Vertical distribution of relative numbers of the main groups of sound-scattering fishes in the Central Indian Ocean

Findings made in 31 catches with an Isaacs-Kidd midwater trawl in the light (09.00-16.00) and dark (21.00-04.00) periods of a day within a survey area of about 100 sq. miles with approximate center coordinates of 13°S and 78°E have been used to investigate vertical distribution of the main groups of sound-scattering fishes (35 species of the family Myctophidae and 16 species of other families). It has been shown that during daylight hours all fishes sink to depths deeper than 400 m. Data are presented concerning the fish population of night-time sound-scattering layers at depths of 70-150 m and about 400 m and of the daytime ones at depths of about 450 m.

Palaeoclimate reconstructions of the Oligocene to Pliocene from eight sites in northwest Germany using the Coexistence Approach

The first detailed reconstruction of the continental palaeoclimate evolution of the Northwest German Tertiary (Late Oligocene to Pliocene) is presented. The paleoclimate data are derived from the paleobotanical record using the coexistence approach, a method recently introduced that employs climatic requirements of the Nearest Living Relatives of a fossil flora. Twenty six megafloras (fruits and seeds, leaves, woods) from the Tertiary succession of the Lower Rhine Basin and neighboring areas are analyzed with respect to ten meteorological parameters. Additionally, two sample sets from Late Miocene to Early Pliocene sediments comprising 396 palynofloras are analyzed by the same method providing a higher temporal resolution. The temperature curves show a comparatively cooler phase in the Late Oligocene, a warm interval the Middle Miocene, and a cooling starting at 14 Ma. The cooling trend persisted until Late Pliocene with a few higher frequency temperature variations observed. From the beginning of Late Miocene to the present, the seasonality increases and climate appears to have been less stable. As indicated by the precipitation data, a Cfa climate with wet summers persisted in NW Germany from Late Oligocene to Late Pliocene. The results obtained are well in accordance with regional and global isotope curves derived from the marine record, and allow for a refined correlation of the Tertiary succession in the Lower Rhine Basin with the international standard. It is shown that the reconstructed data are largely consistent with the continental climate record for the Northern Hemisphere, as reported by various authors. Discrepancies with previous reconstructions are discussed in detail.

Calcification is not the Achilles'heel of cold-water corals in an acidifying ocean

Ocean acidification is thought to be a major threat to coral reefs: laboratory evidence and CO2 seep research has shown adverse effects on many coral species, although a few are resilient. There are concerns that cold-water corals are even more vulnerable as they live in areas where aragonite saturation (Omega ara) is lower than in the tropics and is falling rapidly due to CO2 emissions. Here, we provide laboratory evidence that net (gross calcification minus dissolution) and gross calcification rates of three common cold-water corals, Caryophyllia smithii, Dendrophyllia cornigera, and Desmophyllum dianthus, are not affected by pCO2 levels expected for 2100 (pCO2 1058 µatm, Omega ara 1.29), and nor are the rates of skeletal dissolution in D. dianthus. We transplanted D. dianthus to 350 m depth (pHT 8.02; pCO2 448 µatm, Omega ara 2.58) and to a 3 m depth CO2 seep in oligotrophic waters (pHT 7.35; pCO2 2879 µatm, Omega ara 0.76) and found that the transplants calcified at the same rates regardless of the pCO2 confirming their resilience to acidification, but at significantly lower rates than corals that were fed in aquaria. Our combination of field and laboratory evidence suggests that ocean acidification will not disrupt cold-water coral calcification although falling aragonite levels may affect other organismal physiological and/or reef community processes.