Harris and McGovern: Changes in the life history of Pagrus pagrus 
741 
could reflect a gradual movement of red porgy to- 
wards deeper water as they age. Grimes et al. ( 1982) 
suggested that red porgy associated with shallow 
reefs may temporarily move to deep water in response 
to unusually cold water temperatures. However, tag- 
ging studies have shown that settled red porgy un- 
dertake very little long-term movement (Grimes et 
al., 1982; Parker, 1990). Another reef species, black 
sea bass ( Centropristis striata), has shown limited 
movement of larger fish to deeper water (Ulrich and 
Low 3 ; Harris and McGovern, personal obs.). 
Fishing mortality (F) of red porgy has increased 
since 1972, although between 1972 and 1975 it 
showed a slight decline (Vaughan et al., 1992). The 
3 Ulrich, G. F., and R. A. Low. 1992. Movement and utiliza- 
tion of black sea bass, Centropristis striata, in South 
Carolina. Final Unpubl. Rep. NOAA Award No. NA90AA-D- 
FM656, 11 p. 
F for fully recruited ages (5-9) increased from 0.2 in 
1976 to 1.3 in 1991 (Huntsman et al. 2 , Murphy VPA, 
M= 0.28). The F for ages 1-4 showed similar trends, 
although the magnitude of the increase was less 
(Huntsman et al. 2 , Murphy VPA, M= 0.28). Owing to 
the changes in the life history of red porgy since 1972, 
these estimates of fishing mortality are probably 
high; yet, the increasing trend in fishing pressure is 
evident. Except for an increase during 1981-83, land- 
ings of red porgy have been declining since 1973 (Fig. 1). 
Similarly, the number of recruits to age 1 have de- 
clined steadily since 1974 (Huntsman et al. 2 , Murphy 
VPA, M= 0.28). An estimate of SSR in 1993 was only 
18% (Huntsman et al. 2 , Murphy VPA, M- 0.28). 
Again, the changes in the life history of red porgy since 
1972 indicate that Huntsman et al. 2 may have under- 
estimated the decline in the abundance of age-1 fish. 
Concurrent with the fishery becoming increasingly 
overexploited, there has been corresponding change 
Mean back-calculated fork length (mm 
Table 8 
) at age for red porgy (most recent annulus; standard error in parenthesis). 
Age (yr) 
1988 
1989 
1990 
1991 
1992 
1993 
1994 
1 
163 (2) 
180 (3) 
173 (4) 
166(2) 
159 (2) 
171 (2) 
161 (2) 
77=124 
n= 70 
77=78 
77 = 126 
oo 
ii 
£ 
77 = 70 
77=53 
2 
230(2) 
233 (2) 
218 (2) 
219 (2) 
210 (2) 
227 (3) 
237 (2) 
h=107 
n=148 
77=218 
77 = 110 
77=119 
OO 
II 
e 
77 = 101 
3 
266(3) 
273 (3) 
252 (2) 
259 (3) 
246 (3) 
257 (3) 
253 (3) 
n= 95 
77=54 
77 = 180 
77 = 71 
77=72 
77 = 104 
77=50 
4 
316(6) 
300 (6) 
286 (5) 
271 (3) 
274 (3) 
281 (4) 
275 (3) 
n= 26 
77=38 
77=26 
77 = 70 
77=64 
77=59 
77=106 
5 
382 (31) 
325 (7) 
304 (11) 
292 (8) 
298 (4) 
301 (5) 
291 (3) 
n= 2 
77=18 
77 = 16 
77 = 17 
77=43 
77=35 
77=86 
6 
328(7) 
301 (32) 
311 (13) 
326(6) 
299(7) 
298 (6) 
307 (5) 
n= 4 
77=3 
77 = 5 
77=13 
77 = 14 
77=25 
77=32 
7 
369 (10) 
339 (34) 
294 (7) 
331 (18) 
313 (6) 
354 
329 (5) 
n= 5 
77=3 
77 = 6 
77=5 
77=8 
77 = 1 
77=9 
8 
347 (3) 
335 
300(10) 
314 (5) 
320(4) 
351 (20) 
320 (6) 
ti= 4 
n- 1 
77=3 
77 = 4 
77 = 2 
n-1 
77=4 
9 
389 
392 (40) 
354 
335 (8) 
292 
n- 1 
77 = 2 
n= 1 
n=6 
n= 1 
10 
371 (27) 
378 (17) 
350 (16) 
336(4) 
382 
77=2 
77 = 2 
77=4 
n= 2 
77 = 1 
11 
362 
n- 1 
12 
367 
356 
349 
n- 1 
n- 1 
77 = 1 
13 
382 (8) 
77=2 
