Environmental parameters that shape zooplankton diversity in coastal wetlands of the Valencian Community, Spain

Abstract

Along the Valencian coastline, numerous coastal wetlands persist as remnants of extensive alluvial plains that once dominated the region. Historically, many of these wetlands were drained due to human activity, accelerated by urban development along the Mediterranean coast. Despite this, several larger or strategically located wetlands have endured and are now under protection. These ecosystems encompass diverse aquatic habitats including marshes, fens, springs, canals, and lagoons that support a rich variety of organisms, notably zooplankton, which are essential to aquatic food webs.

This research aims to study the diversity (alpha, beta and gamma) of zooplankton and to  assess how environmental variables influence their composition and diversity. Seasonal samples of zooplankton and water were collected from multiple sites within six selected wetlands:  Prat de Cabanes-Torreblanca, Marjal dels Moros, Albufera de Valencia, Marjal Pego-Oliva, Salinas de Santa Pola, and Hondo de Elche. Zooplankton species were identified and quantified, different diversity metrics were estimated (Richness, Shannon and inverse Simpson indeces, local contribution to beta diversity and chao index) while also physicochemical parameters, nutrient levels, and pigment concentrations were measured. Multiple linear regressions evaluated the influence of environmental variables on diversity metrics.

Findings indicate that key factors influencing zooplankton community structure and diversity include water conductivity, phosphate concentrations, chlorophyll a concentration, seasonal changes and kind of environment. Freshwater wetlands presented a higher alpha and gamma diversity. Albufera de Valencia sites showed significantly higher contribution to beta diversity than other sampling sites during all seasons, reflecting consistently unique communities.