Proefschrift -- Leiden. / In Dutch and English. "Stellingen" ([2] p.) inserted. Bibliography: p. 151-166.

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Graduation date: 1967

Thesis (doctoral)--Universität Bremen, 2004. / Includes bibliographical references (p. 145-159).

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No description available.

Thesis (Ph. D.)--Rutgers University, 2009. / "Graduate Program in Oceanography." Includes bibliographical references (p. 160-173).

In samples from 4095 m and 398 m in the Porcupine Seabight foraminiferans constitute 58.4 - 79.3~ of the total~meiofauna. Nematodes followed by harpacticoid copepods are the most abundant meiofaunal metazoan taxa. Foraminiferal densities (967 - 1331 individuals 10 cm-2 ) and diversities (68 - 95 species; Shannon- Wiener index = 3.21 - 4.15) are higher than recorded in most previous studies. This is attributed to the detailed sorting procedure adopted which also provides information on the sizestructure and vertical distribution of foraminiferal assemblages in the top 5 cm of sediment. Most specimens were smaller than 150 ~m and some were infaunal. Komokiaceans only occurred at the deeper site. Allogromiids, hormosinaceans and unilocular agglutinating forms had increased relative abundances at the deeper site while the Rotaliina were relativelY,less common. The composition of these assemblages is discussed in relation to changes in the sediment structure, as observed in resin impregnated sediment cores. The morphology and fine structure of two large agglutinating foraminiferans, Rhizammina al&aeformis Brady and Pelosina aff. aborescens Pearcy, was examined using light microscopy, SEM and TEM. In R. al&aeformis the test is a long, branching tube which sometimes forms a tangled mass on the sediment surface. It contains a protoplasmic strand and extracellular mass of stercomata. The protoplasm is deeply invaginated to produce a system of labyrinthine spaces communicating with the tube lumen and possibly providing sites for extracellular digestion. The stercomata are enveloped in an organic sheet-like system and contain clay minerals. In f. aff. arborescens the tree-like test projects above the sediment surface. Protoplasm occurs in the central lumen. in fine branching canals which ramify through the thick. muddy. test wall. as well as in the distal branching complex. In TEM the protoplasm has a highly vacuolated appearance. There are no stercomata. Differences between the two species seem to reflect different feeding strategies; R. alKaeform1s 1s probably a deposit feeder and f. aff. arbor esc ens a suspension feeder.

The Avon-Heathcote Estuary, located in Christchurch, New Zealand, experienced coseismic deformation as a result of the February 22nd 2011 Christchurch Earthquake. The deformation is reflected as subsidence in the northern area and uplift in the southern area of the Estuary, in addition to sand volcanoes which forced up sediment throughout the floor of the Estuary altering estuary bed height and tidal flow. The first part of the research involved quantifying the change in the modern benthic foraminifera distribution as a result of the coseismic deformation caused by the February 22nd 2011 earthquake. By analysing the taxa present immediately post deformation and then the taxa present 2 years post deformation a comparison of the benthic foraminifera distribution can be made of the pre and post deformation. Both the northern and the southern areas of the Estuary were sampled to establish whether foraminifera faunas migrated landward or seaward as a result of subsidence and uplift experienced in different areas. There was no statistical change in overall species distribution in the two year time period since the coseismic deformation occurred, however, there were some noticeable changes in foraminifera distribution at BSNS-Z3 showing a landward migration of taxa. The changes that were predicted to occur as a result of the deformation of the Estuary are taking longer than expected to show up in the foraminiferal record and a longer time period is needed to establish these changes. The second stage involved establishing the modern distribution of foraminifera at Settlers Reserve in the southern area of the Avon-Heathcote Estuary by detailed sampling along a 160 m transect. Foraminifera are sensitive to environmental parameters, tidal height, grainsize, pH and salinity were recorded to evaluate the effect these parameters have on distribution. Bray-Curtis two-way cluster analysis was primarily used to assess the distribution pattern of foraminifera. The modern foraminifera distribution is comparable to that of the modern day New Zealand brackish-water benthic foraminifera distribution and includes species not yet found in other studies of the Avon-Heathcote Estuary. Differences in sampling techniques and the restricted intertidal marshland area where the transect samples were collected account for some of the differences seen between this model and past foraminifera studies. xiii The final stage involved sampling a 2.20 m core collected from Settlers Reserve and using the modern foraminiferal distribution to establish a foraminiferal history of Settlers Reserve. As foraminifera are sensitive to tidal height they may record past coseismic deformation events and the core was used to ascertain whether record of past coseismic deformation is preserved in Settlers Reserve sediments. Sampling the core for foraminifera, grainsize, trace metals and carbon material helped to build a story of estuary development. Using the modern foraminiferal distribution and the tidal height information collected, a down core model of past tidal heights was established to determine past rates of change. Foraminifera are not well preserved throughout the core, however, a sudden relative rise in sea level is recorded between 0.25 m and 0.85 m. Using trace metal and isotope analysis to develop an age profile, this sea level rise is interpreted to record coseismic subsidence associated with a palaeoseismic event in the early 1900’s. Overall, although the Avon-Heathcote Estuary experienced clear coseismic deformation as a result of the 22nd of February 2011 earthquake, modern changes in foraminiferal distribution cannot yet be tracked, however, past seismic deformation is identified in a core. The modern transect describes the foraminifera distribution which identifies species that have not been identified in the Avon-Heathcote Estuary before. This thesis enhances the current knowledge of the Avon-Heathcote Estuary and is a baseline for future studies.

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