Universidade Federal Do Para

The Brazilian Equatorial Margin (BEM) holds major ecological, climatic, and socio-economic importance and is emerging as a new frontier for offshore oil exploration in Brazil. This study aims to identify and characterize the preferential surface transport pathways of oil spills from four potential spill points located in the Potiguar (SPO), Barreirinhas (SBAR), Pará-Maranhão (SPAMA), and Foz do Amazonas (SFZA) basins. Lagrangian simulations were conducted with the OpenDrift model using surface velocity fields from the Surface Merged Ocean Current (SMOC) model. Validation confirms that SMOC accurately reproduces the spatio-temporal variability of surface currents, while OpenDrift proves reliable for simulating oil transport and dispersion. Results indicate that most of the BEM could be affected by potential spills, with preferential pathways and coastal stranding zones varying according to spill location. Spills from SPO and SBAR (points 1 and 2) show the highest impacts, with over 80 % intrusion on the continental shelf and more than 30 % coastal stranding, whereas SFZA (point 4) shows no intrusion or stranding. These pathways are modulated by trade wind variability and mesoscale activity of the North Brazil Current (NBC). Higher intrusion and stranding generally occur in summer and spring, though without a strong seasonal trend. The findings highlight the importance of identifying oil transport pathways to support region-specific contingency planning, as elevated stranding risks threaten sensitive coastal ecosystems and local livelihoods, underscoring the need to integrate operational oceanographic modeling into coastal management.

The Cosmetocleithrum represents the most diverse group of monogenoids parasitizing Neotropical doradid catfishes. In this study, based on morphological and molecular data, we describe two new species, Cosmetocleithrum guamaensis n. sp. and Cosmetocleithrum taeniophallum n. sp., and assess their phylogenetic relationships within the Dactylogyridae using partial 28S rDNA sequences. Our analyses support the validity of these new taxa and suggest their phylogenetic affinity with Cosmetocleithrum species parasitizing auchenipterid catfishes. Additionally, we confirm the presence of Cosmetocleithrum falsunilatum and Cosmetocleithrum bulbocirrus in Megalodoras uranoscopus and Pterodoras granulosus, respectively, with C. falsunilatum exhibiting notable morphological variation across river basins, possibly influenced by environmental factors. Our phylogenetic results corroborate previous studies indicating two distinct Cosmetocleithrum lineages, one exclusively associated with doradids and another with both doradids and auchenipterids, with weak support for the genus' monophyly. Furthermore, we discuss morphological diversity within Cosmetocleithrum, highlighting significant variation in key diagnostic features, including haptoral structures, copulatory complex morphology, and vaginal opening orientation. These findings reinforce previous hypotheses suggesting that Cosmetocleithrum may not constitute a natural group and that taxonomic revisions are needed. The limited molecular data available for Cosmetocleithrum species (with only 13 out of 31 described species studied) and the disparity between the number of known doradid hosts and those surveyed for monogenoids highlight the urgent need for further integrative taxonomic and phylogenetic studies. This approach will be crucial for providing valuable insights and advancing our understanding of the complex evolutionary puzzle of one of the largest genera of monogenoids parasitizing Neotropical Siluriformes.

To better understand the impacts of marine litter, this study focused on the development and application of the Macro-Litter Risk Index-MLRI using two Amazonian beaches, rural and village beaches. This index facilitates comparisons between different beaches, offering a detailed classification of risks and contributing to impact assessment and mitigation through the formulation of appropriate public policies. The MLRI is based on five sub-indices, of which two were adapted for non urban beach settings to ensure its applicability. No weighting was assigned to the sub indices, reinforcing their equal importance in the final result. Each sub-index was rated on a scale from 1 (Very High risk) to 5 (Very Low risk), with the MLRI value calculated as the arithmetic mean of these ratings. On each beach, macro-litter was manually collected in four pre-defined areas, each measuring 400 m². These areas were located within the intertidal zone, with their upper boundary set at the high tide line. The items were quantified and characterized according to marine litter survey and monitoring protocols. According to the MLRI, the rural beach was classified as Low risk (score 4) due to its low level of impact, while the village beach was classified as Moderate risk (score 3), indicating moderate environmental, public health, and economic impacts. The results highlight the vulnerability of each beach according to the sub-indices and emphasize the need for public policy implementation. Overall, this index can be applied to any non-urban beach worldwide, providing valuable insights to support the development of public policies.