Estimation of biomass of horse mackerel (Trachurus trachurus L.) in northern-Spain ( Nortbern IXa and VIIIc ) using the daily egg production method.

In order to estimate the spawning stock biomass of horse mackerel in the North Atlantic Spanish waters, a series of egg and adult cruises were carried out by lEO (Instituto Español de Oceanografía) and AZTI -SIO (Instituto de Investigación y Tecnología para la Oceanografía, Pesca y Alimentación) . The survey was carried out from 23 April to 25 May 1992. A total of 627 plankton samples and 37 adults samples were collected. A total daily egg production of 3.3 X 1012 egg (SE = 7.26 X 1011 , CV = 0.22) was estimated for the whole area sarnpled (ICES Division Vlllc and subdivision northern IXa north). The estirnate of horse mackerel spawning biornass ranged from 486,549 tons (CV = 0.34, when using adult pararneter estirnates exclusively frorn the Spanish survey, down to 368,814 tn (C = 0.32), when alternatively using an estimate of relative batch fecundity from the southern region of horse rnackerel western stock

Stability of a neural network model with small-world connections

Small-world networks are highly clustered networks with small distances among the nodes. There are many biological neural networks that present this kind of connections. There are no special weightings in the connections of most existing small-world network models. However, this kind of simply-connected models cannot characterize biological neural networks, in which there are different weights in synaptic connections. In this paper, we present a neural network model with weighted small-world connections, and further investigate the stability of this model.Comment: 4 pages, 3 figure

Hydrographic features and dynamics of blue whiting, mackerel and horse mackerel in the bay of biscay, 1994-1996. A multidisciplinary study on sefos

Hydrographic and climatic conditions have been found to be one of the most important factors that can influence the distnbution and behaviour of adults, juveniles and early stages of fish. This relationship, which has been pointed out by several authors, is also the main objective ofthe SEFOS project, which studies the relationship between the distnbutions and migrations of commercially important fish species and the oceanography of the European shelf edge. Within this framework, the Bay of Biscay presents special oceanographic and climatic conditions that could intluence the aggregations of food and larvae in retention areas throughout this zone, which is one of the most important nursery areas for several fish species and seasonal migrations of blue whiting, horse mackerel and mackerel This paper presents the results of a multidisciplinary study of the relationship between the oceanographic conditions ofthe Bay ofBiscay and the distribution ofboth early stages - eggs and larvae - and adult fish ofhorse mackerel, mackerel and blue whiting for the period 1994-1996

Ising model in small-world networks

The Ising model in small-world networks generated from two- and three-dimensional regular lattices has been studied. Monte Carlo simulations were carried out to characterize the ferromagnetic transition appearing in these systems. In the thermodynamic limit, the phase transition has a mean-field character for any finite value of the rewiring probability p, which measures the disorder strength of a given network. For small values of p, both the transition temperature and critical energy change with p as a power law. In the limit p -> 0, the heat capacity at the transition temperature diverges logarithmically in two-dimensional (2D) networks and as a power law in 3D.Comment: 6 pages, 7 figure

Results of sardine daily egg production off the northern coast of Spain for April 2008.

This document presents the results of the SAREVA0408 ichthyoplankton survey conducted by IEO (Instituto Español de Oceanografía). This survey was carried out on board R/V Cornide de Saavedra during April 2008. The covered area was the North and North-western Iberian Peninsula waters and the inner part of the Bay of Biscay (from 42°N to 45°N).The present paper includes data on sardine (Sardina pilchardus) egg distribution and abundance from the SAREVA0408 survey, as well as the estimation of daily egg production (DEPM) for sardine in the North Spanish Atlantic, Cantabrian waters and south of the Bay of Biscay

Preliminary results of sardine daily egg production off the northern coast of Spain in April 2008.

This document presents the results of the SAREVA0408 ichthyoplankton survey conducted by IEO (Instituto Español de Oceanografía). This survey was carried out on board R/V Cornide de Saavedra for April 2008. The covered area was the North and North-western Iberian Peninsula waters and the inner part of the Bay of Biscay (from 42°N to 45°N).The present paper includes data on sardine (Sardina pilchardus) egg distribution and abundance from the SAREVA0408 survey, as well as the estimation of daily egg production (DEPM) for sardine in the north Spanish Atlantic, Cantabrian waters and south of the Bay of Biscay

Kinetic-growth self-avoiding walks on small-world networks

Kinetically-grown self-avoiding walks have been studied on Watts-Strogatz small-world networks, rewired from a two-dimensional square lattice. The maximum length L of this kind of walks is limited in regular lattices by an attrition effect, which gives finite values for its mean value . For random networks, this mean attrition length scales as a power of the network size, and diverges in the thermodynamic limit (large system size N). For small-world networks, we find a behavior that interpolates between those corresponding to regular lattices and randon networks, for rewiring probability p ranging from 0 to 1. For p < 1, the mean self-intersection and attrition length of kinetically-grown walks are finite. For p = 1, grows with system size as N^{1/2}, diverging in the thermodynamic limit. In this limit and close to p = 1, the mean attrition length diverges as (1-p)^{-4}. Results of approximate probabilistic calculations agree well with those derived from numerical simulations.Comment: 10 pages, 7 figure

DEPM 2014. Preliminary Egg Results for the Atlanto-Iberian Sardine ICES VIII and IXa

The triennial DEPM for estimation of sardine spawning biomass for the Atlanto-Iberian stock areas IXa – VIIIc and VIIIb up to 45 º N took place in the S and W (IPMA) from 15th March to 26th April and in the N (Galicia, Cantabrian Sea and French coast, IEO) between 29th March and 21st April. The whole area was surveyed however the Portuguese survey occurred much later than usual and suffered several interruptions; part of IPMA´s DEPM survey was conducted simultaneously to the acoustics survey onboard the same vessel. The number of fishing samples was maintained at levels similar to other years but it was evident that sardine schools were less available than during previous surveys in particular in the western and northern shores. Preliminary estimates highlighted a sharp decrease in egg production from 2011 to 2014; this pattern was particularly clear in the northern stratum