EARTH SCIENCE > BIOSPHERE > ECOLOGICAL DYNAMICS > ECOSYSTEM FUNCTIONS > BIOMASS DYNAMICS
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Raw and processed acoustic data were collected in East Antarctica from the RSV Aurora Australis during two surveys: the Krill Availability, Community Trophodynamics and AMISOR Surveys (KACTAS) and the Krill Acoustics and Oceanography Survey (KAOS) in the East Antarctic. Seabed alias example file used to make Figure 3. 38_false_bottom.sv.csv (file size: 10.7 MB) This file is an example of seabed aliasing (false bottom echo) that occurred during the KAOS survey. The data in this file are acoustic (mean volume backscattering strength, Sv) sample-by-sample and in a CSV format. Ping_index - ping number Distance_GPS - along track distance from the vessel’s GPS (nautical miles). Distance_vl - along track distance from the vessel’s log (nautical miles). Not used here, so is populated by Echoview’s ‘don’t care’ value (-9.90E+37) to keep the file format consistent. Ping_date - format yyyy-mm-dd Ping_time - format hh:mm:ss Ping_milliseconds - format (integer; ms) Latitude - position from the vessel’s GPS (degrees) Longitude position from the vessel’s GPS (degrees) Depth_start - start depth of vessel echosounder logging range (m) Depth_stop - stop depth of vessel echosounder logging range (m) Range_start - start range of vessel echosounder logging range (m) Range_stop - stop range of vessel echosounder logging range (m) Sample_count number of samples in a ping. Acoustic Sv samples follow in column-wise vector (dB re 1 m-1) Transect metadata all_transects.csv (file size: 14.8 K) This is the transect metadata for both the KACTAS and KAOS surveys: Transect - transect number startDate - start date of transect dd/mm/yyyy startTime - start time of transect hh:mm endDate - end date of transect dd/mm/yyyy endTime - end time of transect dd/mm/yyyy Ping_subset - a ping subset specified between two timestamps to isolate acoustic data that occurred on transect , i.e start timestamp to stop timestamp (yyyy-mm-dd hh:mm = yyyy-mm-dd hh:mm). Direction - Direction traveled along the transect (N - north or S- south). Light - day or night when transect was observed Survey - Either KACTAS or KAOS Leg - Krill box 1 or 2 (there were two surveys only during the KAOS voyage). Pass - Sampling bout for a transect in a given direction. Example R-code FigureAndDataprocessingExample.R (12KB) This R-code provides examples of scripting acoustic data processing using EchoviewR, specifically, using ping-subsets to isolate acoustic data along a transect of interest, detecting schools and exporting echo integrations for 38, 120 and 200 kHz. The R-code for making the figures in the paper is also given. GPS vessel positions for both the KACTAS and KAOS surveys KACTASandKAOS_GPS.csv (3 MB) This CSV file gives the vessel track for both the KACTAS and KAOS surveys. GPS_date - dd/mm/yyyy GPS_time - HH:MM:SS GPS_milliseconds - integer Latitude - position from the vessel’s GPS (degrees) Longitude - position from the vessel’s GPS (degrees) x - relative grid position (x) used for plotting Figure 1 y - relative grid position (y) used for plotting Figure 1 Survey - either: KACTAS_Krillbox, KAOS_Krillbox1, or KACTAS_Krillbox2 Krill swarms for both the KACTAS and KAOS surveys KACTASandKAOSswarms.csv (2.1 MB) Krill swarms descriptors for the KACTAS and KAOS surveys in CSV format (see Table 2 for description of the data fields). Echoview file for the KACTAS survey KACTAS-survey.EV (21.8 MB) An Echoview file (version 12.0) for the KACTAS acoustic data analysis KACTAS EK60 scientific echosounder calibration values KACTAS_EK500_calibration.ecs 3,623 16/05/2022 21:21 -a-- An Echoview format calibration file for the KACTAS survey (see Table 3 for calibration values and Demer et al.20 for a description of the calibration parameters). Echoview file for the KAOS survey KAOS-survey.EV (16.4MB) An Echoview file (version 12.0) for the KAOS acoustic data analysis KAOS EK60 scientific echosounder calibration values KAOS_EK60_calibration.ecs 5,711 01/11/2021 04:36 -a– An Echoview format calibration file for the KAOS survey (see Table 3 for calibration values and Demer et al. (2015) for a description of the calibration parameters).
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This dataset contains the data from Voyage 7.2 1989-90 of the Aurora Australis. The observations were taken from around Heard Island between May and June 1990. The objective of the zooplankton program was to determine the composition, distribution and abundance of zooplankton with the Heard Island-Kerguelen area, thus providing information of food availability to planktivorous fish. Surveys of krill and other zooplankton were made to obtain species identity and abundance data, length and age. Euphausia valentini and Themisto gaudichaudi were found to be the dominant species in the region. Other major species included the euphausiid Thysanoessa, the copepod Rhincalanus gigas and chaetognaths of the genus Sagitta. This dataset is a subset of the full cruise.
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This data set is a supplement to the R package, EchoviewR. EchoviewR is a free software package that acts as an interface between R and Echoview. It uses Component Object Model scripting to enable automated processing of active acoustic data. This data set contains the data necessary to run the vignette tutorials and package examples. The .raw files are acoustic data collected using an EK60 echosounder. They are a subset of the full acoustic data collected on the Krill Acoustic and Oceanographic Survey (KAOS) off Antarctica in the summer of 2003. The .EV template file was created using Echoview v6.1. The .ecs calibration file, .evl line object file and .evr region files are for use with this template. The region files designate off transect regions. The three pdf vignettes contain examples of reading data using EchoviewR, conducting school detection and running biomass estimation of Antarctic Krill. These data are intended only as a supplement to demonstrate the use of EchoviewR. This data is a subset of the KAOS data and as such, must NOT be used to formally estimate krill biomass. These data are a subset of data described in the metadata record at the provided URL.
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This dataset contains results from the Aurora Australis Voyage 6 1990-91. Surveys of krill and other zooplankton were taken in Prydz Bay, Antarctica between January and February 1991. Species identity and abundance data, length, age, growth rate and mortality rate data were obtained. The major species investigated were Euphausia superba, Euphausia frigidia, Euphausia crystallorophias and Thysanoessa macrura. Other pteropods and cephalopods were also studied. This dataset is a subset of the full cruise.
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This dataset contains the data from Voyage 6 1990-91 of the Aurora Australis. The observations were taken from the Prydz Bay area, Antarctica in January and February 1991. Taxonomic identity and abundance data were obtained, together with an extensive range of pigment analysis. Over 60 pigments are analysed (only the major ones are listed here). The major phytoplankton investigated were diatoms, dinoflagellates and flagellates. This dataset is a subset of the full cruise.
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The variation in the phytoplankton biomass over a decadal time scale, and its relationship with the Antarctic Circumpolar Wave (ACW) and climate change, has been poorly interpreted because of the limited satellite chlorophylla (chl a) data compared with the physical parameters from satellite. We analysed a long-term chl a dataset along the Japanese Antarctic Research Expedition (JARE) cruise tracks since 1965 to investigate inter-annual variation of phytoplankton biomass. In the Southern Ocean, increasing trends of chl a and the spreading of higher chl a area to the north with 3-7 year cycles were found. Although relationships between the decadal change in chl a and climate change such as variation of sea ice extent and the El Nino are still obscure, large variation of primary production in proportion to the chl a is implied. The chl a concentration of sea surface water has been measured routinely on board the icebreakers Fuji and Shirase during almost every cruise of the JARE. The download file contains chlorophyll a data collected from ship tracks on JARE voyages between 1965 and 2002. The field in this dataset are: Date (local time) Year Latitude Longitude Corrected Chlorophyll a See the attached paper for more details. The publications on the data collected during the 1965-1976 and 1988-1993 cruises are listed in Fukuchi [1980] and Suzuki and Fukuchi [1997], respectively. For data on the 1977-1985 and 1994-1997 cruises, see [Kanda and Fukuchi, 1979; Fukuchi and Tamura, 1982; Tanimura, 1981; Watanabe and Nakajima, 1983; Ino and Fukuchi, 1984; Sasaki, 1984; Hamada et al., 1985; Fukuda et al., 1986; Hattori and Fukuchi, 1988; Midorikawa et al., 2000]. Data post 1998-2002 cruises is in Hirawake and Fukuchi [2004]. Data from the 1986-1987 will be published in the JARE data report of digital media, including all cruise data. Auxiliary Material for paper 2004GL021394 Long-term variation of surface phytoplankton chlorophyll a in the Southern Ocean during 1965-2002. Toru Hirawake, Tsuneo Odate and Mitsuo Fukuchi (National Institute of Polar Research, Tokyo) Geophys. Res. Lett., Vol (Num), doi:10.1029/2004GL021394 All of the chl a data have been reported in the publications of the National Institute of Polar Research (NIPR).
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Metadata record for data from AAS (ASAC) project 3046. Public 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. Taken from the 2008-2009 Progress Report: Progress against objectives: Because of logistical delays to the Aurora Australis shipping schedule, ship time for this project was deferred to the 2009/2010 season. We have made progress in analysing other materials form previous voyages which will assist in the sampling design for the upcoming season. We are making good progress in planning the upcoming voyage currently scheduled for late 2009. Taken from the 2009-2010 Progress Report: Progress against objectives: Project scientists participated in Voyage 2 of the Aurora Australis, from Hobart to Casey Station in December 2009. Using the Rectangular Midwater Trawl we collected a total of eight plankton samples for examination of calcareous plankton distribution and shell characteristics in the summer Southern Ocean. We were targeting pteropods and planktonic foraminifera, two sets of calcifiers whose calcification response to ocean acidification we had previously reported on in publications in Nature Geoscience, Biogeosciences Discussions, and Deep-Sea Research Part II (in press). Project participants included collaborators from Australian National University and Scottish Natural Heritage, UK. There were low abundance of planktonic calclfiers in this particular seasons and sector, but we consider the initial collection a god start. Samples included approx. 18 pteropods; other samples are still being held by Biosecurity Australia and will be examined as soon as they are released. Other samples have already been sent to researchers at the Australian Institute of Marine Science for genetic (RNA) sequencing. This latter collaboration is a key one which will help answer questions about evolutionary responses to ocean acidification; if there are genotypes which are more or less vulnerable to acidification we may already be seeing selective pressure in the ecosystem and a change in the structure of assemblages as "winners" and "losers" are differentially affected by the impact.
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This metadata record is the parent umbrella under which data from the 2008/09, 2013/14 and 2014/15 summer will be housed. See the child records for access to the data. Manmade CO2 has increased ocean acidity by 30% and it is projected to rise 300% by 2100. Antarctic waters will be amongst the earliest and most severely affected by this increase. Microbes are the base of the marine food chain and primary drivers of the biological pump. This project will incubate natural communities of Antarctic marine microbes in minicosms at a range of CO2 concentrations to quantify changes in their structure and function, the physiological responses that drive these changes, and provide input to models that predict effects on biogeochemical cycles and Antarctic food webs
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From the abstract of one of the papers: Phytoplankton biomass and speciation were monitored at an inshore site near Davis Station, East Antarctica during three consecutive summer seasons (December-February, 1992-5). Four distinct phytoplankton assemblages were identified in which the dominant species were: Phaeocystis sp., an undescribed Cryptomonas species, Thalassiosira dichotomica, and a mixed assemblage containing Fragilariopsis spp. and Nitzschia spp. Little interannual consistency was found in either the timing of the appearance or disappearance of the various assemblages. Similarly, the seasonal trends in biomass varied dramatically from year to year. Variations in the phytoplankton community can be ascribed, to some extent, to the random variation in a number of factors, including the date of fast ice break out, water column stratification, temperature and salinity, zooplankton grazing and strong winds. Periods of strong wind result in the introduction of offshore or deeper water masses into the shallow inshore environment, where the physical and chemical conditions allow blooms to develop. A number of the papers listed in the reference section are available as pdf's in the download section.
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Season whale catch records for austral summers from 1931/32 to 1979/80. Data have been aggregated into one degree cells centered on the reported position. The dataset covers five whale species - Blue, Fin, Sei, Minke and Humpback. These data have been exposed as an OBIS (Ocean Biogeographic Information System) resource via DiGIR (Distributed Generic Information Retrieval (DiGIR)).