Data/hora: 07/06/2024 05:16:48

Provedor de dados: | 97
País: | Chile
Título: | Living (stained) calcareous benthic foraminifera from recent sediments off Concepción, central-southern Chile (&amp;#126;36° S)
Autores: | TAPIA,RAÚL; LANGE,CARINA B; MARCHANT,MARGARITA.
Data: | 2008-09-01
Ano: | 2008
Palavras-chave: | Benthic foraminifera; Sediments; Oxygen minimum zone; Concepción; Chile.
Resumo: | This study examines onshore-offshore and vertical distribution of living (Rose Bengal stained) benthic foraminifera (&gt; 180 &amp;#956;m fraction) from three sediment stations along a bathymetric transect off Concepción, Chile (station 18 = 88 m water depth, station 26 = 120 m, station 40 = 1,030 m), within and below the oxygen minimum zone. All cores were collected in austral winter. Calcareous foraminifera dominated the three stations. The species composition, living foraminifera density, and vertical distribution patterns within the sediment changed in accordance with bottom water dissolved oxygen concentration and food availability. Onshore-offshore pattern revealed overall highest living foraminiferal densities at shelf stations 18 and 26 where bottom water dissolved oxygen was lowest (~ 0.2 mL-1) and content in labile organic matter highest. Within the sediment, maximum relative abundances (50-60 %) of living organisms were found in the 0-1 cm interval at the organic-rich and oxygen-poor shelf stations 18 and 26. In the well-oxygenated (2.7 mL-1) slope station 40, 70 % of living foraminifera were observed deeper than the first centimeter. The number of species and the contribution of the &gt; 250 &amp;#956;m fraction to the total fauna larger than 180 &amp;#956;m increased offshore. Nonionella auris (d'Orbigny) dominated at stations 18 and 26 while a more diverse foraminifera fauna was found at station 40. This study provides the first quantitative data on living benthic foraminifera in the area; seasonal and interannual changes are not addressed.
Tipo: | Journal article
Idioma: | Inglês
Identificador: | http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2008000300009
Editor: | Sociedad de Biología de Chile
Formato: | text/html
Fonte: | Revista chilena de historia natural  v.81 n.3 2008