Vertical fluxes of coccolithophores and foraminifera and their contributions to CaCO3 flux off the coast of Ensenada, Mexico
Coccoliths and foraminifera fluxes and their contributions to CaCO 3 were estimated by analyzing the material collected by a sediment trap installed in the area adjacent to Ensenada, Baj a California (Mexico). Coccoliths were identified and counted f rom images obtained with a Zeiss-Supra 55VP scann...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2017 |
| País: | México |
| Institución: | Universidad Autónoma de Baja California Sur |
| Repositorio: | Redalyc-UABCS |
| OAI Identifier: | oai:redalyc.org:48054149005 |
| Acceso en línea: | https://www.redalyc.org/articulo.oa?id=48054149005 |
| Access Level: | acceso abierto |
| Palabra clave: | Ciencias de la Tierra CaCO 3 fluxes Sediment traps Baja California Coccolith fluxes Foraminifera fluxes |
| Sumario: | Coccoliths and foraminifera fluxes and their contributions to CaCO 3 were estimated by analyzing the material collected by a sediment trap installed in the area adjacent to Ensenada, Baj a California (Mexico). Coccoliths were identified and counted f rom images obtained with a Zeiss-Supra 55VP scanning electron microscope. Foraminifera were identified and analyzed with a Leica EZ4 ster eoscope. Total CaCO 3 was determined by coulometry. A total of 33 species of coccoli ths were recorded; the most abundant species were Emiliania huxleyi type A, Gephyrocapsa oceanica (Equatorial), E. huxleyi type B, and G. oceanica ( Larger ), contributing 74% of total coccolith flux. The maximum flux of coccoliths was 1,539 × 10 6 m –2 ·d –1 in sample A-8, the minimum zero in sample A-10, and the averag e 1,028 × 10 6 m –2 ·d –1 . Coccolith contribution to CaCO 3 content ranged from 0.14 mg·m –2 ·d –1 in sample A-12 to 25.00 mg·m –2 ·d –1 in sample A-1, with an average of 5.60 mg·m –2 ·d –1 . Helicosphaera carteri made the highest contribution with 10.00 mg·m –2 ·d –1 in sample A-1, and the rest of the species con- tributed <7.00 mg·m –2 ·d –1 . Six genera of planktonic foraminifera were identified: Globigerina , Neogloboquadrina , Globorotalia , Pulleniatina , Globigerinoides , and Orbulina . The maximum flux of foraminifera was recorded in summer (513 m –2 ·d –1 ) and the minimum in spring (9 m –2 ·d –1 ). Benthic foraminifera were found to make an important contributi on, even greater than the contribution from planktonic foramini fera, reflecting horizontal resuspension and/or transport processes. CaCO 3 contributions by coccoliths and foraminifera were <1% of total CaCO 3 , and the rest was contributed by fragments of the other calcareous groups. |
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