EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > PROTISTS > AMOEBOIDS > RADIOLARIANS
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Radiolarian data from IN2017_V01 These data were generated by Kelly-Anne Lawler (corresponding author, kelly-anne.lawler@anu.edu.au) with taxonomic assistance from Dr Giuseppe Cortese. These data are based on samples collected during voyage IN2017_V01 of the RV Investigator, co-chief scientists, Leanne Armand and Phil O’Brien. The IN2017-V01 post-cruise report is available through open access via the e-document portal through the ANU library. https://openresearch-repository.anu.edu.au/handle/1885/142525 The preferred citation is: L.K. Armand, P.E. O’Brien and On-board Scientific Party. 2018. Interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles (IN2017-V01): Post-survey report, Research School of Earth Sciences, Australian National University: Canberra, http://dx.doi.org/10.4225/13/5acea64c48693 Samples for radiolarian analysis were collected on board immediately after core recovery. Samples were air dried at ambient temperature (~21 degrees C), and their processing in preparation for microscopy was based on the method of Cortese and Prebble (2015). Cover slips were adhered to the slides using Canada Balsam and slides were observed using Olympus BH-2 inverted light microscope at up to 400x magnification. Slides were first counted to determine absolute radiolarian abundance (ARA) and, for samples where ARA was high enough, more than 400 individuals were identified per sample to species/subspecies or genus level. Taxonomic nomenclature used while preparing the dataset was per Lazarus et al. (2015) with additional clarification sought from the World Register of Marine Species (WoRMS Editorial Board, 2018) and radiolaria.org (radiolaria.org, 2018). Station_core Longitude Latitude C013_KC05 119.0183 -64.6538 C022_KC11 120.049 -65.1313 These data were collected to provide palaeoceanographic information. Cortese, G., and Prebble, J. (2015). A radiolarian-based modern analogue dataset for palaeoenvironmental reconstructions in the southwest Pacific. Marine Micropaleontology, 118, 34-49. WoRMS Editorial Board, (2018). World Register of Marine Species. Available from http://www.marinespecies.org at VLIZ. Lazarus, D. B., Suzuki, N., Caulet, J.-P., Nigrini, C., Goll, I., Goll, R., Dolven, J.K. Diver, P. and Sanfilippo, A., (2015). An evaluated list of Cenozic-Recent radiolarian species names (Polycystinea), based on those used in the DSDP, ODP and IODP deep-sea drilling programs. Zootaxa, 3999(3), 310-333. radiolaria.org, 2018. radiolaria.org, (http://www.radiolaria.org/) Kelly-Anne Lawler and Giuseppe Cortese unpublished data
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This spreadsheet contains species lists and counts from four sediment trap records. The sediment traps were deployed for ~1 year north and south of the Chatham Rise, New Zealand, between 1996 and 1997. Sheets 1a and 1b refer to North Chatham Rise (NCR). 1a = the 300m trap. 1b = the 1000m trap. Sheets 2a and 2b are for the South Chatham Rise traps (SCR). 2a= 300m, 2b= 1000m. Counting was undertaken on 1/16th splits. Material was cleaned of organics before diatom counting under light microscopy. Coccolith counting on uncleaned material was only undertaken at the 300m traps. Radiolarians and silicoflagellates were counted but not identified. Diatoms and coccoliths were counted along non-overlapping transects until 300 specimens had been counted per sample, or until 10 transects had been made. This dataset includes counts of diatom, coccolithophores, radiolarians and silicoflagellates for four sediment trap records- North Chatham Rise (NCR) and South Chatham Rise (SCR) at two trap depths each (300 m and 1000 m). It is intended as supplementary material to Wilks et al. 2018 (submitted) "Diatom and coccolithophore assemblages from archival sediment trap samples of the Subtropical and Subantarctic Southwest Pacific." Numbers are raw count per sample cup. Authorities are given. Coordinates of traps given in degrees, minutes and seconds.
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High-throughput DNA-sequencing data for mesopelagic fish stomach contents sampled during the Kerguelen Axis voyage (January-Februay 2016). Mesopelagic fish form an important link between zooplankton and higher trophic levels in Southern Ocean food webs, however their diets are poorly known. Most of the dietary information available comes from morphological analysis of stomach contents and to a lesser extent fatty acid and stable isotopes. DNA sequencing could substantially improve our knowledge of mesopelagic fish diets, but has not previously been applied. We used high-throughput DNA sequencing (HTS) of the 18S ribosomal DNA and mitochondrial cytochrome oxidase I (COI) to characterise stomach contents of four myctophid and one bathylagid species collected at the southern extension of the Kerguelen Plateau (southern Kerguelen Axis), one of the most productive regions in the Indian sector of the Southern Ocean. Diets of the four myctophid species were dominated by amphipods, euphausiids and copepods, whereas radiolarians and siphonophores contributed a much greater proportion of HTS reads for Bathylagus sp. Analysis of mitochondrial COI showed that all species preyed on Thysanoessa macrura, but Euphausia superba was only detected in the stomach contents of myctophids. Size-based shifts in diet were apparent, with larger individuals of both bathylagid and myctophid species more likely to consume euphausiids, but we found little evidence for regional differences in diet composition for each species over the survey area. The presence of DNA from coelenterates and other gelatinous prey in the stomach contents of all five species suggests the importance of these taxa in the diet of Southern Ocean mesopelagics has been underestimated to date. Our study demonstrates the use of DNA-based diet assessment to determine the role of mesopelagic fish and their trophic position in the Southern Ocean and inform the development of ecosystem models. For more detail, see Clarke LJ, Trebilco R, Walters A, Polanowski AM, Deagle BE (2018). DNA-based diet analysis of mesopelagic fish from the southern Kerguelen Axis. Deep Sea Research Part II: Topical Studies in Oceanography. DOI: 10.1016/j.dsr2.2018.09.001.
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These data have been collected as part of ASAC (AAS) project 3046 on voyage 3 of the Aurora Australis in the 2011-2012 season. Data were collected from a series of RMT Trawls conducted from the trawl deck of the ship. Public Description of the Project The overall objective is to characterise the response of Southern Ocean calcareous zooplankton to ocean acidification resulting from anthropogenic CO2 emissions. Simulated increases in anthropogenic CO2 suggest a reduction in the calcification rates of calcareous organisms. A change in the calcification in the Southern Ocean may cause marine ecosystem shifts and in turn alter the capacity for the ocean to absorb CO2 from the atmosphere. We plan to take advantage of naturally-occurring, persistent, zonal variations in Southern Ocean primary production and biomass to investigate the effects of CO2 addition from anthropogenic sources on Southern Ocean calcareous zooplankton communities. A download file containing an excel spreadsheet of data can be found at the provided URL. Project objectives: The overall objective of this project is to characterise the impacts of recent, primarily anthropogenic, increases in atmospheric CO2 and related changes in the carbonate chemistry on shell formation by calcareous zooplankton in the Australian sector of the Southern Ocean. Calcareous zooplankton (e.g. planktonic foraminifera and pteropods) will be collected using plankton nets at five Southern Ocean localities during high seasonal flux periods. Planktonic foraminiferal and pteropod species and abundances, calcification rates and geochemistry (stable isotope and trace-metal) will be determined on plankton tow samples. Data from recent plankton tow samples will be compared with data deposited historically in the Southern Ocean and recovered from existing deep ocean sediment cores to provides insights about the extent to which modern carbon conditions may have already generated ecological impacts. The project will also provide a baseline of the present-day impact of ocean acidification and can be used to monitor the influence of future anthropogenic CO2 emissions in Southern Ocean ecosystems.