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552
<br />MARSH ET AL.
<br />TABLE 3.-Size-class distribution of juvenile repatriate razorback suckers released and later captured during March
<br />censuses in Lake Mohave, Arizona-Nevada, 1999-2002. Numbers of fish released were used to perform log-linear
<br />analysis (see Table 4). The upper portion of the table represents only the released fish that were not caught, and the
<br />lower portion represents only the released fish that were caught; the sum of the two subtotals represents the total number
<br />of fish released.
<br /> Percent of total
<br /> Number of fish released by TL (mm) released by TL (mm)
<br />Year !5300 301-350 >350 Subtotal x300 301-350 >350
<br /> Fish released that were not captureda
<br />2002 16,391 5,693 988 23,0726 71 25 4
<br />2001 11,775 3,233 413 15,421b 76 21 3
<br />2000 5,903 1,962 304 8,169c 72 24 4
<br />1999 3,951 979 183 5,113° 77 19 4
<br /> Fish released that were capturedd
<br />2002 28 28 10 66 42 42 15
<br />2001 30 26 4 60 50 43 7
<br />2000 23 14 6 43 53 33 14
<br />1999 7 10 6 23 30 43 26
<br />a Each number is a cumulative number of fish released based on data from repatriates released 4
<br />Years before the population estimate (N*). year in Table 2 (e.g., in 2002, the number 23,072 is
<br />the number released from 1992 to 1998).
<br />b Three records without TL data were omitted.
<br />c One record without TL data was omitted.
<br />d Each number is a cumulative number of fish captured that were originally released 4 years
<br />before the population estimate (N*) year in Table 2 (e.g., in 2002, the number 66 is the number
<br />of captured fish originally released in 1998 or earlier).
<br />proximately 3 years (Figure 2). From the VBG,
<br />L00 was 44 mm greater for females (597 mm) than
<br />males (553 mm), whereas K was slightly greater
<br />for males (0.856) than females (0.845), which
<br />caused males to asymptote earlier than females.
<br />Discussion
<br />More than a decade after this restoration project
<br />began, the NFWG is far from its goal of estab-
<br />lishing a repatriated population of 50,000 razor-
<br />back suckers in Lake Mohave. Nonetheless, every
<br />new fish counts because the wild population has
<br />plummeted to fewer than 3,000 (Marsh et al.
<br />2003), and continues to decline. In a context of
<br />historical abundance it seems the end is swiftly
<br />approaching, which can be catastrophic to success
<br />of a program that depends upon catching wild lar-
<br />vae.
<br />Beck et al. (1994) defined success in reintro-
<br />duction programs as the restored species ultimate-
<br />ly becoming a viable population of at least 500
<br />individuals capable of surviving without human
<br />intervention. By this definition the razorback suck-
<br />er repatriation program in Lake Mohave has been
<br />successful only in part. A population of more than
<br />1,000 repatriated fish has been established, and
<br />these fish represent the genetic diversity of the
<br />original wild stock (Dowling et al. 2005). Razor-
<br />TABLE 4.-Program MARK results comparing the fit of several mark-recapture models used to obtain survival and
<br />recapture parameter estimates for repatriated razorback suckers in Lake Mohave, Arizona-Nevada, 1999-2002. The
<br />parameters column indicates the number of estimable parameters and not the total number of parameters in the model
<br />(symbols are from Lebreton et al. 1992).
<br />
<br />Model Total length
<br />covariate
<br />AIC Model
<br />likelihood
<br />Parameters
<br />Deviance
<br />'a,(3) Pa,(4) (P(1,2) P(1,2) 6,829.01 1.000 9 6,811.003
<br />d'a,(3) Pa,(4) 0(1) P(1,2) 6,831.01 0.368 10 6,811.003
<br />(%,(3) Pa,(4) (D(1.2) P(1) 6,831.09 0.353 8 6,815.088
<br />4).,(3) Pa,(4) 00) PM 6,831.09 0.353 8 6,815.089
<br />Or P. 7,141.80 0.000 20 7,101.787,
<br />4).,(3) Pa,(4) 7,316.94 0.000 7 7,302.942
<br />0a P. 7,326.37 0.000 19 7,288.354
<br />1Da Pt 7,344.53 0.000 20 7,304.517
<br />4)i Pr 7,496.35 0.000 20 7,456.333
<br />1
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