Abstract
Seasonal abundances of two large fishes, common snook Centropomus undecimalis and largemouth bass Micropterus salmoides, were surveyed in the lower portion of the Peace River, Florida, 2004–2010. During and just prior to the study period, a number of environmental disturbances occurred: the passage of five hurricanes over the river's basin in 2004 and 2005, resulting in high river flows and one large-scale hypoxic event, and extreme cold temperatures in 2010. The two species responded differently to these events. In the year following hurricane-induced hypoxia (2004–2005), adult largemouth bass were absent from our collections. Common snook, however, were up to three times more abundant than during subsequent years (2007–2010); increased river flow, abundance of prey, and lack of interspecific competition may have contributed to the high abundance. A record cold winter in 2010 initially reduced the abundance of common snook in the lower river, but abundance quickly returned to pre-event levels. Largemouth bass abundance appeared unaffected by the extreme cold event. These results illustrate how disturbance events can temporarily affect the community structure of aquatic systems and create challenges for managers striving to track long-term trends in species populations.