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Fishery Bulletin 96(2), 1 998 
be compared between protected sites and those un- 
protected from spear fishing. 
It was hypothesized that spear fishermen were 
targeting some species more than others owing to 
their larger size. Targeted species were assumed to 
be red grouper, black grouper, scamp, and gag. The 
latter two species were rare, constituting <14% of 
individuals observed by site. Nassau grouper were 
assumed to be a nontargeted species because of the 
ban on harvest. Differences in the relative abundance 
of targeted grouper were assessed with a £-test on 
the arcsine-transformed percentage of the total num- 
ber of grouper observed at a site. Individual sites were 
the replicates for the analysis. 
It was also hypothesized that the average size of 
targeted species would be significantly different be- 
tween protected sites and those unprotected from 
spear fishing. A nested ANOVA was used to test this 
hypothesis, with the main factor being protection 
level (spear fished or protected) and sites nested 
within protection level. The mid points of size cat- 
egories were used as an estimate of the individual 
sizes of sampled fish. Thus, for this analysis, indi- 
vidual fish sizes were the replicates. A value of 40 cm 
was used for individuals in the >35 cm category. This 
results in a conservative analysis because many of 
the fish in this category were much larger than 40 cm 
(R. Sluka, personal observation). 
Results 
There was no significant influence of spear fishing 
on the relative abundance of targeted grouper spe- 
cies (£=0.658, P>0.55). Targeted species constituted 
an average of 65% (rc=9) and 71% (n=4) on protected 
and unprotected sites, respectively. Nontargeted spe- 
cies (graysby, Epinephelus cruentatus, coney, E. 
fulvus, rock hind, E. adscensionis, red hind, E. 
guttatus, and Nassau grouper, E. striatus) constituted 
on average 35% and 29% of the total number of indi- 
viduals on protected and unprotected sites, respec- 
tively. Nassau grouper constituted a greater propor- 
tion of the individuals observed at protected (15%) 
than at unprotected (2%) sites. These values were 
statistically different (£=2.46, P<0.05). 
Patch reefs protected from spear fishing had a sig- 
nificantly greater size of targeted individuals than 
did unprotected patch reefs (F, , )n =3.874, P= 0.05). 
The mean size (+/- 1 SE) of targeted grouper species 
on protected patch reefs was 29.3 (0.7) cm, whereas 
the mean size of targeted species on unprotected sites 
was 26.0 (0.8) cm. There was also a significant dif- 
ference among sites nested within protection levels 
(Fn 2n =5 - 151 , P cO.OOD. 
Discussion 
In this study, spear fishing appears to primarily in- 
fluence the average size of groupers. Sites in which 
spear fishing was not allowed had grouper assem- 
blages that were characterized by larger-size indi- 
viduals. This result is similar to those found in stud- 
ies examining the effects of hook-and-line fishing, 
where fishermen target the larger individuals in a 
population and thus decrease the average size of a 
fish species (Roberts and Polunin, 1991). Overall, 
grouper species composition was not significantly 
influenced by the presence or absence of spear fish- 
ing; targeted species were similarly abundant on 
protected and unprotected patch reefs. Sluka and 
Sullivan (1996) have shown that grouper species, 
such as black grouper, red grouper, and Nassau grou- 
per, are more abundant, but smaller, on inshore patch 
reefs than on offshore bank reefs of the upper Florida 
Keys. It is likely that species such as these are re- 
cruiting inshore before they move offshore (Ross and 
Moser, 1995). Nassau grouper, however, were more 
abundant on patch reefs protected from spear fish- 
ing than on unprotected patch reefs. Although there 
is a ban on harvesting these species, spear fisher- 
men may still collect individuals. It is important to 
examine how effective the ban on harvesting this 
species is in the Florida Keys. 
Offshore bank reef sites in the upper Florida Keys 
protected from spear fishing had snappers (Lutjani- 
dae) and grunts (Haemulidae) of larger size and 
greater abundance than did a lower Keys site sub- 
jected to spear fishing (Bohnsack, 1982). Clark et al. 
(1989) found similar results when sites inside Looe 
Key National Marine Sanctuary (lower Florida Keys) 
were compared before and after protection from spear 
fishing. The present study did not examine differ- 
ences in abundance between protection levels. How- 
ever, it is expected that there would be no signifi- 
cant differences in abundance between these sites; 
this result is due to the nature of both spear fishing 
and grouper growth and reproductive characteristics. 
Spear fishing targets the largest fish in an assem- 
blage but only accounts for a small percentage of the 
total fishing effort (PDT, 1990). For example, spear 
fishing accounted for 10.5% of the total recreational 
fishing catch in Biscayne National Park. 1 Thus the 
magnitude of the selection pressure is likely much 
less than that from hook-and-line fishing because of 
1 Tilmant, J. T., and R. Stone. 1984. Reef fish harvest trends, 
Biscayne National Park, Dade County Florida. Unpublished 
report presented to the 1984 stock assessment workshop. South- 
east Fisheries Center, National Marine Fisheries Service, Mi- 
ami, Florida, 26 p. 
