Egg production, hatching, faecal pellet production of Calanus finmarchicus in the North Atlantic

The samples were collected using a T-80 net (375 µm mesh size) equipped with a non-filtering cod-end in the North Atlantic during the G.O. Sars Trans-Atlantic cruise in 2013. Within 15-30 minutes after the recovery, 20 Calanus finmarchicus females were sorted out under microscope in ice chilled petri dishes and incubated individually in 600 ml polycarbonate culture bottles resulting in 20 replicate measurements. The bottles were filled with 50 µm screened seawater originated from 6 m water depth. The samples were incubated upright in thermoroom for 24 hours at the surface temperature (3°C). After the samples had been filtered (40 µm filter), female prosome length, egg as well as pellet abundance were determined. Subsequently, eggs from six females were incubated in petri dishes at 5°C. After 4 days, the number of nauplii and eggs were counted in order to calculate hatching success.

Distribution of phytolithes in CRP sediment cores from the Ross Sea, Antarctica

Phytoliths (siliceous plant microfossils) have been recovered from Cenozoic sediments (c. 34 to 17 Ma) in the CRP-2/2A and CRP-3 drillholes cored off Cape Roberts, Victoria Land Basin, Antarctica. The phytolith assemblages are sparse, but well-preserved and dominated by spherical forms similar to those of modern trees or shrubs. Rare phytoliths comparable to modern grass forms are also present. However, due to the paucity of phytolith data, any interpretations made are necessarily tentative. The assemblages of CRP-2/2A and the upper c. 250 m of CRP-3 are interpreted as representing a predominantly woody vegetation, including Nothofagus and Libocedrus with local areas of grass in the more exposed locations. A cool climate is interpreted to have prevailed throughout both cores. However, beneath c. 250 metres below sea floor in CRP-3, the dominant woody vegetation is supplemented by pockets of Palmae, ?Proteaceae and 'warm' climate grasses. This association represents vegetation growth in sheltered, moist sites - possibly north-facing mid-slopes or the coastal fringe. It may also represent remnant vegetation that grew in moist, temperate conditions during the Middle to Late Eocene, previously interpreted from the Southern McMurdo Sound erratics and lower part of the CIROS-1 drillhole. The phytolith analysis compares well to the terrestrial palynomorph record from both cores and provides additional independent taxonomic and climatic interpretations.

14C ages of core top samples from Ontong-Java Plateau

Radiocarbon measurements on core tops from the Ontong-Java plateau confirm a previous finding by Berger and Killingley [1982] that at any given water depth, cores taken on the equator have higher accumulation rates and younger core top ages than their off-equator counterparts. Further, these new results fortify the conclusion by Broecker et al. [1991] that the increase in core top radiocarbon age with water depth rules out homogeneous dissolution within the pore waters as the dominant mechanism. Either most of the dissolution must occur prior to burial or it must occur during the first pass through the respiration-CO2-rich upper pore waters after which the calcite grains become armored against further dissolution. A puzzling aspect of this new data set is that despite the sizable difference in accumulation rate, the extent of dissolution as measured by either the CaCO3 content or the ratio of CaCO3 in the >150-µm size fraction to that in the < 63-µm fraction is no different off than on the equator. In order to reconcile the results of this study with those obtained by Hales and Emerson [1996] using in situ electrodes, it is necessary to call upon calcite armoring.