Influence of density on growth and survival of freshwater prawn Macrobrachium americanum (Bate, 1868) (Caridea: Palaemonidae) cultured in a cage-pond system

The domestication and culture of freshwater shrimp native of tropical and subtropical American Pacific zone requires the study and development of technologies in open systems where their response to types of farming, feeding and management strategies generate practical information for the production of this species. The aim of this study was to evaluate the effect of stocking density on growth and survival in M. americanum juvenile-adult, cage-cultured and to determine the optimal density for grow-out production. The caridean shrimp Macrobrachium americanum was cultured for 152 days in a 16 cage-culture (3 m3 each) at densities of 1, 3, 6 and 9 org / m3, respectively, with stocking sizes from 12.1 ± 1.7 to 13.5 ± 2.3 g. The prawns were fed twice daily with Camaronina 35%. Water quality parameters were within standard range for caridean shrimp culture. There was a significant effect of density on final weight, growth rate, specific growth rate, K condition and survival, and an inversely proportional relationship with the feed conversion ratio. The growth was affected by density, resulting to a maximum increase of 6 org / m3 in the asymmetry of the prawn and also increasing the number of small organisms by 9 org / m3. However, it is necessary to study such aspects as the rate and frequency of feeding, the initial size-grade and the implementation of shelter, among others

Presencia de formas parasitarias de importancia zoonótica en arena de playas que inciden en el Parque Nacional Sistema Arrecifal Veracruzano

Background. The Veracruz coastal zone in Mexico has a vast coastline where different tourist (use of beaches), economic (urban-port, commercial, and gastronomic), social, cultural, and sports activities are carried out. In Mexico, the only regulation that refers to the quality of beaches is NMX-AA-120-SCFI-2016, in which the absence of fecal matter is determined as an indicator of its sanitary quality. However, the inadequate management of fecal material in recreational beaches compromises public health and contributes to water and sand quality deterioration. Objective. To evaluate the presence of parasitic forms of zoonotic importance in the sand of the beaches of the Veracruz-Boca del Río metropolitan area that affect the Veracruz Reef System National Park. Methods. A total of 100 samples of beach sand and 19 samples of fecal matter were taken in the period from June to October 2021. The analyzes were carried out at the Boca del Río Technological Institute/Aquatic Resources Research Laboratory by the Willis flotation technique and cup sedimentation. The presence of helminths was identified and quantified as bioindicators of fecal matter contamination. Results. Of the sand samples, 28 % were positive for parasitic forms with a recovery of 112 parasitic forms, of which 67.85 % correspond to parasites of the genus Strongyloides sp. and Hookworms. 32.35 % corresponds to non-pathogenic parasites for humans. Of the fecal matter samples collected, only 42.1 % showed positivity to the parasitized forms mentioned above. Conclusions. The presence of parasitic pathogenic forms in the sand samples indicates fecal contamination, which compromises the sanitary and environmental quality of the beach sand of the Veracruz-Boca del Río metropolitan area and the Veracruz Reef System National Park.Antecedentes. La zona costera de Veracruz cuenta con un amplio litoral en donde se realizan diferentes actividades turísticas (uso de playas), económicas (urbano-portuario, comercial y gastronómico), sociales, culturales y deportivas. En México, la única norma que hace referencia a la calidad de playas es la NMX-AA120-SCFI-2016, en la cual se determina la ausencia de materia fecal como indicador de su calidad sanitaria; sin embargo, el inadecuado manejo de la materia fecal canina en playas recreativas compromete la salud pública y contribuye al deterioro de la calidad del agua y arena. Objetivo. Evaluar la presencia de formas parasitarias de importancia zoonótica en arena de playas de la zona conurbada Veracruz-Boca del Río que inciden en el Parque Nacional Sistema Arrecifal Veracruzano. Métodos. Se tomaron en total 100 muestras de arena de playa y 19 muestras de materia fecal en el período comprendido de junio a octubre de 2021. Los análisis se realizaron en el Instituto Tecnológico de Boca del Río/Laboratorio de Investigación de Recursos Acuáticos, por la técnica de flotación de Willis y sedimentación en copa. Se identificó y cuantificó la presencia de helmintos como bioindicadores de contaminación por materia fecal. Resultados. 28 % de las muestras fueron positivas a formas parasitarias con una recuperación de 112 formas parasitarias, de las cuales el 67.74 % corresponden a parásitos del género Strongyloides sp. y anquilostomídeos. El 32.35 % corresponde a parásitos no patógenos para el hombre. De las muestras de materia fecal recolectadas solo 42.1 % mostraron positividad a formas parasitadas mencionadas anteriormente. Conclusiones. La presencia de formas parasitarias patógenas en las muestras de arena es un indicio de contaminación fecal que pone en riesgo la calidad sanitaria y ambiental de las playas arenosas de la zona conurbada Veracruz-Boca del Río y del Parque Nacional Sistema Arrecifal Veracruzano

Pathogenic vibrios in the oyster Crassostrea virginica in the lagoon system of Mandinga, Veracruz, Mexico

Oyster consumption has been associated to the transmission of pathogenic bacteria, including those from the genus Vibrio. The objective of this investigation was to determine the concentrations of Vibrio parahaemolyticus and V. alginolyticus in Crassostrea virginica from the lagoon system of Mandinga, Veracruz, and their relationships with salinity and water temperature. Only the periods of greater production and consumption of oysters were examined: the dry and rainy seasons during 2008. Four sampling sites were selected, from which three samples were collected per site per season, resulting in a total of 24 samples. Each sample consisted of 30 oysters of commercial size that were subsequently analyzed using serial dilution. Biochemical analysis of the resulting bacterial colonies revealed concentrations of V. parahaemolyticus and V. alginolyticus ranged from < 3 to 150 MPN/g. A positive correlation was observed between temperature and the concentration of V. parahaemolyticus (r = 0.69, p < 0.05), while the correlation with salinity was negative (r = -0.68, p < 0.05). No significant correlations between the concentration of V. alginolyticus and water temperature and salinity were observed for the rainy season. The main contribution of this paper is to establish safe areas and periods for oyster extraction

Contaminación del agua con nitratos y nitritos y su impacto en la salud pública en la zona de influencia del módulo de riego (I-1) La Antigua, Ver. México.

La contaminación de las aguas emerge como una consecuencia de los asentamientos humanos y de las actividades rurales, agrícolas, silvícolas e industriales en una región. Se ha encontrado que al incrementarse el uso de fertilizantes nitrogenados también se produce un mayor impacto contaminante en las aguas. Los nitratos y nitritos disueltos en agua subterránea, destinada al consumo humano, ocasionan efectos negativos en la salud, tales como; la producción de nitrosaminas (causa del cáncer) y la disminución de la capacidad de transporte de oxígeno por la sangre, conocida como síndrome del bebe azul. El objetivo del presente estudio fue determinar la relación entre la concentración de nitratos y nitritos disueltos en el agua de consumo humano, y la incidencia de cáncer de esófago y estómago en la población aledaña a las zonas cañeras del Módulo de Riego I-1 La Antigua, Ver. La investigación se realizó en un área aproximada de 1,000 ha. Se empleó la técnica de encuesta y se elaboró un cuestionario que fue aplicado a una muestra de 130 productores rurales. Se identificaron las fuentes de abastecimiento de agua para consumo humano y se realizó un muestreo de agua por época (estiaje, lluvias y nortes), de marzo a septiembre de 2009. En éstas, se determinó, de acuerdo a las normas oficiales mexicanas, la concentración de nitratos y nitritos disueltos. Las concentraciones máximas de nitratos en aguas superficiales, subterráneas y envasadas fueron de 2.9, 7.7, 7.5 mgL-1, respectivamente. Se identificaron 45 casos de cáncer de estómago y esófago, distribuidos en los municipios de La Antigua, Manlio Fabio Altamirano, Paso de Ovejas, Puente Nacional y Úrsulo Galván. Se encontró una correlación de r = 0.46 (p<0.05) entre el factor de Uso Racional de Nitrógeno (URN) en el cultivo y el número de casos de cáncer registrados en la zona de estudio. _______________ WATER CONTAMINATION BY NITRATES AND NITRITES AND ITS IMPACT ON PUBLIC HEALTH IN AREAS INFLUENCED BY THE MODULO DE RIEGO (I-1) LA ANTIGUA, VER. ABSTRACT: The water pollution has emerged as a consequence of human settlements and the rural, agricultural, forestry and industrial activities of any region. It has been found that increasing use of nitrogen fertilizer also produces a greater impact in water quality. Nitrates and nitrites that are dissolved in groundwater used for human consumption, cause adverse health effects, such as the production of nitrosamines (cancer), and a decrease of the oxygen carrying capacity of the blood, known as the blue baby syndrome. The aim of this study was to determine the relationship between the concentration of dissolved nitrates and nitrites in drinking water, and the cases of cancer in the population living in areas influenced by the “Modulo de Riego (I-1)”. This research was carried out in an area of 1,000 ha. A survey was applied to a sample of 130 farmers. Sources of drinking water supply were identified and sampled once in each of the following seasons: dry, rainy and windy, from March to September 2009. Nitrates and nitrites concentration were determined from these water samples, according to Mexican Official standards. The maximum concentrations of nitrate in surface, ground and bottled water were 2.9, 7.7 and 7.5 mgL-1 respectively. A number of 45 cases of stomach and esophagus cancer were identified, which were distributed in the municipalities of La Antigua, Manlio Fabio Altamirano, Paso de Ovejas, Ursulo Galvan and Puente Nacional. A correlation of r = 0.46 (p <0.05) was found between the Rational Use factor of Nitrogen (RUN) in sugar cane and the number of cancer cases recorded for studied area.Tesis (Doctorado en Ciencias, especialista en Agroecosistemas Tropicales).- Colegio de Postgraduados, 2010.Consejo Nacional de Ciencia y Tecnología (CONACYT)

Determining water quality of the lower basin of the Usumacinta River in Tabasco, Mexico: Determinación de la calidad del agua de la cuenca baja del Río Usumacinta en Tabasco, México

Objective: The objective of this study was to determine the water quality of the lower basin of the Usumacinta River, based on its physicochemical and microbiological characteristics. Design/methodology/approach: There were taken 11 monthly samplings of surface water during the rainy season, from June to December, 2017 and in the dry season, from April to May, 2018, in three different sites. The parameters of temperature, pH, Electrical Conductivity (EC), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), total phosphorus (TP) and Nitrogen nitrate (N-nitrate) were evaluated. Significant statistical differences (p≤0.05) between seasons and between sites were determined. Results: The results obtained were compared with Mexican regulations and Ecological Criteria for water quality. The parameters such as EC, TDS, TSS and total phosphorus showed substantial differences among seasons. The temperature, pH, EC and N-nitrate, did not exceed the maximum permissible limits for the use of irrigation water, urban public use and protection of aquatic life. However, the presence of E. coli and total coliforms from 530 to&gt; 24 196 MPN/100 ml was recorded throughout the study period. Findings/conclusions: Parameters under study did not show significant differences between sites. The rainy season had an important effect on the increase in concentrations of TSS, TP, N-nitrate and total coliforms. Also, that maximum concentrations were recorded during the study period in the sampling sites of Boca del Cerro (R1) and Puente Chablé (R2).Objective: To determine the water quality of the lower basin of the Usumacinta River (Tabasco, Mexico), based on its physicochemical and microbiological characteristics. Design/methodology/approach: There were taken 11 monthly samplings of surface water during the rainy season, from June to December, 2017 and in the dry season, from April to May, 2018, in three different sites. The parameters of temperature, Hydrogen potential (pH), Electrical Conductivity (EC), Total Dissolved Solids (TDS), Total Suspended Solids (TSS), total phosphorus (TP) and Nitrogen nitrate (N-nitrate) were evaluated. Significant statistical differences (p ≤ 0.05) between seasons and among sites were determined. Results: The results obtained were compared with Mexican regulations and Ecological Criteria for water quality. The parameters such as EC, TDS, TSS and TP showed substantial differences among seasons. Values for temperature, pH, EC and N-nitrate, did not exceed the maximum permissible limits for the use of irrigation water, urban public use and protection of aquatic life. However, the presence of E. coli and total coliforms from 530 to &gt; 24,196 MPN 100 mL-1 were recorded throughout the study period. Findings/conclusions: Parameters under study did not show significant differences among sites. The rainy season had an important effect on the increase in concentrations of TSS, TP, N-nitrate and total coliforms. Also, maximum concentrations were recorded during the study period in the sampling sites of Boca del Cerro (R1) and Puente Chablé (R2)

Heavy Metals in Oysters, Shrimps and Crabs from Lagoon Systems in the Southern Gulf of México

Abstract Lagoon systems in the southern Gulf of Mexico are highly productive. These aquatic systems have been severely negatively impacted by anthropogenic and industrial activities. The objective of this research was to estimate the concentration of heavy metals Pb, Cu, Cd and Zn in oysters, shrimp and crabs from the Carmen-Pajonal-Machona and Mecoacán lagoon systems in Tabasco, México. Samples were collected from fishing zones within these lagoon systems and included oysters Crassostrea virginica, and crustaceans such as Litopenaeus setiferus (shrimp) and Callinectes sapidus (crab). Concentrations of Pb, Cu, Cd and Zn were determined by atomic absorption using flame spectrophotometry. The heavy metal concentration pattern in oysters, shrimp and crab in the Carmen-Pajonal-Machona system was Cu &gt; Pb &gt; Cd. The maximum average concentration of Cu was 259.12 ± 12.312 in oyster; 0.516 ± 0.154 in shrimp, and in crab 0.907 ± 0.273 µg g -1 . Pb had a maximum concentration of 1.37 ± 0.77 in oyster, in shrimp was 0.059 ± 0.044, and for crab was 0.0055 µg g -1 (p&gt;0.05), while in the Mecoacán lagoon system the pattern showed Pb &gt; Cd &gt; Zn. The maximum average concentration of Pb was 321.15 ± 28.828 µg g -1 , the minimum was 84.70 ± 8.612 µg g -1 . The highest concentration of Cd was 63.74 ± 8.446 µg g -1 , and the minimum 13.00 ± 0.64 µg g -1 . For Zn the maximum average concentration obtained was 24.42 ± 2.665 µg g -1

Implications of Extracellular Polymeric Substance Matrices of Microbial Habitats Associated with Coastal Aquaculture Systems

Coastal zones support fisheries that provide food for humans and feed for animals. The decline of fisheries worldwide has fostered the development of aquaculture. Recent research has shown that extracellular polymeric substances (EPS) synthesized by microorganisms contribute to sustainable aquaculture production, providing feed to the cultured species, removing waste and contributing to the hygiene of closed systems. As ubiquitous components of coastal microbial habitats at the air–seawater and seawater–sediment interfaces as well as of biofilms and microbial aggregates, EPS mediate deleterious processes that affect the performance and productivity of aquaculture facilities, including biofouling of marine cages, bioaccumulation and transport of pollutants. These biomolecules may also contribute to the persistence of harmful algal blooms (HABs) and their impact on cultured species. EPS may also exert a positive influence on aquaculture activity by enhancing the settling of aquaculturally valuable larvae and treating wastes in bioflocculation processes. EPS display properties that may have biotechnological applications in the aquaculture industry as antiviral agents and immunostimulants and as a novel source of antifouling bioproducts

Influence of density on growth and survival of freshwater prawn Macrobrachium americanum (Bate, 1868) (Caridea: Palaemonidae) cultured in a cage-pond system

The domestication and culture of freshwater shrimp native of tropical and subtropical American Pacific zone requires the study and development of technologies in open systems where their response to types of farming, feeding and management strategies generate practical information for the production of this species. The aim of this study was to evaluate the effect of stocking density on growth and survival in M. americanum juvenile-adult, cage-cultured and to determine the optimal density for grow-out production. The caridean shrimp Macrobrachium americanum was cultured for 152 days in a 16 cage-culture (3 m3 each) at densities of 1, 3, 6 and 9 org / m3, respectively, with stocking sizes from 12.1 ± 1.7 to 13.5 ± 2.3 g. The prawns were fed twice daily with Camaronina 35%. Water quality parameters were within standard range for caridean shrimp culture. There was a significant effect of density on final weight, growth rate, specific growth rate, K condition and survival, and an inversely proportional relationship with the feed conversion ratio. The growth was affected by density, resulting to a maximum increase of 6 org / m3 in the asymmetry of the prawn and also increasing the number of small organisms by 9 org / m3. However, it is necessary to study such aspects as the rate and frequency of feeding, the initial size-grade and the implementation of shelter, among others