by Ron Loehman
Last Saturday, May 11, I assisted Dave Menicucci with an eyeball survey of the fish population in the fourteen-mile stretch of Rio San Antonio in the Valles Caldera. Dave has gotten approval for a study to determine if trout can be relocated to even out the apparent patchy distribution of fish in the San Antonio in the aftermath of the Las Conchas fire. See article below for a fuller description.
We each walked upstream along a seven-mile stretch with a GPS and recorded the fish we saw in each quarter-mile section. I had the lower half, Reaches 4 and 3, and Dave had Reaches 2 and 1. The water was off color with visibility of 8 to 12 inches, a water temperature between 52° and 54°F and a pH of 8.6 in the part I walked. The survey technique certainly undercounted the fish population, but the results say something about relative fish numbers that should be of interest to anyone considering fishing the San Antonio when the Valles Caldera season opens this week.
The fish population in the lower two reaches (4 and 3) was very low, with less than four fish spooked in most quarter mile sections. I saw fewer than ten fish bigger than 6″ in the whole seven-mile stretch. Much of the stream bottom is mud or fine silt, with rare stretches of gravel, implying relatively poor habitat for trout. These results are consistent with fish numbers found in the Valles Caldera part of the San Antonio using more rigorous shocking surveys since the Las Conchas fire.
By contrast, Dave found that the trout numbers increased substantially as he moved up through Reaches 2 and 1, with the numbers peaking in the 40 fish range about the midpoint of Reach 1. He reported seeing significant numbers of fish of 8″ or larger.
Based on Saturday’s results, I’d suggest Reaches 1 and 2 to anyone fishing the San Antonio in the Valles Caldera. The situation may change as the season progresses, but for now, the upper part of the San Antonio seems to have a lot more fish.