Temporal variation of phytoplankton in two neighbouring Mediterranean shallow lakes in Doñana National Park (Spain)

A study on two neighboring Mediterranean shallow lakes, Santa Olalla and Dulce, within Doñana National Park, Spain, reveals distinct phytoplankton dynamics despite their proximity. Both lakes exhibit low Shannon diversity indices (1.11 for Santa Olalla and 1.79 for Dulce) and high phytoplankton chlorophyll a concentrations (365.2 mg/m³ in Santa Olalla vs. 230 mg/m³ in Dulce), with primary production rates also higher in Santa Olalla (1.29 g C m⁻³ h⁻¹ vs. 0.88 g C m⁻³ h⁻¹). The research identifies eight functional groups in Santa Olalla, dominated by H₁, K, and S₁ groups after the initial four months, while Dulce shows a more complex distribution with ten groups over time. Canonical correspondence analysis confirms that shifts in phytoplankton composition are linked to changes in physical-chemical features and hydrological conditions, which vary between the two systems. These findings highlight the resilience of phytoplankton communities under stressful conditions such as rapid water volume fluctuations, low light penetration, and low nutrient concentrations, contributing to our understanding of eutrophic wetland ecosystems.

López-Archilla, Ana Isabel, Coleto, Mª Carmen, Montes, Carlos, Peñín, Ignacio, & Guerrero, Mª Carmen. (2012). Temporal variation of phytoplankton in two neighbouring Mediterranean shallow lakes in Doñana National Park (Spain). Limnetica, (31), 289–304. https://doi.org/10.23818/limn.31.25