littering, microplastics production, leaching of chemicals, and an extended period of ghost fishing due to its durability. The use of biodegradable co-polyester material such as polybutylene succinate co-adipate-co-terephthalate (PBSAT) and polybutylene succinate-co-butylene adipate (PBSA) as fishing gear materials have been considered as a potential solution to reduce the associated impact. Ocean is a complex environment in which multiple degradation paths can occur for plastic materials, and decoupling of factors could aid in understanding the impact of each potential factor. In this study, the focus is on the impact of pure water hydrolysis phenomena on biodegradable co-polyester PBSAT and PBSA in comparison to PA monofilaments through accelerated aging at 40 °C, 60 °C, 70 °C and 80 °C. As a single factor accelerated aging process, the prediction of loss of mechanical strength over time was possible at other temperatures namely 2 °C, 10 °C, 15 °C, 20 °C and 30 °C. Different end-of-life criteria were used. This study concluded that solely through pure hydrolysis, a drastic reduction of the time to reach end-of-life criteria was observed by using biodegradable monofilaments instead of PA, but still longer than the expected service time. For example, at 2 °C, it would take approximately 10 years, 20 years and 1000 years for PBSAT, PBSA and PA to have lost 50 % of their initial stress at break respectively.

Human sewage is the main source of contamination of environmental waters with human enteric viruses, that can contaminate food such as shellfish. Metagenomic represents a new way of analyzing viral diversity through an a priori massive parallel sequencing approach. However, the precise identification of enteric viruses in sewage or shellfish matrices, is still challenging due to the low viral load, large diversity of viral genera and the large amounts of matrix masking viral sequences. This work compared three commercial kits using capture-based enrichment during the library preparation, for the diversity of detected enteric viruses and for the identification of viral strains in sewage and shellfish samples, focusing on four families impacting human health. Triplicate libraries were prepared for each sample and each kit. All three kits allowed the characterization of a variety of viral genera. In sewage samples, a large number of long contigs was obtained allowing a precise identification of more than 35 strains. In shellfish samples, long contigs were rarer but allowed the identification of one human astrovirus and one norovirus strains. Of the tested kits, one displayed lower variation between replicates, allowed to sequence a higher diversity of viruses from the four families of interest and yielded a higher number of nearly-whole genomes.

Water quality is under threat due to the presence of pathogenic and antibiotic-resistant bacteria. Escherichia coli (E. coli) serves as an indicator of faecal contamination and the potential presence of other harmful pathogens. Understanding E. coli concentrations helps in assessing the overall health risks associated with waterborne diseases and developing effective water management strategies. Therefore, we developed the first large-scale model, GloWPa-Ecoli C1 to simulate E. coli loads and concentrations in rivers and apply this model to China. The model provides the first comprehensive overview of microbial water quality across China's rivers. The model simulates E. coli concentrations in 2020 to range from 10−1.2 to 106.3 CFU/L, with 45.6 %–78.1 % of rivers exhibiting poor microbial water quality. Major hotspots of E. coli pollution are Haihe, Huaihe and Pearl River Basins. Direct discharge of human faecal waste contributes 80.2 % of the total E. coli load, while directly discharged livestock waste accounts for 13.1 %. To mitigate E. coli pollution in rivers in China, we recommend increasing human faecal waste collection rates, expanding wastewater treatment plant (WWTP) coverage, phasing out primary treatment WWTPs and eliminating direct livestock faecal waste discharge, particularly from smallholder farms. The study underscores the urgent need to improve microbial water quality in China's rivers. The findings provide actionable insights to inform policy development aimed at safeguarding water quality and public health. Furthermore, the modelling approach is applicable to other regions and microorganisms, offering a foundation for developing models to address antibiotic-resistant bacteria and other emerging water quality challenges.