ABSTRACT
One of the most populated areas of the world is the Metropolitan Zone of the Mexican Valley, which has serious atmospheric pollution problems. To the north of the Metropolitan Zone is the Protected Natural Area Sierra de Guadalupe (PNASG), an area with a high diversity of birds, close to an industrial zone, and poor air quality (AQ). It is known that a poor AQ affects biodiversity. Therefore, this study aimed to evaluate the AQ using O3, CO, NO2, PM10 and PM2.5 polar graphics atmospheric pollutants (PGAP) and the Integrated Air Quality Index (IAQI) to examine its relationship with the structural diversity (SD) and the functional diversity (FD) of the bird community of the PNASG. In autumn-2019 and winter-2020, bird surveys and the PGAP with the pollutant concentrations were performed using data from Mexico City air quality network. The IAQI, SD and FD were estimated. Autumn-2019 registered the worst IAQI (334), the lowest wind speed (1.5 m/s), and the highest PGAP values (90). These worst AQ and the highest PGAP values were outside the PNASG but into a green urban area. This site also showed the highest SD scores (87), reflecting that the green urban areas function as a refuge for birds. The study sites with the best AQ (130.37), the lowest PGAP values (0.1) and the highest FD (0.7) were inside the PNASG. We conclude that a poor AQ minimizes the FD and that the PNASG is an essential buffer and a biological conservation area. The combined use of an integrated index of air quality with the polar graphics and diversity of birds (SD and FD) allow a better interpretation of air quality. It is necessary to establish mechanisms ensuring the conservation of the protected natural areas and green urban areas to improve air quality and biodiversity conservation.
Subject(s)
Air Pollutants , Air Pollution , Air Pollutants/analysis , Air Pollution/analysis , Animals , Birds , Cities , Environmental Monitoring , Mexico , Particulate Matter/analysisABSTRACT
Wetland ecosystems are subject to severe impacts (physical and chemical) and to the input of various xenobiotics that provoke toxicological consequences. Waterbirds are potential sentinel species of these environments. To analyze how habitat conditions affect the health of Fulica americana, early-warning biomarkers, histopathology, somatic indices, and water quality were examined in two wetlands of the Basin of Mexico: Xochimilco, an urban wetland highly eutrophic with a mixture of pollutants, and Tecocomulco (the reference site), a rural wetland with hunting migratory birds in winter, and with some agricultural contaminants. Coots were collected over 1 year, and the birds were aged, eviscerated, and weighed. Liver samples were analyzed biochemically and histologically. Biomarkers revealed that coots displayed higher lipid peroxidation and elevated activities of gamma-glutamyl transferase and alanine aminotransferase, suggesting hepatic damage during autumn and winter. In Tecocomulco, coots during winter has the highest thiobarbituric acid reactive substances (as a measure of oxidative stress), which may be associated with the presence of predators. In Tecocomulco, the higher gonadosomatic index was detected in spring and summer, while in Xochimilco it was elevated in summer, indicating a delayed egg laying and reproduction in coots from the latter study site. In both wetlands, leukocyte infiltration, alone or combined with vasocongestion, reflected alterations in the inflammatory processes in liver throughout the annual cycle and thus potentially altered hepatic function and organism survival. In both wetlands, coots were permanent residents and chronically exposed to different stressors, suggesting damage may be irreversible with potentially adversely reproductive consequences.
Subject(s)
Birds/metabolism , Environmental Monitoring , Eutrophication , Oxidative Stress , Water Quality , Wetlands , Animals , Biomarkers/metabolism , Female , Liver/enzymology , Liver/metabolism , Male , Mexico , SeasonsABSTRACT
Los humedales son cuerpos de agua muy productivos y son refugio para aves migratorias; sin embargo, continuamente reciben contaminantes que ejercen daños en los organismos acuáticos. El objetivo del trabajo fue evaluar el estado de salud de Fulica americana mediante biomarcadores histopatológicos, de estrés oxidativo, e índices somáticos en dos humedales de la Cuenca de México, para evaluar el efecto de las condiciones del hábitat en la salud de las aves. Se obtuvieron ejemplares en los humedales, Xochimilco (X) y Tecocomulco (T) en diferentes períodos de un año. Se determinó su edad, se evisceraron y pesaron, se obtuvieron porciones del hígado para el análisis histológico y para la cuantificación del nivel de lipoperoxidación (LPO). Se analizó la calidad del agua de X y T. Se realizó la técnica histológica de inclusión en parafina y la tinción Hematoxilina-Eosina. El mayor deterioro de la calidad del agua se observó en X. Se encontró infiltración leucocitaria (IN) y vasocongestión (VA) en tres grados. En T se observó la mayor prevalencia de ejemplares con daños combinados, en particular en las hembras; mientras que en X se presentó un mayor porcentaje de organismos con IN. La LPO más alta se observó durante el invierno en T lo que pudiera estar relacionado con el arribo de aves migratorias y la cacería; mientras que en X la mayor LPO estuvo relacionada con la reproducción. La mayor masa corporal eviscerada se presentó en los machos de T y la menor en las hembras de X. En todas las gallaretas los índices hepatosomáticos máximos se alcanzaron en otoño y los mínimos en primavera. F. americana puede ser utilizada como centinela debido a que presentó respuestas diferenciadas en los índices somáticos y en los biomarcadores histopatológicos y de estrés oxidativo en las distintas localidades, sexo y épocas del año.
Wetlands are very productive ecosystems and water birds complete their lifecycle there. Unfortunately, they constantly receive xenobiotics which can cause damage in aquatic organisms. This work assessed the health conditions of Fulica americana through histopathological and oxidative stress biomarkers and somatic indices in two wetlands from the Mexico Basin to evaluate the effect of habitat conditions on the birds health. The specimens were collected from Xochimilco (X) and Tecocomulco (T) wetlands during an annual cycle. They were eviscerated and weighed. Liver samples were taken for histological analysis and to quantify the lipid peroxidation (LPO) in the laboratory. The coots were aged. The water quality from both wetlands was analyzed. The liver tissue was embedded in liquid paraffin and was stained with hematoxylin and eosin. Two pathologies were detected in three levels each (I, II and III): leukocyte infiltration (IN) and vasocongestion (VA). The highest prevalence of both damages were observed in T coots, while the highest IN percentage was detected in X coots. The maximum LPO levels were detected during winter at T, which could be related to hunter season and the wintering migratory birds. In X the highest LPO levels were related to breeding season. The biggest eviscerated body mass was noted in T males and the smallest in the X females. All coots reached the highest hepatosomatic index during autumn and the minimum during spring. American coot can be used as sentinel because it is able to present differentiated responses, somatic indices, histopathological biomarkers and oxidative stress in different locations, sex and periods of the year.
