An approach to the spatial distribution of fishing effort in the Gulf of Cadiz.

The spatial distribution of the fishing effort exerted by the trawl fleet of Isla Cristina port (Huelva, Spain) is simulated by means of an application (FAST) for Geographic Information Systems (ArcView), which can offer results just with limited input data. The simulation were carried out with three input variables: depth, distance from fishing grounds to port and the fishing laws in force in the area. The results obtained from two simulations tested match up the effort distribution detected in the area for both the fleet as a whole and a given segment of the same.Postprin

Historical and ecological drivers of the spatial pattern of Chondrichthyes species richness in the Mediterranean Sea

Chondrichthyes, which include Elasmobranchii (sharks and batoids) and Holocephali (chimaeras), are a relatively small group in the Mediterranean Sea (89 species) playing a key role in the ecosystems where they are found. At present, many species of this group are threatened as a result of anthropogenic effects, including fishing activity. Knowledge of the spatial distribution of these species is of great importance to understand their ecological role and for the efficient management of their populations, particularly if affected by fisheries. This study aims to analyze the spatial patterns of the distribution of Chondrichthyes species richness in the Mediterranean Sea. Information provided by the studied countries was used to model geographical and ecological variables affecting the Chondrichthyes species richness. The species were distributed in 16 Operational Geographical Units (OGUs), derived from the Geographical Sub-Areas (GSA) adopted by the General Fisheries Commission of the Mediterranean Sea (GFCM). Regression analyses with the species richness as a target variable were adjusted with a set of environmental and geographical variables, being the model that links richness of Chondrichthyes species with distance to the Strait of Gibraltar and number of taxonomic families of bony fishes the one that best explains it. This suggests that both historical and ecological factors affect the current distribution of Chondrichthyes within the Mediterranean Sea.Postprin

INFORME CAMPAÑA ARSA 0308

Durante los días 10 al 21 de Marzo del 2008 se ha llevado a cabo la campaña con arte de arrastre de fondo ARSA 0308. Al igual que en años anteriores, la zona prospectada ha correspondido a la zona de plataforma y talud continental de la parte española del Golfo de Cádiz, comprendida entre el meridiano 7º 20’ W, o la frontera con Portugal, el paralelo 36º 15’ N, entre las isóbatas de 15 y 800 metros, siendo su límite inferior la distancia de 6 millas a la costa. Dicha campaña se encuentra inmersa dentro del programa de recopilación de datos básico de la Unión Europea considerada como prioridad 1. La campaña se realizó a bordo del B/O "Cornide de Saavedra", siendo el objetivo previsto la estimación de los índices de abundancia (número y biomasa), de las especies demersales de mayor interés pesquero, así como de la fauna asociada a ellas

Demersal Resources

En prens

Origin and driving mechanisms of marine litter in the shelf-incised Motril, Carchuna, and Calahonda canyons (northern Alboran Sea)

Introduction and methodsMarine litter density, distribution and potential sources, and the impact on canyon seafloor habitats were investigated in the Motril, Carchuna and Calahonda canyons, located along the northern margin of the Alboran Sea. During the ALSSOMAR-S2S oceanographic survey carried out in 2019, canyon floor imagery was collected by a Remotely Operated Vehicle along 5 km in the Motril Canyon, 10 km in the Carchuna Canyon, and 3 km in Calahonda Canyon, together with 41 surficial sediment samples. Additionally, coastal uses, maritime traffic and fishing activity data were analyzed. A 50 m resolution multibeam bathymetry served as base map. ResultsIn the Motril and Calahonda canyons, the density of marine litter was low and the material was dispersed, very degraded and partially buried. In contrast, the Carchuna Canyon contained a greater amount and variety of litter. The Carchuna Canyon thalweg exhibited a density of marine litter up to 8.66 items center dot 100 m(-1), and litter hotspots with a density of up to 42 items center dot m(2) are found along the upper reaches of the canyon thalweg. DiscussionLow litter abundances found in the studied canyons most likely reflect low population densities and the absence of direct connections with streams in the nearby coasts. The high shelf incision of the Carchuna Canyon and its proximity to the coastline favor littoral sediment remobilization and capture as well as the formation of gravity flows that transport the marine litter along the thalweg toward the distal termination of the channel. Litter hotspots are favored by the canyon morphology and the occurrence of rocky outcrops. Most debris is of coastal origin and related to beach occupation and agricultural practices in the adjacent coastal plain. A third origin was represented by fishing gear in the study area. Fishing activity may be producing an impact through physical damage to the skeletons of the colonial scleractinians located in the walls of the Carchuna Canyon. In contrast, the Motril and Calahonda canyons can be considered passive systems that have mainly acted as depositional sinks in the recent past, as evidenced by buried marine litter.18-ESMARES2-CIRCA project of the Instituto Español de Oceanografıa; DL57/2016/CP1361/CT0009info:eu-repo/semantics/publishedVersio

Primer registro de anomalía intersexual gonadal de Trachurus mediterraneus (Steindachner, 1868) desde el mar de Alborán

First record of intersexuality gonad anomaly in Trachurus mediterraneus (Steindachner, 1868) from Alboran SeaEl objetivo principal de este trabajo es dar a conocer el primer registro de una anomalía intersexual gonadal de Trachurus mediterraneus desde el mar de Alborán (Mediterráneo occidental). Este espécimen es el primer registro de intersexualidad para un jurel en el mundo

Spatial distribution of fishing fleets in a future Fishery Protected Area in the Malaga Bay (Northwestern Alboran Sea).

Málaga Bay is an important area from the icthyoplankton viewpoint where it is possible to find more than 80 species belonging to 68 genera and 41 families. Furthermore, the bay is an essential spawning and nursery area for many species of commercial interest, such as sardine (Sardina pilchardus), anchovy (Engraulis encrasicolus), Atlantic horse-mackerel (Trachurus trachurus), Mediterranean horse-mackerel (T. mediterraneus) or hake (Merluccius merluccius). Local bottom trawl, purse seine and polyvalent artisanal fleets, have traditionally fished in this bay targeting on many species of fishes, crustaceans and molluscs. An ecological and fisheries study was undertaken in 2013 and 2014 with the purpose of assessing the suitability of Málaga Bay as a Fishery Protected Area. One of the important aspects taken into account is the spatial distribution of the fishing effort to evaluate its impact in the area. The findings achieved in this study are essential and valuable information for a proper fisheries management integrating the ecosystem-based approach into fisheries advice. The results show that Málaga Bay supports a heavy fishing pressure in all the fishing grounds which may affect both its commercial resources and sedimentary habitats.Versión del edito