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| Hansen, J.E.; Gru, D.L.; Perrotta, R.G.. |
| An extensive area of the continental shelf -between 37°20' and 34°40'S - was reviewed through hidroacoustical methods in order to evaluate the anchovy biomass. Within the area of highest concentration, further data on anchovy abundance were recorded, and fish samples were taken. Large anchovy shoals were located at about 170 nm from Mar del Plata, mainly in zones with sharp changes in oceanographic conditions. The distribution of the species was not uniform, but "contagious", and the log-normal distribution provided the best fit for the echo-integrator recorded data. The biomass was estimated at 1,061,727 tons (Confidence limits in between 921,010 and 1,223,930 tons). Some parameters of the population were estimated, such as: lenght-weight relationship,... |
| Tipo: Journal Contribution |
Palavras-chave: Length-weight relationships; Sex ratio; Age composition; Growth curves; Echo surveys; Mortality; Age composition; Sex ratio; Mortality; Http://aims.fao.org/aos/agrovoc/c_29093; Http://aims.fao.org/aos/agrovoc/c_7014; Http://aims.fao.org/aos/agrovoc/c_4945. |
| Ano: 1986 |
URL: http://hdl.handle.net/1834/2038 |
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| Hansen, J.E.; Cousseau, M.B.; Gru, D.L.. |
| A total of 7263 otoliths were collected from anchovy samples taken during two pelagic cruises which were carried out in the Spring of 1978. An statistical analysis of back calculated length distributions of one-year-old fish (L1)was made. The L1 mean values taken by geographical latitude form a cline, with higher values in the northern samples, and decreasing Southwards. Within this latitudinal gradient two main anchovy populations can be identified, one in the region of Buenos Aires Province and the other in Patagonian waters. The L1 of the females is significatively larger than that of the males for the former population, whereas in the Patagonian area differences between sexes are not significant. The parameters of the von Bertalanffy Growth curves, as... |
| Tipo: Journal Contribution |
Palavras-chave: Stock identification; Otolith reading; Growth curves; Mortality; Mortality; Http://aims.fao.org/aos/agrovoc/c_4945. |
| Ano: 1984 |
URL: http://hdl.handle.net/1834/2043 |
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| Cousseau, M.B.; Gru, D.L.. |
| Samples of Sardina fueguina (Sprattus fuegensis)were taken during research cruises carried out in 1974 and 1978. Length and age frequency distributions were analyzed, and von Bertalanffy growth parameters were calculated for the coastal waters of two geographical regions: Province of Santa Cruz and northern part of Malvinas Islands. Lenght and weight growth curves have been calculated for each region and each year. Marked differences have been found between gowth parameters of both regions, and the calculated values showed a good fit with the observed ones. According to these results, it is possible to assume that the sardines of both regions constitute two different populations. However, more information on the total distribution of the species will have... |
| Tipo: Journal Contribution |
Palavras-chave: Age composition; Growth curves; Stock identification; Sardine fisheries; Age composition; Http://aims.fao.org/aos/agrovoc/c_29093. |
| Ano: 1982 |
URL: http://hdl.handle.net/1834/2052 |
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