734 
Fishery Bulletin 95(4), 1997 
bottom area that was verified with underwater tele- 
vision. Each of the three trap types (blackfish, 
Florida, and chevron) was deployed either from the 
bow, stern, or midships of the research vessel (see 
Collins, 1990). Hook-and-line collections were taken 
with rod and reel and with the three-hook terminal 
rig. Fishes were processed as described for 1979-87. 
All red porgy collected in 1988 and 1989 were kept 
for life history studies. 
Based on the data collected during 1988 and 1989, 
a decision was made to discontinue the use of black- 
fish and Florida traps in 1990 because chevron traps 
sampled a greater species diversity (Collins, 1990). 
During the late 1980’s, all live bottom locations iden- 
tified during underwater television surveys and from 
sampling in previous years were plotted with LO- 
RAN-C coordinates to the nearest 0.1 ps and included 
in a sample site database. Currently, there are over 
2,500 live bottom sites in the MARMAJP database, 
from which 300-600 randomly chosen sites have been 
sampled each year since 1989. In addition, since 1989, 
the SAB has been stratified on the basis of latitude. 
Zone 1 includes all sites sampled south of 32°N, zone 
2 all sites between 32°N and 33°N, and zone 3 all 
sites north of 33°N. Buoyed chevron traps were de- 
ployed from the research vessel and soaked for ap- 
proximately 90 minutes. Hook-and-line (rod-and-reel) 
collections were made for 30 minutes at dawn or dusk. 
All fishes sampled were processed as in previous years. 
Because of concerns about potential gear selectivity, 
the length frequency of all red porgy caught by all four 
gear types during 1988 and 1989 was compared. 
Since 1989, fork lengths (cm) and total weight (10 
g) were recorded for all red porgy sampled in each 
zone for each year with a Limnoterra FMB-IV elec- 
tronic fish measuring board and a Toledo electronic 
scale interfaced with a XT-type personal computer. 
In 1990 and 1994, all red porgy collected during sam- 
pling were used for life history studies. In 1991-93, 
up to 15 fish from each 1-cm size class and all fish 
larger than 350 mm FL were kept from each zone for 
life history studies. Red porgy used for life history 
studies were measured to the nearest mm (total 
length [TL], FL, and standard length [SL J ) with a 
Limnoterra FMB-IV electronic fish measuring board 
interfaced with a XT-type personal computer. Indi- 
vidual weights were measured to the nearest gram 
with a triple beam balance. 
Age and growth 
Sagittae were removed at sea and stored dry. In the 
laboratory, the whole right otolith was immersed in 
cedar wood oil and examined for annuli (one trans- 
lucent and one opaque zone) (Manooch and Hunts- 
man, 1977) with a dissecting microscope with incan- 
descent reflecting light and an ocular micrometer 
(1979-87) or with a dissecting microscope and re- 
flected light from a fiber-optic light source (1988- 
94). The latter microscope had an attached Hitachi 
KP-C550 video camera connected to a personal com- 
puter equipped with a MATROX frame grabber and 
OPTIMAS image analysis software. The digitized 
image was viewed on a television monitor, and an- 
nuli were measured with OPTIMAS software. For 
both systems, measurements were taken from the 
core of each otolith to the outer edge of each opaque 
zone and to the edge of the otolith on a straight line 
midway between the posterodorsal dome and the 
most posterior point on the otolith (Frizzel and Dante, 
1965). Annuli on this plane were consistently clearer 
and easier to enumerate, especially for older fish. For 
years where large numbers of red porgy were col- 
lected, a minimum of 350 randomly chosen fish were 
aged per year. All fish larger than 350 mm (FL) were 
aged for all years. The first reader collected measure- 
ments from all otoliths, whereas the second reader 
counted increments from a randomly chosen 35% of 
otoliths for each year. If agreement between the two 
counts was less than 90% for any year, the second 
reader read all otoliths for that year. When counts 
differed, otoliths were reread by both readers and 
discarded from further analyses if a difference in 
readings persisted. 
Back-calculated lengths-at-age were computed by 
using the scale proportional hypothesis (Francis, 1990): 
L ( = - (a/b) + ( L c + alb ) (0 ; /O c ), 
where L ( = length at the formation of the zth incre- 
ment; 
O i - otolith radius at the formation of the ith 
increment; 
O c - otolith radius at the time of capture; 
L c = fish length at the time of capture; 
a = intercept of otolith radius on fish length 
regression; 
b = slope of the otolith radius on fish length 
regression. 
Lengths were backcalculated to the most recently 
formed increment for comparisons of annual growth 
(1988-94) and to all increments for comparisons be- 
tween periods (1979-81, 1988-90, and 1991-94). The 
SigmaPlot curve-fitting module with the Marquardt- 
Levenburg algorithm was used to fit von Bertalanffy 
growth curves to the mean back-calculated length- 
at-age for each year or period (SigmaPlot, 1994). 
Because red porgy are protogynous sparids, and 
undergo a size- and behavior-related transition from 
