Laserfiche WebLink
<br />002794 <br /> <br />6.4.3 Experimental Stocking Plan for Middle Green River <br /> <br />An experimental stocking plan for razorback sucker was developed in 1995 for the Middle Green <br />River (Wydoski 1995a). An updated version of this plan entitled "Augmentation Plan for razorback <br />sucker in the Middle Green River 1996-1997" was presented in the spring of 1996 (Wydoski 1996c). <br />Like the original stocking plan, the goal of the updated plan was to increase the number of adult <br />razorback suckers in the Middle Green River from the existing aging and declining population of <br />approximately 500 to a population of 1000 fish by the year 2000 (Wydoski 1996c). The purpose of <br />this exercise is to prevent extinction of this rapidly declining population. The initial goal of 1,000 <br />adult 'fish is not a recovery goal. <br /> <br />This augmentation plan was similar to the stocking plan for razorback sucker in the Upper Colorado <br />and Gunnison Rivers in that it provided details regarding the following stocking activities: <br /> <br />. source of broodstock, <br />. number offish to be released, <br />. size of fish to be released, <br />. condition of fish when released, <br />. time and location of release, <br />. monitoring of stocked fish, <br />. disposition of surviving razorback sucker. <br /> <br />During 1996, 1,068 captive-reared razorback suckers ranging in size from 209-308 mm (8-12 in) TL <br />were stocked into the Middle Green River (HamillI996b). The estimated survival rates and mean <br />total lengths at the end of each growing season are summarized in Table I of Appendix B. Based on <br />the estimated survival rates in Table I, about 203 adult razorbacks should be produced by the fall of <br />the year 200 I from the 1996 stocking. (Wydoski I 996c) <br /> <br />During 1997, approximately 394 razorback suckers averaging about 12-inches in mean total length <br />will be stocked in the Middle Green River to augment the wild stock (Table 3 Appendix B). These <br />fish will be derived from 1.000 wild razorback sucker larvae from the Middle Green River and 3,030 <br />captive-reared larvae from 5 pedigreed family lots. The fish will be reared at Ouray. About 128 <br />razorback suckers are expected to survive from 1996 through the year 2000. (Wydoski 1996c) <br /> <br />The total number of razorback suckers that are expected to survive to the years 2000 and 2001 from <br />the stockings in 1996 and the proposed 1997 stocking is 331 fish (Tables 2 and 3 - Appendix B) <br />(Wydoski 1996c). A much higher rate is needed to achieve the goal of 1,000 adults in the year 2000. <br />given that the existing population is experiencing mortality. Given existing facility limitations, the <br />goal ofl,OOO adult razorback suckers in the Middle Green River by the year 2000 will likely not be <br />met <br /> <br />7.0 Stocking Facility Needs <br /> <br />Restoration stocking will be required to provide a "jump-start" mechanism to supplement fish in <br />habitats where the wild populations are very depressed. Restoration stocking will also be necessary <br /> <br />34 <br />