Amazonian Aquatic Food Webs, Their Variation, and Vulnerability in Regard to Climate and Land-Use Changes

The Amazon rainforest’s aquatic food webs are facing unprecedented challenges due to climate and land-use change. A diverse array of organisms is supported by these intricate and interconnected ecosystems, but the increasing threat of droughts and deforestation is disrupting the delicate balance of life. The Amazon food webs derive their energy from two primary sources: an autochthonous source, dependent on the productivity of the aquatic ecosystem (such as phytoplankton and aquatic macrophytes), and an allochthonous source, mainly from seasonally flooded forests (comprising fallen fruits and seeds that enter the water). The Amazonian food webs are currently influenced by various factors, including climate change and flooding patterns. These factors impact the structure, function, and energy sources of the food webs, affecting the abundance and distribution of organisms such as phytoplankton, bacteria, macrophytes, and invertebrates. The flood pulses have a pivotal role in shaping these food webs, affecting nutrient availability and impacting the abundance and biomass of fish. The interactions between the terrestrial and aquatic components are vital for the operation of Amazonian food webs, where floodplains serve significant functions as both nursery and feeding areas for numerous fish species. The disruption of food chains in the Amazon as a result of climate and land-use change is exemplified by the drying of aquatic habitats and changes in the fish community of floodplain lakes. This event generates a new scenario that has significant consequences for the ecological balance and productivity of the region, highlighting the urgent need for conservation and protection efforts.