Habitat Improvement for the Endangered Mohave Tui Chub (fish) at Mojave National Preserve

Description

A.Project Goals - Historically, Lake Tuendae, which hosts one of the primary populations of Mohave tui chub (fish), had to be dredged every 10 years to remove cattail and aquatic ditchgrass (Ruppia maritime) detritus. This activity leads to substantial tui chub mortality just to maintain its habitat. This requires lengthy Section 7 formal consultation with the US Fish and Wildlife Service. After the last dredging action in 2001, members of the interagency recovery team have been able to postpone the need for dredging by over five years due through conducting annual cattail control actions. However, in the past two years several key participants have retired or been reassigned. As a result, cattail control has been minimal and growth has expanded by over 30 square meters in Lake Tuendae and MC Spring due to the inability of MOJA staff alone to keep up. Thus, to minimize the need for dredging, cattail control needs to continue and transplant of native plants completed to prevent re-establishment of cattails. B.Project Objectives - MOJA staff has identified by completing these three objectives towards the endangered Mohave Tui Chub habitat enhancement in Lake Tuendae, MC Spring, West Pond and Morning Star Mine Lake, should help with their survival rates. a. Objective one, involves obtaining water body dimensions such as depth, width and vegetation cover along with water quality measurements of temperature, dissolved oxygen and total dissolved solids (TDS). Results will be compared with previous data. b. For Objective two, the cattail will be cut with cutters with handles of varying length and a flat bottom boat to access cattail stems for cutting as close to soil level as possible. Cutting will be done monthly and continue monthly during the cooler part of the year, to control any regrowth. Some dead mats of Ruppia spp. will be raked from the water to reduce its extent across open water. c. For Objective three, dig up local stocks of bulrush and Cooper¿s rush from non-tui chub bearing waters and transplant immediately to cattail infested areas at the water¿s edge. Follow up visits to cutback cattails from around the transplants will be conducted until the transplants have established. It is anticipated 250 to 300 individuals of each species would be needed to cover the required area. This project should further minimize the need for any future dredging of the habitat that results in mortality of tui chub (fish). The Research Associate (RA) will be able to conduct about half of the tasks independently and the rest with existing MOJA staff.

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