Estimated Commercial Landings
Commercial Purchase System Data Processing
The Estimated Commercial Landings Tables and Graphs in this web site are based on summarized data from the Commercial Purchase System. The processing for the Commercial Purchase System data collected from the fish wholesalers is fairly straightforward. A Commercial Fishery Receipt form is completed by the wholesaler each time fish are purchased from a fisherman. Catches are divided into categories for weighing by species or species group, and where practicable, the number of pieces is recorded.
All purchase data back to July 1979 was coded and computerized but only data beginning in 1980 is shown on this web site because the 1979 data is incomplete.
In earlier years Commercial Fishery Receipt Forms were collected by DAWR and sent to the WPacFIN central office in Honolulu. Preferably, initial quality control of the forms are done by Coop or DAWR personnel before they are entered for computer processing; however, these activities must sometimes be done by WPacFIN staff.
The data was entered into a computer and loaded into central WPacFIN data bases in Honolulu, where edit reports were generated and used to locate and correct any errors in the data base. Once all edits, verifications, and corrections were made, summary reports were generated. These reports included total monthly and annual landings by species, total landings by fisherman, and landings by fisherman by species. Commercial Fishery Receipt Forms were returned to DAWR along with summary reports and graphs for their use and for distribution to dealers.
Beginning in 1994 DAWR staff took over this task in Guam using a computer and software provided by WPacFIN. Numerous standard reports are available, but only the monthly and annual landings by species and species groups are provided in this web site.
Annual Percent Coverage Factors
Receipts submitted by all participating wholesalers on Guam are adjusted to create the estimated total commercial landings by dividing by an estimated annual percent coverage factor. This factor compensates for non-participating wholesalers and for casual sales of fish directly to consumers.
The annual percent coverage factor is subjectively created based on as much information as possible depending on the year, including: an analysis of the "disposition of catch" data available from the Offshore Creel Survey; an evaluation of the fishermen in the fishery and their entry/exit patterns; general "dock side" knowledge of the fishery and the status of the marketing conditions and structure; the overall number of records in the data base; and a certain measure of best guesses.
The values of these annual percent coverage factors used to compute the values shown on this web site are given below
| Year | Percent Coverage | Year | Percent Coverage | |||
| 1980 | 75.0% | 1994 | 60.0% | |||
| 1981 | 80.0% | 1995 | 60.0% | |||
| 1982 | 85.0% | 1996 | 70.0% | |||
| 1983 | 90.0% | 1997 | 80.0% | |||
| 1984 | 90.0% | 1998 | 80.0% | |||
| 1985 | 90.0% | 1999 | 80.0% | |||
| 1986 | 90.0% | 2000 | 85.0% | |||
| 1987 | 80.0% | 2001 | 85.0% | |||
| 1988 | 75.0% | 2002 | 85.0% | |||
| 1989 | 55.0% | 2003 | 85.0% | |||
| 1990 | 75.0% | 2004 | 85.0% | |||
| 1991 | 80.0% | 2005 | 85.0% | |||
| 1992 | 80.0% | 2006 | 85.0% | |||
| 1993 | 75.0% | 2007 | 65.0% |