Plasma Biochemistry values in wild female hawksbill turtle (Eretmochelys imbricata) during nesting in Mexican coast

Para obter valores da bioquímica plasmática, foram coletadas amostras de sangue durante a desova de 47 tartarugas marinhas fêmeas aparentemente saudáveis da espécie Eretmochelys imbricata, utilizando heparina sódica como anticoagulante. Amostras de sangue foram coletadas durante dois anos entre os meses de abril e junho (época de nidificação). Mediu-se os parâmetros hematológicos (incluindo hematócrito, contagem de glóbulos brancos e vermelhos e nível de hemoglobina) e os valores da bioquímica plasmática (incluindo creatinina, ureia, ácido úrico, triglicérides, colesterol total e glicose). Os dados gerados a partir deste estudo podem ser úteis para a avaliação clínica de saúde e de doença em tartarugas-de-pente em habitats próximos ao litoral no Golfo do México, contribuindo para a conservação dessa espécie.To obtain plasma biochemistry values, blood was collected for 47 nesting females of apparently healthy Eretmochelys imbricata sea turtles using sodium heparin as an anticoagulant. Blood samples were collected in April-Jun for two years (nesting season). Hematologic characteristics, including packed cell volume, white blood cell counts, red blood cell count and hemoglobin level; and plasma chemistry values, including creatinine, blood urea nitrogen, uric acid, triglyceride, total cholesterol, and glucose were measured. The data generated from this study may be useful for clinical assessment of health and disease of wild hawksbill sea turtles on nearshore habitats in the Gulf of Mexico, thus contributing to a conservation of this species

Potentially harmful cyanobacteria in oyster banks of Términos lagoon, southeastern Gulf of Mexico

Cyanobacteria inhabit hypersaline, marine and freshwater environments. Some toxic and non-toxic species can form harmful blooms. The aim of this study was to identify potentially harmful cyanobacterial species in the oyster banks of Términos Lagoon, the southeastern Gulf of Mexico. Six sample sites (up to 2-m depth) were monitored monthly from August 2012 to September 2013. Water temperature, salinity, pH, dissolved oxygen saturation (% DO), inorganic nutrients and abundance of cyanobacteria were determined. Temperature and salinity were characterized by marked seasonal differences (26.8 to 30.6 °C and 6.1 to 19.5, respectively). The pH values (ranging from 7.1 to 8.4) and the % DO (88.4 to 118.2 %) suggest a predominance of photosynthetic activity in the windy season (October-February). Elevated nutrient contents are associated with the period of increased river discharge, determined by water circulation and biogeochemical processes. Fourteen taxa were identified, of which Anabaena sp., Merismopedia sp., Oscillatoria sp. and Cylindrospermopsis cuspis produced blooms. Cyanobacterial abundances were on the order of magnitude of 106 cells L-1 in October 2012 at stations S1-S6, with an average value of 3.2x105 cells L-1 and a range of 2000 to 3.1x106 cells L-1 throughout the study period; however, they showed a remarkable absence during the windy season (October to January). Anabaena sp. and C. cuspis reached abundances of 1.9x106 and 1.3x106 cells L-1, respectively. The latter caused the temporary closure of oyster Crassostrea virginica harvesting for 15 days in October 2012.Las cianobacterias habitan en ambientes hipersalinos, marinos y de agua dulce. Algunas especies tóxicas y no tóxicas pueden formar florecimientos nocivos. El objetivo de este estudio fue identificar las especies de cianobacterias potencialmente nocivas en los bancos ostrícolas de laguna de Términos, sureste del Golfo de México. Seis sitios de muestreo (hasta 2 m de profundidad) fueron monitoreados mensualmente de agosto de 2012 a septiembre de 2013. Se midió la temperatura del agua, salinidad, pH, saturación de oxígeno, nutrientes inorgánicos y abundancia de cianobacterias. La temperatura y la salinidad se caracterizaron por marcadas diferencias estacionales (26,8 a 30,6 °C y 6,1 a 19,5, respectivamente). Los valores de pH (de 7,1 a 8,4) y la saturación de oxígeno disuelto (de 88,4 a 118,2 %) sugieren un predominio de la actividad fotosintética en la temporada de nortes (octubre-enero). Las concentraciones elevadas de los nutrientes están asociados al periodo de mayor descarga de los ríos, determinados por la circulación y los procesos biogeoquímicos. Se identificaron 14 taxa, de los cuales Anabaena sp., Merismopedia sp., Oscillatoria sp. y Cylindrospermopsis cuspis formaron florecimientos. Las abundancias de cianobacterias fueron del orden de magnitud de 106 células L-1 en octubre de 2012 en las estaciones S1-S6, con un valor promedio de 3.2x105 células L-1 y un rango de 2000 a 3.1x106 células L-1 a lo largo del periodo de estudio. Sin embargo, mostraron una ausencia notable durante la temporada de nortes (octubre a enero). Anabaena sp. y C. cuspis alcanzaron abundancias de 1.9x106 y 1.3x106 células L-1, respectivamente. Este último causó el cierre temporal de la colecta del ostión Crassostrea virginica durante 15 días en octubre de 2012

Using regression tree analysis to determine size class intervals and sexual dimorphism in the Morelet's crocodile Crocodylus moreletii

Assignment of Morelet's crocodile Crocodylus moreletii individuals into size groups or classes based on ecological and morphological similarities has not yet been associated with species-specific ontogeny related changes. Age or size of first reproductive behavior is not precisely known for C. moreletii, but differences in allometric patterns and relative cranial size between juveniles and adults might be used as an indicator of sexual maturity. In this study, a regression tree analysis was used to investigate the relationship between age and body size in 1266 crocodiles by using both simple and generalized linear models, with gender and origin (captivity or wild) as factors. Total length (TL), snout–vent length (SVL) and cranial length (CL) were used as predictor variables and the logarithm of body mass as the response variable. Four length intervals with well-defined thresholds (514, 899 and 1497 mm of TL) were established using all three predictors (TL, SVL and CL). Relationship between SVL and TL was described, and a strong positive relationship (r2 = 0.98), unaffected by crocodile gender, was observed. The observed CL–TL and CL–SVL relationships were also positive but significantly different between males and females (p < 0.001) and length interval classes (p = 0.01). These results suggest that our estimated size thresholds seem to correspond to important ontogenetic changes in C. moreletii and that sexual maturity is closely related to size in this species, where sexual dimorphism in body length occurs, particularly in large individuals (size group IV)

Environmental impact of anthropogenic activities on human and animal populations from Palizada, Campeche, Mexico

Doutoramento em BiologiaThe present research concerns the environmental impact of pesticides used in the Fluvio Lagoon Palizada River Subasin (FLPRS) in Campeche, Mexico on environmental health using biomarkers in wild mosquitofishes (Gambusia yucatana) and whistling ducks (Dendrocygna autumnalis), likewise in campesinos (peasants). Mosquitofishes (G. yucatana) and black-bellied whistling duck (D. autumnalis) were chosen as bioindicators as they are abundant species, the fishes in small streams of the region; and the whistling ducks (D. autumnalis) in wetlands, being most abundant in flooded savannahs and irrigated rice fields. In this work were included human been because they applied the pesticide and are exposed at the first time. The biomarkers used to asses the environmental exposures to pesticides were acetylcholinesterase (AChE, EC 3.1.1.7), glutathione-S-transferases (GST, EC 2.5.1.18) and lactate dehydrogenase (LDH, EC 1.1.1.28). In this research was evaluated the environmental impact of pesticide use in the FLPRS in order to 1) know the environmental conditions of PRS in relation to water quality and land use, 2) evaluate in laboratory the use of biomarkers such as AChE, GST and LDH in wildlife exposed to pesticides, 3) estimate with biomarkers the environmental pesticide effects on organisms from aquatic (mosquitofish, G. yucatana) and terrestrial (whistling ducks, D. autumnalis) compartments, and 4) evaluate the adverse effects of pesticides used by fieldworkers from El Juncal, Palizada using symptoms related to pesticide exposure and a biomarker. The assessing of environmental impact of pesticide was carry out with the biomarkers mentioned with a test battery in situ through a biomonitoring study and toxicity test chambers in aquatic organisms, and with a survey on brain cholinesterase biomarker in terrestrial organisms. The results of this study indicated that during the last 20 years, in the Palizada River Subasin (PRS) the land use change has been drastic mainly in agriculture cover because this increase in more than 1,000 %, and the total amount of pesticide used is parallel to this increase in agricultural hectares. The use of an index of water quality (WQI) identified that from the nine sampling sites studied in the PSR, sites with cattle ranching (WQI= 0.58) and agricultural (WQI= 0.65) activity were the sites with a significant average of WQI worse than the others sites (WQI = 0.68 – 0.73). In mosquitofish (G. yucatana), the characterization of cholinesterases seems that the main form present in both muscle and head is AChE. The ranking of in vivo toxicity (LC50) of the tested pesticides to G. yucatana was chlorpyrifos > carbofuran > glyphoste. ChE activities of muscle and head of mosquitofish were significantly inhibited by furadan after 24 hrs of exposure with an inhibition of 60% at 0.06 mg/L. The mixture chlorpyrifos/glyphosate is 34% more toxic than the chlorpyrifos tested alone. In the test with 6 chlorpyrifos, fish that survived after an exposure of 96h to concentrations between 0.006 and 0.012 mg/L showed a ChE inhibition near to 80%. Muscle and head AChE activity was inhibited by chlorpyrifos and carbofuran; gill GST was inhibited by carbofuran; and muscle LDH activity was not altered by any of pesticides tested. In the case of whistling duck (D. autumnalis), the forebrain ChE seems to be AChE. The carbofuran-chlorpyrifos mixture was the most potent in vitro inhibitor of D. autumnalis brain ChE tested. This is important because in real conditions the exposure is with a mixture of pollutants which can cause possible synergistic effects. The field study in the PRS was focused to three different sampling sites, one with cattle ranching activity, other with agricultural activity, and the last one was the Palizada River. The first phase of the in situ study demonstrated the possibility of a link between the water quality index (WQI) and the variation of abiotic conditions that may cause effects on survival, growth, and biomarkers on fishes exposed not related with direct effects of pollutants. In the biomonitoring studies using enzymatic biomarkers in wild fish present the advantage of diagnosing the real exposure and/or effects of environmental contaminants but they may underestimate the actual contamination of the water, since organisms with a reasonable degree of mobility may avoid the exposure. The results obtained in this study indicate that some water variables can influence directly or indirectly on enzymatic activity, and consider it as a natural variability of activity. The integration of information generated in situ toxicity test and wild fishes reflected a concordance between percentages of AChE activity in wild fishes and exposed in situ in the Palizada River during February, July and November. The results of the study with whistling duck (D. autumnalis) suggest that ducks are exposed to pesticides (inhibition above 30% of ChE activity), at least during the season of intensive application. The evaluation of the adverse effects of pesticides in fieldworkers from El Juncal, Palizada using AChE as a biomarker showed no conclusive results from the regression analysis of symptoms and AChE inhibition activity. Some symptoms are probably compatible with acute organophosphate and carbamate poisoning such as headache, weakness, nausea, sweating and tiredness. No differences were observed with respect to use of protective clothing. It is recommended the use of pesticide less aggressive to environment and human health, also further field studies incorporating a systematic monitoring of wild populations and investigating also population parameters are particularly important for local pesticide management

Contaminação por compostos organoclorados em alguns alimentos procedentes de uma região do México

Organochlorine pesticide residues were determined in hen's eggs and cheese samples from the agricultural town Villa de Ahome, Sinaloa, México, using gas-liquid chromatography with electron capture detection. In eggs, the compounds identified most frequently and in greatest concentrations were heptachlor epoxide, p, p'-DDT and p, p'-DDE, while in cheese the most frequent contaminants were, p, p'-DDE and dieldrin. Simultaneously, by means of a preliminary epidemiological survey several pathologies prevalent in the area were detected.Fueran determinados los residuos de plaguicidas organoclorados en huevos y quesos de la población agricola de la Villa de Ahorne, Sinaloa, México, mediante cromatografia gas-líquido con detector de captura de eletrones. En los huevos, los compuestos detectados con mayor frecuencia y concentración fueran: epóxido de heptacloro, p, p'-DDT e p, p'-DDE. Simultáneamente fué realizado en la Villa de Ahorne un estudio epidemiológico preliminar en la cual se detectó varias manifestaciones patológicas en las personas entrevistadas y en sus familiares.Foram determinados os residuos de praguicidas organoclorados em ovos e queijos da população agrícola da Villa de Ahome, Sinaloa, México, mediante cromatografía gas-líquido com detector de captura de elétrons. Nos ovos, os compostos detectados com maior freqüência e concentração foram: epóxido de heptacloro, p, p'-DDT e p, p'-DDE; nos queijos os contaminantes mais freqüentes foram: dieldrín e p, p'-DDE. Simultaneamente foi realizado na Villa de Ahome um estudo epidemiológico preliminar no qual se detectou várias manifestações patológicas nas pessoas entrevistadas e em seus familiares

Prácticas de utilización para plaguicidas en la localidad Nueva Libertad, La Concordia, Chiapas

Some of the pesticides used in the Irrigation District (DDR) Num. 101 Cuxtepeques, Chiapas, are banned in other countries and restricted in Mexico. This represents a risk for the environment and the health of people who uses them. The aim of this study was to determine the socio-demographic characteristics and determinants of exposure to pesticides in agricultural workers in Nueva Libertad as part of a project that was conducted in the eight locations covered by the irrigation district, whose agricultural production is maintained throughout the whole year. This is a cross-sectional study conducted from November 2008 to May 2009, to a 197 settlers. The working's process analysis was done as well as the application of a semi-structured questionnaire and open interviews with key people in Nueva Libertad, La Concordia, Chiapas. The data revealed that 96% of the agricultural workers in the locality know about the health problems associated with the improper handling of pesticides. However,the risks and danger were minimized and denied. For example, the lack of use of personal protection when applying the products, as the 99.5% answered, or the improper handling of pesticide containers, as 92.9% didAlgunos de los plaguicidas que se utilizan en el Distrito de Riego (DDR) Núm. 101 Cuxtepeques, Chiapas, están prohibidos en otros países y restringidos en México. Esto representa un riesgo para el medio ambiente y la salud de las personas que lo usan. El objetivo del presente trabajo consistió en conocer las características sociodemográficas y las determinantes de la exposición a los plaguicidas en los trabajadores agrícolas de Nueva Libertad, como parte de un proyecto que se realizó en las ocho localidades que abarca el distrito de riego, cuya producción agropecuaria se mantiene todo el año. Este es un estudio descriptivo transversal realizado entre noviembre de 2008 a mayo de 2009 a 197 pobladores. Se llevó a cabo el análisis del proceso de trabajo, así como la aplicación de un cuestionario semiestructurado y de entrevistas abiertas a actores claves en Nueva Libertad, La Concordia, Chiapas. Los datos revelan que 96% de los trabajadores agrícolas de la localidad conocen los problemas de salud asociados al manejo inadecuado de plaguicidas. No obstante, fueron minimizados los riesgos y la negación del peligro. Por ejemplo, la falta de uso de protección personal al aplicar los productos en el 99.5% de los entrevistados o bien el manejo inadecuado de los envases de los plaguicidas en donde 92.9% los dispone inadecuadament

Hawksbill Sea Turtle (<i>Eretmochelys imbricata</i>) Blood and Eggs Organochlorine Pesticides Concentrations and Embryonic Development in a Nesting Area (Yucatan Peninsula, Mexico)

Environmental contaminants with chemical origins, such as organochlorine pesticides (OCPs) have major impacts on the health of marine animals, including sea turtles, due to the bioaccumulation of those substances by transference throughout the food chain. The effects of environmental pollution on the health of marine turtles are very important for management strategies and conservation. During recent decades, the south Gulf of Mexico and the Yucatan Peninsula have suffered from increasingly frequent disturbances from continental landmasses, river systems, urban wastewater runoff, port areas, tourism, industrial activities, pesticides from agricultural use, and other pollutants, such as metals, persistent organic pollutants (POPs) and hydrocarbons (from the oil industry activities), which contaminate water and sediments and worsen the environmental quality of the marine ecosystem in this region. In this study, we assessed the concentrations of OCPs in the blood and eggs of 60 hawksbill turtles (Eretmochelys imbricata) nesting at the Punta Xen turtle camp, and their effects on the nesting population’s reproductive performance: specifically, maternal transfer and embryonic development were analyzed. Hematologic characteristics, including packed cell volume, white blood cell count, red blood cell count, and haemoglobin levels, and plasma chemistry values, including creatinine, blood urea nitrogen, uric acid, triglyceride, total cholesterol and glucose, were also measured. The general health of the turtles in this study, as well as their levels of urea, serum creatinine, glucose, uric, acid, cholesterol, and triglyceride, fell within normal ranges and was similar to other normal values, which could indicate the turtles’ good energy levels and body conditions for nest-building activity, with all of the turtles able to successfully come ashore to nest. All the same, the obtained results also indicate that OCPs affect the nesting and reproductive performance of the hawksbill turtles, as well as their fertility and the development of the population of eggs and reproductive performance, specifically in terms of maternal transference and embryonic development. There were significant differences in the concentrations of OCPs (ΣHCHs and ΣDienes) between maternal blood and eggs, indicating that these chemicals are transferred from nesting females to eggs and, ultimately, to hatchlings. OCPs may, therefore, have an effect on the health and reproductive performance of hawksbill turtles, both in terms of their fertility and egg development. Conservation strategies need to be species-specific, due to differences in feeding, and address the reasons for any decline, focusing on regional assessments. Thus, accurate and comparable monitoring data are necessary, which requires the standardization of monitoring protocols

Size, blood organochlorine pesticide concentrations and biochemical indicators measured in hawksbill sea turtles (Eretmochelys imbricata) nesting at Punta Xen (Campeche, Mexico) in August 2010

Data on the impact of environmental pollution on the homeostasis of sea turtles remains scarce, particularly in the southern Gulf of Mexico. As many municipalities along the coastline of the Yucatan Peninsula do not rely on a waste treatment plant, these organisms could be particularly vulnerable. We searched for relationships between the presence of organochlorine pesticides (OCP) and the level of several oxidative and pollutant stress indicators of the hawksbill sea turtle (Eretmochelys imbricata) during the 2010 nesting season at Punta Xen (Campeche, Mexico). Of the 30 sampled sea turtles, endosulfans, aldrin related (aldrin, endrin, dieldrin, endrin ketone, endrin aldehyde) and dichlorodiphenyldichloroethylene (DDT) families were detected in 17, 21 and 26, respectively. Significant correlation existed between the size of sea turtles with the concentration of methoxychlor, cholinesterase activity in plasma and heptachlors family, and catalase activity and hexachlorohexane family. Cholinesterase activity in washed erythrocytes and lipid peroxidation were positively correlated with glutathione reductase activity. Antioxidant enzyme actions seem adequate as no lipids damages were correlated with any OCPs. Future studies are necessary to evaluate the effect of OCPs on males of the area due to the significant detection of methoxychlor, which target endocrine functioning and increases its concentration with sea turtles size