-Managing adequately the exploitation of commercial species subject to technical interactions is a key step towards the ecosystem approach to fisheries. We evaluate here, using a bio-economic modelling approach building on the ISIS-Fish simulation platform, the relative impact of total allowable commercial catches (TACC) and of taxes applicable to over-quota landings (deemed value) on the sustainability of a selection of species exploited by the New Zealand hoki (Macruronus novaezelandiae) fishery. We investigate some aspects of the hoki mixed fisheries, consisting of four fleets and nineteen métiers, by considering the technical interactions between hoki and Southern hake (Merluccius australis). The dynamics of effort allocation were modelled using gravity model, using value per unit of effort (VPUE) as attractivity coefficient. Several management scenarios, based on different levels of TACC, effort limits and deemed value have been defined. The impact of these strategies on spawning biomass and catches has been investigated. The results confirm that the deemed value may, in combination with TACC, be an efficient management tool. By increasing the hoki deemed value, we could somehow limit the decrease in the hoki TACC needed to harvest Western hoki sustainably. Constraining hoki fishing also restricts Southern hake fishing in the Chatham Rise and in the West Coast South Island, but leads to increased targeting of this species in the Sub-Antarctic area. The relative costs of renting/buying quota or paying the deemed value are most constraining when the hoki TACC is at relatively low level and when the hoki deemed value is more than 1.5 times the current value.Key words: Fleet dynamics / New Zealand hoki fishery / Deemed value / Fisheries management Résumé -La gestion adéquate de l'exploitation d'espèces commerciales sujettes à des interactions techniques constitue un premier pas dans la direction de l'approche écosystémique des pêches. Nous évaluons ici, au moyen d'une approche de modélisation bio-économique s'appuyant sur la plate-forme de simulation ISIS-Fish, l'impact relatif du total admissible de captures commerciales (TACC) et de taxes appliquées aux débarquements « hors quota » (taxes sur leur valeur estimée), sur la conservation d'une sélection d'espèces exploitées par la pêcherie de hoki (Macruronus novaezelandiae) néo-zélandaise. Nous étudions certains aspects de la pêcherie mixte de hoki, représentée par quatre flottilles et dix-neuf métiers, en considérant les interactions techniques entre le hoki et le merlu austral (Merluccius australis). La dynamique de l'allocation de l'effort de pêche a été modélisée en utilisant un modèle de gravité, dans lequel la valeur par unité d'effort (VPUE) représente le coefficient d'attractivité. On a défini plusieurs scénarios de gestion, basés sur différents niveaux de TACC, de limitation d'effort de pêche et de la taxe. L'impact de ces stratégies sur la biomasse féconde et les captures a été étudié. Les résultats confirment que la taxe, combinée avec les TA...
History.-His previous health seems to have been fairly good. He had an attack of acute articular rheumatism three or four years ago. He never worked in lead. He denied syphilis. He had never had sorethroat. About a year ago, he had an eruption on the chest, for which he was ordered baths, but no medicine ; and it disappeared after a fortnight's treatment. He was in good healtlh until six weeks or two months before admission, when he began to suffer from very severe frontal headache, which was worse at night, and was sufficiently severe to keep him awake. At the begirnniing of 'May, he had an attack one evening, with loss of colnsciousness. Oni coming to himself next morning, he found that he was paralysed oni the left side. He could not stand for four days, and it was still longer before he could hold anything in his hand. There was some difficulty in speaking; he did not forget his words, but could not pronounce them properly. He had gradually grown stronger; and, on admission, could walk about the ward, dragging the left leg a little. The grasp of the left hand was considerably lss than that of the right, and he had difficulty in raising Lhe arm over his head.When he was looking at an object in front of himii, ther-e was from time to time a little irregular movement in the eyes-a slight involuntary roll. If, however, either eye were shut, the other eye became the subject of very marked niystagmus-mainly horizontal, and coarse in quality. If he were looking with both eyes in such a way as to put the muscles on the strain, the nystagmus again came on, but to a less extent. The pupils were equal, and acted well to light. There was distinctly deficientaction on theleft side of the face; the left cornerof the mouthwas lessretractedthan
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