Gafftopsail Catfish in Texas estuaries: Population trends and ecosystem implications

Abstract

ObjectiveGiven the limited information on population dynamics of Gafftopsail Catfish Bagre marinus in the western Gulf of Mexico, the objectives of this study were to determine the status of this species in Texas estuaries by assessing trends in relative abundance, length, and habitat preferences from fishery‐independent trawl (juvenile) and gill net (adult) data as well as angler harvest trends from fishery dependent creel surveys collected in all Texas estuaries.MethodsFishery independent and dependent monitoring data were collected by Texas Parks and Wildlife Department in all major bay systems of the Texas coast from 1983‐2022. Linear trend analysis was used to assess trends across the full timeseries and all major bay systems for both juvenile and adult specimens and for total recreational harvest. Boosted regression tree analysis was used to assess habitat preference for both juveniles and adults.ResultBoth juvenile and adult catch rates consistently increased in most Texas estuaries, with the most extreme increases occurring in central Texas coast estuaries beginning in the early 2000's. During the same timeframe, mean lengths of adult specimens significantly decreased in many of the same estuaries. Habitat suitability analysis suggested that Gafftopsail Catfish were primarily influenced by salinity, though they still exist across a very broad range of salinity conditions. Angler catch rates showed some localized patterns of increasing or decreasing trends, though they generally did not follow fishery independent trends for most estuaries.ConclusionThese trends interpreted in the context of the known trophic role of Gafftopsail Catfish imply the potential for larger ecosystem‐level effects on both prey organisms and competitors. A more thorough awareness of these trends and potential interactions should help fisheries managers operate in an ecosystem‐based context when investigating population dynamics and recommending management strategies.