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Fishery Bulletin 104(3) 



important influence on the spatial pattern of effort 

 because results indicated that IPUE for all gears was 

 also highest on the fishing grounds near the reserve. 

 However, one cannot discount that the northern side of 

 Apo Island may be regarded by the local community as 

 their main traditional fishing ground. This area has 

 probably been fished for decades, providing the income 

 for families generation after generation. 



Other characteristics of the CPUE and IPUE data 

 may also provide a partial explanation. CPUE and 

 IPUE were more variable on the fishing grounds near 

 Apo Reserve (Fig. 4). In fact, the fishing grounds near 

 the reserve often had both the highest and lowest CPUE 

 and IPUE per month for all types of fishing gears (Ta- 

 ble 3, Fig. 5). The only exception was for spear gun, 

 which had the lowest CPUE and IPUE on the western 

 fishing grounds (Table 3). These findings may indi- 

 cate that near the reserve, fishermen could obtain very 

 high average monthly catch rates and income rates. 

 However, they may also indicate that near the reserve, 

 fishermen (using hooks and lines and gill nets) could 

 obtain very low average monthly catch rates and income 

 rates. Monthly CPUE and IPUE were least variable on 

 the northern fishing grounds (Fig. 4). In addition, the 

 highest minimum average monthly CPUE and IPUE 

 were always found in this area (Table 3). Therefore, 

 a plausible explanation for the spatial pattern of fish- 

 ing effort at the island scale is that fishermen prob- 

 ably tend to avoid fishing near Apo Reserve in order 

 to make their monthly incomes more stable and avoid 

 occasional very low catch rates. Fishermen may prefer 

 the northern fishing grounds even if catch rates in this 

 area are not as high as near the reserve because they 

 are assured of obtaining higher minimum yields and 

 a more stable income. This strategy may be a form of 

 financial "risk aversion" (Hilborn and Walters, 1992). It 

 is further postulated that such a risk aversion strategy 

 could explain why total spear gun effort was higher 

 on the fishing grounds near Apo Reserve than on the 

 western fishing grounds (Tables 1 and 3). Also, a risk 

 aversion strategy may partly explain why fishing with 

 gill nets and hook and line transferred to the western 

 fishing grounds instead of near the reserve during the 

 NE monsoon (Fig. 2B, Table 3). 



Other factors may also influence the decision by fish- 

 ermen to concentrate effort on the northern side of Apo 

 Island. For example, the largest and most valuable fish 

 recorded in this study, a 31.9-kg Caranx ignobilis worth 

 almost PHP 2400, was captured from the northern 

 fishing grounds. A high-priced catch such as this one 

 may have a tremendous psychological impact on local 

 fishermen. Anecdotal information seems to indicate 

 that the income from such a yield may be enough to 

 provide for 80% of the daily expenses of one family for 

 one month at Apo Island (Pascobello-Rhodes'^). In com- 



^ Pascobello-Rhodes, L. 2003. Personal commun. Apo Island 

 resident. Apo Island, Dauin Municipality, Negros Oriental, 

 Philippines, 6217. 



parison, the largest and most valuable fish caught near 

 Apo Reserve, also C. ignobilis, was only two-thirds the 

 weight (20.2 kg) and value (PHP 1515) of the largest 

 fish caught from the northern fishing grounds. This 

 fish was the only one caught near the reserve with a 

 value greater than PHP 1000. Local fishermen probably 

 consider fish of this size more common on the northern 

 fishing grounds. During this study, five individuals of 

 C. ignobilis (range: 15.0-19.0 kg) that were captured 

 from the northern fishing grounds had weights similar 

 to the largest fish caught near the reserve. Therefore, 

 the biggest psychological impact on fishermen may not 

 be due to spillover from the reserve. 



A perception by local fishermen that the northern 

 fishing grounds are productive areas for high-value spe- 

 cies may not only have a psychological basis. Results in- 

 dicate that the probability of capturing high-value reef- 

 associated species (Carangidae) and the probability of 

 landing a high yield of such species were highest on the 

 northern fishing grounds (Table 4). The same was true 

 for high-value reef planktivores (Caesionidae) (Table 4). 

 The probability of landing a high yield of high-value 

 open water species (Scombridae) was also greatest on 

 the northern fishing grounds (Table 4). Assuming that 

 fishermen prefer to target high-value species, these 

 findings indicate that fishermen have better chances 

 of making higher incomes from the northern fishing 

 grounds than from other areas. The better prospect of 

 making a higher income probably influences the deci- 

 sion by fishermen to concentrate effort on the northern 

 side of Apo Island whenever it is accessible. Similarly, 

 some fishermen probably shift to the western fishing 

 grounds during the NE monsoon (the "off-season") be- 

 cause of better chances of gaining higher incomes by 

 targeting high-value off-reef species (A. furca [Lutjani- 

 dae]) (Table 4). 



However, the results indicated that the probability 

 of capturing high-value reef species (Serranidae, Lut- 

 janidae, and Lethrinidae), or landing a high yield of 

 such species, was greatest on the fishing grounds near 

 Apo Reserve (Table 4). Fishing intensity for high-value 

 reef species, on the other hand, appears to be greatest 

 on the northern fishing grounds, because capturing or 

 landing a high yield of high-value reef species was most 

 frequent there (Table 4). Thus, it seemed that most 

 fishermen avoided fishing for high-value reef species 

 near Apo Reserve despite better chances of making high 

 incomes from high-value reef species. One plausible 

 explanation for avoiding the fishing grounds hear the 

 reserve is that fishermen would still prefer to fish the 

 northern fishing grounds because they can target the 

 high-value species that come in larger sizes (Carangidae 

 and Scombridae) or greater numbers (Caesionidae) and 

 at the same time occasionally capture high-value reef- 

 species. The high-value reef species (Serranidae, Lut- 

 janidae, Lethrinidae) are unsatisfactory alternatives for 

 fishermen because they come in smaller sizes (compared 

 to Carangidae and Scombridae) or in smaller numbers 

 (compared to Caesionidae), and therefore would fetch a 

 lower price. 



