8118 - Laserfiche WebLink

Home Browse Search

I I I I I I I I I I I I I I I I I I I (UDNR) to develop specific population goals for an adult razorback sucker population within Lake Powell. Discussions thus far have dealt with stocking fish directly into Lake Powell. However, there are opportunities elsewhere. Reared fish could also be used by the San Juan Recovery Implementation Program to meet their recovery goals and there might be opportunities to stock fish below Glen Canyon Dam. These scenarios would not require a Utah entry permit and the associated sacrifice of 50 fish for health certification. Potential Problems Fish Losses To our knowledge, the fish did not cause any inconveniences to golf course personnel. Routine maintenance of the ponds and course met the fishes biological needs. While this is all good news, we must caution that it only covers a 16 mouth period. Problems with disease and equipment failure can easily occur and some degree of mortality must be expected There is always the potential of problems which can lead to fish die offs. Lawn chemicals can enter the ponds by heavy rains, water supplies can be interrupted, aerators can break or be shut off accidently, are all actions that can result in fish dying. These potential problems must be recognized, guarded against, and when they occur, must be accepted as part of aquaculture. A close working alliance needs to be fostered with professional fish culturists to minimize potential problems and insure that steps are taken to corrections problems when they arise. Small Fish Restrictions The method in which these ponds are used as an irrigation reservoir restricts their use as larval or small fish rearing ponds. Fish less than 100 mm should not be stocked. We estimate that during the summer, possibly 25-35% of the ponds volume is pumped out daily for irrigation demands. We're not certain if the pump intakes are screened or if there is some type of filtering system. If there are screens, they're probably fairly large to reduce plugging. There is the potential that larvae or small fish could not only be lost through the pumps, but there isn't a filtering system they could also plug irrigation nozzles and valves. The suckers that are currently in the pond are four years old and reaching sexual maturity. It is quite possible these fish will spawn this coming spring. If they do, the resulting larval suckers could cause the problems previously described. Algae Control There is an obvious alga problem which is experienced at nearly all municipal ponds. Floating mats of algae collect along shore, are unsightly, and can clog circulation or irrigation systems. There has been some discussion about controlling this algae by stocking white amur (grass carp) or tilapia, two fish used for aquatic weed control. Unfortunately, these fish normally only feed on stemmed plants. Only in a few instances, where fish were near starvation, has it been shown that they feed on algae. Algal growth is a similar problem at the Boulder City golf course. There algal mats are removed manually using rakes. 5