McKenna: Structure and dynamics of the fishery harvest in Broward County, Florida 
I 19 
spadefish ( Chaetodipterus faber), and tripletail 
( Lobotes surinamensis). 
The persistence of each group in the harvest var- 
ied throughout the year. Offshore pelagics (OP, e.g. 
swordfish, Xiphias gladius) and tuna (Thunnus spp.), 
grouper-snapper (GS), bait fish (BF, e.g. ballyhoo, 
Hemiramphus brasiliensis ), and unknown miscella- 
neous (UM) fishes occurred in each month. Lobsters 
(LB ) occurred during each month of the open season 
(August-March) but declined steadily from the open- 
ing of the season. Blue crabs (BC, Callinectes sapidus) 
occurred in summer and fall (May-September and 
December). Inshore pelagics (IP, e.g. mullet, Mugil 
spp.) occurred in January, March, April, and August. 
Stone crabs (SC, Menippe mercenaria) and inshore 
demersals (ID, e.g. sheepshead, Archosargus 
probatocephalus) were landed in November and De- 
cember. Shrimps ( Penaeus spp.) occurred in Febru- 
ary and April. Offshore demersals (OD, e.g. tileflsh 
[Malacanthidae]) occurred only in July. 
Offshore pelagics (OP) accounted for the largest 
proportion of landings in all months (Fig. 2). They 
also accounted for the majority of landings on most 
of the fishing trips from May through July, again in 
October and November. Groupers and snappers ac- 
counted for much of the remaining landings and 
dominated trips in January and December. Together 
the offshore pelagics (OP) and the grouper-snappers 
(GS) accounted for over 80% of landings in all months, 
except August, September, and October. The addi- 
tion of lobster (LB) landings raises the totals for 
August and October to more than 80%. Inclusion of 
bait fish landings helps to account for more than 80% 
of September landings. Unknown miscellaneous 
(UM) fishes account for most of the remaining land- 
ings in each month. 
Species associations 
Despite the classification of landings (trip assem- 
blages) into distinct groups of species assemblages, 
associations between individual species were weak. 
Less than 4% of the unique pair-wise comparisons of 
species occurrence in any given month were signifi- 
cant. One fourth to half of these accounted for more 
than 50% of the variation in their ranked abun- 
dances. Four associations accounted for more than 
70% and only one association accounted for more than 
80% of the variation in correlated species abun- 
dances. Roughly half of the significant associations 
were positive. However, most of these were between 
two uncommon (landed on less than ten trips per 
month) species. Only the swordfish-tuna association 
was consistently strong (r'>50%) and positive. Mut- 
ton snapper ( Lutjanus analis) was positively associ- 
ated with black grouper ( Mycteroperca bonaci), 
mojarras ( Gerreidae), and a number of other species, 
but these associations were not evident in every month 
and were usually weak (r'<50%). Only significant as- 
sociations are considered in the following discussion. 
Table 3 
Dissimilarity and probabilities in comparing all pair-wise combinations of species assemblages landed in Broward County, Florida, 
during each month of 1989. The upper half matrix contains the dissimilarity values based on the Heterogeneity Ratio (HR), which 
is a measure of beta diversity. The lower half matrix contains the associated probabilities, generated by faunal similarity analysis 
(FAUNSIM), that the number of species observed to be common to each pair was less than that expected. Values in boldface are 
significant at the 0.05 level or greater. 
Month 
HR 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
1 
— 
1.057 
1.073 
1.107 
1.084 
1.179 
1.186 
1.143 
1.104 
1.181 
1.112 
1.112 
2 
0.07 
— 
1.071 
1.141 
1.157 
1.262 
1.201 
1.118 
1.137 
1.176 
1.109 
1.128 
3 
0.53 
0.40 
— 
1.069 
1.101 
1.233 
1.149 
1.087 
1.050 
1.150 
1.089 
1.089 
4 
0.80 
0.99 
0.43 
— 
1.098 
1.205 
1.182 
1.101 
1.064 
1.163 
1.158 
1.105 
5 
0.38 
0.99 
0.67 
0.75 
— 
1.160 
1.161 
1.137 
1.098 
1.124 
1.081 
1.082 
6 
0.71 
1.00 
0.98 
0.87 
0.47 
— 
1.161 
1.159 
1.201 
1.245 
1.234 
1.212 
7 
1.00 
0.99 
0.95 
1.00 
0.99 
0.62 
— 
1.157 
1.137 
1.229 
1.212 
1.151 
8 
0.93 
0.80 
0.66 
0.73 
0.99 
0.66 
1.00 
— 
1.063 
1.187 
1.130 
1.089 
9 
0.80 
0.97 
0.33 
0.51 
0.86 
0.96 
0.83 
0.10 
— 
1.148 
1.110 
1.090 
10 
1.00 
1.00 
1.00 
0.99 
0.95 
0.99 
1.00 
1.00 
0.99 
— 
1.115 
1.095 
11 
0.76 
0.88 
0.75 
1.00 
0.58 
0.97 
1.00 
0.94 
0.96 
0.86 
— 
1.070 
12 
0.77 
0.96 
0.75 
0.84 
0.50 
0.90 
0.95 
0.66 
0.88 
0.67 
0.44 
— 
FAUNSIM probability 
