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Well-preserved remains of a Posidonia oceanica meadow have been found in a Lower Pleistocene (Calabrian) succession cropping out near Fauglia (Tuscany, Italy). This paper analyses and describes the benthic foraminiferal community associated with this well-preserved Pleistocene P. oceanica meadow, with the purpose of testing the usefulness of foraminifera as an Indirect Palaeo-Seagrass Indicator (IPSI), providing both qualitative and quantitative parameters to recognize other meadow-related environments where fossil remains of seagrasses are not preserved. Despite being influenced by some diagenetic processes that might have affected the foraminiferal assemblage, the Fauglia succession represents a suitable setting for testing benthic foraminifera as IPSI in a temperate environment. Considering this limitation, together with other ecological constraints such as seawater temperature, this study provides evidence of the high potential of benthic foraminifera as IPSI. Several parameters such as the modified Foraminifera Index (FI’), the “long vs. short life-span index” (ILS), and the presence of permanently attached, encrusting foraminifera were tested. New indexes were also developed, namely the K/R ratio, consisting of the ratio between keeled Elphidium and the sum of rounded elphidiids (e.g., Elphidium translucens, Cribroelphidium, Porosononion) and Haynesina, and the K/REXT ratio, consisting of the ratio between keeled Elphidium and the sum of rounded elphidiids, Haynesina and other related genera that display a rounded periphery (i.e., Astrononion, Melonis, Nonion, Nonionella, Valvulineria). All these indexes were examined, suggesting their potential use for recognizing seagrass-related palaeoenvironments. The K/REXT ratio (and K/R) in association with the presence of permanently attached foraminifera revealed to be the most reliable palaeo-seagrass indicators, suggesting that this combination could be very useful also in other case studies where diagenesis altered the foraminiferal association.

Biotic indices are tools to assess the ecological status of marine systems, and can be based on different metrics (such as ecological groups, specific diversity). The present study applies five biotic indices based on living (stained) benthic foraminiferal assemblages to assess ecological conditions in a wide area of the Mediterranean Sea in the heavily polluted Gulf of Gabes and along the western and eastern coasts of the Djerba Island, with the eastern coast considered as “pristine”. The applied indices are based on epiphytic foraminifera e.g., the “long versus short life span” index (ILS) and the modified FoRAM-Index (FI’), benthic foraminiferal assemblage composition and diversity, e.g., the Tolerant Species index (TSstd), the Foram Stress Index (FSI), the diversity Index (exp(H’bc)) and the newly developed Foram-AZTI Marine Biotic Index (Foram-AMBI). This latter index was tested using species of benthic foraminifera presently assigned to ecological groups in the Mediterranean Sea. All indices confirm good ecological conditions eastern of Djerba. The FI’ and ILS, % TSstd, FSI, indicate a severe anthropogenic impact especially in the central part of the Gulf of Gabes, next to the phosphate industry of Skhira and along the western coast of Djerba Island and confirm direct observations and geochemical data. The indices based on epiphytic foraminifera seem to better reflect actual environmental conditions in the investigated region because of the extended Posidonia oceanica meadow in the area. The exp(H’bc) reflects lower degrees of pollution. The application of the Foram-AMBI index presents limitations that prevent its current use. It strongly underestimates the pollution impact along the Tunisian coast, and additional work is needed to increase the number of species attributed to ecological groups and to possibly modify the coefficients to be used in its equation.

Changing components, rock textures, lithofacies, platform types and architecture throughout time are unique characteristics of carbonate rocks. Characterizing these attributes has been approached by 1) building reference models for specific Phanerozoic intervals, 2) recognizing the climatic impact in modulating carbonate production, and 3) analyzing the influence of changing bio-geochemical conditions. The reference-model approach is mostly based on biological evolution, the climatic-impact approach emphasizes temperature, and the bio-geochemical approach considers the changes in Mg/Ca ratios and Ca ++ concentrations in the oceans. To date, however, an analysis integrating all of these factors is still missing. The analysis presented here includes all these factors but also CO 2 , which is fundamental for both photosynthesis and CaCO 3 precipitation. Here we analyze the waxing and waning of Cenozoic reef limestones from the central Tethys region through several steps: 1) on the basis of rock volume, rock textures, associated sediments and light-dependent skeletal components, as records of light penetration and wave energy (depth); 2) on global environmental conditions (δ 13 C, δ 18 O, p CO 2 , temperature); and 3) on the basis of functionality, nutritional requirements and available resources. Through the Cenozoic, water motion, whether induced by surface or internal waves or by currents, increased as the thermal gradients strengthened, both with depth and with latitude. Active water motion is essential for plankton catchers such as corals, but less so for many larger benthic foraminifers (LBF). Pycnoclines in the meso-oligophotic zone would then favor the benthic plankton catchers such as corals, but would be detrimental for many LBF. Warm temperatures favored LBF. The Eocene LBF families predominated during lowering of atmospheric p CO 2 by using respiratory CO 2 to enhance the symbiont production of photosynthates under oligotrophic conditions and limited turbulence, whereas the Miocene families had to adapt to a progressive increase in turbulence. The eurythermal coralline red algae, however, became preponderant producers in the mesophotic zone during times when the δ 13 C was relatively high. This explains two apparent paradoxes: 1) corals thrive best when the Earth's high latitudes cool, and 2) the dominance of corals and LBF is inversely correlated, despite they both require tropical conditions and have similar trophic strategies (mixotrophy).