Ehrhardt and Deleveaux: Fishing capacity in a trap fishery for Panulirus argus 
193 
Table 1 
Simulated total seasonal revenues in dollars per vessel for the highest (1997-98) and lowest (2001-02) spiny lobster ( Panulirus 
argus ) stock abundance seasons with catch per unit of effort standardized to the lowest (1991-92) and highest (2001-02) trap 
fishing seasons observed during the study period in the Florida trap fishery. 
Region 
Abundance 
Catchability 
Key West 
Lower Keys 
Middle Keys 
Upper Keys 
Miami 
High 
Low 
36,298 
12,006 
26,893 
23,635 
23,949 
High 
High 
54,920 
18,165 
40,690 
35,761 
36,236 
Low 
Low 
7,919 
2,132 
2,819 
4,178 
10,851 
Low 
High 
11,985 
3,227 
4,266 
6,324 
16,422 
scenario, which had distinct effects on the different 
regions. 
Case scenario 2: In this case scenario the catch per 
trap day per trip for the 1997-98 and 2001-02 fish- 
ing seasons were each standardized to the 1991-92 
and 2001-02 catching efficiencies. The trap catching 
efficiencies were estimated as the simple ratio of the 
corresponding catchability coefficients estimated for 
each season to those obtained for the 1991-92 and the 
2001-02 seasons. The results of the case scenarios are 
presented in Table 1. 
The total revenues in Table 1 are indicative of the 
significant impact of the TCP on the potential revenues 
for each region under conditions of the minimum and 
maximum stock abundance observed during the study 
period. The greater catching efficiency of the traps, as 
reflected by the higher 2001-02 catchability coefficient 
relative to the 1991-92 catchability, generated much 
larger revenues. In the absence of the TCP those gener- 
ated revenues are much less than those that created the 
recent economic hardships in the fishery. 
Conclusions 
The analyses in this study indicate several very fun- 
damental impacts of the TCP. First, it generated a sig- 
nificant increase in the catching efficiency of the traps 
used in the fishery. Second, if the TCP had not been 
implemented, given the significant decrease in the stock 
abundance observed since the mid-1990s, the fishermen 
most likely would have encountered much greater eco- 
nomic hardships. 
There are many positive consequences of the TCP, 
the traps are now more efficient because they retain a 
higher fraction of the fishable stock, and the fishery- 
wide investment on traps is at least 40% less than dur- 
ing the 1991-92 fishing season. It is important to note, 
however, that fewer fishermen now participate in the 
fishery and the number of traps per fisherman appears 
to have increased. Thus, the trap certificates are allot- 
ted among fewer fishermen; hence, the revenue of the 
resource is now distributed among fewer participants. 
The revenues by regions are very different, portraying 
the economic conditions that differ among the regions. 
The TCP appears to have benefited the overall econom- 
ics of the participating fishermen but the decreased 
stock abundance observed in the last few seasons of the 
study period has had a profound and different impact on 
the economics of fishing operations within the regions. 
Finally, this assessment demonstrates that the TCP 
had succeeded with regard to its original objectives. 
The truly significant problem is the reduction in the 
stock abundance, which may not only be due to the lo- 
cal exploitation. 
Acknowledgments 
We thank the sponsors of this project, the Florida Fish 
and Wildlife Conservation Commission. Special thanks 
are given to J. Hunt and R. Muller of the FWC for their 
support and guidance regarding the spiny lobster data- 
base used in this research. Thanks are also extended 
to M. Shivlani of the University of Miami who was 
responsible for the collection of the socio-economic data 
in the FWC census carried out in 2003-04. We thank 
three anonymous reviewers for their comments that 
significantly improved the paper. 
Literature cited 
Angelsen, K., and S. Olsen. 
1987. Impact of fish density and effort level on catching 
efficiency of fishing gear. Fish. Res. 5:271-278. 
Chien, Y., and R. E. Condrey. 
1985. A modification of the DeLury method for use when 
natural mortality is not negligible. Fish. Res. 3:23-28. 
Ehrhardt, N. 
2005. Population dynamic characteristics and sustain- 
ability mechanisms in key Western Central Atlantic 
spiny lobster, Panulirus argus, fisheries. Bull. Mar. 
Sci. 76:501-526. 
FAO (Food and Agriculture Organization of the United Nations). 
2001. Report on the FAO/DANIDA/CFRAMP/WECAFC 
regional workshops on the assessment of the Caribbean 
