Variation of shrimp total catch related to the geographic distribution of sediments at fishing zone 90, Gulf of Tehuantepec, Oaxaca, Mexico

Abstract

The fishing zone 90 is located in the Gulf of Tehuantepec and this is composed of five sub-sectors from S-91 to S-95. The Oaxaqueña Coast is located between Salina Cruz City and The Boca de Tonalá (in the Mar Muerto lagoon sytem), where the S-91 and S-92 sub-sectors are located. The Chiapaneca Coast is located between the Boca de Tonalá and Puerto Chiapas, where the S-93, S-94 and S-95 sub-sectors are located. From S-91 towards S-95 sub-sectors the total catch of shrimp resource increased from 160 to 1,030 Kg, coincided with a descendent gradient of gravel and an ascendant gradient of mud (g). Sand was present in all sub-sectors, but was not dominant at the coast level except towards the oceanic front. Based on geographic information system techniques, at the fishing zone 90 two shrimp harvest sub-systems were observed and delimited. The first of those is the Oaxaqueña Coast where was recorded a lower shrimp catch level with gravel dominant in the S-91 sub-sector and a gravel-sand mix in the S-92 sub-sector. The second the Chiapaneca Coast where was recorded a higher shrimp catch level with mud dominant in the S-93, S-94 and S-95 sub-sectors. In this last place, shrimp resource showed an ecological distribution aggregate (Negative Binomial). Estimated correlation between total catch of shrimp resource and mud was significant (R = 0.867, p < 0.05) but it was not significant with gravel and sand.