Book ChapterDOI
Benthic foraminifera (Protista) as tools in deep-water palaeoceanography: environmental influences on faunal characteristics.
Reads0
Chats0
TLDR
Despite often clear qualitative links between environmental and faunal parameters, the development of quantitative foraminiferal proxies remains problematic, particularly those concerning the calibration of proxies, the closely interwoven effects of oxygen and food availability, and the relationship between living assemblages and those preserved in the permanent sediment record.Abstract:
Foraminiferal research lies at the border between geology and biology. Benthic foraminifera are a major component of marine communities, highly sensitive to environmental influences, and the most abundant benthic organisms preserved in the deep-sea fossil record. These characteristics make them important tools for reconstructing ancient oceans. Much of the recent work concerns the search for palaeoceanographic proxies, particularly for the key parameters of surface primary productivity and bottom-water oxygenation. At small spatial scales, organic flux and pore-water oxygen profiles are believed to control the depths at which species live within the sediment (their 'microhabitats'). Epifaunal/shallow infaunal species require oxygen and labile food and prefer relatively oligotrophic settings. Some deep infaunal species can tolerate anoxia and are closely linked to redox fronts within the sediment; they consume more refractory organic matter, and flourish in relatively eutrophic environments. Food and oxygen availability are also key factors at large (i.e. regional) spatial scales. Organic flux to the sea floor, and its seasonality, strongly influences faunal densities, species compositions and diversity parameters. Species tend to be associated with higher or lower flux rates and the annual flux range of 2-3 g Corg m-2 appears to mark an important faunal boundary. The oxygen requirements of benthic foraminifera are not well understood. It has been proposed that species distributions reflect oxygen concentrations up to fairly high values (3 ml l-1 or more). Other evidence suggests that oxygen only begins to affect community parameters at concentrations < 0.5 ml l-1. Different species clearly have different thresholds, however, creating species successions along oxygen gradients. Other factors such as sediment type, hydrostatic pressure and attributes of bottom-water masses (particularly carbonate undersaturation and current flow) influence foraminiferal distributions, particularly on continental margins where strong seafloor environmental gradients exist. Epifaunal species living on elevated substrata are directly exposed to bottom-water masses and flourish where suspended food particles are advected by strong currents. Biological interactions, e.g. predation and competition, must also play a role, although this is poorly understood and difficult to quantify. Despite often clear qualitative links between environmental and faunal parameters, the development of quantitative foraminiferal proxies remains problematic. Many of these difficulties arise because species can tolerate a wide range of non-optimal conditions and do not exhibit simple relationships with particular parameters. Some progress has been made, however, in formulating proxies for organic fluxes and bottom-water oxygenation. Flux proxies are based on the Benthic Foraminiferal Accumulation Rate and multivariate analyses of species data. Oxygen proxies utilise the relative proportions of epifaunal (oxyphilic) and deep infaunal (low-oxygen tolerant) species. Yet many problems remain, particularly those concerning the calibration of proxies, the closely interwoven effects of oxygen and food availability, and the relationship between living assemblages and those preserved in the permanent sediment record.read more
Citations
More filters
Book
Ecology and Applications of Benthic Foraminifera
TL;DR: This book presents the ecological background required to explain how fossil forms are used in dating rocks and reconstructing past environmental features including changes of sea level and demonstrates how living foraminifera can be used to monitor modern-day environmental change.
Journal ArticleDOI
Effects of natural and human-induced hypoxia on coastal benthos
Lisa A. Levin,Werner Ekau,Andrew J. Gooday,Frans Jorissen,Jack J. Middelburg,S. W. A. Naqvi,Carlos Neira,Nancy N. Rabalais,Jing Zhang +8 more
TL;DR: Large areas of low oxygen persist seasonally or continuously beneath upwelling regions, associated with the upper parts of oxygen minimum zones (SE Pacific, W Africa, N Indian Ocean), and support a resident fauna that is adapted to survive and reproduce at oxygen concentrations.
Journal ArticleDOI
Exponential Decline of Deep-Sea Ecosystem Functioning Linked to Benthic Biodiversity Loss
Roberto Danovaro,Cristina Gambi,Antonio Dell'Anno,Cinzia Corinaldesi,Simonetta Fraschetti,Ann Vanreusel,Magda Vincx,Andrew J. Gooday +7 more
TL;DR: This study provides scientific evidence that the conservation of deep-sea biodiversity is a priority for a sustainable functioning of the worlds' oceans and suggests that mutually positive functional interactions can be common in the largest biome of the authors' biosphere.
Book ChapterDOI
Chapter Seven Paleoceanographical Proxies Based on Deep-Sea Benthic Foraminiferal Assemblage Characteristics
TL;DR: In this paper, the authors focus on the paleoceanographic proxies based on deep-sea benthic foraminiferal assemblage characteristics, and present the following three proxy relationships that are promising: those between BFR faunas and BFR oxygenation, export productivity, and deep sea water mass characteristics.
Journal ArticleDOI
Natural and human-induced hypoxia and consequences for coastal areas: synthesis and future development
Jing Zhang,Denis Gilbert,Andrew J. Gooday,Lisa A. Levin,S. W. A. Naqvi,Jack J. Middelburg,M. I. Scranton,Werner Ekau,Angelica Peña,Boris Dewitte,Temel Oguz,Pedro M. S. Monteiro,Ed Urban,Nancy N. Rabalais,Venugopalan Ittekkot,W. M. Kemp,Osvaldo Ulloa,Ragnar Elmgren,Elva Escobar-Briones,A.K. van der Plas +19 more
TL;DR: Based on the collective contributions of members of SCOR Working Group #128, the present study provides an overview of the major aspects of coastal hypoxia in different biogeochemical provinces, in-cluding estuaries, coastal waters, upwelling areas, fjords and semi-enclosed basins, with various external forcings, ecosys-
References
More filters
Macrobenthic succession in relation to organic enrichment and pollution of the marine environment
T.H. Pearson,Rutger Rosenberg +1 more
Book
Foraminiferal Genera and Their Classification
Alfred R. Loeblich,Helen Tappan +1 more
TL;DR: Systematic descriptions of family group taxa based on genera of uncertain status and available family-group names used for foraminifera and genera erroneously regarded as foraminifers.
Book
Ecological Geography of the Sea
TL;DR: In this article, the authors used CZCS images to partition the Pelagic ecology of the oceans into four primary biomes: Atlantic Ocean, Indian Ocean, Pacific and Southern Ocean.