ALBERT

Description: Living (stained) benthic foraminiferal faunas were analyzed in 51 surficial sediment samples taken from the northern Gulf of Cadiz continental shelf between the mouths of the Guadiana and Guadalquivir rivers. The distribution and abundance of 26 species with relative abundance 〉5% were related to water depth, sediment type, river discharge, water temperature, salinity, turbidity, and primary productivity. Hierarchical classification using R- and Q-mode cluster analyses, and individual distributions, allowed these taxa to be categorized into four general groups. Group 1 is represented by Bolivina ordinaria and Hopkinsina atlantica. These species are linked to river discharge, and are associated with muddy sediments. They are considered the most opportunistic species in the assemblage, and are associated with the limits of productivity. Group 2, contains Ammonia beccarii, Eggerelloides scaber, Elphidium gerthi, Quinqueloculina laevigata, and Q. stelligera, and is characteristic of shallow water depths. Its species are associated with different sediment types and their distribution is influenced by river discharge. Group 3 is dominated by Bulimina aculeata, B. elongata, Elphidium excavatum, E. cuvillieri, Epistominella vitrea, and Rectuvigerina phlegeri. These species display the highest abundances between 30–100 m water depths. They prevail in muds associated with weak hydrodynamics, low oxygenation, and high organic matter. Group 4 includes species that are more abundant in deep stations and is divided into two subgroups. Subgroup 4A includes Bolivina catanensis, B. italica, B. striatula, Cassidulina laevigata, Stainforthia sp., Nouria polymorphinoides, and Nouria sp., with higher abundances in one or two samples. Subgroup 4B, with Brizalina dilatata, B. spathulata, Bulimina marginata, Nonionella iridea, N. stella, and N. turgida, has patchy distribution. Higher abundances of Nonionella species off the Guadiana River are related to low temperature and salinity.

Description: Habitat patterns of subtropical and tropical planktic foraminifers in the Caribbean Sea were obtained from plankton samples collected in spring 2009 and 2013. The spatial distribution in surface waters (3.5 m water depth) and depth habitat patterns (surface to 400 m) of 33 species were compared with prevailing water-mass conditions (temperature, salinity, and chlorophyll-a concentration) and planktic foraminiferal test assemblages in surface sediments. Distribution patterns indicate a significant relationship with seawater temperature and trophic conditions. A reduction in standing stocks was observed close to the Orinoco River plume and in the Gulf of Paria, associated with high turbidity and concomitant low surface-water salinity. In contrast, a transient mesoscale patch of high chlorophyll concentration in the eastern Caribbean Sea was associated with higher standing stocks in near surface waters, including high abundances of Globigerinita glutinata and Neogloboquadrina dutertrei. Globorotalia truncatulinoides mainly lives close to the seasonal pycnocline and can be linked to winter conditions indicated by lower sea-surface temperatures (SSTs) of ∼20°C. Globigerinoides sacculifer and Globoturborotalita rubescens were associated with oligotrophic conditions in the pelagic Caribbean Sea during early spring and showed a synodic lunar reproduction cycle. The live assemblages in the water column from 2009 and 2013 were similar to those reported in earlier studies from the 1960s and 1990s and to assemblages of tests in the surface sediments. Minor differences in faunal proportions were attributed to seasonal variability and environmental differences at the local scale. An exception was the low relative abundance of Globigerinoides ruber in the Caribbean Sea in 2009 compared to surface sediment samples and plankton net samples collected in the 1960s and 1990s. Decreasing abundance of Gs. ruber white in the Caribbean Sea may be associated with increasing SSTs over past decades and changes in nutrient flux and primary production.

Description: The pore-densities (PD) in the tests of 232 specimens of the shallow infaunal foraminiferal species Bolivina spissa from eight locations off the Peruvian continental margin were investigated and compared to different environmental factors as water-depth, temperature, bottom-water oxygen ([O2]BW) and nitrate concentrations ([NO3–]BW). There is a negative exponential PD-[O2]BW correlation, but at oxygen-concentrations 〉10 µmol/l PD approaches a constant value without any further correlation to [O2]BW. The PD-[NO3–]BW relationship is better constrained than that for PD-[O2]BW. We hypothesize that the pores in the tests of B. spissa largely reflect the intracellular nitrate, and to a smaller extent the oxygen respiration. We also compared PD and porosity (P) of two single B.spissa and B.seminuda specimens from the same habitat. The comparison showed that P is significantly higher in B.seminuda than in B. spissa indicating that B.seminuda is much better adapted to strong oxygen-depleted habitats than B.spissa.

Description: Living (stained) benthic foraminiferal faunas were analyzed in 51 surficial sediment samples taken from the northern Gulf of Cadiz continental shelf between the mouths of the Guadiana and Guadalquivir rivers. The distribution and abundance of 26 species with relative abundance 〉5% were related to water depth, sediment type, river discharge, water temperature, salinity, turbidity, and primary productivity. Hierarchical classification using R- and Q-mode cluster analyses, and individual distributions, allowed these taxa to be categorized into four general groups. Group 1 is represented by Bolivina ordinaria and Hopkinsina atlantica. These species are linked to river discharge, and are associated with muddy sediments. They are considered the most opportunistic species in the assemblage, and are associated with the limits of productivity. Group 2, contains Ammonia beccarii, Eggerelloides scaber, Elphidium gerthi, Quinqueloculina laevigata, and Q. stelligera, and is characteristic of shallow water depths. Its species are associated with different sediment types and their distribution is influenced by river discharge. Group 3 is dominated by Bulimina aculeata, B. elongata, Elphidium excavatum, E. cuvillieri, Epistominella vitrea, and Rectuvigerina phlegeri. These species display the highest abundances between 30–100 m water depths. They prevail in muds associated with weak hydrodynamics, low oxygenation, and high organic matter. Group 4 includes species that are more abundant in deep stations and is divided into two subgroups. Subgroup 4A includes Bolivina catanensis, B. italica, B. striatula, Cassidulina laevigata, Stainforthia sp., Nouria polymorphinoides, and Nouria sp., with higher abundances in one or two samples. Subgroup 4B, with Brizalina dilatata, B. spathulata, Bulimina marginata, Nonionella iridea, N. stella, and N. turgida, has patchy distribution. Higher abundances of Nonionella species off the Guadiana River are related to low temperature and salinity.

Description: The present study investigated the combined effects of ocean acidification, temperature, and salinity on growth and test degradation of Ammonia aomoriensis. This species is one of the dominant benthic foraminifera in near-coastal habitats of the southwestern Baltic Sea that can be particularly sensitive to changes in seawater carbonate chemistry. To assess potential responses to ocean acidification and climate change, we performed a fully crossed experiment involving three temperatures (8, 13, and 18uC), three salinities (15, 20, and 25) and four pCO2 levels (566, 1195, 2108, and 3843 matm) for six weeks. Our results highlight a sensitive response of A. aomoriensis to undersaturated seawater with respect to calcite. The specimens continued to grow and increase their test diameter in treatments with pCO2 ,1200 matm, when Vcalc .1. Growth rates declined when pCO2 exceeded 1200 matm (Vcalc ,1). A significant reduction in test diameter and number of tests due to dissolution was observed below a critical Vcalc of 0.5. Elevated temperature (18uC) led to increased Vcalc, larger test diameter, and lower test degradation. Maximal growth was observed at 18uC. No significant relationship was observed between salinity and test growth. Lowered and undersaturated Vcalc, which results from increasing pCO2 in bottom waters, may cause a significant future decline of the population density of A. aomoriensis in its natural environment. At the same time, this effect might be partially compensated by temperature rise due to global warming.

Description: Benthic foraminiferal faunas from the shelf and upper continental slope of the Celtic Sea (NE Atlantic) show a rich variety of Trochamminidae species. We recognized 31 taxa, of which 18 could be determined to species level. These 18 species comprise about 9% of all species of the family Trochamminidae that are described from Recent sediments worldwide. For species determination and generic classification, we used existing taxonomic concepts and assessed their applicability. Besides the morphology of the test and internal structures, different apertural. features play a fundamental role in the systematic subdivision of the Trochamminidae. The position of the aperture controls the chamber arrangement and, therefore, the final shape of the test. However, we found no relationship between the apertural features and shape of the chambers as well as between apertural features and mode of life. Using apertural features for a sound taxonomic designation of our specimens proves difficult, because apertures are often obscured. Further, combined morphological and molecular-phylogenetic studies are required to constrain the taxonomic relevance of apertural characteristics.

Description: Die Untersuchung der Mikrofauna an einem neu aufgeschlossenen Eem-Profil ergab eine gute Übereinstimmung mit den Ergebnissen KONRADl's (1976) über das Eem-Vorkommen von Steensigmoos (Dänemark). Die durchschnittliche Wassertemperatur und der Salzgehalt der eemzeitlichen Kieler Bucht konnte aus der Zusammensetzung der Makro- und Mikrofauna auf 10-12° C und 25-30 %o eingegrenzt werden. Die Faziesabfolge im Profil der Scholle weist auf eine isostatische Landhebung Skandinaviens während des Eem-lnterglazials hin.

Description: Abnormal tests were commonly found in recent benthic foraminiferal assemblages in two fjords of the Kiel Bay, the western Baltic Sea. We assessed 18 different types of abnormalities, which were classified into five groups: chamber, apertural, umbilical, coiling and test abnormalities. In both fjords, test abnormalities are over-represented in Ammonia beccarii and under-represented in Elphidium excavatum subspecies compared to their average proportions in the living assemblages. We found two species-specific abnormality types that occurred only in Ammonia beccarii: a bulla-like chamber covering the umbilicus and spiroconvex tests. In the outer Kiel and Flensburg Fjords, the highest frequencies of abnormal tests were associated with occasional salt-rich, bottom-water inflows from the Belt Sea. Based on the predominance of megalospheric specimens of living foraminifera, it is suggested that coincidence of salinity changes with a reproduction period might be harmful, especially for young individuals, leading to development of abnormal tests. On the other hand, pollution by heavy metals led to higher percentages of abnormal tests in the inner parts of both fjords. Our data show different relationships between abnormal tests and heavy metals in both fjords due to different hydrographical conditions. Tests of Ammonia beccarii found in the Gelting Bay, the Flensburg Fjord, showed traces of dissolution and development of double tests. Such specific abnormal tests mirror the peculiar environmental setting characterized by changes in salinity and enhanced sediment redeposition. It is concluded that abnormal tests as an indicator of environmental pollution have to be used cautiously in areas with strong environmental instability.