Sulfoxaflor is an insecticide belonging to the recent sulfoximine class, acting as a nicotinic acetylcholine receptor (nAChRs) agonist. There are few studies regarding sulfoxaflor’s toxicity to non-target organisms. The present study aimed to investigate the acute and sub-lethal effects of sulfoxaflor on Carcinus maenas by addressing survival, behaviour (feed intake and motricity), and neuromuscular, detoxification and oxidative stress, and energy metabolism biomarkers. Adult male green crabs were exposed to sulfoxaflor for 96 h and an LC₅₀ of 2.88 mg L⁻¹ was estimated. All biomarker endpoints were sampled after three (T3) and seven (T7) days of exposure and behavioural endpoints were addressed at T3 and day six (T6). Sulfoxaflor affected the feed intake and motricity of C. maenas at T6. From the integrated analysis of endpoints, with the increase in concentrations of sulfoxaflor, after seven days, one can notice a lower detoxification capacity (lower GST), higher LPO levels and effects on behaviour (higher motricity effects and lower feed intake). This integrated approach proved to be valuable in understanding the negative impacts of sulfoxaflor on green crabs, while contributing to the knowledge of this pesticide toxicity to non-target coastal invertebrates.

Sea turtles, with their global distribution and complex life cycle, often accumulate pollutants such as metals and metalloids due to their extended lifespan and feeding habits. However, there are limited studies exploring the impact of metal pollution on the reproductive health of female sea turtles, specifically focusing on the quality of their eggs, which has significant implications for the future generations of these charismatic animals. São Tomé Island, a crucial nesting and feeding habitat for green sea turtles, underscores the urgent need for comprehensive research in this ecologically significant area. This study aimed to investigate whether metals and metalloids in the blood of nesting female green sea turtles induce genotoxic effects in their erythrocytes and affect their egg morphometric characteristics and the composition of related compartments. Additionally, this study aimed to evaluate whether the quality of energetic reserves for embryo development (fatty acids in yolk's polar and neutral lipids) is influenced by the contamination status of their predecessors. Results revealed correlations between Cu and Hg levels and increased "lobed" erythrocytes, while As and Cu negatively influenced shell thickness. In terms of energy reserves, both polar and neutral lipid fractions contained primarily saturated and monounsaturated fatty acids, with prevalent 18:1n-9, 18:0, 16:0, 14:0, and 12:0 fatty acids in yolk samples. The yolk polar fraction was more susceptible to contaminant levels in female sea turtles, showing consistent negative correlations between pollution load index and essential n3 fatty acids, including linolenic, eicosatrienoic, eicosapentaenoic, and docosapentaenoic acids, crucial for embryonic development. These metals accumulation, coupled with the reduced availability of these key fatty acids, may disrupt the eicosanoid and other important pathways, affecting reproductive development. This study reveals a negative correlation between metal contamination in female sea turtles' blood and egg lipid reserves, raising concerns about embryonic development and the species' future generations.

Persistent organic pollutants (POPs) including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochloride pesticides (OCPs) affect biodiversity by bioaccumulating through food webs, impacting marine organisms like endangered sea turtles. This study represents the first evaluation of these contaminants in sea turtles nesting in São Tomé and Príncipe. The main goal was to evaluate PCBs, PBDEs and OCPs levels in sea turtles' blood and investigate their potential effects on erythrocytic nuclear abnormalities (ENAs) and oxidative stress and reproduction-related gene expression. The relative mean abundance for contaminants was ΣPCBs > ΣOCPs > ΣPBDEs. Contaminants such as PCB-28, PCB-138, PCB-153, PCB-180 and p,p'-DDE were associated with ENAs, suggesting potential genetic instability and cellular disruption. PCB-126, PBDE-100, and o,p'-DDD correlated with antioxidant and detoxification genes (glrx3, gst, txnip, txnrd2, and gclc), suggesting oxidative stress responses. The reproduction-related gene est17 was correlated with α- and β-HCH, potentially affecting ovary development. Correlations between ace2 and various PCBs, PBDEs, and o,p'-DDD suggest disruptions in follicular development and egg transport. Embryo development genes (hoxA1 and tuba1) were associated with PBDE-154, PBDE-100 and o,p'-DDD, suggesting possible embryonic alterations. These findings highlight the impacts of POPs on nesting female green turtles in São Tomé, threatening this endangered population.

Metals and metalloids can pose a significant threat to sea turtles, as these contaminants tend to accumulate in their bodies over time, due to their long lifespans and varied feeding habits. São Tomé and Príncipe's archipelago hosts the last remaining rookery for hawksbill sea turtles (Eretmochelys imbricata) in the region. The study aimed to determine the levels of metals and metalloids accumulated by this population and to investigate their possible genotoxicity in nesting females' blood as well as potential effects on their eggs in terms of morphometric characteristics and the quality of their lipidic reserves, essential for embryo development. Higher levels of Hg were found to be correlated with increased "lobed-shaped nuclei" in erythrocytic count, suggesting genotoxicity effects in this population. Higher levels of Se were correlated with thicker and heavier eggshells, while Pb levels were associated with the reduction of the egg's diameter. Metal contamination in females' blood significantly affected yolk polar fatty acids. Significant negative correlations were found between general metal contamination (PLI) and saturated fatty acids (SFA), while positive correlations were observed for essential omega-6 fatty acids (n6), mostly influenced by Cu, Fe, and Hg concentrations. This suggests that these omega-6 fatty acids are being synthesized from SFA, potentially indicating stress response by metal exposure. The present results point to some potential alterations in the normal embryonic development of these turtle eggs, influenced by metal contamination, which should raise some concerns about the future of this critically endangered species and call for additional conservation efforts in the region.

São Tomé Island harbors important sea turtle nesting and feeding sites. However, insufficient enforcement of environmental laws to avoid illegal take of nesting females and eggs, associated with a great lack of knowledge about how these species interact with their environment and how human activities impact their survival in the region, constitute significant challenges for sea turtle conservation. Through current local conservation projects, some information on genetics and nutrition of sea turtle populations is being unveiled but very little is known about how ocean pollution is impacting these turtles. The main objective of this study was to assess the metal concentrations accumulated by one species of S. Tomé sea turtles (Chelonia mydas) and infer about possible impacts of such contamination on their general stress responses and health status. More specifically, the final goal was to find correlations between metal concentrations and the expression of key genes involved in detoxification/sequestration and metal transport, antioxidant responses and oxidative stress, immunological responses, mitochondrial respiratory and energy production, among others, which could be indicative of these organisms health and future viability. To achieve these goals, nesting female turtles were sampled for blood, immediately after egg laying in their well-documented spawning sites in S. Tomé. Blood samples were withdrawn from the external jugular vein, a portion was stored in EDTA treated tubes at -20ºC until analysis of metal concentrations, and another portion was stored in RNAlater at -20°C until RNA extraction and gene expression analysis using quantitative real-time PCR (qPCR). Additionally, body mass and carapace length were also recorded, along with all information regarding egg spawning and its success. Results showed significant correlations between expression of some genes and metal contaminant levels, pinpointing some candidate genes to be used as biomarkers of interest for biomonitoring campaigns, which worrying function highlights the need for a close follow-up of these organisms. This study represents the first attempt to address pollutant levels and the biological impairments of such stressors in these turtle species nesting in S. Tomé which, given their classification as endangered species (IUCN red list), is of paramount importance to contribute for conservation measures and management.