[1] In order to assess the dissolution effect on foraminiferal Mg/Ca ratios, we analyzed Mg/Ca of seven planktonic foraminiferal species and four of their varieties from Caribbean core tops from $900-4700 m water depth. Depending on the foraminiferal species and variety, Mg/Ca start to decline linearly below ], similar to decreases of $0.5-0.8 mmol/mol per kilometer below $2500-3000 m water depth. Above these speciesspecific critical levels, Mg/Ca remains stable with higher intraspecific Mg/Ca variability than below. We developed routines to correct Mg/Ca from below these critical thresholds for dissolution effects, which reduce the overall intraspecific variability by $24-64%, and provide dissolution-corrected Mg/Ca appropriate to calculate Holocene paleotemperatures. When taking into account only dissolutionunaffected Mg/Ca from <2000 m, the systematic succession of foraminiferal species according to their Mg/ Ca reflects expected calcification depths.

We compare several statistical routines that may be used to calculate d 18 O sw and SSS from paired coral Sr/Ca and d 18 O measurements. Typically, the d 18 O coral -SST relationship is estimated by linear regression of coral d 18 O vs. SST. If this method is applied, evidence should be given that at a particular site SST and SSS do not co-vary. In the tropical oceans, SST and d 18 O sw (SSS) often co-vary, and this will bias the estimate of the regression slope of d 18 O coral -SST. Using a stochastic model, we show that covariance leads to a bias in the coefficients of the univariate regression equations. As the slope of the d 18 O coral -SST relationship has known, we propose to insert this value for c 1 in the regression models. This requires that the constants of the regression equations are removed. To omit the constants, we propose to center the regression equations (i.e., to remove the mean values from the variables). The statistical error propagation is calculated to assess our ability to resolve past variations in d 18 O sw (SSS). At Tahiti, we find that the combined analytical uncertainties of coral d 18 O and Sr/Ca equal the amplitude of the seasonal cycle of d 18 O sw (SSS). Therefore, we cannot resolve the seasonal cycle of SSS at Tahiti. At Timor, the error of reconstructed d 18 O sw (SSS) is lower than the magnitude of seasonal variations of d 18 O sw (SSS), and the seasonal cycle of d 18 O sw (SSS) can be resolved.

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The cold-water coral Lophelia pertusa (Scleractinia, Caryophylliidae) is a key species in the formation of cold-water reefs, which are among the most diverse deep-sea ecosystems. It occurs in two color varieties: white and red. Bacterial communities associated with Lophelia have been investigated in recent years, but the role of the associated bacteria remains largely obscure. This study uses catalyzed reporter deposition fluorescence in situ hybridization to detect the in situ location of specific bacterial groups on coral specimens from the Trondheimsfjord (Norway). Two tissue-associated groups were identified: (i) bacteria on the host's tentacle ectoderm, "Candidatus Mycoplasma corallicola," are flasklike, pointed cells and (ii) endoderm-associated bona fide TM7 bacteria form long filaments in the gastral cavity. These tissue-bound bacteria were found in all coral specimens from the Trondheimsfjord, indicating a closer relationship with the coral compared to bacterial assemblages present in coral mucus and gastric fluid.Lophelia pertusa (L., 1758) (Scleractinia, Caryophylliidae) is a eurybathic, stenothermal cold-water coral that occurs as white and red color varieties. Its habitat is characterized by high biological production and vigorous hydrodynamic regimes (27), comprising continental slopes, seamounts, and fjords. L. pertusa is a key species in the formation of cold-water reefs, which are among the most diverse deep-sea ecosystems. More than 980 invertebrate species are known to be associated with cold-water corals, belonging to a broad range of taxa:

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