THE FISHERY

Catch data from 36 years of HIBT shows that after the first decade, that is since 1970, there has been no overall trend in catch or catch per unit effort. This suggests that as far as can be detected from these data there is no decline in the availability of Pacific blue marlin off Kona. This raises some very important questions. First, it is known that there has been an impressive increase in the commercial longline catch and fishing effort in Hawaiian waters over the last 6 years mainly as a consequence of increased domestic longline fishing. An explanation is required to explain why no effect of this pressure is apparent in the HIBT data. Second, if the Pacific wide CPUE is in decline, as it has been since 1960, why also is this overarching trend in CPUE not reflected in the HIBT data? Third, HIBT data do not reflect the trend in increasing local recreational fishing CPUE as assessed by recreational angler surveys. This indicates that HIBT catch and CPUE data may not be representative of the overall patterns of fishing. This is probably so as a consequence of them being collected from a restricted period of the year and can easily be influenced by short term events such as weather or seismic activity, a feature of the Kona coast. The fact that they are taken in a single week means that they are a "snapshot" rather than a full length feature movie of the total picture. While these are drawbacks, they also can also lend weight to the analysis since the data are taken at the same time of the year, each year and the "sample" is collected in the same manner each year by people whose skills and backgrounds are very similar using relatively standard gear. The validation of this "sample" may never be achieved in a rigorous sense but the time span of the collection is a strong factor in its favour and, despite some apparent contradictions, we remain Committed to maintaining the vigil.

Does recreational billfish catch data from other parts of the world show trends and influences of commercial fishing pressure? In short, yes. In Australia, Mexico and New Zealand there have now been gathered significant sets of data which demonstrate clear but not necessarily tight relationships between commercial fishing pressure and recreational fishing catch per unit effort (CPUE). These have most often been as a consequence of fishing area closures where gear conflict has been excluded and the result has most often been dramatic increases in the recreational catch. Our commitment to maintenance of the monitoring in Hawaii is therefore well founded. We are cognizant of the fact that the size of the ocean billfish "pool" into which Hawaii provides a window may be very large and that significant changes may take decades to become apparent. The down side is that it may take decades for any improvements to appear, unlike the rapid responses seen in Mexicn and New Zealand.

The rise in catch through the first 10 years is thought to be derived in part from application of improved technology to the recreational fishery. For example faster boats which cover more ocean. Until 1970, 11 or fewer areas were fished. After 1970 11 or more areas were fished with two exceptions, l983 and 1993. During the 1970's improved lines and tackles and increased skills in recreational fishing are also components of this increase. Average capture times have in general declined with the years. Such improvements seem to have resulted in a general decline in capture times. In the 1960's average capture times ranged between 50 and 60 minutes. In the 1970's there was a decrease from around 50 minutes toward the 30-40 minute range where we currently see average capture times.

The data show a 2 or 3 year cycle of high and low catch per tournament. This is matched by CPUE showing that more fish means more fish caught. This trend is apparent in the yellowfin catch data as well, although the match between the two dominant species is not always perfect. The two year gyre is also apparent in bait fish species and is documented for the Hawaiian waters. Should this regular fluctuating pattern cease and the good and not so good years become random, then we will have cause for concern even although the overall trend may not yet have become apparent.

The Catch