Fresh water is vital for human activities; however, an increase in the contamination of water bodies has been observed, so it is necessary to monitor the degree of contamination and take measures to preserve it. In Altamira, Tamaulipas, the Guayalejo-Tamesí River basin has three estuaries and seven lagoons, including Laguna El Conejo, of which the National Water Commission only monitors one. The objective of this research is to determine water quality on the basis of the parameters COD, BOD₅, T, pH, and sediment characteristics. The open reflux method was used according to NMX-AA-030-SCFI-2012 for COD, BOD Track II, HACH equipment for BOD₅, and the granulometric characterization recommended by the Unified Soil Classification System ASTM D-2487-17. The water was found to be uniformly contaminated throughout its length in the range of 117.3–200 mg/L COD, and BOD₅ ranged from 15.8–112.75 mg/L throughout the study period, with sediments dominated by poorly graded soil and fine clay. Comprehensive management is needed because the BOD₅/COD ratio varies between 0.11and 0.56, indicating that it contains recalcitrant organic matter, which is difficult to biodegrade.

This work analyzed the presence of microplastics (MP) in the gills and digestive tract of the fish Dormitator maculatus and its relationship with biological parameters in the Alvarado Lagoon (AL). In 127 organisms, 1,134 MP were found: 561 in the digestive tract and 573 in the gills, with an average of 8.9 MP per individual. Central tendency, Mann-Whitney, Kruskal-Wallis, and linear regression tests were performed to examine the relationship between the number of MP and the biological parameters of D. maculatus. A slight correlation was found between the number of MP in the gut and gills. The biological parameters analyzed - weight, length, condition index, and gut fullness - lacked a relationship between the amount of MP present in the gut and gills. The MPs were classified by color and type: fibers, pellets, films, and fragments. All fish analyzed presented MP in digestive tracts and gills, which indicates a uniform distribution of contamination and suggests that it originates from nearby populations, resulting from daily activities such as washing synthetic clothes and fishing. Fibers were the most dominant material (97.53%), comprising 62% blue and 12% transparent fibers. The presence of these is a threat to the health of both fauna and humans.

Microplastics (MP) are emerging pollutants found in the Veracruz Reef System National Park (PNSAV). They are widely distributed in the aquatic environment and are ingested by organisms either accidentally or because they are mistaken for food. In this article, the author analyses the physicochemical characteristics of reef sediments using visual identification, Nile Red (NR), scanning electron microscopy (SEM), and Energy Dispersive Spectroscopy (EDS) of microplastics found in sediments adjacent to reefs; this allowed us to determine their distribution within the PNSAV. A total of 687 microplastics per kilogram of dry sediment were quantified, including fibres (98.5%), films (1.4%), and fragments (0.01%). The predominant colour was transparent (60.2%), followed by blue (16%) and red (12%). Based on their MP distribution, the sites were classified into two groups: north and south. The sampling stations with the highest concentrations of MP are located in the group of reefs south of the PNSAV, with the Anegadilla Reef being the most affected station. SEM/EDS analyses revealed elemental spectra dominated by carbon and oxygen, which is consistent with the expected elemental composition of polymeric materials. Peaks of chlorine were detected in some MP particles, suggesting the possible presence of chlorinated polymers, such as polyvinyl chloride (PVC). In addition, elements such as titanium, silicon, and nickel were identified, which could be associated with inorganic particles adhering to the surface or with additives commonly incorporated during the manufacture of plastics such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), and polyethylene terephthalate (PET). The presence of elements such as titanium and nickel were detected; these are found in additives used in the manufacturing of polymers.

Objective: Identify the current state of knowledge, the most relevant research areas, and the current and potential forms of use of S. bigelovii. Design/methodology/approach: A detailed review of articles from the main databases and academic repositories was conducted, considering their characteristics based on the research approach and objectives. Results: S. bigelovii is a very versatile halophyte due to its properties, so the potential use of its biomass is of commercial and industrial interest. Limitations on study/implications: This study includes research related to Salicornia and halophytes from 2000 to 2022 mostly. Findings/conclusions: This species has the potential to be the main input in various processes in the food, pharmaceutical, cosmetic, agricultural, and even energy industries.