Assessing fish and angler utilization of instream habitat enhancement structures in restored stream reaches

The placement of instream habitat structures for fisheries enhancement is a commonly implemented stream restoration technique, typically evaluated by assessing either associated changes in habitat structure (e.g., pool formation) or using point-in-time observations of fish utilization (e.g., holding patterns). We hypothesize that: 1) artificial instream habitat structures do serve as preferred fish holding locations, but 2) these structures are also easily identified and targeted by anglers. To test our hypotheses, we will survey and observe reference, degraded, and restored stream reaches in southwest Montana to assess spatial patterns of: 1) habitat structure; 2) fish holding locations; and 3) fishing pressure (e.g., casting) and success (e.g., fish landed from various locations). An increase in spatial correlation among habitat structures, fish holding locations, and angling patterns in restored stream reaches will provide initial evidence that artificial habitat structures obvious to anglers might act as fish population sinks by focusing fishing pressure over fish holding areas. Results from this research will elucidate relationships between instream structures, fish utilization, and angler behavior, and underpin a more holistic framework for assessing the role of fisheries enhancement structures in the context of the larger stream network.