Red snapper demographic structure in the northern Gulf of Mexico based on spatial patterns in growth rates and morphometrics

Fishery Bulletin, Oct, 2004 by Andrew J. Fischer, M. Scott Baker, Jr., Charles A. Wilson

Table 1
Numbers of red snapper (Lutjanus campechanus) sampled
from recreational sources by state and year.

State      Males   Females   Unknown sex        Total

Alabama
  1999      434      396          5               835
  2000      355      415          7               777
  2001      189      209          0               398
                                          Total  2010
Louisiana
  1999      367      339         31               737
  2000      399      397          8               804
  2001      160      179         25               364
                                          Total  1905
Texas
  1999      268      293         14               575
  2000      278      284         22               584
  2001       52       56         10               118
                                          Total  1277

Table 2
Differences between two readers in average percent error (APE),
coefficient of variation (CV), index of precision (D), and in
percentages of agreement (O) for counts of opaque annuli in red
snapper (Lutjanus campechanus) otoliths after first and second
readings for each sample year. n=number of otoliths sampled.

Year            1st reading   2nd reading

1999 (n=2100)
  APE              0.483        0.499
  CV               0.014        0.0008
  D                0.010        0.0006
  0               89.48%       99.43%
  [  or -] 1       8.62%        0.48%
  [  or -] 2       1.19%        0.095%
  [  or -] 3       0.71%

2000 (n=2069)
  APE              0.487        0.499
  CV               0.034        0.0006
  D                0.024        0.0004
  0               73.79%       99.47%
  [  or -] 1      22.49%        0.53%
  [  or -] 2       1.78%
  [  or -] 3       1.93%

2001 (n=866)
  APE              0.459        0.498
  CV               0.032        0.0005
  D                0.023        0.0003
  0               74.73%       99.42%
  [  or -] 1      22.06%        0.58%
  [  or -] 2       2.27%
  [  or -] 3       0.94%

Table 3
Chi-square ([chi square]), degrees of freedom (df), and P-values
for likelihood ratio tests for comparing FL and TW von Bertalanffy
growth models and parameters among sample locations (states). AL =
Alabama; LA = Louisiana; and TX = Texas. n/a = not available.

                   AL-LA

                 FL model

[chi square]       2.54
df                 1, 28
P                  0.11

                 TW model

[chi square]       2.15
df                 1, 29
P                  0.14

                                    AL-TX

                 FL model             L                 k

[chi square]       5.14             13.67             21.53
df                 1, 34            1, 34             1, 34
P                  0.023           0.0002       3.48x[10.sup.-6]

                 TW model             L                 k

[chi square]       38.8             21.3              37.8
df                 1, 27            1, 27             1, 27
P             4.7x[10.sup.-6]  3.9x[10.sup.-6]  7.97x[10.sup.-10]

                                    LA-TX

                 FL model             L                 k

[chi square]       5.80             10.16              9.8
df                 1, 32            1, 32             1, 32
P                  0.015            0.001             0.002

                 TW model             L                 k

[chi square]       16.77            15.1               n/a
df                 1, 26            1, 26              n/a
P             4.2x[10.sup.-5]       0.001              n/a