Post-Mortem Onshore Transportation of Epiphytic Foraminifera: Recent Example from the Tunisian Coastline

Abstract

AasTgACr: The harder-island system that connects Jerba Island to the Tunisian coastline is composed mainly of carbonate biodasfie sands. Wellpreserved tests of dead epiphytic forantim'fera are abundant on the foreshore and backshore, but they are scattered and poorly preserved on the shoreface, where very fine sand-size eolian quartz, peloids, and broken bioclasts are the main components. The reason for this paradoxical pattern is that most epiphytic foramialfera are very easily removed as suspended load by store-generated currents and concentrated on beaches, washover fans, and small eolian dunes, kilometers away from their" original life environment. Similar bioaccnmulations are common in the fossil record and have often been interpreted incorrectly as prolific biocoenuses.

Benthic foraminiferal assemblages and test accumulation in coastal microhabitats on San Salvador, Bahamas

“…However, our results indicate that when variation associated with grain size has been partialled out, the calcareous macroalgae Halimeda incrassata accounts for a significant fraction of the residual foraminiferal variation of the thanatocoenoses. In general, Halimeda is highly abundant in shallow bays in the northern Caribbean, especially on coarse or solid substrates (Brasier, 1975;Hillis-Colinvaux, 1980;Liddell et al, 1988;Davaud and Septfontaine, 1995). Halimeda is colonized by various epiphytic foraminifera (Wilson, 2007;Buchan and Lewis, 2009).…”

“…leaves, exposed rhizomes, algae thalli and seagrasses (Cushman, 1922;Wright and Hay, 1971;Waszczak and Steinker, 1978;Langer, 1993;Alve, 1999;Wilson, 1998Wilson, , 2007Wilson, , 2008Wilson and Ramsock, 2007). Distinctive epiphytic foraminiferal communities develop on different macrophyte taxa (Langer, 1993;Fujita and Hallock, 1999;Ribes et al, 2000;Wilson, 2000Wilson, , 2008Fujita, 2004;Debenay and Payri, 2010), leav-Published by Copernicus Publications on behalf of The Micropalaeontological Society.…”

“…As epiphytic foraminifera are very abundant in nearshore environments, especially in tropical and subtropical regions (Renema and Troelstra, 2001;Renema, 2006), they are often used in palaeoecological studies as indicators of the presence of macroalgae or seagrasses or for determining the degree of allochthonous influence in assemblages of deeper-water sites (Thomas and Schafer, 1982;Davaud and Septfontaine, 1995; see also review of Reich et al, 2015). However, several studies have indicated a disparity between the living foraminiferal populations (biocoenoses) found in macroalgae and standing seagrass and macroalgae and the dead assemblages (thanatocoenoses) found in the sea-floor sediment below (e.g.…”