44 
Fishery Bulletin 1 13(1) 
Table 2 
A comparison of the growth of 11 banana prawns (Fenneropenaeus mer- 
guiensis) that were released and recaptured in waters of the Strait of 
Hormuz, along the coast of the Persian Gulf in Hormozgan Province, Iran, 
in 2010. Gw=growth increment, or change in weight (g) from release to 
recapture; Gr=growth rate (g weeks" 1 ); CL=carapace length (mm); and 
W=weight (g). 
Released shrimp 
Recaptured shrimp 
Gw (g) Gr (g weeks" 1 ) 
CL (mm) 
W (g) 
CL (mm) 
W(g) 
13.95 
1.2 
28.57 
17.4 
16.2 
0.88 
13.95 
1.2 
28.63 
17.5 
16.3 
0.88 
12.90 
1.2 
28.63 
17.5 
16.3 
0.88 
12.95 
1.2 
28.63 
17.5 
16.3 
0.88 
13.95 
1.2 
29.57 
17.5 
16.3 
0.88 
13.00 
1.1 
29.57 
19.1 
18.0 
1.02 
12.50 
1.0 
33.69 
27.2 
26.1 
1.41 
11.55 
1.0 
33.69 
27.2 
26.3 
1.42 
13.90 
1.1 
33.69 
27.2 
16.1 
0.87 
13.95 
1.1 
33.74 
27.3 
16.2 
0.88 
13.80 
1.1 
33.74 
27.3 
16.2 
0.88 
et al., 2006). The similarly low recapture percentages 
observed in our study may also have been affected by 
the first 2 of those factors. 
The low number of recaptured prawns identified 
in our study makes extrapolation of contribution of 
released prawns to the total catch tentative. The cal- 
culated contribution derived from the 11 recaptured 
prawns that were reported must be considered a mini- 
mum estimate because other tagged prawns may have 
been recaptured but not recognized or reported. How- 
ever, the extremely low number of recaptured prawns 
that was reported gives no evidence that the contribu- 
tion of released prawns to the total catch was profit- 
able at the study area in 2010. 
In this study in Hormozgan waters, banana prawn 
juveniles moved from shallow mangrove estuaries 
to deeper waters. The movement of juvenile banana 
prawns from mangrove habitat to offshore waters has 
been described already in different regions (Rothlis- 
berg et al., 1985; Staples and Vance, 1985; Vance et 
ah, 1996). Although the rate of recapture of marked 
prawns, at 0.022%, is too small to allow for making 
well-supported inferences, our findings show that the 
seasonal movement of the banana prawn is from in- 
shore to offshore areas. The results of this study in- 
dicate that the banana prawn is not highly migratory 
and that recaptured prawn were caught mostly within 
46 km of their release location, despite a period of lib- 
erty of 126 days. 
Frusher (1985) reported that banana prawns in the 
northern Gulf of Papua (Papua New Guinea) exhib- 
ited maximum movements of 167 km for males and 
190 km for females. The majority of all recaptured ba- 
nana prawns exhibited rates of movement of less than 
500 m days -1 . A comparison of the movement of ba- 
nana prawn in our study in Iranian waters and in the 
Frusher (1985) study in Papua New Guinea indicates 
that this species migrates over greater distances dur- 
ing its entire life cycle than it does in the limited time 
of our study and that the number of recaptured shrimp 
might have been greater if the fishing season had been 
longer. 
The main goal of the stock enhancement program 
for management of the prawn fishery in Iran was to 
increase the biomass of banana prawns. Management 
goals in most fisheries require accurate catch data, 
abundance estimates, measures of genetic diversity, 
and estimates of enhancement costs, as well as on a 
fisherman’s willingness to pay and on the monitoring 
of conflicts (Lorenzen et ah, 2010). Release of cultured 
juveniles would not be effective if there is insufficient 
nursery habitat to support them (Loneragan et al., 
2004; Hamasaki and Kitada, 2006). In our study, the 
percentage of recaptured prawns did not support the 
economic feasibility of this type of release operation. 
An increase in total prawn catch due to the release of 
shrimp was estimated to account for about 2.5 t, a low 
proportion (<1%) of total catch. The difference between 
costs and revenue indicates that the stock enhance- 
ment program was not profitable, with a ratio of catch 
benefit to expenditures of 0.0041. This ratio would un- 
doubtedly be reduced further if capital expenditures 
were considered. 
The economic findings from stock enhancement 
reported from other areas indicate varying degrees 
of success. A shrimp stock enhancement program for 
