Biomasa y composición del zooplancton de interés trófico pesquero en areas del Atlántico Sudoccidental. Campaña H-01/93, 42°S – 51°S, enero 1993.
Autor: Betina Andrea Santos.
Contribución INIDEP 906
Santos, B.A. 1994. Biomasa y composición del zooplancton de interés trófico pesquero en areas del Atlántico Sudoccidental. Campaña H-01/93, 42°S – 51°S, enero 1993. INIDEP Informe Técnico 2, 5-21. Disponible en: http://hdl.handle.net/1834/6985.
Abundance and composition of zooplankton preys in the main fishing grounds off Argentina. Cruise: H-01/93, 42°S – 51°S, January 1993. Few is known about the distribution of patagonian zooplankton biomass and its seasonal variation. This paper studies the mesozooplankton and macrozooplankton (0,5 cm and 0,5 cm in length, respectively) biomasses shelf distribution and their composition, during a summer survey (42° to 51°S).Samples (84) were obtained by a Nackthai sampler (400um). Wet weight and volume were calculated for each fraction and also their predicted relation. Gelatinous biomass corresponding to salps and ctenophores were estimated only as volume. Southpatagonian mesozooplankton biomass was higher than macrozooplankton, and corresponded specially to copepods. At shelf break front the highest mesozooplankton value was found (0,88 g.m-3), and for macrozooplankton at San Jorge Gulf saline front (0,29 g.m-3). On an average, the biomass was lower than 0,30 g.m-3. Amphipods and euphausiids aItemated their dominance in the macrozooplankton fraction. Good estimations were obtained for wet weight from volume for the two fractions. In the northpatagonian sector, biomass was lower than the southem sector (0,10 g.m-3 on an average), but at the shelf break front the highest value of the research cruise was found (1,58 g.m-3) belonging almost exc1usively to copepods. Macrozooplankton biomass and occurrence sharply decreased. High concentrations of ctenophores were found in waters off Valdés Península. A good estimation was obtained for wet weight mesozooplankton from volume.