Sea-floor videos and photographs (benthos) along 6 shelf profiles from the eastern Weddell Sea, Antarctica taken with remote operated vehicel CHEROKEE during Polarstern cruise ANT-XXI/2

The ROV operations had three objectives: (1) to check, whether the "Cherokee" system is suited for advanced benthological work in the high latitude Antarctic shelf areas; (2) to support the disturbance experiment, providing immediate visual Information; (3) to continue ecological work that started in 1989 at the hilltop situated at the northern margin of the Norsel Bank off the 4-Seasons Inlet (Weddell Sea). The "Cherokee" is was equipped with 3 video cameras, 2 of which support the operation. A high resolution Tritech Typhoon camera is used for scientific observations to be recorded. In addition, the ROV has a manipulator, a still camera, lights and strobe, compass, 2 lasers, a Posidonia transponder and an obstacle avoidance Sonar. The size of the vehicle is 160 X 90 X 90cm. In the present configuration without TMS (tether management system) the deployment has to start with paying out the full cable length, lay it in loops on deck and connect the glass fibres at the tether's spool winch. After a final technical check the vehicle is deployed into the water, actively driven perpendicular to the ship's axis and floatings are fixed to the tether. At a cable length of approx. 50 m, the tether is tightened to the depressor by several cable ties and both components are lowered towards the sea floor, the vehicle by the thruster's propulsion and the depressor by the ship's winch. At 5 m intervals the tether has to be tied to the single conductor cable. In good weather conditions the instruments supporting the navigation of the ROV, especially the Posidonia system, allow an operation mode to follow the ship's course if the ship's speed is slow. Together with the lasers which act as a scale in the images they also allow a reproducible scientific analysis since the transect can be plotted in a GIS system. Consequently, the area observed can be easily calculated. An operation as a predominantly drifting system, especially in areas with bottom near currents, is also possible, however, the connection of the tether at the rear of the vehicle is unsuitable for such conditions. The recovery of the system corresponds to that of the deployment. Most important is to reach the surface of the sea at a safe distance perpendicular to the ship's axis in order not to interfere with the ship's propellers. During this phase the Posidonia transponder system is of high relevance although it has to be switched off at a water depth of approx. 40 m. The minimum personal needed is 4 persons to handle the tether on deck, one person to operate the ship's winch, one pilot and one additional technician for the ROV's operation itself, one scientist, and one person on the ship's bridge in addition to one on deck for whale watching when the Posidonia system is in use. The time for the deployment of the ROV until it reaches the sea floor depends on the water depth and consequently on the length of the cable to be paid out beforehand and to be tightened to the single conductor cable. Deployment and recovery at intermediate water depths can last up to 2 hours each. A reasonable time for benthological observations close to the sea floor is 1 to 3 hours but can be extended if scientifically justified. Preliminary results: after a first test station, the ROV was deployed 3 times for observations related to the disturbance experiment. A first attempt to Cross the hilltop at the northern margin of the Norsel Bank close to the 4- Seasons Inlet was successful only for the first hundreds of metres transect length. The benthic community was dominated in biomass by the demosponge Cinachyra barbata. Due to the strong current of approx. 1 nm/h, the design of the system, and an expected more difficult current regime between grounded icebergs and the top of the hilltop the operation was stopped before the hilltop was reached. In a second attempt the hilltop was successfully crossed because the current and wind situation was much more suitable. In contrast to earlier expeditions with the "sprint" ROV it was the first time that both slopes, the smoother in the northeast and the steeper in the southwest were continuously observed during one cast. A coarse classification of the hilltop fauna shows patches dominated by single taxa: cnidarians, hydrozoans, holothurians, sea urchins and stalked sponges. Approximately 20 % of the north-eastern slope was devastated by grounding icebergs. Here the sediments consisted of large boulders, gravel or blocks of finer sediment looking like an irregularly ploughed field. On the Norsel Bank the Cinachyra concentrations were locally associated with high abundances of sea anemones. Total observation time amounted to 11.5 hours corresponding to almost 6-9 km transect length.

Acoustic records of the underwater soundscape at PALAOA with links to audio stream files, 2005-2011

Scientific background: Marine mammals use sound for communication, navigation and prey detection. Acoustic sensors therefore allow the detection of marine mammals, even during polar winter months, when restricted visibility prohibits visual sightings. The animals are surrounded by a permanent natural soundscape, which, in polar waters, is mainly dominated by the movement of ice. In addition to the detection of marine mammals, acoustic long-term recordings provide information on intensity and temporal variability of characteristic natural and anthropogenic background sounds, as well as their influence on the vocalization of marine mammals Scientific objectives: The PerenniAL Acoustic Observatory in the Antarctic Ocean (PALAOA, Hawaiian "whale") near Neumayer Station is intended to record the underwater soundscape in the vicinity of the shelf ice edge over the duration of several years. These long-term recordings will allow studying the acoustic repertoire of whales and seals continuously in an environment almost undisturbed by humans. The data will be analyzed to (1) register species specific vocalizations, (2) infer the approximate number of animals inside the measuring range, (3) calculate their movements relative to the observatory, and (4) examine possible effects of the sporadic shipping traffic on the acoustic and locomotive behaviour of marine mammals. The data, which are largely free of anthropogenic noise, provide also a base to set up passive acoustic mitigation systems used on research vessels. Noise-free bioacoustic data thereby represent the foundation for the development of automatic pattern recognition procedures in the presence of interfering sounds, e.g. propeller noise.

Concentrations of perfluorinated carboxylic acids (PFCAs) and sulfonic acids (PFSAs) in liver samples of different marine mammals (1984-2009)

Temporal variations in concentrations of perfluorinated carboxylic acids (PFCAs) and sulfonic acids (PFSAs), including perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) structural isomers, were examined in livers of pilot whale (Globicephala melas), ringed seal (Phoca hispida), minke whale (Balaenoptera acutorostrata), harbor porpoise (Phocoena phocoena), hooded seal (Cystophora cristata), Atlantic white-sided dolphin (Lagenorhynchus acutus) and in muscle tissue of fin whales (Balaenoptera physalus). The sampling spanned over 20 years (1984-2009) and covered a large geographical area of the North Atlantic and West Greenland. Liver and muscle samples were homogenized, extracted with acetonitrile, cleaned up using hexane and solid phase extraction (SPE), and analyzed by liquid chromatography with negative electrospray tandem mass spectrometry (LC-MS/MS). In general, the levels of the long-chained PFCAs (C9-C12) increased whereas the levels of PFOS remained steady over the studied period. The PFOS isomer pattern in pilot whale liver was relatively constant over the sampling years. However, in ringed seals there seemed to be a decrease in linear PFOS (L-PFOS) with time, going from 91% in 1984 to 83% in 2006.

Ichthyolith (fish tooth and denticle) counts from DSDP Site 91-596 and ODP Site 145-886

While the history of taxonomic diversification in open ocean lineages of ray-finned fish and elasmobranchs is increasingly known, the evolution of their roles within the open ocean ecosystem remains poorly understood. To assess the relative importance of these groups through time, we measured the accumulation rate of microfossil fish teeth and elasmobranch dermal denticles (ichthyoliths) in deep sea sediment cores from the North and South Pacific gyres over the past 85 million years. We find three distinct and stable open ocean ecosystem structures, each defined by the relative and absolute abundance of elasmobranch and ray-finned fish remains. The Cretaceous Ocean (pre-66 Ma), was characterized by abundant elasmobranch denticles, but low abundances of fish teeth. The Paleogene Ocean (66-20 Ma), initiated by the Cretaceous/Paleogene Mass Extinction, had nearly 4 times the abundance of fish teeth compared to elasmobranch denticles. This Paleogene Ocean structure remained stable during the Eocene greenhouse (50 Ma) and the Eocene-Oligocene glaciation (34 Ma), despite large changes in overall accumulation of both groups during those intervals, suggesting that climate change is not a primary driver of ecosystem structure. Dermal denticles virtually disappeared from open ocean ichthyolith assemblages about 20 Ma, while fish tooth accumulation increased dramatically in variability, marking the beginning of the Modern Ocean. Together, these results suggest that open ocean fish community structure is stable on long timescales, independent of total production and climate change. The timing of the abrupt transitions between these states suggests that the transitions may be due to interactions with other, non-preserved pelagic consumer groups.

2003 Habitat Maps derived from Grey Nurse Shark (GNS) Project of Wolf Rock, Double Island Point, Queensland, Australia

Surveying habitats critical to the survival of grey nurse sharks in South-East Queensland has mapped critical habitats, gathered species inventories and developed protocols for ecological monitoring of critical habitats in southern Queensland. This information has assisted stakeholders with habitat definition and effective management. In 2002 members of UniDive applied successfully for World Wide Fund for Nature, Threatened Species Network funds to map the critical Grey Nurse Shark Habitats in south east Queensland. UniDive members used the funding to survey, from the boats of local dive operators, Wolf Rock at Double Island Point, Gotham, Cherub's Cave, Henderson's Rock and China Wall at North Moreton and Flat Rock at Point Look Out during 2002 and 2003. These sites are situated along the south east Queensland coast and are known to be key Grey Nurse Shark aggregation sites. During the project UniDive members were trained in mapping and survey techniques that include identification of fish, invertebrates and substrate types. Training was conducted by experts from the University of Queensland (Centre of Marine Studies, Biophysical Remote Sensing) and the Queensland Parks and Wildlife Service who are also UniDive members. The monitoring methods (see methods) are based upon results of the UniDive Coastcare project from 2002, the international established Reef Check program and research conducted by Biophysical Remote Sensing and the Centre of Marine Studies. Habitats were mapped using a combination of towed GPS photo transects, aerial photography, bathymetry surveys and expert knowledge. This data provides georeferenced information regarding the major features of each of Sites mapped including Wolf Rock

Manganese nodule geochemistry from the Challenger Expedition

C. W. Gümbel received nodules from J. Murray which were collected at a depth of 2740 fathoms, between Japan and the Sandwich Islands, by the "Challenger" Expedition. They were either round or long in shape, with a dull, dirty-brown coloured surface, and enclosed fragments of pumice-stone, and more rarely teeth of sharks or fragments of mussels. They were analysed by A. Schwager.

Sea-bed photographs (benthos) from the AWI-Hausgarten area along OFOS profile PS62/191-1

Although the use of deep-sea imagery considerably increased during the last decades, reports on nekton falls to the deep seafloor are very scarce. Whereas there are a few reports describing the finding of whale carcasses in the deep north-eastern and south-eastern Pacific, descriptions of invertebrate or vertebrate food-falls at centimetre to metre scale are extremely rare. After 4 years of extensive work at a deep-sea long-term station in northern polar regions (AWI-"Hausgarten"), including large-scale visual observations with various camera systems covering some 10 000 m2 of seafloor at water depths between 1250 and 5600 m, this paper describes the first observation of a fish carcass at about 1280 m water depth, west off Svålbard. The fish skeleton had a total length of 36 cm and an approximated biomass of 0.5 kg wet weight. On the basis of in situ experiments, we estimated a very short residence time of this particular carcass of about 7 h at the bottom. The fast response of the motile deep-sea scavenger community to such events and the rapid utilisation of this kind of organic carbon supply might partly explain the extreme rarity of such an observation.