370 



Fishery Bulletin 104(3) 



A Hook and line 



Lil 



0-100 100-200 200-300 >300 W >300 N 



B Gill net 



Ml 



0-100 100-200 200-300 >300 W ;-300 N 



2 5 C Spear gun 



ik linn 



4—^ 1— r-1 1— . 



0-100 100-200 200-300 >300 W >300 N 



Distance from boundary (m) 



Figure 6 



Mean catch per unit of effort (CPUEl 

 for (A) hook-and-line, (B) gillnet, and 

 (C) spear gun gear deployed at three 

 distances from the boundary of Apo 

 Reserve (0-100, 100-200, 200-300 m 

 [shaded columns]; refer to Fig. 1) and 

 at two areas far (>300 m) from reserve 

 boundaries (W = western Apo Island 

 fishing ground, N=northern Apo Island 

 fishing ground [open columns]; refer 

 to Fig. 1). Error bars are 1 standard 

 error. 



Spatial patterns of CPUE near reserve boundaries 



Spatial patterns of CPUE away from reserve boundaries 

 differeci for hook-and-line, gillnet, and spear gun gear 

 (Fig. 6). Gillnet CPUE exhibited a pattern of decrease 

 from 0-100 to 200-300 m from the reserve boundar- 

 ies (from 0.88 to 0.70 kg/person per hour; Fig. 6B). 

 Gillnet CPUE further decreased >300 m from reserve 

 boundaries (western and northern fishing grounds). In 

 contrast, hook-and-line and spear gun CPUE was lowest 

 near (0-100 m) reserve boundaries, but much higher 

 at distances of 100-300 m from the boundaries (Fig. 

 6, A and C). Hook-and-line and spear gun CPUEs at 

 100-300 m from reserve boundaries were higher than 

 farther away (>300 m) from the boundaries (western 

 and northern fishing grounds). However, hook-and-line 

 and spear gun CPUEs were highest at 100-200 m from 

 reserve boundaries (Fig. 6, A and C). An ANOVA with 

 data for 0-300 m indicated only that CPUE did not 

 differ significantly with distance from reserve boundar- 

 ies (F,, o„=0.73, P=0.49) or with fishing gear {F^ 39=2.52, 



Table 5 



Frequency of fishing trips for each of the three distances 

 from the boundaries of Apo Reserve (see Fig. 1), for each 

 of hook and line, gill net, and spear gun. Fishing trips 

 were made between 22 July 2003 and 29 February 2004. 



Number of times fished 



Hook and line Gill net Spear gun 



Distance from reserve boundaries 



0-100 m 2 3 



100-200 m 43 24 



200-300 m 25 28 



4 

 33 



7 



P=0.09). However, an ANOVA with data for 0-300 and 

 >300 m indicated that CPUE (log [.v+1] transformed) 

 did not differ significantly with distance from reserve 

 boundaries (F^ -g=1.19, P=0.32) but differed significantly 

 among fishing gear (F., -^=7.28, P=0.001). 



Contrasting patterns were also found in fishing ef- 

 fort (frequency of fishing trips) at different distances 

 from the boundaries of Apo Reserve (Table 5). Hook- 

 and-line and spear fishing occurred most frequently 

 at intermediate distances from reserve boundaries, 

 but gillnet fishing occurred most frequently at the far- 

 thest distances. However, all types of fishing occurred 

 very infrequently within 100 m of reserve boundaries 

 (Table 5). 



Discussion 



Results indicate that the maximum possible contribution 

 of spillover from the no-take reserve to the overall yield 

 and income of the fishery at Apo Island is small. If one 

 assumes that the spillover of coral reef fishes is most 

 likely to operate on spatial scales of hundreds of meters 

 (Russ, 2002), and, thus, would be unlikely to affect fish- 

 ery yields on the western and northern fishing grounds, 

 the maximum possible contribution would be 10% of 

 the total fishery yield, but the real value is probably 

 much less than this. We assumed that the eight months 

 sampled in 2003-2004 are representative of the general 

 spatial pattern of fishing at Apo Island. Furthermore, 

 we assumed that the spatial pattern of fishing during 

 the four months not sampled (IVIarch to June) remains 

 consistent with the general pattern of fishing. It can be 

 estimated from the present study that the total fishery 

 yield at Apo Island in 2003-2004, excluding the yield 

 consumed locally, was around 10.4 tons/km- per year 

 (to the 60-m isobath). Thus, spillover from Apo Reserve 

 would have contributed very much less than 1.0 ton/km' 

 per year in 2003-2004. 



Fishing effort was often lowest on the fishing grounds 

 near the reserve. The fishery at Apo Island is primarily 

 hook and line, targeting reef-associated species (Caran- 

 gidae), and to a lesser extent reef planktivores iNaso 



