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| Registros recuperados: 40 | |
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| Perrotta, R.G.; Pertierra, J.P.; Viñas, M.D.; Macchi, G.J.; Tringali, L.S.. |
| Both mackerel mean biomass and mean fishing effort in Buenos Aires (Argentina) shelf during the period 1990-91/1994-95 were estimated. Those values were 85,792 t and 42,051 minutes, respectively. However, the best economic profit from the fishery (about $15,390,036)($1=U$S1) was estimated to take place at 28,000 minutes. It was observed a waste in fishing effort of the commercial fleet related with sea surface temperatures of 19°C or more. Moreover, adult mackerel find better trophic conditions on the continental shelf (depth 50m), while larvae originated from massive spawning in late November-early December, i.e., during the main fishing season, find their optimum at lower depths. Mackerel shoals enter and leave fishing grounds in a counterclockwise way... |
| Tipo: Journal Contribution |
Palavras-chave: Mackerel fisheries; Biomass; Catch/effort; Environmental conditions; Economic models; Commercial fishing; Biomass; Environmental conditions; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_32980. |
| Ano: 1998 |
URL: http://hdl.handle.net/1834/2465 |
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| Saavedra, A.; Gálvez, P.; Barria, P.; Espejo, M.; Barbieri, M.A.; Núñez, S.; Ortiz, J.; Torres, P.; Véjar, F.; Molina, E.; Cerna, F.; López, A.A.; Bustos, L.. |
| Se presentan los resultados de la evaluación acústica de la biomasa, abundancia y distribución espacial; oferta ambiental de alimento, y las condiciones oceanográficas físicas asociadas a la anchoveta (Engraulis ringens) y sardina común (Strangomera bentincki) en el período de reclutamiento de enero del año 2004 entre Topocalma (33º 50' S) y Punta Galera (40º 00' S). |
| Tipo: Report |
Palavras-chave: Biomass; Abundance; Geographical distribution; Environmental conditions; Stock assessment; Echo surveys; Biomass; Geographical distribution; Stock assessment; Environmental conditions; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_24251; Http://aims.fao.org/aos/agrovoc/c_32980. |
| Ano: 2004 |
URL: http://hdl.handle.net/1834/1738 |
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| Perrotta, R.G.; Madirolas, A.; Viñas, M.D.; Akselman, R.; Guerrero, R.A.; Sánchez, M.F.; López, F.; Castro Machado, F.; Macchi, G.J.. |
| In August 1996 acoustic methods were employed to estimate mackerel (Scomber japonicus) abundance in the Buenos Aires, Argentina shelf area of "El Rincón" (4,287 mn2), located between 39°- 40° 30' S. Results showed a biomass estimate of 77,260 t. ASIMRAD EK-500 equipment operated with a 38 KHz split-beam transducer was used. Midwater fishing trawls were employed to identify echotraces and to collect mackerel samples.Trawls 4 and 5 were the most successful. Samples included only adult fish (310-470 mm Lt and ages ranging 2-11). Length and weight growth parameters and mortality rates were estimated. Analysis of the stomach contents revealed that mackerel was feeding exclusively on zooplankters over 2 mmlength. The analysis of the characteristics (dimensions... |
| Tipo: Journal Contribution |
Palavras-chave: Abundance; Biomass; Population structure; Zooplankton; Environmental conditions; Echo surveys; Biomass; Population structure; Zooplankton; Environmental conditions; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_6115; Http://aims.fao.org/aos/agrovoc/c_15490; Http://aims.fao.org/aos/agrovoc/c_32980. |
| Ano: 1999 |
URL: http://hdl.handle.net/1834/2529 |
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| Alonso, R.. |
| El presente estudio se llevó a cabo con el propósito de conocer algunas de las condiciones hidrológicas y ambientales presentes durante la formación, el desarrollo y la terminación de eventos de “marea roja” en la temporada invierno-primavera en la bahía de Mazatlán, ello con el interés de explicar su origen. Los cambios de temperatura y salinidad a mediados de marzo del 2000, provocaron el aumento de la densidad del agua (-t) de manera significativa, coincidiendo con el inicio de la temporada de “mareas rojas” en el período de estudio. Las condiciones hidrológicas, durante el desarrollo de estos eventos, estuvieron enmarcadas por condiciones de alta estratificación de la columna de agua, lo cual fue corroborado por la aplicación de varios índices que... |
| Tipo: Theses and Dissertations |
Palavras-chave: 972; Red tides; Environmental conditions; Environmental conditions; Http://aims.fao.org/aos/agrovoc/c_32980. |
| Ano: 2004 |
URL: http://hdl.handle.net/1834/3446 |
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| Córdova, J.; Barbieri, M.A.; Espejo, M.; Núñez, S.; Ortiz, J.; Torres, P.; Bustos, L.; Véjar, F.; Catasti, V.; Valenzuela, V.. |
| El presente informe contiene los resultados de la cuantificación de la biomasa por hidroacústica del jurel (Trachurus murphyi) en la zona centro-sur, la distribución e indicadores biológicos del jurel, las condiciones ambientales y las relaciones entre éstas y la distribución del recurso. |
| Tipo: Report |
Palavras-chave: Biomass; Population number; Echo surveys; Environmental conditions; Vertical distribution; Geographical distribution; Biomass; Geographical distribution; Environmental conditions; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_5083; Http://aims.fao.org/aos/agrovoc/c_32980. |
| Ano: 2004 |
URL: http://hdl.handle.net/1834/1731 |
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| Njoka, S.W.; Ochiel, G.S.; Mailu, A.M.; Gitonga, W.. |
| The Kenya Agricultural Research Institute imported 12,300 curculionid weevils (Neochetina spp.) from diverse sources, for biological control of water hyacinth in Lake Victoria, as part of the World Bank-funded Lake Victoria Environmental Management Project in East Africa. In addition to the rearing and quarantine facility at Muguga, a second rearing facility was established in 1996 at Kibos, near Lake Victoria. The Kibos rearing facility and two community rearing facilities at the lakeshores, have produced approximately 100,000 adult weevils and 42,000 weevil eggs over a three-year period. Since January 1997, some 73,500 Neochetina weevils have been released at 29 sites and an additional 10,000 redistributed at several sites. Visual observations and... |
| Tipo: Proceedings Paper |
Palavras-chave: Environmental conditions; Environmental effects; Environmental protection; Inland waters; Biological control; Environmental conditions; Environmental protection; Inland waters; Water hyacinth; Http://aims.fao.org/aos/agrovoc/c_32980; Http://aims.fao.org/aos/agrovoc/c_15898; Http://aims.fao.org/aos/agrovoc/c_3876; Http://aims.fao.org/aos/agrovoc/c_15267. |
| Ano: 2001 |
URL: http://hdl.handle.net/1834/1283 |
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| Registros recuperados: 40 | |
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