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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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| Perrotta, R.G.; Viñas, M.D.; Madirolas, A.; Reta, R.; Akselman, R.; Castro Machado, F.; Garciarena, A.D.; Macchi, G.J.; Moriondo Danovaro, P.; Llanos, V.; Urteaga, J.R.. |
| Between September 1st and 6th a research cruise was carried out in the Buenos Aires shelf area of "El Rincon" 39°40'-41°30'S, Argentine Sea SW Atlantic. The total area studied was 2,527.8 nautical mile2. Knowledge of the commercial fleet location at the time of the survey allowed to intensify sampling in a 'miniarea' of 52,8 nautical mile2. The acoustic assessment of chub mackerel (Scomber japonicus) biomass was 49,511.9 t, 94 of which corresponded to this last area. Fish samples coming from fishing trawls included only adult individuals of 240-460 mm total length (TL) and ages ranging 2-11 years. The limit age was estimated at 13 years and natural and total mortality rates at 0.23 and 0.54, respectively. Oceanographic conditions were those typical of the... |
| Tipo: Journal Contribution |
Palavras-chave: Population characteristics; Echo surveys; Mackerel fisheries; Fishery oceanography; Biomass; Environmental conditions; Fishery oceanography; Biomass; Environmental conditions; Http://aims.fao.org/aos/agrovoc/c_2938; Http://aims.fao.org/aos/agrovoc/c_926; Http://aims.fao.org/aos/agrovoc/c_32980. |
| Ano: 2003 |
URL: http://hdl.handle.net/1834/2418 |
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