Guatemala
Golfo de Tehuantepec, Mexico
Figure 4 illustrates the distribution of all fish as observed with the acoustic integration system. The unit of fish abundance is 0.1 m2 per nm2 acoustic reflection and the categories of abundance are the same as those used in the previous reports.
The pattern of distribution is similar to that found in Surveys I and II with acoustic detection of fish almost wholly limited to a band along the coast not more than 20 - 25 nm wide. The highest concentrations are as previously found between San Jose and the border with Mexico. The main part of this biomass consisted of small pelagics dominated by anchovy but including also sardines, scads, especially Pacific bumper, barracudas, and some demersal. Some surface schools presumably of sardine were observed in shallow waters.
Figure 4 shows that the inshore belt of pelagic fish along the Guatemalan coast continues along the Tehuantepec Gulf coast, but with diminishing abundance especially north of the San Marcos bar. The dominating species were anchovy, bumper and other scads, sardine and barracudas, and among the demersal fish butter fish and grunts. As in previous surveys there is a tendency for the inshore fish distribution in the Gulf to extend further away from shore than off most of the Central American coast, out to a bottom depth of about 60 m.
Over the offshore parts of the shelf only mesopelagic fish (Myctophids) were recorded (not included in Figure 4).
