The Impacts of Drought on Puerto Rican Streams

The University of Georgia’s own Dr. Catherine Pringle and Dr. Alan Covich have collaborated with other researchers on a study about what the effects of global climate change, specifically extreme weather events, can mean for tropical stream ecosystems in Puerto Rico.

Their research was recently published in the journal, Freshwater Science, and it was centered around the variety of impacts caused by an intense drought in the Caribbean islands in 2015. They used this drought to assess how the stream ecosystems within Puerto Rico’s Luquillo Experimental Forest (LEF) responded. Pringle, Covich, and their colleagues discovered a wide variety of reactions in the stream ecosystems when precipitation and stream discharge were reduced. They first noticed the creation of isolated pools and a reduction of flow between pre-existing pools. They also discovered higher nutrient levels within those pools, which in turn led to an increase in biofilm productivity and increases in organic matter deposits. Macroinvertebrate density and omnivorous shrimp abundance both increased in response to a reduction of stream flow as well. Varying changes were also noticed among higher collector-gatherer and grazing taxa. This research conducted by Pringle and Covich brings to light the widespread changes that can occur within stream ecosystems when extreme weather events, like drought, begin to increase in frequency. It also shows a need to examine entire ecosystems when studying streams in order to accurately understand how they will respond to global climate change in the future.

Link to Dr. Catherine Pringle and Dr. Alan Covich’s study: https://www.journals.uchicago.edu/doi/full/10.1086/708808

Written by Cammie Caldwell