Response of Zooplankton to Climate Variability: Droughts Create a Perfect Storm for Cladocerans in Shallow Eutrophic Lakes

Abstract

Abstract:A major attribute of the Earth's climate that may be affected by global warming is the amplitude of variability in teleconnections. These global-scale processes involve links between oceanic conditions in one locale and weather in another, often distant, locale. An example is the El Niño Southern Oscillation (ENSO), which can affect rainfall and then the properties of lakes in Europe, Africa, North and South America. It affects rainfall, droughts and the depth of lakes in Florida, USA. It is predicted that the amplitude of variation in the ENSO will increase with global warming and, therefore, droughts will become more severe and periods of rain more intense. We investigated possible effects of climate on the zooplankton in shallow subtropical lakes by studying 16 years of monthly data from six shallow eutrophic lakes located north of Orlando, Florida. Results indicate that water depth and lake volume are tightly coupled with rainfall, as expected. During droughts, when lake depth and volume were greatly reduced, there were intensified cyanobacterial blooms, and the zooplankton shifted towards greater relative biomass of copepods compared to cladocerans. The change of zooplankton was likely due to the intensified selective fish predation in the reduced water volume, and/or selective adverse effects of cyanobacteria on cladocerans. The greatly reduced volume might lead to a 'perfect storm' of top-down and bottom-up factors that favor copepods over cladocerans. The mechanism needs further study. Regardless, this study documents a direct link between climate variability and zooplankton composition, and suggests how future changes in climate might affect plankton communities.

Ecological Responses of Lakes to Climate Change

“…In this special issue, Ji et al [25] examine how a regular cycle of high and low water levels, linked to the condition of the ENSO, affects water quality and zooplankton in shallow lakes of central Florida, USA. Water depth, chemistry, phytoplankton, and zooplankton were examined from a 15-year dataset with monthly samples from 6 shallow (mean depth 1.4 to 3.4 m) eutrophic (Chl-a 35 to 65 µg L −1 annual mean) polymictic lakes.…”

Crecimiento poblacional de Macrothrix spinosa alimentada con Chlorella sp.

“…Otro aspecto relevante en el manejo de los cladóceros es la calidad del agua en cultivo. El adecuado desarrollo y éxito en el cultivo está condicionado por factores ambientales que influyen en el crecimiento, la reproducción y la sobrevivencia; particularmente, la calidad y la disponibilidad del agua y del alimento en el medio de cultivo (Pérez et al, 2015;Tian et al, 2017;Ji et al, 2017). En cladóceros, se ha comprobado un efecto de la temperatura sobre el tiempo de desarrollo embrionario y post-embrionario, la fecundidad, la edad de la primípara, el tamaño corporal y la longevidad (Ismail et al, 2011;Huang et al, 2011;Viti et al, 2013).…”