Northern Shrimp (Pandalus borealis) on Flemish Cap in July-August 1997

A stratified random bottom-trawl surveys on Flemish Cap was carried out in July-August 1997 following the same method used since 1988. Results of shrimp population (Pandalus borealis) are presented in this paper and compared with those previously observed

Some Aspects of the Thorny Skate, Amblryraja radiata, Reproductive Biology in NAFO Division 3N (Elasmobranch Fisheries – Oral)

Thorny skate samples from August to December 2000 were examined to determine both sexes maturity stages, length at maturity and females potential fecundity. The size and number of the ovarian oocytes increase as the maturation progress. In fully mature ovaries the average number of developed eggs is between 40 and 45 and its final mean size is 12.5 mm. The minimum number of developing eggs per female found in the ovaries was 2 and the maximum 88. Very few females at either the capsule extrusion or other of the active uterine stages have been found. On the contrary most part of the adult males were at the fully mature stages, suggesting that the samples could be taken on a mating aggregation season. Using data from 1997, 1999 and 2000, both maturity ogives have been fitted. The females length at maturity obtained ranged between 60 and 54 cm and that of the males between 43 and 51 cm

Correlation between Risk Aversion and Wealth distribution

Different models of capital exchange among economic agents have been proposed recently trying to explain the emergence of Pareto's wealth power law distribution. One important factor to be considered is the existence of risk aversion. In this paper we study a model where agents posses different levels of risk aversion, going from uniform to a random distribution. In all cases the risk aversion level for a given agent is constant during the simulation. While for a uniform and constant risk aversion the system self-organizes in a distribution that goes from an unfair ``one takes all'' distribution to a Gaussian one, a random risk aversion can produce distributions going from exponential to log-normal and power-law. Besides, interesting correlations between wealth and risk aversion are found.Comment: 8 pages, 7 figures, submitted to Physica A, Proceedings of the VIII LAWNP, Salvador, Brazil, 200

Some Aspects of the Thorny Skate (Raja radiata Donovan, 1808) Reproductive Biology in NAFO Division 3N Regulatory Area

Thorny skate samples from August to December 2000 were examined to determine both sexes maturity stages, length at maturity and females potential fecundity. The size and number of the ovarian oocytes increase as the maturation progress. In fully mature ovaries the average number of developed eggs is between 40 and 45 and its final mean size is 12.5 mm. The minimum number of developing eggs per female found in the ovaries was 2 and the maximum 88. Very few females at either the capsule extrusion or other of the active uterine stages have been found. On the contrary most part of the adult males were at the fully mature stages, suggesting that the samples could be taken on a mating aggregation season. Using data from 1997, 1999 and 2000, both maturity ogives have been fitted. The females length at maturity obtained ranged between 60 and 54 cm and that of the males between 43 and 51 cm

Seasonality and reproductive parameters of the thorny skate (Raja radiata Donovan, 1808) in NAFO Division 3N

In this paper the seasonal and geographic pattern of the fishing effort distribution targeting thorny skate is described. The fishery is performed in fall and in a quite restricted area of Div. 3N, in shallow waters of less than 100 m. The results support that the fishery is largely based on a skate mating concentration. The estimated length at 50 % maturity in males and females is 51 and 55 cm respectively

Preliminary results of research cruises carried out by IEO on the High Seas of the SW Atlantic (2008-2009), regarding cephalopod target species (Illex argentinus and Loligo gahi).

In March 2008 the Instituto Español de Oceanografía (IEO) through its Oceanographic Centre in Vigo (IEO-COV) initiated a historical series of research cruises aiming the assessment of the main commercial stocks on the High Seas (HS) of the SW Atlantic, including the study of two cephalopod species of important commercial interest, Argentine short-fin squid (Illex argentinus) and Patagonian squid (Loligo gahi). This working document presents a brief description of the methodology used in the cruises and preliminary results concerning CPUE by depth strata and geographical distribution of both mentioned species

Spanish Skate (Raja radiata Donovan, 1808) Fishery in the Grand Bank (NAFO Division 3N): 1997-2000.

The Spanish skate fishery in NAFO Regulatory Area is performed from August to November in a quite restricted area of Div. 3N at depths between 51 and 100 m. Fishing effort, unstandardized catch rates, length composition, sexual maturity, by-catch, discards and sex-ratios are presented in this paper. The length range of thorny skate in the catches is mainly between 30 and 85 cm, with a mode of 50-51 cm. Both sexes appeared equally represented in the catches. The main by-catch in this fishery is American plaice and yellowtail flounder. A large proportion of mature males are observed

Results of the Spanish Experimental Fishing in NAFO Subarea 1

An experimental fishing was carried out with a commercial Spanish vessel from October to December of the year 2003 in the Subarea 1. The main objective of the experimental fishing was to search for cephalopods species concentrations inside the territorial waters of Greenland. During the experimental fishing a scientific observer stayed on board to collect effort data, catches and yields by haul and Division, strata and gear. The observer carried out length distributions samplings of the following species: Pandalus borealis, Sebastes spp., Hippoglossoides platessoides, Gadus morhua and Macrourus berglax. Biological samplings of Reinhardtius hippoglossoides, Hippoglossoides platessoides, Gadus morhua and Gadus ogac were also carried out. Greenland halibut was the main species caught and the cephalopods, target species, have not been found in the experimental fishing

Emergence of communities on a coevolutive model of wealth interchange

We present a model in which we investigate the structure and evolution of a random network that connects agents capable of exchanging wealth. Economic interactions between neighbors can occur only if the difference between their wealth is less than a threshold value that defines the width of the economic classes. If the interchange of wealth cannot be done, agents are reconnected with another randomly selected agent, allowing the network to evolve in time. On each interaction there is a probability of favoring the poorer agent, simulating the action of the government. We measure the Gini index, having real world values attached to reality. Besides the network structure showed a very close connection with the economic dynamic of the system.Comment: 5 pages, 7 figure