Characterisation and standardisation of a red shrimp <i>Aristeus antennatus</i>, (Risso, 1816) fishery off the Alicante gulf (SE Spain)

Abstract

SUMMARY: The red shrimp (Aristeus antennatus) is a target species of a deep trawl fishery in the Gulf of Alicante. This paper describes the fishery by following the activity of this trawl fleet between 1992 and 1999. Principal Components Analysis (PCA) of specific catch compositions identified five main components that explained 92% of the variability, and the catches were grouped into three main species: red shrimp, hake and blue whiting. Hierarchical Clustering Grouping of the percentage species catch composition allowed the fleet to be considered as two main groups, according to monthly landings and by differentiating the origin of the catches (slope or shelf). The species composition of the catch and the red shrimp catch rates (CPUE) differed between the two fleet groups. The application of Generalised Linear Modelling (GLM) to the CPUE series gave consistent indices of abundance. The fleet group, year and season had significant effects on shrimp catch rates, with the fleet group being the most important, and these models explained up to 62% of the total deviance. The abundance indices showed little variation from 1992, although 1994 had the highest value and 1997-1998 the lowest. Comparison with survey indices showed similar trends, while mean uncorrected CPUE differed. Monthly variations of shrimp indices showed a lower abundance in summer, which was attributed to the reproductive patterns of the species. As a result, the use of some fleet grouping techniques is recommended before standardising CPUEs to obtain trends or to calibrate assessment in a fishery. ESPAÑA). -La gamba roja (Aristeus antennatus) es la especie objetivo de la pesquería de arrastre profundo en el Golfo de Alicante. En este estudio se describe la pesquería siguiendo la actividad de la flota de arrastre entre 1992 y 1999. El Análisis de las Componentes Principales (PCA) de la composición de especies de las capturas, identificó cinco componentes principales que explican el 92% de la variabilidad, agrupándose las capturas en torno a tres especies principales; gamba roja, merluza y caballa. El agrupamiento jerárquico (Clúster) de las contribuciones porcentuales de las especies en cada desembarco, permite considerar la flota en dos grupos principales en función de sus capturas mensuales, diferenciando el origen de las capturas según procedan de la plataforma o del talud. La composición de especies en las capturas, así como las tasas de captura (CPUE) de gamba roja, resultan diferentes en los dos grupos de flota identificados. La aplicación de Modelos Lineales Generalizados (GLM) a la serie de CPUE de gamba roja proporciona índices de abundancia consistentes. El grupo de flota, el año y la estación tienen efectos significativos en las tasas de captura de gamba, siendo el grupo de flota el factor más importante, explicando los modelos más del 62% de la desviación total. Los índices de abundancia muestran pequeñas variaciones a lo largo del periodo estudiado, resultando 1994 el año de valor más alto y 1997-1998 los años de valores más bajos. La...

Characterisation, analysis and catch rates of the small-scale fisheries of the Alicante Gulf (SE Spain) over a 10 years time series

“…Analyses (Becker et al, 1988) were carried out on clusters in which the selected species represented at least 50% of landings, removing all those boats that landed less than 10 times per year. To avoid an excessive number of levels in the boat factor, four boat groups were established according to boat length: group 1 (G1) with length <6 m; group 2 (G2) with length >6 and <8 m; group 3 (G3) with length >8 and <10 m and group 4 (G4) with length >10 m. Frequency distributions for nominal CPUE are usually skewed, and the variances of the catch rates are not independent of the mean, with coefficient values for regression slope: log(CPUE variance) − log(CPUE mean) close to 2 (Stefansson, 1996;Goñi et al, 1999Goñi et al, , 2004García-Rodriguez, 2003;Maynou et al, 2003). In the present study, the CPUE distributions for the selected species were checked, showing the same pattern as previously described for fisheries modelling, with regression slope coefficients ranging from 1.5 to 2.8.…”

An introduction to Mediterranean deep-sea biology

“…Nowadays, thousand of tons of these species are landed along the Mediterranean coasts of the western and central basin (Relini et al, 1999;Demestre and Martín, 1993;Tudela et al, 2003;Carbonell et al, 1999;García-Rodríguez, 2003). Red shrimp fisheries are often distinct even if a degree of overlapping exists: the main A. foliacea fisheries are located in the Strait of Sicily and in Southern Sardinia, whereas A. antennatus is mostly caught in the western Mediterranean and in the Ionian Sea (Fig.…”

Deep-sea distribution, biological and ecological aspects of <i>Aristeus antennatus</i> ( Risso, 1816) in the western and central Mediterranean Sea

“…During the last ten years a variety of aspects of Aristeus antennatus (Risso, 1816) have been studied in detail in the western and central Mediterranean Sea, such as fisheries (Demestre and Lleonart, 1993;Demestre and Martín, 1993;Bianchini and Ragonese, 1994;Martínez-Baños, 1997;Sardà et al, 1998a;García-Rodríguez and Esteban, 1999;Carbonell, et al, 1999Carbonell, et al, , 2003Ragonese et al, 2001;Mytilineou et al, 2001;Papaconstantinou and Kapiris, 2001;Cau et al, 2002;Tudela et al, 2003), biology (Matarrese et al, 1992Sardà and Cartes, 1993;Ragonese and Bianchini, 1996;Mura et al, 1997;Follesa et al, 1998;Orsi Relini and Relini, 1998;Sardà et al, 1998b;Kapiris et al, 2002;García-Rodríguez, 2003), ecology (Sardà et al,1994;Sardà and Cartes, 1997;D'Onghia et al, 1997;Cartes and Maynou, 1998;Mura et al, 1998;Kapiris et al, 1999), and physiology (Company and Sardà, 1998;Puig et al, 2001). A number of research projects have been carried out on this species recently (RESHIO, COCTEL, DESEAS, INTERREG II, MEDITS, MEDBARI, MED-AQUA...).…”