http://hdl.handle.net/1834/1574 Wed, 19 Jun 2013 20:11:11 GMT 2013-06-19T20:11:11Z http://hdl.handle.net/1834/2568 Title: Zooplankton biomass in the reproductive area of the southern blue whiting (Micromesistius australis). Authors: Sabatini, M.; Alvarez Colombo, G.L.; Ramirez, F.C. Abstract: Total and size-fractioned zooplankton biomass (larger and smaller than 5 mm) were analyzed over two cruises conducted in the late austral winter (September 1994 and 1995) in the area surrounding Malvinas Islands at the time that massive spawning of southern blue whiting was expected to take place. Biomass was rather uniformly distributed in the area and dominated by the fraction larger than 5 mm in which euphausiids and secondarily chaetognaths were dominating in terms of both weight and number. The smaller fraction was mostly made up of copepods. From the high occurrence of euphausiids and seasonal abundance of the several species of copepods normally present within the area it was hypothesised that the feeding requirements of juvenile and adult blue whiting as well as those of larvae and postlarvae may be met during the winter spawning season. The data were also examined in conjunction with the general pattern of zooplankton biomass occurring in autumn and spring in the Southern Patagonian shelf. Fri, 01 Jan 1999 00:00:00 GMT http://hdl.handle.net/1834/2568 1999-01-01T00:00:00Z http://hdl.handle.net/1834/2571 Title: Sobre la dinámica poblacional de la caballa en la pesquería de Mar del Plata. Período 1980-1990 Authors: Perrotta, R.G.; Pertierra, J.P. Abstract: This species is a principal basic product of the local canned industry. The results show that the biomass and capture were variable for the studied period as a consequence of change in the capturability, and the fishstock is underexploited. Also was estimated the contribution of recruitment, growth and mortality in the total biomass. Fri, 01 Jan 1993 00:00:00 GMT http://hdl.handle.net/1834/2571 1993-01-01T00:00:00Z http://hdl.handle.net/1834/2554 Title: Report of the INIDEP working group on assessment of hake (Merluccius hubbsi) north of 48° S (Southwest Atlantic Ocean) Authors: Bezzi, S.I.; Cañete, G.R.; Pérez, M.; Renzi, M.A.; Lassen, H. Abstract: The assessment covers hake between 34° and 48°S (Argentina and Uruguay), excluding Golfo San Matías. Total international landings and Argentine catch-at-age and effort data available for the 1983-1991 period allowed an analytical assessment. Tunning of the VPA was made using Laurec-Shepherd analysis and Extended Survivor analysis. The results of these analysis are congruent with the information about the state of the stock. VPA biomass estimates are aound 2.1 and 2.7 mill. Tonnes, which are similar to those calculated through surveys. The Spawning Stock Biomass estimated for 1991 is considered to be within limits where the stock shows stable recruitment. At the present effort level, yield and Spawning Stock Biomass appear to remain stable. Management measures are also discussed. Sat, 01 Jan 1994 00:00:00 GMT http://hdl.handle.net/1834/2554 1994-01-01T00:00:00Z http://hdl.handle.net/1834/2572 Title: Presencia de veneno paralizante de moluscos en higado de caballa de la región costera bonaerense Authors: Carreto, J.I.; Akselman, R.; Cucchi Colleoni, A.D.; Carignan, M.O.; Pájaro, M. Abstract: During november 1992 an intense bloom of the toxic dinoflagellate Alexandrium tamarense accurred in coastal waters from Mar del Plata, Argentina. Toxicity testing of Mytilus edulis populations of the region revealed high levels of paralytic shellfish poison. In order to study the possible PSP accumulation in mackerel (Scomber japonicus), mouse bioassay(AOAC) was performed in livers from individuals captured during December 1992. Liver extracts were lethal to mice; the sumptoms observed were typical of those caused by paralytic shellfish toxins. Although PSPS concentration is below the established limit for human consumption, it suggests that mackerel can accumulate PSP toxins from its food. On the basis of stomach content analysis of sampled mackerel and the related literature, the occurrence of possible toxins vector organisms is discussed. Fri, 01 Jan 1993 00:00:00 GMT http://hdl.handle.net/1834/2572 1993-01-01T00:00:00Z