Acidification effects on larval striped bass, Morone saxatilis in Chesapeake Bay tributaries: A review

Abstract

Reduced striped bass populations along the East Coast of the United States have prompted numerous studies to assess various factors contributing to the decline. Available data from in-situ, on-site and laboratory studies with striped bass in conjunction with water quality and contaminants data confirm that the eastern shore rivers of the Chesapeake Bay (Choptank, Nanticoke, and Pocomoke Rivers) are susceptible to acidic conditions. The Choptank and Nanticoke Rivers are significant striped bass spawning areas. Acidification conditions (low pH, Al, low hardness) were documented in these systems in 1984 at levels reported to cause high mortality to striped bass larvae. Striped bass populations in several western shore tributaries such as the Mattaponi, Pamunkey, Patuxent, and Rappahannock Rivers also appear to be vulnerable to acidic pH conditions. In-situ toxicity studies documenting actual striped bass larval mortality are lacking in these systems; however, based on laboratory data it appears that potentially toxic acidic conditions can exist. Although certain Chesapeake Bay spawning tributaries do exhibit acidic conditions during spawning periods, other systems are resistant to acidification. The Chesapeake and Delaware Canal (C & D Canal), Elk River and Susquehanna River of the Upper Chesapeake Bay and the Potomac River on the western shore appear to be resistant to reductions in pH. The upper Chesapeake Bay and Potomac River are major striped bass spawning areas. Therefore, reduced striped bass production in these systems may be related to factors other than acidification.