232 
Fishery Bulletin 1 10(2) 
85°30 , 0’ , w 84°20'0"W 
Figure 1 
Location of the Gulf of Mexico Shark Pupping and Nursery (GULFSPAN) survey in 
northwest Florida. Sampling sites were located in St. Andrew Bay, Crooked Island 
Sound, St. Joseph Bay, the gulf side of St. Vincent Island, and Apalachicola Bay. 
Sampling occurred from 1994 through 2010. 
Table 1 
Gillnet specifications used in the Gulf of Mexico Shark Pupping and Nursery (GULFSPAN) survey 1994-2010. For all net con- 
figurations, the hanging ratio (length to height ratio of the meshes) was 0.5, leadline weight was 4.5 kg, 2.3 kg of buoyancy was 
used, and each panel length was 30.1 m. 
Stretch mesh 
size (in/cm) 
Twine 
size no. 
No. of 
meshes deep 
Thickness of twine 
(mm) 
Breaking strength 
(kg) 
Years fished 
3. 0/7.6 
208 
45 
0.52 
11.8 
2006-2010 
3. 5/8. 9 
208 
40 
0.52 
11.8 
1994-2010 
4.0/10.2 
208 
35 
0.52 
11.8 
1994-2010 
4.5/11.4 
208 
35 
0.52 
11.8 
1994-2010 
5.0/12.7 
277 
30 
0.62 
18.2 
1994-2010 
5.5/14.0 
277 
25 
0.62 
18.2 
1994-2010 
8.0/20.3 
24 
20 
1.00 
115.9 
1994-2005 
where p f = the relative fishing intensity of gillnet j: 
A- = the abundance of sharks in length class i; 
and 
r = the selection curve for each gillnet j. 
Relative fishing intensity represents fishing effort and 
fishing intensity combined and is the conditional prob- 
ability that a fish contacted gillnet pane! j, with the 
assumption that it made single contact with the entire 
combined gillnet panel (Millar, 1992). The normal, 
gamma, and lognormal models observe geometric simi- 
larity (mean p • and spread a, proportional to mesh size), 
whereas the normal model with fixed spread is not geo- 
metrically similar (mean p ■ and spread cr equal across 
mesh sizes). When p ; is assumed to be equal among 
mesh sizes, the form of the log-linear model is as follows: 
1 o g ( v J = fac to r ( /, ) + /3, f x ( m J , j ) + /J 2 ■ f 2 ( m J , j ) , ( 2 ) 
