Identification and characterization of nursery areas of red mullet Mullus barbatus in the Central Tyrrhenian Sea

Red Mullet Mullus barbatus is an important target of fishing activities in the central Tyrrhenian Sea, so it is essential to identify its critical habitats in order to manage this resource efficiently. Our research specifically focused on the identification and characterization of nursery areas. The use of spatial interpolation techniques enabled us to identify five nurseries that were highly persistent through time. Moreover, the estimate of juvenile density confirmed the strong aggregation effect of these nursery grounds, as a great portion of young individuals were concentrated in a relatively small surface of the study area. The environmental characterization of these areas showed that juveniles were mainly distributed on bottoms with a relatively high percentage of sand (>70%; P <0.05). Shannon biodiversity index analysis indicated that the southern nurseries reached the highest values of habitat quality (P < 0.0001). Multivariate analysis showed that nursery grounds were divided into three main groups, and analysis of spatial dynamics showed that two different strategies characterized Red Mullet juveniles when density changes over time. In particular, in some areas young individuals selected habitats in a density-dependent way following the basin model scheme, while in other zones they selected habitats in a density-independent way according to the proportional density model. Results also showed that juveniles followed the proportional density model strategy into nursery areas with the highest Shannon biodiversity index values

Patrón reproductivo y características de la población de la salema, Sarpa salpa (Osteichthyes: Sparidae) en el mar Mediterráneo

The sexual maturation and the growth of the salema, Sarpa salpa (Linnaeus, 1758), along the Italian Mediterranean coast (central Italy), were studied in fish (n = 105) killed incidentally by underwater explosions during the construction of Civitavecchia harbour in 1999 and specimens collected with trammel nets (n = 339). This species is characterized by a protandric hermaphroditism and the sex change process occurs between 24 and 31 cm TL corresponding to a wide range of ages (3-7 years). Size at maturity (L50) was 19.5 cm, at which almost all the individuals were males. Two distinct spawning periods were observed: one in spring, from March to May, and the other in autumn, from the end of September to November. During the first year, compensatory growth occurred in the individuals born in the two periods. An annual regular pattern of ring deposition was identified in the otoliths: the translucent ring was laid down during the winter months, while the opaque ring was formed during the summer months. Back-calculated lengths at age were used to estimate the parameters of the Von Bertalanffy growth equation which were: L∞ = 37.27 cm, K = 0.27 year-1 and t0 = -0.53 year. Salema showed isometric growth (b = 3.04; P = 0.84; t = 0.19).La maduración sexual y crecimiento de Sarpa salpa (Linnaeus, 1758) en las costas del Mediterráneo italiano (Italia central) fueron estudiadas a partir de la recolecta de ejemplares muertos accidentalmente (n = 105) como consecuencia de las explosiones submarinas acaecidas durante la construcción del puerto de Civitavecchia en 1999, así como de ejemplares recolectados mediante redes de arrastre (n = 339). Esta especie se caracteriza por un hermafroditismo protándrico, ocurriendo el proceso de cambio sexual entre los 24 y 31 cm TL, los cuales corresponden a un amplio rango de edades (3-7 años). La talla de maduración (L50) fue de 19,5 cm, siendo la casi la totalidad de los individuos eran de sexo masculino. Se observaron dos períodos diferentes de reproducción: uno en primavera, de marzo a mayo y otro en otoño, de finales de septiembre a noviembre. Se observó, durante el primer año, un crecimiento compensatorio ocurrido entre los individuos nacidos en los dos períodos. Se identificó en los otolitos un modelo anual y regular de deposición de anillos. Se observó el depósito de un anillo translúcido durante los meses invernales, mientras que otro opaco se formó durante los meses de verano. Las composición por edades y tallas retrocalculadas se utilizaron para estimar los parámetros de la ecuación de crecimiento de Von Bertalanffy, es decir: L∞ = 37,27 cm, K = 0,27 año-1 y t0 = -0,53 año. S. salpa demostró un crecimiento isométrico (b = 3,04; P = 0,84; t = 0,19)

Comportamiento alimenticio y ración diaria de la solleta Citharus linguatula (Osteichthyes: Pleuronectiformes) en el mar Tirreno Central

Spotted flounder Citharus linguatula (Linnaeus, 1758) is one of the most abundant species within demersal fish assemblages next to the continental shelf (up to 200 m depth) of the Mediterranean Sea. In spite of the ecological importance of this species in the central Tyrrhenian Sea, many aspects of its biology (e.g. feeding behaviour) are poorly described. In order to analyze how feeding habits are related to the ontogenetic changes in this species, 2636 specimens (between 9 and 26 cm of total length TL) were collected from November 2000 to January 2002. During ontogenetic development spotted flounder occupied different trophic levels: diet shifted from mysids, predominantly in the smaller spotted flounder ( 19 cm TL). Before the transition to the icthyophagous phase, a more generalist foraging behaviour including decapods (Processa sp., Alpheus glaber), molluscs (Turitella sp.) and benthic fish (Lesuerigobius spp., Gobius niger, Callionymus spp., Arnoglossus laterna) dominated the diet. Seasonal analysis of the diet showed an increase in the presence of mysids in summer and autumn, and of decapods in summer and spring. Teleosteans are present throughout the year without significant variations. Daily ration values, computed from the Eggers method, ranged from 1.57% to 2.83% wet body weight, showing a negative relationship between reproduction and daily consumption rate.La solleta, Citharus linguatula, es una de las especies más abundantes entre las comunidades de peces de la plataforma continental (hasta los 200 m de profundidad) del Mediterráneo. A pesar de su importancia ecológica en el mar Tirreno central, muchos aspectos de la biología de C. linguatula (e.g. alimentación) continúan siendo desconocidos. Con el objetivo de investigar cómo los hábitos alimenticios están relacionados con los cambios ontogénicos en esta especie, se analizaron 2636 individuos, entre 9 y 26 cm de longitud total (LT), que fueron muestreados entre noviembre de 2000 y enero de 2002. Durante el desarrollo ontogénico C. linguatula ocupa diferentes niveles tróficos: la alimentación varía desde los misidáceos, que son predominantes para las solletas más pequeñas ( 19 cm LT). Antes de llegar a la fase piscívora, el régimen alimenticio es más generalista, incluyendo crustáceos decápodos (Processa sp., Alpheus glaber), moluscos (Turitella sp.) y peces bentónicos (Lesueurigobius spp., Gobius niger, Callionymus spp., Arnoglossus laterna). Los análisis estacionales de la dieta muestran un aumento de la presencia de misidáceos en verano y otoño, y un aumento de decápodos en verano y primavera. Los teleósteos están presentes todo el año sin ninguna variación significativa. Las valores de la tasa diaria de alimentación, calculados con el método de Eggers, variaron entre 1.57% y 2.83% del peso húmedo individual, con una relación negativa entre la reproducción y el consumo diario

Feeding behaviour and daily ration of the spotted flounder <i>Citharus linguatula</i> (Osteichthyes: Pleuronectiformes) in the central Tyrrhenian Sea

Spotted flounder Citharus linguatula (Linnaeus, 1758) is one of the most abundant species within demersal fish assemblages next to the continental shelf (up to 200 m depth) of the Mediterranean Sea. In spite of the ecological importance of this species in the central Tyrrhenian Sea, many aspects of its biology (e.g. feeding behaviour) are poorly described. In order to analyze how feeding habits are related to the ontogenetic changes in this species, 2636 specimens (between 9 and 26 cm of total length TL) were collected from November 2000 to January 2002. During ontogenetic development spotted flounder occupied different trophic levels: diet shifted from mysids, predominantly in the smaller spotted flounder ( 19 cm TL). Before the transition to the icthyophagous phase, a more generalist foraging behaviour including decapods (Processa sp., Alpheus glaber), molluscs (Turitella sp.) and benthic fish (Lesuerigobius spp., Gobius niger, Callionymus spp., Arnoglossus laterna) dominated the diet. Seasonal analysis of the diet showed an increase in the presence of mysids in summer and autumn, and of decapods in summer and spring. Teleosteans are present throughout the year without significant variations. Daily ration values, computed from the Eggers method, ranged from 1.57% to 2.83% wet body weight, showing a negative relationship between reproduction and daily consumption rate

MAREA PROJECT : MEDISEH (Mediterranean Sensitive Habitats) specific contract no 2 (SI2.600741)

Based on the following Terms of Reference (TOR) of the content of the European Commission DG MARE request Ares (2011)665688: “Compile information supporting the identification and location of nursery areas (juveniles in their first and, if appropriate, second year of life) and spawning aggregations. This information, which is to be collated and archived in formats adequate for GIS rendering, shall refer to all the demersal and small pelagic species in the Mediterranean included in Appendix VII of Council Regulation (EC) No 199/2008 as well as for the species subject to minimum size (Council Regulation (EC) No 1967/2006-Annex III). In addition, ecological characterisation of these areas, both in terms of biological community (assemblage) and habitats therein, must be provided.” The technical tender form of the Specific Contract 2 (MEDISEH) defined the following objectives: Review of historical and current data on the locations and the status of seagrass beds, coralligenous and mäerl beds in different GSAs (Geographical Sub-Areas amending amending the Resolution GFCM/31/2007/2) all over the Mediterranean basin. Transform the information into a digitilized format within the framework of a geodatabase Review and map of all existing specific Marine Protected Areas (MPAs) in the Mediterranean area as well as areas that are under any form of national or international regulation. Identify and map suitable areas for Posidonia, coralligenous and mäerl communities by developing habitat distribution models at different spatial scales. Review and map all existing information on historical and current data of nurseries and spawning grounds of certain small pelagic (i.e., Engraulis encrasicolus, Sardina pilchardus, Scomber spp., Trachurus spp.) and demersal species (i.e., Aristaeomorpha foliacea, Aristeus antennatus, Merluccius merluccius, Mullus barbatus, Mullus surmuletus, Nephrops norvegicus, Parapenaeus longirostris, Pagellus erythrinus, Galeus melastomus, Raja clavata, Illex coindetti, Eledone cirrosa) that are included in the Data Collection Framework for the Mediterranean and subjected to minimum landing size based on Council Regulation No 1967/2006-Annex II. Analyze existing survey data and apply spatial analysis techniques in order to identify locations that are more likely to be density hot spot areas or are being more suitable for fish nurseries and spawning grounds for Engraulis encrasicolus, Sardina pilchardus, Scomber spp., Trachurus trachurus, Aristaeomorpha foliacea, Aristeus antennatus, Merluccius merluccius, Mullus barbatus, Mullus surmuletus, Nephrops norvegicus, Parapenaeus longirostris, Pagellus erythrinus, Galeus melastomus, Raja clavata, Illex coindetti, Eledone cirrosa These areas will also be characterized from an environmental and ecological perspective upon data availability. Integrate and present the aforementioned information through a Web-based GIS viewer with an associated geo-referenced database that will operate as a consulting tool for spatial management and conservation planning. Following the revision of the knowledge base, to identify gaps and suggest future research priorities. In order to meet these objectives, an expert team was composed within the MAREA Consortium from scientists with established expertise in the different topics required, and working in different areas of the Mediterranean basin. The team formed to execute the project includes the main Institutes of EU countries in the Mediterranean, all having solid reputations in the fields covered. The participating Institutes/Entities operate in the Western, Central and Eastern parts of the Mediterranean basin, and this ensures familiarity with the geographical areas that are related to the specific tendering. Moreover, a large number of scientists outside of the MAREA Consortium collaborated on a volunteer basis with data and other input. Details on the list of experts and external collaborators can be found in each Work Package in the present report. For CV details, check the MAREA expert web-site http://www.mareaproject.net/.peer-reviewe

Seagrass meadows (Posidonia oceanica) distribution and trajectories of change.

Posidonia oceanica meadows are declining at alarming rates due to climate change and human activities. Although P. oceanica is considered the most important and well-studied seagrass species of the Mediterranean Sea, to date there has been a limited effort to combine all the spatial information available and provide a complete distribution of meadows across the basin. The aim of this work is to provide a fine-scale assessment of (i) the current and historical known distribution of P. oceanica, (ii) the total area of meadows and (iii) the magnitude of regressive phenomena in the last decades. The outcomes showed the current spatial distribution of P. oceanica, covering a known area of 1,224,707 ha, and highlighted the lack of relevant data in part of the basin (21,471 linear km of coastline). The estimated regression of meadows amounted to 34% in the last 50 years, showing that this generalised phenomenon had to be mainly ascribed to cumulative effects of multiple local stressors. Our results highlighted the importance of enforcing surveys to assess the status and prioritize areas where cost-effective schemes for threats reduction, capable of reversing present patterns of change and ensuring P. oceanica persistence at Mediterranean scale, could be implemented.This study was supported and financed by the Commission of the European Union (DG MARE) within the MAREA Framework contract (Call for tenders MARE/2009/05_Lot1) through the Specific Project MEDISEH (SI2.600741): Mediterranean Sensitive Habitats, that received 568.996 euro. The opinions expressed are those of the authors of the study only and do not represent the Commission’s official position. The European Commission is thankfully acknowledged.This is the final version of the article. It first appeared from NPG via http://dx.doi.org/10.1038/srep1250

Interpretazione di immagini sonar nella cartografia di Posidonia oceanica. Analisi e descrizione dei sonogrammi.

In this paper a series of characteristics of Posidonia meadows of the central Tyrrhenian Sea are described based on a detailed analysis of SSS sonograms and ROV images, The correct interpretation of SSS signals is fundamental to have detailed maps of Posidonia oceanica meadows and, in some cases, particular aspects of the meadows characteristics could create errors

La cartografia come strumento di analisi per i paesaggi marini. Le praterie di Posidonia oceanica: un caso di studio.

In this study the regression of a Posidonia oceanica meadow of central Tyrrhenian Sea is analyzed through a detailed study of actual and historic cartography. A seascape analysis was carried out on the current map to evaluate the habitat fragmentation. Moreover this approach enabled us to test the efficiency of a landscape study for the management of a coastal ecosystem