[Abundance variations of fishes from sites with different levels of pollution in the sublittoral sector of Havana City, Cuba].

The impact of human activity affects fish populations. We studied the abundance of three selected fish species (Stegastes partitus, Thalassoma bifasciatum and Halichoeres bivittatus) in four sites with different degrees of pollution in Havana City: 30th street and 16th street; Miramar; Red Boy of Havana Bay; and the ending ofAlmendares's River. The sites were divided into five zones depending on their bottom characteristics.

Natural and human-induced variability in the composition of fish assemblages in the Northwestern Cuban shelf.

The main goal of the study was to obtain field data to build a baseline of fish assemblage composition that can be used comparatively for future analyses of the impact of human actions in the region. A basic network of 68 sampling stations was defined for the entire region (4,050 km2). Fish assemblage species and size composition was estimated using visual census methods at three different spatial scales: a) entire region, b) inside the main reef area and c) along a human impact coastal gradient.

[Trophie webs of reef fishes at Cuba's NW area. II. Functional groups].

A conceptual model of the food webs, mainly with fish, was built in a rocky shore of Havana City with data covering from October 2004 to February 2006. The stomach contents of the most abundant fish was complemented with the literature. We used the Relative Importance Index method to describe diets of carnivorous and omnivorous fish; and a modification of the Relative Abundance method for sponge eaters and herbivorous fish.

[Trophic webs of reef fishes in northwestern Cuba. I. Stomach contents].

Trophic webs of reef fishes in northwestern Cuba. I. Stomach contents.

Effects-based assessment in a tropical coastal system: status of bicolor damselfish (Stegastes partitus) on the north shore of Cuba.

The research was carried out to determine whether there are individual-level differences in the bicolor damselfish (Stegastes partitus) within the altered fish communities located on the north coast of Havana, Cuba. There was strong evidence of changes in some morphological and physiological characteristics associated with the impact of land-based pollution in the coastal zone. A combination of impaired recruitment due to habitat degradation with increased food supply due to eutrophication seems to be the best explanation for fishes being heavier and longer at polluted sites.