Physical Characterisation and Microphytobenthos Biomass of Estuarine and Lagoon Environments of the Southwest Coast of Portugal

• Published in: Limnetica Vol. 21; no. 1; pp. 69 - 79
• Main Author: Fidalgo e Costa, P.
• Format: Journal Article
• Language: English
• Published: 2002
• Subjects: Brackish; ANE, Portugal
• ISSN: 0213-8409
• DOI: 10.23818/limn.21.07

Three lagoon-estuarine systems of the Southwest coast of Portugal were compared, on the basis of their physical characteristics and microphytobenthos. During a 14-month period (April 1993 to May 1994), monthly samples of sediment were collected intertidally at low tide, in order to characterize the sediment. Organic matter content, granulometry, chlorophyll a and phaeopigment concentration were estimated. Temperature, salinity, dissolved oxygen and pH of the bottom layer of water were also measured in situ. Principal Component Analysis (PCA) was used to define and explain relationships between location and the measured variables. Sediment dynamics, driven by tidal currents and runoff during wet periods, apparently control the behaviour of abiotic parameters in these systems.Original Abstract: El objetivo de este estudio es la comparacion de tres sistemas de lagunas estuaricas de la costa suroeste de Portugal en base a sus caracteristicas fisicas y a la biomasa del microfitobentos. Se han tomado muestras mensuales de sedimento en el intermareal durante la marea baja, a lo largo de un periode de 14 meses (de abril de 1993 a mayo de 1994), para caracterizar el sedimento (contenido en materia organica, granulometria, clorofila a y feopigmentos). Tambien se han medido in situ los parametros de la capa de agua adyacente o "bottom layer" (temperatura, salinidad, oxigeno disuelto y pH). Para estudiar la relacion entre los lugares de muestreo y la distribution de los parametros se ha utilizado el Analisis de Componentes Principales (PCA). La dinamica del sedimento, causada por las corrientes de marea y por los aportes durante el periode de lluvias, parece ser el factor mas influyente en el comportamiento de los parametros abioticos y tambien para la distribucion de microfitobentos en estos sistemas.