Nursery and spawning areas of deep-water rose shrimp, Parapenaeus longirostris (Decapoda : Penaeidae), in the strait of Sicily (Central Mediterranean Sea)

Abstract

The identification of nursery and spawning areas of coastal fish and shellfish populations represents fundamental information for stock assessment essential for giving advice for managers within the framework of Ecosystem Approach to Fisheries. This study investigates the bathymetric and spatial distribution of young-of-the-year and mature females of the deep-water rose shrimp, Parapenaeus longirostris, in the Strait of Sicily (Central Mediterranean Sea) in order to describe the species nursery and spawning areas. Data were obtained from trawl surveys carried out yearly in spring and autumn from 1994 to 2004, and nursery and spawning areas were inferred by means of GIS techniques. Species maximum abundance occurred between 100 and 300 m. We found that young-of-the-year concentrated on the outer shelf while mature females occurred mostly between the outer shelf and the upper slope. We detected four large areas of aggregation of young-of-the-year, and three areas of aggregation of mature females. High concentrations of young-of-the-year and mature females persistently occupied some of these areas, representing stable nursery and spawning areas. Young-of-the-year and mature females aggregate where retention and enrichment processes occur, linked to the semi-permanent patterns resulting from the meanders of the Atlantic Ionian Stream. We highlight the importance of studying the spatial distribution pattern of commercial species to identify habitats essential to those species’ life cycle. We detected deep-water rose shrimp nursery and spawning areas in the Strait of Sicily and discuss their spatial pattern in relation to the hydrological characteristics of the area.