Habitat Modeling of Invasive Blue Catfish in the Patuxent River, Chesapeake Bay

Dunn, Daniel

McCabe, Patrick

2019-04-25T20:02:28Z

2019-04-25T20:02:28Z

2019-04-25

Nicholas School of the Environment and Earth Sciences

Invasive blue catfish (Ictalurus furcatus) populations have expanded to many tributaries of the Chesapeake Bay, negatively impacting native species through predation and competition. To mitigate this problem, the state of Maryland has recently launched programs to aid the growth of the commercial fishery targeting the species to reduce the negative ecological impact of blue catfish while also benefitting the local economy. However, little is known about habitat use and movement of invasive blue catfish within these tributaries. This study presents a predictive model of blue catfish habitat use within the Patuxent river utilizing acoustic telemetry and a binary Boosted Regression Tree (BRT) modelling approach to identify seasonal habitat and movement as well as abiotic environmental covariates that may influence its distribution. Salinity had the largest relative influence on the BRT models, followed by depth and water temperature. Acoustic telemetry and model results reveal that primary blue catfish habitat is in the freshwater upper reaches of the Patuxent during the winter and late summer, with some individuals observed year-round. Downstream shifts in presence probability occurred in spring/early summer and fall, possibly associated with spawning and feeding respectively. Model results predict that blue catfish are most often present, and thus likely have the greatest ecological impacts, in tidal freshwater areas of the Patuxent and management should concentrate fishing effort in this area.

https://hdl.handle.net/10161/18416

en_US

Habitat Modeling of Invasive Blue Catfish in the Patuxent River, Chesapeake Bay

Master's project

0