Seasonal Patterns of Movement and Residency by Striped Bass within a Subestuary of the Chesapeake Bay

Although often generalized as anadromous, striped bass Morone saxatilis show varying degrees of residency in natal estuaries and exhibit diverse seasonal migration patterns in estuarine and coastal waters. Most coastal striped bass originate from the Chesapeake Bay, but the bay and its subestuaries also harbor substantial numbers of striped bass throughout the year. The degree to which resident striped bass inhabit individual subestuaries was evaluated by use of acoustic telemetry. We investigated seasonal patterns of movement within and outside of the Patuxent River, a centrally located, intermediate-size subestuary of the Chesapeake Bay. A fixed acoustic receiver array was deployed in the Patuxent River, and 42 acoustic-tagged striped bass were monitored for a 2-year period (2008-2009). Seasonal patterns of movement within the subestuary were similar between years and were generally consistent with overall anadromous behavior: striped bass moved downestuary during winter to points outside the Patuxent River, and they moved upestuary in spring, presumably for spawning, feeding, or both. However, a substantial fraction (similar to 40%) of individuals was present in the Patuxent River during summer months. Most of the tagged fish returned to the Patuxent River during fall. Striped bass were present in the Patuxent River for significant time periods (5-7 months), indicating that subestuaries like the Patuxent River are utilized by Chesapeake Bay striped bass during a major part of the year.