Attributes { s { study_name { String column_name "studyName"; String comment "Study name"; String ioos_category "Unknown"; String long_name "Study"; } time { String _CoordinateAxisType "Time"; Float64 actual_range 6.954336e+8, 1.517184e+9; String axis "T"; String calendar "proleptic_gregorian"; Float64 column_id 1421; String column_name "col_1421"; String ioos_category "Time"; String long_name "Time"; String lter_column_description "Date of sample collection / observation, UTC"; String lter_column_name "Sample Collection Date"; String lter_mscale "dateTime"; String standard_name "time"; String time_origin "01-JAN-1970 00:00:00"; String units "seconds since 1970-01-01T00:00:00Z"; } sample_number { Int16 _FillValue 32767; Int16 actual_range -32071, 32509; Float64 colorBarMaximum 100.0; Float64 colorBarMinimum 0.0; Float64 column_id 1422; String column_name "col_1422"; String ioos_category "Statistics"; String long_name "Sample Number"; String lter_column_description "record number of a sampling event"; String lter_column_name "Sample Number"; String lter_mscale "interval"; String lter_num_type "natural"; String lter_units_string "number"; String units_conventions "EML-2.0.1,EML-2.1.0,EML-LTER"; } total_krill_abundance { Int16 _FillValue 32767; Int16 actual_range 0, 199; Float64 column_id 1423; String column_name "col_1423"; String ioos_category "Unknown"; String long_name "Total Krill Abundance"; String lter_column_description "abundance of krill"; String lter_column_name "Total Number"; String lter_mscale "ratio"; String lter_num_type "real"; String lter_units_string "number"; String units "1"; String units_conventions "EML-2.0.1,EML-2.1.0,EML-LTER"; } krill_abundance_16mm_to_20mm { Int16 _FillValue 32767; Int16 actual_range 0, 38; Float64 column_id 1424; String column_name "col_1424"; String ioos_category "Unknown"; String long_name "Krill Abundance 16mm To 20mm"; String lter_column_description "abundance of krill"; String lter_column_name "16-20mm"; String lter_mscale "ratio"; String lter_num_type "real"; String lter_units_string "number"; String units "1"; String units_conventions "EML-2.0.1,EML-2.1.0,EML-LTER"; } krill_abundance_21mm_to_25mm { Int16 _FillValue 32767; Int16 actual_range 0, 41; Float64 column_id 1425; String column_name "col_1425"; String ioos_category "Unknown"; String long_name "Krill Abundance 21mm To 25mm"; String lter_column_description "abundance of krill"; String lter_column_name "21-25mm"; String lter_mscale "ratio"; String lter_num_type "real"; String lter_units_string "number"; String units "1"; String units_conventions "EML-2.0.1,EML-2.1.0,EML-LTER"; } krill_abundance_26mm_to_30mm { Int16 _FillValue 32767; Int16 actual_range 0, 52; Float64 column_id 1426; String column_name "col_1426"; String ioos_category "Unknown"; String long_name "Krill Abundance 26mm To 30mm"; String lter_column_description "abundance of krill"; String lter_column_name "26-30mm"; String lter_mscale "ratio"; String lter_num_type "real"; String lter_units_string "number"; String units "1"; String units_conventions "EML-2.0.1,EML-2.1.0,EML-LTER"; } krill_abundance_31mm_to_35mm { Int16 _FillValue 32767; Int16 actual_range 0, 72; Float64 column_id 1427; String column_name "col_1427"; String ioos_category "Unknown"; String long_name "Krill Abundance 31mm To 35mm"; String lter_column_description "abundance of krill"; String lter_column_name "31-35mm"; String lter_mscale "ratio"; String lter_num_type "real"; String lter_units_string "number"; String units "1"; String units_conventions "EML-2.0.1,EML-2.1.0,EML-LTER"; } krill_abundance_36mm_to_40mm { Int16 _FillValue 32767; Int16 actual_range 0, 61; Float64 column_id 1428; String column_name "col_1428"; String ioos_category "Unknown"; String long_name "Krill Abundance 36mm To 40mm"; String lter_column_description "abundance of krill"; String lter_column_name "36-40mm"; String lter_mscale "ratio"; String lter_num_type "real"; String lter_units_string "number"; String units "1"; String units_conventions "EML-2.0.1,EML-2.1.0,EML-LTER"; } krill_abundance_41mm_to_45mm { Int16 _FillValue 32767; Int16 actual_range 0, 87; Float64 column_id 1429; String column_name "col_1429"; String ioos_category "Unknown"; String long_name "Krill Abundance 41mm To 45mm"; String lter_column_description "abundance of krill"; String lter_column_name "41-45mm"; String lter_mscale "ratio"; String lter_num_type "real"; String lter_units_string "number"; String units "1"; String units_conventions "EML-2.0.1,EML-2.1.0,EML-LTER"; } krill_abundance_46mm_to_50mm { Int16 _FillValue 32767; Int16 actual_range 0, 92; Float64 column_id 1430; String column_name "col_1430"; String ioos_category "Unknown"; String long_name "Krill Abundance 46mm To 50mm"; String lter_column_description "abundance of krill"; String lter_column_name "46-50mm"; String lter_mscale "ratio"; String lter_num_type "real"; String lter_units_string "number"; String units "1"; String units_conventions "EML-2.0.1,EML-2.1.0,EML-LTER"; } krill_abundance_51mm_to_55mm { Int16 _FillValue 32767; Int16 actual_range 0, 47; Float64 column_id 1431; String column_name "col_1431"; String ioos_category "Unknown"; String long_name "Krill Abundance 51mm To 55mm"; String lter_column_description "abundance of krill"; String lter_column_name "51-55mm"; String lter_mscale "ratio"; String lter_num_type "real"; String lter_units_string "number"; String units "1"; String units_conventions "EML-2.0.1,EML-2.1.0,EML-LTER"; } krill_abundance_56mm_to_60mm { Int16 _FillValue 32767; Int16 actual_range 0, 19; Float64 column_id 1432; String column_name "col_1432"; String ioos_category "Unknown"; String long_name "Krill Abundance 56mm To 60mm"; String lter_column_description "abundance of krill"; String lter_column_name "56-60mm"; String lter_mscale "ratio"; String lter_num_type "real"; String lter_units_string "number"; String units "1"; String units_conventions "EML-2.0.1,EML-2.1.0,EML-LTER"; } krill_abundance_61mm_to_65mm { Int16 _FillValue 32767; Int16 actual_range 0, 8; Float64 column_id 1433; String column_name "col_1433"; String ioos_category "Unknown"; String long_name "Krill Abundance 61mm To 65mm"; String lter_column_description "abundance of krill"; String lter_column_name "61-65mm"; String lter_mscale "ratio"; String lter_num_type "real"; String lter_units_string "number"; String units "1"; String units_conventions "EML-2.0.1,EML-2.1.0,EML-LTER"; } } NC_GLOBAL { String _NCProperties "version=1|netcdflibversion=4.6.1|hdf5libversion=1.10.6"; String acknowledgement "Funding and support provided by the National Science Foundation"; String cdm_data_type "Other"; String comment "The Palmer, Antarctica, Long-Term Ecological Research project is a member site of the Long-Term Ecological Research program, a network of sites investigating diverse biomes. A team of researchers seeks to understand the structure and function of the Western Antarctic Peninsula's marine and terrestrial ecosystems in the context of seasonal-to-interannual atmospheric and sea ice dynamics, as well as long-term climate change. The PAL measurement system (or grid) is designed to study marine and terrestrial food webs consisting principally of diatom primary producers, the dominant herbivore Antarctic krill, and the apex predator Adelie penguin. An attenuated microbial food web is also a focus. PAL studies these ecosystems annually over a regional scale grid of oceanographic stations and seasonally at Palmer Station. \\n\\nPalmer Station is located on Anvers Island west of the Antarctic Peninula. The peninsula runs perpendicular to a strong climatic gradient between the cold, dry continental regime to the south, characteristic of the Antarctic interior, and the warm, moist, maritime regime to the north. North-south shifts in the gradient give rise to large environmental variability to climate change. Sea ice extent and variability affects ecosystem changes at all trophic levels. In addition to the long-term field and research activities, information management, graduate student training, education and outreach are an integral part of the program."; String contributor_email "bfraser@3rivers.net"; String contributor_name "William Fraser"; String contributor_role "PrincipalInvestigator"; String contributor_role_vocabulary "https://vocab.nerc.ac.uk/collection/G04/current/"; String Conventions "CF-1.8, ACDD-1.3, COARDS"; String creator_country "USA"; String creator_email "kerfoot@marine.rutgers.edu"; String creator_institution "Rutgers University"; String creator_name "John Kerfoot"; String creator_sector "academic"; String creator_type "person"; String creator_url "https://rucool.marine.rutgers.edu"; String datazoo_dataset_id "96"; String datazoo_datatable_id "96"; String datazoo_datatable_label "Adelie Penguin Diet Composition, Krill"; String datazoo_datatable_name "AdeliePenguinDietEuphausiasuberba"; String date_created "2021-09-01T20:14:25Z"; String date_issued "2021-09-01T20:14:25Z"; String defaultDataQuery "null"; String defaultGraphQuery "time,total_krill_abundance&.draw=markers&.marker=6%7C5&.color=0x000000&.colorBar=%7C%7C%7C%7C%7C&.bgColor=0xffccccff"; String doi "https://doi.org/10.6073/pasta/f331feede8ba321afbcf812445f172ce"; String geospatial_bounds_crs "EPSG:4326"; String geospatial_bounds_vertical_crs "EPSG:5831"; String geospatial_lat_resolution "0.00001 degree"; String geospatial_lat_units "degree_north"; String geospatial_lon_resolution "0.00001 degree"; String geospatial_lon_units "degree_east"; String geospatial_vertical_positive "down"; String geospatial_vertical_units "EPSG:5831"; String history "/Users/kerfoot/data/lter/data/tsv/dat_96/dat_96_PAL9900.tsv 2025-05-04T18:06:01Z (local files) 2025-05-04T18:06:01Z http://pallter-data.marine.rutgers.edu/erddap/tabledap/AdeliePenguinDietEuphausiasuberba.das"; String infoUrl "https://pal.lternet.edu/"; String institution "National Science Foundation"; String keywords "birds, habitats, marine, Population Studies, populations, taxonomy"; String keywords_vocabulary "LTER Controlled Vocabulary,LTER Core Areas"; String license "All data contained herein is licensed under the LTER Network Data Access Policy (https://lternet.edu/data-access-policy/). In accordance with scientific publishing conventions and professional etiquette, the consumer of these data (the \"Data User\") is expected to appropriately cite these data in any publication that results from their use. The Data User should realize that these data may be actively used by others for ongoing research and that coordination may be necessary to prevent duplicate publication. The Data User is urged to contact the authors of these data if any questions about methodology or results occur and should realize that misinterpretation of data may occur if used out of context of the original study. Where appropriate, the Data User is encouraged to consider collaboration or co-authorship with the data authors. While substantial efforts are made to ensure the accuracy of data and associated documentation, complete accuracy of data sets cannot be guaranteed. All data are made available \"as is.\" The Data User should be aware that data are updated periodically and it is the responsibility of the Data User to check for new versions of the data. The data authors and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data."; String license_link "https://lternet.edu/data-access-policy/"; String naming_authority "edu.rutgers.rucool"; String product_version "1.0"; String program "LTER"; String project "Palmer LTER"; String publisher_country "USA"; String publisher_email "kerfoot@marine.rutgers.edu"; String publisher_institution "Rutgers University"; String publisher_name "John Kerfoot"; String publisher_type "person"; String publisher_url "https://rucool.marine.rutgers.edu"; String references "https://pal.lternet.edu/"; String sea_name "Southern Ocean"; String source "/Users/kerfoot/data/lter/data/tsv/dat_96/dat_96_PAL9293.tsv"; String sourceUrl "(local files)"; String standard_name_vocabulary "CF Standard Name Table v77"; String subsetVariables "study_name"; String summary "Adelie penguin diet composition, krill size-frequency distribution, 1991 - present. The fundamental long-term objective of the seabird component of the Palmer LTER (PAL) has been to identify and understand the mechanistic processes that regulate the mean fitness (population growth rate) of regional penguin populations. Two hypotheses have guided this research, with one suggesting that population mean fitness is best explained by changes in regional krill biomass, and the other proposing that long-term changes in sea ice affects mean fitness by tipping the balance in favor of one species over another in accordance with species-specific evolved life history affinities to sea ice. Although these hypotheses are not mutually exclusive, current evidence in the PAL region tends to favor the latter over the former. Since the inception of PAL, Adélie penguin populations have effectively collapsed, while those of gentoo and chinstrap penguins have increased dramatically, trends that are spatially and temporally coherent with decreasing regional sea ice duration. Adélie penguins are an ice-obligate polar species whose life history is intimately linked to the presence of sea ice, while chinstrap and gentoo penguins are ice-intolerant species whose life histories evolved in the sub-Antarctic, where sea ice is a less permanent feature of the marine ecosystem. In contrast, although krill constitute the most important component of the summer diets by mass of these three penguin species, changes in PAL krill abundances have exhibited no long-term trends, and thus fail to explain the divergent patterns in penguin populations evident in our time series. \\n\\nThree species of krill occur in Adélie penguin diet samples, Antarctic krill (Euphausia superba), crystal krill (E. crystallorophias) and Thysanoessa macrura (no common name), but beyond obtaining whole subsample weights following sorting (see DIET), only E. superba is subjected to further analysis. In this case, the original subsample from each individual penguin is searched with the objective of obtaining a minimum of 50 whole krill that when measured (in millimeters) provide an index of within and between season variability in population size-frequency distributions. These data have provided critical insights into a number of ecological processes, including in particular how sea ice affects krill recruitment and, in turn, how krill recruitment impacts Adélie penguin foraging efforts. \\n"; String time_coverage_end "2018-01-29T00:00:00Z"; String time_coverage_start "1992-01-15T00:00:00Z"; String title "Adelie penguin diet composition, krill size-frequency distribution, 1991, present."; } }