This research is corollary to the CWD studies described in Problem 1 and is the experimental component of RWU-sponsored CWD research.

Liming to counteract the effects of acid precipitation is becoming more widely used. We need to understand how fish and macroinvertebrates react to the short- and long-term influence of limestone added in various forms (rock, gravel, powder, etc.) to acid sensitive streams. These studies will assess changes in reproductive success, population age and size structure, survival, and growth in trout populations and changes in the structure and composition of macroinvertebrate communities.

Research by this RWU and others over the last several years has documented the decline of brook trout and near extirpation of blacknose dace because of acidification. Macroinvertebrate communities also have been dramatically altered over the same time. The George Washington National Forest has proposed to lime the headwater portions of the stream to restore water quality and possibly reverse the population trends. In cooperation with the National Forest and the Virginia Department of Game and Inland Fisheries, this study will continue the previous research to evaluate response by trout and macroinvertebrates to the liming.

Efforts to reestablish brook trout populations are more likely to succeed if the donor stock is genetically similar to indigenous stocks. This research will examine the genetic characteristics of potential donor stocks of brook trout from selected watersheds.

For a variety of reasons, including: elimination of recolonization corridors; potential competition with other species; and recurrence of episodic events such as acid rain and floods, brook trout have been extirpated from many streams that could support them. This research will lead to development of techniques to rapidly identify probable limiting factors, strategies for establishing fish populations, and methods for monitoring viability of transplanted fish.

During the planning phase for the Wine Spring Creek Ecosystem Management project, restoration of native southern brook trout populations and experimental removal of rhododendron from the streambanks were identified as desired future conditions. If these activities are scheduled to occur in the next five years, this RWU will lead the experimental efforts for brook trout reintroduction, including identification of a suitable source population (with cooperators from Virginia Tech), construction of a suitable barrier to immigration (with cooperation of the Wayah Ranger District), removal of non-native salmonids (with multiple cooperators), and reintroduction of brook trout. This RWU also will evaluate trout responses to rhododendron removal.