Temporal and spatial changes of demersal fish assemblage in a sea-bob-shrimp fishing area in south Brazil

Abstract

The temporal and spatial variability of demersal fish assemblage in a sea-bob-shrimp fishing area at the coast of northern Santa Catarina was examined over a sampling period of one year. Monthly samplings were conducted by bottom trawl tows during day and night hours in nine stations between October 2003 and September 2004. 8,967 specimens of 72 species representing 31 families were captured. Larimus breviceps, Stellifer rastrifer, Stellifer  brasiliensis, Paralonchurus brasiliensis, Menticirrhus americanus and Isopisthus parvipinnis were  predominant among the fish caught. The average number of species and individuals varied significantly over time and space. A smaller number of fish and species seem to occupy the area in the spring. There was a negative gradient in terms of abundance and species diversity between inner and outer areas. The time of the year and of the day significantly affected the use of the area by the fish, but no significant effects of depth on the fish assemblage were found. This monitoring has contributed to the expansion of knowledge and conservation of fish fauna in the area studied. Key words: spatial variability, temporal variability, demersal fish.