Zeller et al ; Small-scale fishery catches for US Island areas in the Western Pacific 



271 



were reported by taxon, and thus allowed us to exclude 

 large pelagic species. 



Inshore, shore-based catches 



1965-81: The inshore catch data for this period were 

 based on the inshore creel survey data as reported in 

 the DAWR annual reports, including the often sep- 

 arately reported estimates for octopus and shellfish 

 (based on reef-gleaning), fish weirs, and the highly 

 irregular, seasonal catches of juvenile rabbitfishes (Si- 

 ganidae) and big-eye scad. Procedures for expanding 

 the catches were accepted as reported at the time. We 

 applied or accepted adjustment factors for nonsurveyed 

 periods as provided or used by the fishery data sources 

 (Zeller et aP), The years 1980 and 1981 were deemed 

 poorly reported because of limited survey coverage. 

 Therefore, we replaced the reported catches for 1980 

 and 1981 with the average catches for 1978-79 and 

 1982-83, respectively. 



1982-84: Data from Hensley and Sherwood (1993) 

 were used for the 1982-84 period because WPacFIN 

 has reported inshore catches only since 1985. It should 

 be noted that these data did not include those from 

 night fisheries and therefore under-represented actual 

 catches. 



1985-2002: We used the island-wide expanded catch 

 estimates from the inshore creel survey, as undertaken 

 by DAWR, and provided by WPacFIN. 



Supply (imports and catches) versus demand (consump' 

 tion) To assess whether the reported catches as out- 

 lined above accounted for the likely total catches and to 

 derive estimates of likely catches for the undocumented 

 1950-64 period, we compared estimates of total supply 

 (reported catches plus estimated imported catches) with 

 demand as approximated by consumption estimates. 

 For the purpose of supply and demand estimation, we 

 included catches of pelagic species as provided by WPac- 

 FIN and DAWR, with a fixed amount of 39 t/year carried 

 back from 1959 to 1950, based on DAWR's estimated 

 annual pelagic catch for 1960-62. 



Imports Information on reported imports was available 

 for 1999 and 2002 (Guam Department of Commerce'^), 

 which were converted to per capita rates (1999: 19.5 kg/ 

 person; 2002: 20.9 kg/person) using human population 

 statistics (U.S. Census Bureau^'), and for 1980 as an esti- 

 mated annual per capita import rate of 17.7 kg (Table 2). 

 There is a long-standing tradition of bringing fish into 

 Guam as part of personal travel. A large, but unknown 

 portion of these imports are so-called cooler-shipped fish 

 and are primarily from the Federated States of Micro- 

 nesia, Palau, and the Republic of the Marshall Islands. 

 These imports have been poorly recorded, especially 



^ Guam Department of Commerce. 2005. Website: http:// 

 www.admin.gov.gu/commerce (accessed 15 January 2005). 



^ U.S. Census Bureau. 2005. Website: littp://www. census, 

 gov/cgi-bin/ipc/idbsprd (accessed 15 January 2005). 



in the earlier periods. To account for under-reporting 

 of cooler-shipped imports in earlier years, we adjusted 

 the 1980 annual per capita import rate by 20%, to 21.2 

 kg. For 1950, we assumed a level of import of half of 

 the adjusted 1980 import rate (i.e., 10.6 kg; Table 2), to 

 account for the much lower air- and boat-based travel 

 between the various islands in 1950 compared to 1980. 

 We linearly interpolated import rates between the 1950, 

 1980, 1999, and 2002 import data anchor point estimates 

 and expanded these to total import estimates using 

 human population statistics. 



Another factor that may have influenced rates of im- 

 port and harvest is aquaculture. There is potentially a 

 considerable (but unknown) volume of locally farmed 

 tilapia, catfish, and milkfish that is sold without regu- 

 lation through small-scale markets and road-side ven- 

 dors, and these products are not reported or recorded. 

 Currently, it is not possible to estimate the impact of 

 aquaculture on the present estimation of catches. 



Demand Estimates of demand were based on the 

 reported annual per capita consumption rate of 27 kg of 

 seafood for 1980 (Zeller et aV^) — a rate that was carried 

 back unaltered to 1950. We thus assumed the same rela- 

 tive consumption patterns for 1950 as for 1980, which 

 may underestimate the seafood consumption patterns 

 for 1950, and thus is adding a conservative component 

 to our estimation. We accounted for the consumption 

 of pelagic species by removing the reported catches of 

 pelagic species for each year from total consumption 

 for that year, and subsequently derived estimated non- 

 pelagic per capita consumption rates with population 

 statistics (Table 2). 



For 1985-2002, we assumed that total consumption 

 was accounted for by the sum of reported catches plus 

 estimated imported catches. Total consumption was 

 adjusted by removing the reported pelagic catches, 

 and the 1985-2002 per capita nonpelagic consumption 

 rates were derived with human population statistics 

 (Table 2). 



For the 1981-84 period, we interpolated per capita 

 nonpelagic consumption rates between the 1980 and 

 1985 data anchor points. The growing concern about 

 market dumping of incidental bycatch from the pe- 

 lagic transshipment fleet onto the local seafood market 

 was not considered in the present study because it is 

 thought to be a relatively recent phenomenon. It would 

 be reflected in declining commercial reported catch 

 data because it replaces local fish in the commercial 

 market supply. 



Supply versus demand To derive estimates of catches 

 for the 1950-64 period, we assumed that domestic sea- 

 food supply was either locally caught, relying heavily 

 on subsistence fishing, or was part of the cooler-shipped 

 imports. Given the assumed imports, the likely total 

 local catches were derived as the difference between 

 import estimates and consumption estimates (Table 2). 

 Thus, in 1950, an assumed per capita import of 10.6 

 kg of seafood and an estimated per capita consump- 



