Alguns aspectos da ecologia e biologia da Holothuria scabra na ilha da Inhaca

Abstract

The present work took place on the island of Inhaca, on the Sangala and Saco banks, in the period between July 1993 and February 1994. The sampling frequency was monthly and included transects in each of the strata in the low tide of spring tides. The collection of temperature and salinity data was carried out at pre-determined stations, as well as the bimonthly collection of sediment samples to determine, in the laboratory, the organic matter content and granulometry. The measurement of sea cucumbers collected by catchers was also carried out, as well as monthly surveys were carried out in the sea cucumber camps. In both banks, the high levels of organic matter and clay showed that they positively influence the occurrence and abundance of H. scabra . The presence of seagrasses was one of the factors for the abundance of the resource, while temperature and salinity had no influence on either the occurrence or the abundance of H. scabra. Regarding growth, no modal progression was detected, using the length frequencies of sea cucumbers, probably due to the impact of commercial harvesting on the study. The total recorded catch of H. scabra during the study period was 32.31 tons, which is believed to be below the true value. The fact that the reopening of commercial exploitation of this resource took place before its recovery, a process that takes at least two years; in addition to an overexploitation during the study period, these are aspects that may exert a negative influence on the stock of H. scabra in the coming years. (TRADUÇÃO NOSSA)