Seasonal cycle of appendicularians at a coastal station (38°28'S, 57°41'W) of the SW Atlantic Ocean

Temporal fluctuations in appendicularian species composition, abundance, size structure, and biomass, and their relationships with physical and biological factors were studied biweekly to monthly from March 2000 to April 2001 at a coastal station (38°28'S, 57°41'W) off Argentina, SW Atlant...

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Detalles Bibliográficos
Autores principales: Capitanio, F.L., Curelovich, J., Tresguerres, M., Negri, R.M., Viñas, M.D., Esnal, G.B.
Formato: JOUR
Materias:
abundance
biomass
chlorophyll a
community composition
hypothesis testing
metazoan
seasonality
secondary production
size structure
temporal variation
zooplankton
Argentina
Atlantic Ocean
Atlantic Ocean (Southwest)
South America
Animalia
Appendicularia (class)
Appendicularia sicula
Copepoda
Fritillaria (appendicularian)
Fritillaria borealis
Oikopleura dioica
Oikopleura fusiformis
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00074977_v82_n2_p171_Capitanio
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:Temporal fluctuations in appendicularian species composition, abundance, size structure, and biomass, and their relationships with physical and biological factors were studied biweekly to monthly from March 2000 to April 2001 at a coastal station (38°28'S, 57°41'W) off Argentina, SW Atlantic Ocean. The highest abundances and biomasses were recorded during spring-summer with a maximum in early January (4369 ind m-3 = 2321 μg C m -3). Secondary production was 76 mg C m-3 yr-1 and house production was 123 mg C m-3yr-1 Abundance of Fritillaria borealis Lohmann, 1896 was related to temperature changes, being more abundant during fall-winter; however, we measured only low biomasses. Appendicularia sicula Fol, 1874 and Oikopleura fusiformis Fol, 1872 appeared during summer and autumn, but their abundances were low. Oikopleura dioica Fol, 1872 was present all year and was the dominant species. When chlorophyll a concentration was high, and copepod abundance was low (fall-winter period), both juvenile and adult O. dioica were abundant in all of the samples. During the spring-summer period (low chlorophyll a concentration) a high predominance of adult animals (up to 1400 μm TL) was observed, suggesting a strong predation by copepods upon O. dioica eggs and juveniles. However, further field evidence is needed to test this hypothesis. © 2008 Rosenstiel School of Marine and Atmospheric Science of the University of Miami.

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