Electrofishing helps tally annual fish numbers in Lake Powell
GRAND CANYON, Ariz. — Every September we fire up the electrofishing equipment and sample young fish along the shoreline of Lake Powell.
We sample at night when the fish move into shallow water. The fish are stunned, measured, counted and returned to the lake. This survey helps us understand how the 2019 crop of fish compares to those sampled every year since 1975. We survey different sites to get an overview of fish abundance lakewide. Then we compare the results from each site with the same site from previous years. The most common fish species caught each year in shallow water are bluegill and green sunfish. They were in high abundance in each survey.
The 2019 sample is perhaps the most unusual since the survey began. Shad numbers are overwhelming. Young sport fish are in high abundance. Here is a brief summary of our fish collections.
Wahweap — Small threadfin shad were the most abundant fish captured. These small forage fish are ideal forage for all sport fish species. The more we have the better growth and abundance of sport fish. Shad schools are on display all over the lower lake but the prime spot is in the Castle Rock Cut. These small schools are feeding on the surface in the Cut and visible just about every time a boat passes through. Look for the small fish schools dimpling the surface while idling through the shortcut. Young smallmouth bass and largemouth bass, were ranked in larger numbers than in previous surveys.
Good Hope Bay — Gizzard shad were overwhelming in numbers. A normal catch is 25-50 fish per sampling run. In the back of the sampling canyon, 1000 gizzards were caught in 15 minutes. Sport fishing in the northern lake has been much slower than usual. It is obvious that the amount of forage has taken the drive out of striped bass population. When it is time to eat they just open their mouth and grab a shad from the giant wall of shad residing in the backs of canyons. We were able to catch a few stripers in 40-80 feet on jigging spoons. The catch was much less than normal. All sport fish species were shocked in great numbers. Largemouth bass and crappie are making a comeback due to the high water, which has covered the shoreline vegetation.
Rincon — Water clarity at the Rincon was over 10 feet compared to 3 feet at Good Hope, 8 feet at Wahweap and 6 feet at the San Juan. High clarity reduces the catch rate, but we stunned good numbers of bass, sunfish, gizzard and threadfin shad. Rincon results were better than previous years. We also tried bass fishing in my favorite cove and caught only 2 smallmouth. Fishing is slow over then length of the lake. Hopefully, water temperatures dropping to the low 60s will encourage bass to feed more actively.
San Juan — We caught shad of both species in great numbers along with largemouth, smallmouth, small catfish and sunfish. This station had fish abundance similar to the other sampling sites. Sport fishing was slow while waiting for the sun to go down so we could start electrofishing sampling. Our journey all the way up the Great Bend is usually action packed with striper boils and bass along the shore. This time we almost struck out with only a few smallmouth bass caught in open water. These bass act like stripers busting through an open-water shad school. A splash is either an adult gizzard shad jumping for joy, or a smallmouth feeding on shad in open water. Those of you looking for smallmouth along the rocky shoreline need to turn around and look in open water for surface disturbances. One fish splashing is now the new definition of a "Striper or Bass Boil." Look for that one fish and you may be surprised how many fish will end up in the cooler.
Wayne Gustaveson provides an electrofishing report every September on behalf of the Utah Division of Wildlife Resources
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