ABSTRACT The study of surface samples was used to determine the marsh foraminiferal distributions in five marsh areas in Nova Scotia: Chezzetcook Inlet. Chebogue Harbour, Wallace Basin, Summerville marsh, and Newport Landing. Detailed surface sampling in Chezzetcook revealed that marsh foraminifera are distributed in well-defined vertical zonations with respect to mean sea level and closely parallel marsh floral zonations. These zones vary slightly between marshes but appear to remain broadly similar throughout the world. The foraminiferal zonation in Chezzetcook Inlet is used to exemplify the general situation in Nova Scotia. In this estuary the vertical range of the marsh can be divided into two zones, each divisible into two subzones. Zone II, which covers most of the middle and lower marsh, extends from approximately mean sea level (0) to about +75 cm and is characterized by the presence of Cribrononion umbilicatulum, Ammotium salsum , Miliammina fusca and Trochammina inflata . At +75 cm these forms are replaced by Tiphotroca comprimata and Trochammina macrescens which characterize zone I up to +101 cm, where all foraminifera disappear abruptly. The foraminiferal disappearance marks the higher high water level. This distribution can be used to relocate former sea levels in subsurface material to an accuracy of within ±5 cm. Less detailed sampling of marsh areas in the other four study localities indicated that the same relationships observed in Chezzetcook occur there as well. Examination of detailed data from southern California and less detailed data from other parts of the world suggests that marsh foraminiferal assemblages can be used universally as accurate indicators of former sea levels. We describe a new species, Thurammina? limnetis n.sp. and, using an intergradational series, we place Jadammina polystoma in synonymy with its senior, subjective synonym Trochammina macrescens.

Abstract: This study investigated the extent to which deep-dwelling, infaunal foraminifera bias modern and fossil distributions in the subtropical mangroves of the Everglades (southwest Florida), and which sediment interval should be used as a modern analog for paleoenvironmental studies in this area. Typically, these studies are based on modern analogs from the upper 1 to 2 cm of sediments, as most benthic foraminifera live in the surface 1 cm, but in tropical mangrove environments, deep-dwelling infaunal foraminifera may be more common. The vertical distributions of live assemblages in cores from a mudflat and three mangrove sites were investigated. To examine the preservation potential of dead tests, distributions of wall types and inner test linings were recorded. The living depths of benthic foraminifera showed a landward deepening from 1 to 3 cm in mudflats and low mangroves and from 7 to 10 cm in middle and high mangroves, possibly due to a landward increase in oxygenation of the subsurface sediments. Modern assemblages from the top 2 cm included species common in the deep infauna and contained, on average, 36% of the total standing crop. Additions to total assemblages at greater depths by subsurface production were negligible. Thus, the upper 2 cm of the sediment column would be sufficient as a modern analog for paleoenvironmental studies in the southwestern Everglades. Preservation of dead tests is influenced by a landward increase in the degradation of agglutinated taxa through oxidation/bacterial breakdown of organic cements. Fortuitously, calcareous taxa preserve well in the carbonate-buffered sediments of the Everglades.

Abstract Nine non-pollen palynomorph (NPP) groups occur in Quaternary marine and brackish-water sediments; these groups represent various planktonic or micro- to macrobenthic organisms. Some extant NPP were previously classified as fossil Acritarcha, Chitinozoa or scolecodonts. We refer to reviews of these fossils and their applications for Paleozoic–Mesozoic biostratigraphy and palaeoecology but focus on extant marine NPP that can be studied by laboratory culture, genetics or micro-geochemical methods. Marine NPP include resting cysts of planktonic dinoflagellates and prasinophytes, tintinnids and other cilates, copepod eggs and skeletal remains, and various microzoobenthos: microforaminiferal organic linings, ostracod mandibles and carapace linings, various worm egg capsules and mouthparts. New micro-Fourier Transform Infrared spectroscopy spectra suggest the probable affinities of the tintinnid cyst type P and Beringiella . Our applications in marine biodiversity and provincialism studies emphasize under-studied polar regions and neglected ice-algae nano-plankton and compare climate-based NPP distributions to Ocean Biogeographic Information System realms. Trophic relationships are outlined using sediment-trap studies. Seasonal to annual-scale investigations of palaeoproduction provide new perspectives on ocean carbon budgets during times of rapid climate change and atmospheric carbon increase. More taxonomic and source-linkage studies of non-dinocyst marine NPP are needed but we outline potentials for studies of hemispheric or global-scale shifts in marine food webs as driven by ocean warming.