Channel catfish egg harvest. Credit: USFWS
Channel catfish eggs in incubation. Credit: USFWS
Comanche springs pupfish. Credit: USFWS
Fountain darter. Credit: USFWS
Needle with PIT tag. Credit: USFWS
PIT tag with penny to show relative size. Credit: USFWS
Razorback sucker transfer. Credit: USFWS
PIT tagging a Razorback sucker. Credit: USFWS
Texas wild-rice at Uvalde. Credit: USFWS
The Uvalde NFH is a Federal warm-water fish hatchery that specializes primarily on the captive rearing of threatened and endangered species. These efforts are completed in a manner that promotes long term protection for the species in the wild. The station is also involved in the captive propagation and rearing of channel catfish for recreational fishing activities on Tribal, Federal and state lands.
Endangered and Threatened Species Recovery
The razorback sucker is raised at the Uvalde NFH and then released into the wild in New Mexico, supporting programs, such as the San Juan River Basin Recovery Implementation Program, aimed at bringing the species back from the brink of extinction. Prior to being released into the wild, Uvalde NFH staff insert a small tag (PIT Tag) into each razorback sucker so that years later, biologists can track its life history after they have grown in the San Juan River or Lake Powell. This gives us a better idea of how the species is doing in the wild.
Uvalde NFH keeps several different endangered species that come from both the state of Texas and other southwestern waters. These include the Comanche Springs pupfish, fountain darter, San Marcos salamander, and Texas wild rice.
The hatchery's primary mission in the growth of recreational fish is to provide channel catfish for the Tribal waters of the Navajo Nation in New Mexico, and the White Mountain Apache Tribe in Arizona.
When the hatchery has an excess of fish after meeting the Tribal Trust Responsibility they partner with the Texas Parks and Wildlife Department to stock excess channel catfish throughout the state for recreational fishing. In the past, our catfish have been stocked at Federal and state hatcheries, local public lakes and rivers, and used for Texas Parks and Wildlife Department and U.S Fish & Wildlife fishing derbies.
Some of Uvalde NFH's catfish also provide a unique free fishing opportunity during our annual youth fishing derby, an event which has the participation of the local public and businesses. The time of the event is the first week of June during the National Fishing and Boating Week.
Daily Water Quality Monitoring
Water quality is monitored on a daily basis at dawn, which is when oxygen levels are typically at their lowest daily levels. Problems associated with low oxygen levels can be averted by observing declining trends and taking corrective action before fish show signs of stress. Proactive actions may include lowering the pond water level while increasing the incoming water supply. Emergency aeration can also be employed utilizing portable, solar powered aeration systems. Temperature and pH levels are also monitored along with the dissolved oxygen levels to insure they remain in acceptable ranges. Late afternoon dissolved oxygen and temperature readings are regularly taken in the heat of summer. Increasing the water supply is the only corrective action that can be taken to cool high water temperatures.
Uvalde National fish hatchery is fortunate to be located in an area with mild winters. This allows a nearly year round growing season for all species on station, resulting in less time to reach goal size. Fish can be grown and stocked quicker at Uvalde, resulting in overall cost and space savings. Only high quality diets and ingredients are used to promote healthy fish. In some instances, a specially formulated diet is used to meet specific energy and developmental needs. Fish are fed different rates, depending on the species, the average size of the fish in the pond, and the amount of time to reach target size. A few months prior to spawning, catfish adults (broodstock) get their diet supplemented with beef liver or dead bait fish (reared on station) to prepare their bodies for the spawning and egg production process. This supplemental feed improves the size, quality, and quantity of eggs produced. Some species on station are not hand fed since they are natural forage feeders of algae and invertebrates. We monitor and control the algae and invertebrate production to ensure a sustainable, available supply of natural food.
Fish Health Monitoring
Whenever live organisms are kept in close proximity at high numbers diseases and parasites are always a threat. Daily observation is the best way to detect problematic issues. Early detection of a fish health problem is critical to survival. Once the problem is detected and identified, staff prescribes and administers the treatment. This early detection and treatment assists in preventing catastrophic outbreaks from occurring. This early detection is best accomplished during observations made at the time of feeding. Floating feed allows for better observation, but may put smaller fish at increased threat to bird predation. Healthy fish should feed aggressively. When fish are not feeding, a closer look is warranted. The hatchery maintains a lab stocked with equipment and resources that allows accurate diagnosis and treatment of pathogens.
The Uvalde National Fish Hatchery propagates channel catfish to provide recreational fishing opportunities for state, tribal and local partners. Channel catfish propagated by Uvalde NFH are also used during the National Fishing and Boating Week’s annual fishing derby. Propagation techniques of channel catfish at Uvalde NFH are simple, safe and similar to natural spawning conditions. In early spring, spawning cans are placed into ponds to allow for the fish to lay their eggs. Once a nest is selected and eggs are fertilized, the male channel catfish will guard the nest until the eggs are collected by hatchery staff. After the eggs are collected they are placed into hatching trays, hatched out, and raised to sizes appropriate for stocking.
Fish are a high protein source sought after by many predators. Uvalde NFH continually competes with raccoons, water snakes, herons, cormorants and even pelicans on occasion, for the fish that we raise. Propane cannons which produce a loud sound similar to a shotgun are effective deterrents for the short term. This method is used when ponds are being drawn down and fish are particularly vulnerable. Animals are adaptive, and soon learn that there is no real danger associated with the noise. Other measures that have been used with limited success include trapping, placement of vehicles around ponds, ribbons and pie pans that are allowed to move in the wind and string lines that crisscross the surface of the ponds. The only effective long term solution to avian predation has been bird netting suspended above ponds. The endangered species on station are first priority and are kept under the protection of the bird netting.