Abesamis el a\ How much does the fishery at Apo Island benefit from spillover from a marine reserve' 



367 



yield and 19% to the total income from gill- 

 net fishing. Only 28% of the total spear gun 

 effort was made near Apo Reserve. However, 

 the overall spear gun effort near the reserve 

 was about three times higher than that on 

 the western fishing grounds. The fishing 

 grounds near the reserve contributed about 

 six times the yield and seven times the in- 

 come of spear fishing on the western fishing 

 grounds (Table 1). 



Among species groups, the highest yield 

 recorded was for reef-associated species, fol- 

 lowed by reef planktivores, and then reef 

 species (Table 2). Open water and off-reef 

 species were minor contributors to overall 

 yield. Reef-associated species together with 

 reef planktivores accounted for 69% of the 

 overall yield. The northern fishing grounds 

 contributed >80% of the total yield of reef- 

 associated species, reef planktivores, and 

 open water species (Table 2). Much of the 

 total yield of reef species (47%) was also 

 taken from the northern fishing grounds. 

 The western fishing grounds contributed 

 68% of the total yield of off-reef species but 

 accounted for little of the yield for other spe- 

 cies groups (Table 2). The fishing grounds 

 near Apo Reserve often accounted for the 

 smallest contribution to yield for all species 

 groups. However, about a quarter of the to- 

 tal recorded yield of reef species were taken 

 near the reserve. 



Spatial patterns of CPUE and IPUE 

 among fishing grounds 



(wJ (ft 



12 

 1 

 08 

 06 

 04 

 02 

 00 



Hook and line 



X n 



Gill net 



1 



Spear gun 

 25-1 



2.0- I 



'"' I [^ r 



05 ' I 



I W , I 1 , 1 I I 



NR W 



NR W 



NR W N 



LU 

 Q. 



D. 

 I 



40 

 30 

 20 

 10 

 



JL 



NR W N 



NR W N 



Figure 3 



Mean catch per unit of effort (CPUE ) and income per unit of effort 

 (IPUE) for hook-and-line, gillnet and spear at the three fishing 

 grounds at Apo Island. NR = near Apo Reserve, W=western Apo 

 Island, N = northern Apo Island (see Fig. 1). Error bars are 1 stan- 

 dard error. PHP=Philippine peso. 



Table 2 



Composition of total recorded yield of the fishery at Apo Island from 

 22 July 2003 to 29 February 2004. Contributions of the three fishing 

 grounds (see Fig. 1) are shown. Species groups: RA=reef-associated 

 species, RP=reef planktivores, RS=reef species, OW=open water spe- 

 cies, OR=off-reef species. Yield in July adjusted to 30-day period for 

 each species group. Table excludes 16 kg of unidentifiable catch. 



RA 



RP 



RS 



OW 



OR 



Mean hook-and-line, gillnet, and spear gun 

 CPUE were highest in the fishing grounds 

 near Apo Reserve (Fig. 3). CPUE near the 

 reserve was higher than on the northern 

 fishing grounds by a factor of 1.5, 1.4 and 1.4 

 for hook-and-line, gillnet, and spear fishing, 

 respectively. CPUE near the reserve was 

 higher than on the western fishing grounds 

 by a factor of 1.6, 1.1 and 2.0 for hook-and- 

 line, gillnet, and spear fishing, respectively. However, 

 ANOVA indicated that CPUE (log [x+l] transformed) did 

 not differ significantly among the three groups of fishing 

 grounds (F, 57=1.8?, P=0.16), but differed significantly 

 among fishfng gear (F^ 5^=9.26, P<0.001). 



The trends in mean IPUE reflected closely those 

 of CPUE (Fig. 3). Mean IPUE near the reserve was 

 higher than on the northern fishing grounds by a factor 

 of 1.4, 1.2, and 1.4 for hook-and-line, gillnet and spear 

 fishing, respectively. It was higher than on the west- 

 ern fishing grounds by a factor of 1.6, 1.1 and 2.2 for 

 hook-and-line, gillnet, and spear fishing, respectively. 

 However, ANOVA indicated that IPUE (log [.r+1] trans- 

 formed) did not differ significantly among the three 

 groups of fishing grounds (F., -~=0.49, P=0.62), but 



Total yield (kg) 2333 1772 1305 418 111 



Percent contribution 



Northern Apo Island 



Western Apo Island 



Near Apo Reserve 3.7 5.2 24.9 16.4 24.6 



differed significantly among fishing gear (F,, gy=6.77, 

 P=0.002). 



Monthly mean hook-and-line, gillnet, and spear gun 

 CPUE and IPUE near Apo Reserve were more variable 

 than in the other fishing grounds (Fig. 4, A-C). For 

 example, the monthly hook-and-line CPUE near Apo 

 Reserve changed from >1.5 to <1.0 to >2.0 and to <1.5 

 kg/person per hour from July to October. However, from 

 November to February, it remained at <0.5 kg/person 

 per hour, but was zero in January (Fig. 4A). Monthly 

 hook-and-line IPUE near Apo Reserve varied accord- 

 ingly. It changed from >100 to <50 to >150 and to <100 

 PHP/person per hour from July to October, but was less 

 than 30 PHP/person per hour from November to Febru- 

 ary and was zero in January. In contrast, the monthly 



