Over the past month, there has been a high demand from pond owners in receiving information on pond stocking strategies for their recreational fisheries. This topic was covered in depth during the January 2021 Aquatic Webinar, but another topic along the same vein, is fish stocking for aquatic vegetation management. There have been some recent regulation changes that are worth noting.
Triploid grass carp (Ctenopharyngodon idella) and Mozambique tilapia (Oreochromis mossambicus) are the two herbivorous fish options used for aquatic vegetation management in Texas. While both of these species consume aquatic plants, they each have their own preferences. Mozambique tilapia are most effective at controlling floating plants, primarily duckweed and Azolla and are also known to consume some filamentous algae and watermeal. Control effectiveness and longevity are increased significantly when combined with other management practices like mechanical or chemical control, as an integrated pest management strategy. If stocked into a pond with a large bass population, they will be subjected to predation which will reduce any aquatic vegetation control.
Up until recently, only Mozambique tilapia could be obtained from a Texas Parks & Wildlife Department certified dealer, without a requiring a permit. All other species, including hybrids, were illegal to stock in outdoor ponds.
New regulations, effective January 27, 2021, has broadened the tilapia species legally allowed to stock in outdoor ponds to include, not only Mozambique tilapia, but Blue tilapia (Oreochromis aureus), Nile tilapia (Oreochromis niloticus), and Wami tilapia (Oreochromis urolepis), along with their hybrids. This new ruling is put in place to relieve any concerns regarding misidentification for all parties involved in the process.
Additionally, two management zones have been identified in regards to stocking these tilapia species in Texas– a conservation zone and a stocking zone. These zones are largely split by Interstate Highway 35 and created in response to a conservation assessment weighing both environmental and economic impacts. For tilapia to be stocked in outdoor ponds in the conservation zone (approx. West of I-35) a departmental review will be required, at no cost, to determine if tilapia escapes are likely. This process is not necessary for ponds located in the stocking zone (approx.. East of I-35).
These new stocking zones will also play a role in triploid grass carp permits for private ponds. Landowners with ponds in the stocking zone will have the opportunity to be fast tracked through the permit process when requesting 10 or less carp.
For more information tilapia and triploid grass carp stocking regulations please visit the Texas Parks & Wildlife Department webpage. The full list of counties within each zone and a request for approval to stock tilapia in the conservation zone can be found here.