(Table 2) Fatty acid profile of blubber from harp seals and hooded seals from the Greenland Sea and Denmark Strait

Sub-Arctic marine ecosystems are some of the most productive ecosystems in the world's oceans. The capacity of herbivorous zooplankton, such as Calanus, to biosynthesize and store large amounts of lipids during the short and intense spring bloom is a fundamental adaptation which facilitates the large production in these ecosystems. These energy-rich lipids are rapidly transferred through the food chain to Arctic seals. The fatty acids and stable isotopes from harp seal (Phoca groenlandica) and hooded seal (Cystophora cristata) off East Greenland as well as their potential prey, were analysed. The results were used to describe the lipid dynamics and energy transfer in parts of the East Greenland ecosystem. Even if the two seal species showed considerable overlap in diet and occurred at relatively similar trophic levels, the fatty acid profiles indicated that the bases of the food chains of harp and hooded seals were different. The fatty acids of harp seals originate from diatom-based food chain, whereas the fatty acids of hooded seals originate from dinoflagellate and the prymnesiophyte Phaeocystis pouchetii-based food chain. Stable isotope analyses showed that both species are true carnivores on the top of their food chains, with hooded seal being slightly higher on the food chain than harp seal.

Shotgun proteomics reveals physiological response to ocean acidification in Crassostrea gigas

Background. Ocean acidification as a result of increased anthropogenic CO2 emissions is occurring in marine and estuarine environments worldwide. The coastal ocean experiences additional daily and seasonal fluctuations in pH that can be lower than projected end of century open ocean pH reductions. Projected and current ocean acidification have wide-ranging effects on many aquatic organisms, however the exact mechanisms of the impacts of ocean acidification on many of these animals remains to be characterized. Methods. In order to assess the impact of ocean acidification on marine invertebrates, Pacific oysters (Crassostrea gigas) were exposed to one of four different pCO2 levels for four weeks: 400 µatm (pH 8.0), 800 µatm (pH 7.7), 1000 µatm (pH 7.6), or 2800 µatm (pH 7.3). At the end of 4 weeks a variety of physiological parameters were measured to assess the impacts of ocean acidification: tissue glycogen content and fatty acid profile, shell micromechanical properties, and response to acute heat shock. To determine the effects of ocean acidification on the underlying molecular physiology of oysters and their stress response, some of the oysters from 400 µatm and 2800 µatm were exposed to an additional mechanical stress and shotgun proteomics were done on oysters from high and low pCO2 and from with and without mechanical stress. Results. At the end of the four week exposure period, oysters in all four pCO2 environments deposited new shell, but growth rate was not different among the treatments. However, micromechanical properties of the new shell were compromised by elevated pCO2. Elevated pCO2 affected neither whole body fatty acid composition, nor glycogen content, nor mortality rate associated with acute heat shock. Shotgun proteomics revealed that several physiological pathways were significantly affected by ocean acidification, including antioxidant response, carbohydrate metabolism, and transcription and translation. Additionally, the proteomic response to a second stress differed with pCO2, with numerous processes significantly affected by mechanical stimulation at high versus low pCO2 (all proteomics data are available in the ProteomeXchange under the identifier PXD000835). Discussion. Oyster physiology is significantly altered by exposure to elevated pCO2, indicating changes in energy resource use. This is especially apparent in the assessment of the effects of pCO2 on the proteomic response to a second stress. The altered stress response illustrates that ocean acidification may impact how oysters respond to other changes in their environment. These data contribute to an integrative view of the effects of ocean acidification on oysters as well as physiological trade-offs during environmental stress.

Pollen analysis of a peat profile from the Rieseberger Moor, Lower Saxony, Germany

The Rieseberger Moor is a fen, 145 hectares in size, situated about 20 km east of Brunswick (Braunschweig), Lower Saxony, Germany. Peat was dug in the fen - with changing intensity - since the mid-18th century until around AD 1955. According to Schneekloth & Schneider (1971) the remaining peat (fen and wood peat) is predominantly 1.5 to 2 m thick (maximum 2.7 m). Part of the fen - now a nature reserve (NSG BR 005) - is wooded (Betula, Salix, Alnus). For more information on the Rieseberger Moor see http://de.wikipedia.org/wiki/Rieseberger_Moor. Willi Selle was the first to publish pollen diagrams from this site (Selle 1935, profiles Rieseberger Torfmoor I and II). This report deals with a 2.2 m long profile from the wooded south-eastern part of the fen consisting of strongly decomposed fen peat taken A.D. 1965 and studied by pollen analysis in the same year. The peat below 1.45 m contained silt and clay, samples 1.48 and 1.58 m even fine sand. These samples had to be treated with HF (hydrofluoric acid) in addition to the treatment with hot caustic potash solution. The coring ended in sandy material. The new pollen data reflect the early part of the known postglacial development of the vegetation of this area: the change from a birch dominated forest to a pine forest and the later spreading of Corylus and of the thermophilous deciduous tree genera Quercus, Ulmus, Tilia and Fraxinus followed by the expansion of Alnus. The new data are in agreement with Selle's results, except for Alnus, which in Selle's pollen diagram II shows high values (up to 42% of the arboreal pollen sum) even in samples deposited before Corylus and Quercus started to spread. On contrary the new pollen diagram shows that alder pollen - although present in all samples - is frequent in the three youngest pollen spectra only. A period with dominating Alnus as seen in the uppermost part of Selle's pollen diagrams is missing. The latter is most likely the result of peat cutting at the later coring site, whereas the early, unusually high alder values of Selle's pollen study are probably caused by contamination of the pollen samples with younger peat. Selle took peat samples usually with a "Torfbohrer" (= Hiller sampler). This side-filling type of sampler with an inner chamber and an outer loose jacket offers - if not handled with appropriate care - ample opportunities to contaminate older peat with carried off younger material. Pollen grains of Fagus (2 % of the arboreal pollen sum) were found in two samples only, namely in the uppermost samples of the new profile (0.18 m) and of Selle's profile I (0.25 m). If this pollen is autochthonous, with other words: if this surface-near peat was not disturbed by human activities, the Fagus pollen indicates an Early Subboreal age of this part of the profile. The accumulation of the Rieseberg peat started during the Preboreal. Increased values of Corylus, Quercus and Ulmus indicate that sample 0.78 m of the new profile is the oldest Boreal sample. The high Alnus values prove the Atlantic age of the younger peat. Whether Early Subboreal peat exists at the site is questionable, but evidently none of the three profiles reaches to Late Subboreal time, when Fagus spread in the region. Did peat-growth end during the Subboreal? Did younger peat exist, but got lost by peat cutting or has younger peat simply not yet been found in the Rieseberg fen? These questions cannot be answered with this study. The temporary decline of the curve of Pinus for the benefit of Betula during the Preboreal, unusual for this period, is contemporaneous with the deposition of sand (Rieseberger Moor II, 1.33 - 1,41 m; samples 1.48 and 1.58 m of the new profile) and must be considered a local phenomenon. Literature: Schneekloth, Heinrich & Schneider, Siegfried (1971). Die Moore in Niedersachsen. 2. Teil. Bereich des Blattes Braunschweig der Geologischen Karte der Bundesrepublik Deutschland (1:200000). - Schriften der wirtschaftswissenschaftlichen Gesellschaft zum Studium Niedersachsens e.V. Reihe A I., Band 96, Heft 2, 83 Seiten, Göttingen. Selle, Willi (1935) Das Torfmoor bei Rieseberg. - Jahresbericht des Vereins für Naturwissenschaft zu Braunschweig, 23, 46-58, Braunschweig.