The importance of an appreciation of the geographical distribution of economically important activities and their interconnections is essential for activities like statistics gathering and resource management, since distance of fishing areas from the fishing communities exploiting them is an important consideration in relation to costs of fishing, but also in the setting up of sampling systems. Proper location of observers in relation to geographically strategic points is a major factor in reducing the costs in travelling between sampling sites. In a very real sense, a map portraying information from all sectors related to fisheries (a thematic map) can be one of the easiest ways of seeing at a glance, the various factors related to the sector as a whole (see Figure 1).
In talking about the concept of a thematic map, Butler (MS) notes that “…in contrast to the marine navigational tool or the terrestrial reference map, the thematic or geographic map is designed to communicate geographical concepts: distribution of densities, relative magnitudes, gradients, spatial relationships, movements and numerous other distributional relationships”. The information is portrayed visually with the aid of colour and symbology: the presentation of qualitative and quantitative marine resource data in this manner permits the following:
- an indication of existing and potential marine activities, hence assisting in the resolution of conflicts between multiple users of the coastal zone, e.g., aquaculture and tourism;
- an assessment of the current status of national and regional fisheries;
- the identification of information gaps and research needs;
- an indication of the level of reliability of the data; an important point when considering diverse information sources.
We may add that in relation to fisheries statistics collection, a large thematic fisheries map pinned to the wall in the fisheries department office, has the following uses:
- it facilitates discussion of work schedules by ensuring that everyone shares a common perception of the resource and the fishing sector,
- it helps confirm travel plans when visiting landing sites, etc.,
- it is essential to discussion of siting of development projects,
- it provides a logical framework for subdividing the area into statistical districts (= strata),
- it is an important and rapid cross-reference for the statistics and filing system.
Many other uses of such a map or maps will occur in specific situations, and it should be updated as new information is gathered (e.g., Table 1). In particular, the location of new landing points, processing plants and routes for transportation of fish to markets can be indicated, as well as points for import or export of fish or fish products (e.g., Figure 1).
A separate category of map is that used to display the results of a statistical survey. Such a type of map (e.g., Figure 2) may be especially valuable in planning and in illustrating problems to laymen and politicians.