Evaluating Degradation and Temporal Effectiveness of Juniperus Ashei Used As Fish Habitat in a Texas Hill Country Reservoir

Ashe juniper (Juniperus ashei) tree brush piles, used as fish habitat, were evaluated in Canyon Lake, Texas to determine their longevity and temporal effectiveness to attract fish. Texas Parks and Wildlife Department and partners replenish these fish habitat structures in order to maintain their ability to hold fish and improve angler catch rates. Understanding their longevity and effectiveness over time, will help managers coordinate labor-intensive refurbishing events efficiently. Fifteen sites were examined by a team of SCUBA divers in 2014 and 2015. The complexity of fish attractors degraded over time (P ≤ 0.05), characterized by the loss of small branches, increased interstitial spaces, and decrease of periphyton coverage. Attractor effectiveness, characterized by associated fish counts, was correlated to degradation. A negative trend between the number of fish recorded and the age of the brush pile revealed lower numbers of game fish (>50% decrease) observed in structures 3 and 4 years of age, while total fish counts decreased to nearly zero at 4 years. These data suggest that Ashe juniper tree fish attractors in Canyon Lake be replenished by every fourth year to maintain their effectiveness in holding fish and potentially improve angler catch rates.