Seasonal and Spatial Patterns in Salinity, Nutrients, and Chlorophyll α in the Alvarado Lagoonal System, Veracruz, Mexico

Abstract

Ten monthly collections, distributed among three seasons, were taken from July 2000 to June 2001 in the Alvarado lagoonal system, Veracruz, Mexico. Variables measured in situ included dissolved oxygen, salinity, and water temperature. Water samples were collected to determine concentrations of ammonium, nitrates, nitrites, orthophosphates, total phosphorus and chlorophyll a. Collections representing the rainy season were taken in September and October, those for the nortes season were taken in November, December, and January, and dry season collections were taken during February, March, May June, and July. There was seasonal and spatial variation in nutrient concentrations, and they were related to the discharge of the rivers; concentrations increased during the rainy and nortes seasons. Other factors affecting water quality included the constant discharge of organic materials into the system, resuspension of sediments during the nortes season and the biological activity within the system that assimilated the nutrients in the water. The Alvarado lagoonal system has three separate zones based on physicochemical characteristics; Camaronera Lagoon, Buen Pais Lagoon and the urban zone of Alvarado Lagoon, and the river zone in Alvarado Lagoon. RESUMEN Se realizaron diez muestreos durante el periodo comprendido entre Julio de 2000 a Junio de 2001, distribuidos a lo largo de tres estaciones climáticas, en el sistema lagunar de Alvarado, Veracruz, México. Los parámetros que fueron registrados in situ incluyendo oxígeno disuelto, salinidad y temperatura de agua. Al mismo tiempo se colectaron muestras de agua para determinar en laboratorio las concentraciones de amonio, nitratos, nitritos, ortofosfatos, fósforo total y clorofila a. Los meses de colecta que abarcaron las temporada de lluvias fueron tomadas en Julio, Septiembre y Octubre, para Nortes Noviembre, Diciembre, y Enero, y por último, la temporada de secas que correspondieron los muestreos de Febrero, Marzo, Mayo, y Junio. Los nutrientes presentan una variación espaciotemporal presentando relación con: la descarga de los ríos, incrementándose su concentración durante la temporada de lluvias y Nortes; las constantes descargas de agua provenientes de diversas actividades humanas, como son la agricultura y los asentamientos humanos; la resuspensión de los sedimentos durante la temporada de Nortes; y la gran actividad biológica de estaos sistemas que permiten la rápida transformación de la materia orgánica en nutrientes. El sistema lagunar de Alvarado presenta tres zonas diferentes basadas en sus características fisicoquímicas:

Physicochemical Changes of the Water of Alvarado Lagoon, Veracruz, Mexico in Interrupted Periods in Middle Century

“…In this sense the distribution of pigments (chlorophyll "a") should be a first approximation of reality. In the case of chlorophyll "a" in the Alvarado lagoon, Morán-Silva et al [14] , being an example of an extreme case of cultural eutrophication, but 25 years later (2015) determined contents of 43 mg/m 3 decrease that may be the result of phytoplankton patches as mentioned by previous authors. Which corroborates that both "a" chlorophyll and phytoplankton determinations are approximations to reality that can be partially solved by an adequate network of sampling stations and their monitoring.…”

“…but lower in September (1.5 mg/L) were observed in 1987-86 or less than 40% sat) to more of 14 mg /L (116% sat). Contreras Espinosa and Warner [13] reported between 1996-1997 contents of 3 to 11 mg /L with an average saturation of 105%; Morán-Silva et al [14] determined in 2000-01 broad contents of this gas that ranged from 18.3 mg /L to 5.9 mg /L depending on the hour and locality. The wide intervals were the result of this gas considered to be non-conservative, which depends on the hour of the day, the distribution in phytoplankton patches as indicated by Lara-Lara & Alvarez Borrego [20] and consequently the site concentrations of oxygen where determined.…”

“…Although for March and May the contents oscillated between the undetectable up to 5 μM of NO 2 and 43 μM of NO 3 in the case of ammonium fluctuated of 15 to 25 μM which are also considered high. Morán-Silva et al [14] recorded between in 2000-01 high ammonium contents between 42.43 μM and 2.0 μM depending on the epoch and the sampling location; the variation of nitrite was also from 3.54μM to undetectable; in the case of nitrates from 0.67 to 7.9-10.6 μM; the total phosphorus varied from 3.5 μM to 18.8 μM and orthophosphates of 0.37-0.48 to 4.5-6.2 μM.…”

“…The water samples were thawed in the laboratory and the corresponding determinations were made, according to the techniques mentioned in [11], Arriaga Cabrera et al [12], Contreras Espinosa and Warner [13]. Morán Silva et al [14], Calva Benítez and Torres Alvarado [15], Herrera Silveira et al [16], Ruiz Fernandez et al [17]. It should be noted that the oxygen results of the different sources of information were reported in mg / L and others in ml / L that were homogenized based on mg / L = 1.43 x Interrupted Periods in Middle Century 3/6…”

Análisis de la comunidad de peces de descarte en la pesca de arrastre de camarón (temporada de lluvias 2013) en la zona centro-sur del litoral veracruzano, México

“…El comportamiento climático de esta zona permite definir tres temporadas: nortes (octubre a febrero), secas (marzo a mayo) y lluvias (junio a septiembre) (Morán et al 2005).…”