LIVE BENTHIC FORAMINIFERAL ASSEMBLAGES AT THE PACIFIC CONTINENTAL MARGIN OF COSTA RICA AND NICARAGUA
2008-07-01

Research Article| July 01, 2008 LIVE BENTHIC FORAMINIFERAL ASSEMBLAGES AT THE PACIFIC CONTINENTAL MARGIN OF COSTA RICA AND NICARAGUA Petra Heinz; Petra Heinz * Institute of Geosciences, Tübingen University, Sigwartstr. 10, 72076 Tübingen, Germany Correspondence author. E-mail: petra.heinz@uni-tuebingen.de Search for other works by this author on: GSW Google Scholar Wiebke Ruschmeier; Wiebke Ruschmeier Institute of Geosciences, Tübingen University, Sigwartstr. 10, 72076 Tübingen, Germany Search for other works by this author on: GSW Google Scholar Christoph Hemleben Christoph Hemleben Institute of Geosciences, Tübingen University, Sigwartstr. 10, 72076 Tübingen, Germany Search for other works by this author on: GSW Google Scholar Author and Article Information Petra Heinz * Institute of Geosciences, Tübingen University, Sigwartstr. 10, 72076 Tübingen, Germany Wiebke Ruschmeier Institute of Geosciences, Tübingen University, Sigwartstr. 10, 72076 Tübingen, Germany Christoph Hemleben Institute of Geosciences, Tübingen University, Sigwartstr. 10, 72076 Tübingen, Germany Correspondence author. E-mail: petra.heinz@uni-tuebingen.de Publisher: Cushman Foundation for Foraminiferal Research Received: 05 Dec 2006 Accepted: 21 Mar 2008 First Online: 03 Mar 2017 Online ISSN: 1943-264X Print ISSN: 0096-1191 © 2008 Journal of Foraminiferal Research Journal of Foraminiferal Research (2008) 38 (3): 215–227. https://doi.org/10.2113/gsjfr.38.3.215 Article history Received: 05 Dec 2006 Accepted: 21 Mar 2008 First Online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Petra Heinz, Wiebke Ruschmeier, Christoph Hemleben; LIVE BENTHIC FORAMINIFERAL ASSEMBLAGES AT THE PACIFIC CONTINENTAL MARGIN OF COSTA RICA AND NICARAGUA. Journal of Foraminiferal Research 2008;; 38 (3): 215–227. doi: https://doi.org/10.2113/gsjfr.38.3.215 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyJournal of Foraminiferal Research Search Advanced Search Abstract Living (rose-Bengal-stained) foraminifera were investigated from the continental margin off the Pacific Coast of Costa Rica and Nicaragua. Assemblages from seven stations, including mounds and mud volcanoes, were compared in terms of foraminiferal density, distribution patterns, diversity and species composition and related to environmental factors (satellite chlorophyll a imagery, organic carbon content in the sediment, available oxygen data, particle grain sizes). Sediments from mud volcanoes and mounds did not show direct influence of seepage. Highest foraminiferal densities were found on the slope off Nicaragua. The lowest foraminiferal densities were found in the north off Costa Rica where the smooth Cocos Plate segment subducts beneath the Caribbean Plate. Intermediate values were counted in the southern investigated area, where the down-going plate has a rough topography. Observed foraminiferal densities did not always correspond to chlorophyll a imagery or measured organic carbon content in the sediment, suggesting a possible influence of time-limited food supply, lateral transport of sinking organic material and local variability in the investigated area. In total, 187 species were recognized, distributed across the seven stations, which all showed high diversity. Foraminiferal associations contained many Buliminida, pointing to low-oxygen concentrations at the sediment-water interface. Some taxa indicated a possible bathymetric or regional limitation. The assemblage composition varied among the stations to such a degree that no commonalities were identified, based on results from multivariate analysis. This was also the case for samples originating from mounds and mud volcanoes, which did not show any outstandingly different assemblages, meaning that no characteristic foraminiferal assemblage could be used to identify these areas. This mosaic-like distribution pointed to a large degree of habitat heterogeneity in the relatively small area; the habitat heterogeneity could explain the overall high diversity of benthic foraminifera in the region. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.