There is also a great opportunity to increase our knowledge using data collected by gamefish anglers themselves. Existing records of several Papua New Guinea gamefishing clubs have been very useful in compiling this atlas. However, as the club recorders are the first to admit, present records have certain limitations for this kind of study. The first two of these problems, in particular, are not limited to this region but are typical of many recreational fishing data sets. Below we explain the significance of these limitations and how they might be overcome.
Effort is the amount of time spent fishing.
Records might show five times as many billfish caught in one area as in another but this tells us nothing about the numbers present unless we know the relative amount of fishing done in each area. There may simply be five times as much fishing done in the first area as the second. Similarly, most fish might be caught during a particular season but this may simply be the time of year when most of the fishing is done, perhaps because the weather is calmest and fishing most pleasant. Unless the number of fish caught can be standardised to number of billfish caught per hour fished, for example, it is very difficult to compare catch-rates between areas or seasons. Days spent fishing when no fish were caught are just as important to record as the days when big catches are made.