Abstract

A thin layer of medium to coarse calcareous sediments, termed Progreso Blanket sedimentary unit, characterizes the bottom of the sublittoral zone of Yucatán. This extensive sand bottom is the predominant feature of the inner shelf of the Campeche Bank. A very active and productive artisan fishing fleet operates in this area, exploiting populations of groupers, snappers, octopus, and sea cucumber (in terms of catch volume and economic importance). A relatively small area (1,240 km2) within this blanket in the northwestern zone of the Yucatán Peninsula was characterized and monitored during one year employing remote sensed imagery and direct field sampling with SCUBA. A multivariate statistics approach defined six different seascapes in the area, and their variability through the climatic seasons (dry, rainy, north-winds) was deter-mined along with the variability of fish communities and their association to the seascapes. Significant differences in benthic covers were found between dry and rainy seasons with north-winds season, but not between dry and rainy seasons. And fish communities fluctuated in an ascending gradient from the north-winds season up to the rainy season. The term sublittoral desert is appropriate for this area because of the resemblance of the sandy plains to land deserts, and because of the low fish biomass and species richness recorded. This ecological trait has important fisheries management implications: the necessity of an increased fishing effort to have a positive economic benefit, and the inherent fragility of the communi-ties due to their low biodiversity and abundance.

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