Spatiotemporal shifts and influence of environmental parameters on estuarine-dependent fishes in Texas bays

Abstract

Spatiotemporal shifts are occurring for estuarine-dependent species in Texas bays. To better understand what factors are causing these shifts, a random forest classification analysis was applied to the presence-absence data for seven estuarine-dependent species collected over 38 years. Five of the species showed an increase in presence and expanded their distributions northward, while the remaining two species declined in numbers and retracted their distributions to northern bays. The dominant factor influencing the presence of these species was year, followed by distance to major bay inlet and distance to major river mouth. While these factors may not be directly related to climate change, environmental fluctuations can impact year class success and alter the parameters of inlets and river flow. Studies examining multiple environmental and spatial conditions are needed to better understand the complexity of the changes in species composition that are occurring.