Geographical patterns in abundance and population structure of <i>Nephrops norvegicus</i> and <i>Parapenaeus longirostris</i> (Crustacea: Decapoda) along the European Mediterranean coasts

Abstract

SUMMARY:The main characteristics concerning distribution, size structure and total mortality of two of the most important decapod crustaceans of commercial interest in the Mediterranean Sea, Nephrops norvegicus and Parapenaeus longirostris, are studied along the European Mediterranean coasts. The study is based on data collected during a series of six trawl surveys performed in spring from 1994 to 1999 from the Gibraltar Straits to the Aegean Sea. The population size structure identified in the different geographical sectors is analysed taking into account two bathymetric sectors: continental shelf and upper slope. Differences in N. norvegicus population demographic structure among geographical sectors, as well as in total mortality, appear to be highly related to different exploitation levels. Size structure in P. longirostris also shows a great heterogeneity throughout the different geographical sectors. Considering that both species are heavily exploited all along the studied area, the observed differences can be interpreted as different responses to exploitation related to the widely differing life history characteristics of the mentioned species. In fact, N. norvegicus is a long-lived, benthic, burrowing species with low growth and mortality rates, and P. longirostris an epibenthic short-lived species characterised by higher rates of growth and mortality.

Variaciones espacio-temporales a pequeña escala en la dinámica poblacional y biología de la gamba blanca <i>Parapenaeus longirostris</i> (Crustacea: Decapoda) en el Mediterráneo occidental

“…Similar results were obtained by Abad et al (2007) in the Alboran Sea (south-western Mediterranean), where rose shrimp was captured by the bottom trawl fleet between 150 and 350 m depth. However, this is not a general rule for the Mediterranean, as standardised experimental MEDITS surveys reported the presence of this species from 50 m depth (Abelló et al, 2002). According to these authors, it is in these shallow waters that juveniles and larvae are usually found, while larger individuals are distributed in deeper waters, which is also reflected in our study by the increase in the mean length with depth.…”

“…In the Mediterranean, the most abundant information on deep-water rose shrimp comes from the eastern and central basins, where the species is more abundant than in the western basin (Abelló et al, 2002). Thus, in the eastern and central Mediterranean, there is information available on its distribution (e.g.…”

“…Mori et al, 2000;Bayhan et al, 2005), diet (Kapiris, 2004), fishery (Sbrana et al, 2006), including stock assessment (Levi et al, 1995;Lembo et al, 1999), and trawl selectivity (Deval et al, 2006b;Ragonese and Bianchini, 2006). In the western Mediterranean, the available studies have only focused on its distribution (Abelló et al, 2002), diet (Cartes, 1995), energy content (Company and Sardà, 1998) and morphology (Sardà et al, 2005) on the Iberian coast, and on its distribution (Nouar and Maurin, 2001) on the Algerian coast.…”

Spatial structure of the Caribbean lobster (Metanephrops binghami) in the Colombian Caribbean Sea

“…The biomass obtained in this study (26.40 kg km -2 ) was higher than similar Nephopidae species (Nephrops norvegicus) on the Catalan Sea (18.87 kg km (Ward and Davis 1987). However, the Norway lobster (N. norvegicus) is distributed between 200 and 500 m (Maynou et al 1998;Abelló et al 2002), but the highest yields take place at the 500 m stratum (Fonseca et al 2007). The size of M. binghami in this study is similar to other Nephropidae species (Nephrops norvegicus) caught in Portuguese waters, ranging from 18 to 59 mm CL (Fonseca et al 2007) and in the Catalan Sea (Spain, northwest Mediterranean), ranging from 12 to 58 mm CL (Maynou et al 1998), but smaller than reported of Nephrops andamicus in South Africa, ranging from 47 to 55 mm CL (Berry 1969).…”

Feeding ecology of <i>Parapenaeus longirostris</i> (Lucas, 1846) (Decapoda: Penaeidae) from the Ionian Sea (Central and Eastern Mediterranean Sea)

“…This epibenthic short-lived species is the main target species of a large fishing fleet working in the eastern Atlantic Ocean and is characterised by high rates of growth and mortality (Abelló et al, 2002). The principal fishing grounds are located in the south of Spain and Portugal (Pestana, 1991;Sobrino et al, , 2000, as well as areas off Morocco, Mauritania, Senegal, Guinea Bissau, Gabon and Angola (Cervantes and Goñi, 1986;Cervantes et al, 1991;Sobrino andGarcía, 1991, 1992a,b).…”