Fish population responses to hydrological variation in a seasonal wetland in southeast México

Abstract

Hydrological variation differently affects fish species. In the present study, the response of local populations of 13 fish local species to hydrological variation in a tropical wetland was evaluated. The objectives were to analyze the abundance response of fish species with distinct life history strategies and to assess the role of hydrological variation on fish population patterns. We found that opportunistic strategists were favored by high hydrological variation in drought periods, the equilibrium strategists were related to stable habitats, and periodic strategists were regulated by floods and temperature. However, the life history strategies identified for some species in this study do not correspond to the classification reported in other studies. Our results highlight the importance to study the abundance responses of species at local and regional scales to identify variations in life-history strategies, which can reflect local adaptations of species to hydrological changes, this is useful in order to understand and predict the responses of fish populations to the local environment.Key words: Dry season, Fish resilience, Life history strategies, Rainy season, Sian Ka´an.La variación hidrológica afecta de manera diferencial a las especies de peces. En el presente estudio, se evaluó la respuesta de las poblaciones locales de 13 especies de peces considerando la variación hídrica en un humedal tropical. Los objetivos fueron analizar la respuesta de las abundancias de las especies de peces con diferentes estrategias de historia de vida e identificar la importancia de la variación hídrica en los patrones de las poblaciones de peces. Se encontró que los estrategas oportunistas fueron favorecidos por la alta variación hídrica en los periodos de sequía, los estrategas de equilibrio se relacionaron con hábitats estables, y que los estrategas periódicos son regulados por las inundaciones y la temperatura. Sin embargo, para algunas especies las estrategias de historias de vida identificadas en este estudio no corresponden a la clasificación reportada en otros estudios. Nuestros resultados resaltan la importancia de estudiar las respuestas de la abundancia de las especies a escalas locales y regionales para identificar las variaciones en las estrategias de historia de vida, las cuales pueden reflejar adaptaciones locales de las especies a cambios hídricos, esto es útil para entender y predecir las repuestas de las poblaciones de peces a los ambientes locales.Palabras clave: Capacidad de recuperación, Estación seca, Estrategias de historia de vida, Sian Ka´an, Temporada de lluvias.

The Impact of Hydrological Changes on Fish Assemblages in the Zachery Marshes of Southern Iraq

“…The present study found that the results in the fish assemblage composition were in line with the proposals of these studies, through the changes between flood and drought. In wetlands that are exposed to seasonal changes between drought and flooding, there are three strategies for fish reproductive in these wetlands (seasonal strategy, equilibrium, and opportunistic strategy), especially in the assemblage which occur in the temporary pools [1,19,20]. Fish in temporary pools must adapt to successfully survive a period of drought that is strict on evolution and life history.…”

“…In some years, there is a complete dryness of the temporary and permanent pools, so there is a complete extermination of the fish communities and the new fish offspring are small, but in other years, the permanent pools remain to replenish stocks. In the second case, the permanent pools that did not dry up are used as a stockpile to restore the communities of fish to their previous state, and the size spectrum of fish is relatively large [1,20,38]. The ecological indices are important to measure the biological communities, species abundance, monitor temporal and spatial effects of drowning and drought, decline of water depth, and pollution in freshwater environment, and their impacts on fish assemblage [39].…”

“…Occasional fish species catch from one to 5 months. Response to succession drought and flooding on size spectrum of fish assemblage in Zachery marsh the assemblage composition patterns, species life-history strategies are identified into three groups: equilibrium, periodic, and opportunistic according to [19,20]. The dominance index for the most abundant three fish species was…”

The influence of some ecological factors on fish diversity and abundance in Al-Huwyzah marsh / South of Iraq

“…The hydrological system is characterized as a source of creating and enhancing environmental fluctuations that influence species populations and communities, and it plays an essential role in the maintenance of ecological processes in both lentic and lotic ecosystems [20][21][22] . Temperature dramatically influences the hydrological regime by controlling rainfall and evaporation processes and lowering water levels; additionally, climate change has increased the drought of the current wetland due to an accelerating rise in temperature 23 .…”

“…The hydrological measurements included the flat areas, rivers inside the marsh, and low-lying areas as permanent pools. The average depths were labeled for three selected stations as Escalera-Vazquez 20 . Response to hydrological variations and population structure patterns, species life-history strategies are identified into three categories: periodic, equilibrium, and opportunistic, according to Handhal 20,21 .…”