https://calcofi.io/datasets/cdfw_dungeness-crab/ Dungeness Crab Megalopae Laura Rogers-Bennett California Department of Fish and Wildlife (CDFW) Emily Jones Scripps Institution of Oceanography (SIO) data collection Christy Juhasz California Department of Fish and Wildlife (CDFW) other Julia Coates California Department of Fish and Wildlife (CDFW) other 2026-10-21 eng Dungeness crab (Metacarcinus magister) megalopae and larval decapods picked from archived CalCOFI oblique-tow plankton samples, examined for the California Department of Fish and Wildlife. Two efforts: a 2008-2014 time series of 310 sorted samples (A. Klemmedson, 2015) yielding 24 M. magister megalopae from 14 samples, and 216 archived samples from the 1949-2009 sorting log that were examined and found free of M. magister (1984-2009, E. Jones, as of 2012-02-15). Only examined samples are published — the log's remaining unsorted rows are a fact of the archive's inventory, not a sample of this dataset. Spring cruises, CalBOBL oblique tows, lines < 80 / stations < 90. Counts are occurrence in the examined aliquot, not standardized density. Sorting was performed at the SIO Pelagic Invertebrate Collection, where the removed megalopae are archived in vials. EARTH SCIENCE > BIOSPHERE > ECOSYSTEMS > AQUATIC ECOSYSTEMS > PLANKTON > ZOOPLANKTON EARTH SCIENCE > BIOLOGICAL CLASSIFICATION > ANIMALS/INVERTEBRATES > ARTHROPODS > CRUSTACEANS > DECAPODS GCMD Science Keywords Invertebrate Abundance and Diversity Zooplankton Biomass and Diversity CalCOFI Network Zooplankton abundance count Fish Eggs & Larvae This work is licensed under a Creative Commons Attribution 4.0 International. Creative Commons Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ CC-BY-4.0 https://calcofi.io/datasets/cdfw_dungeness-crab/ 33.5–51.0°N, 132.2–120.7°W -132.25 -120.675 51.05 33.46 1984 2014 Zooplankton family Cancridae rock crabs 106749 order Decapoda decapods 1130 species Metacarcinus magister Dungeness crab 440388 archived CalCOFI data@calcofi.io Oblique tow; the CDFW Dungeness megalopae sorting log records the tow geometry but not the net. sample One row per physical sampling event at its native grain (site, tow, net, subsample, cast, bottle, water, filter, underway, transect, sighting, deployment, scan, region pool). An adjacency list: parent_sample_key points at the containing event and root_sample_key at the top of the chain, so counting distinct events at any level is a single GROUP BY. sample_key Sample Key Globally unique event key, namespaced dataset_key:sample_type:id so the same integer id in two datasets — or at two event levels in one dataset — never collides. VARCHAR Globally unique event key, namespaced dataset_key:sample_type:id so the same integer id in two datasets — or at two event levels in one dataset — never collides. sample_type Sample Type Event grain: site, tow, net, subsample, cast, bottle, water (an eDNA water sample), filter (an eDNA water filter), underway, transect (a visual-survey effort segment), sighting, deployment (a sonobuoy), scan (one analysed hour of a recording) or region_pool. VARCHAR Event grain: site, tow, net, subsample, cast, bottle, water (an eDNA water sample), filter (an eDNA water filter), underway, transect (a visual-survey effort segment), sighting, deployment (a sonobuoy), scan (one analysed hour of a recording) or region_pool. parent_sample_key Parent Sample Key The containing event (net → tow → site; bottle → cast; sighting → transect; scan → deployment). NULL at the top of the chain. Flat adjacency list: attributes are not inherited. VARCHAR The containing event (net → tow → site; bottle → cast; sighting → transect; scan → deployment). NULL at the top of the chain. Flat adjacency list: attributes are not inherited. root_sample_key Root Sample Key Top of this event's containment chain; equals sample_key for single-level datasets. Use count(DISTINCT root_sample_key) to count stations/casts irrespective of grain. VARCHAR Top of this event's containment chain; equals sample_key for single-level datasets. Use count(DISTINCT root_sample_key) to count stations/casts irrespective of grain. dataset_key Dataset Key Provenance stamp: provider_dataset. VARCHAR Provenance stamp: provider_dataset. grid_key Grid Key CalCOFI station grid cell. NULL where the dataset has no station assignment (region-pooled phytoplankton). VARCHAR CalCOFI station grid cell. NULL where the dataset has no station assignment (region-pooled phytoplankton). site_key Site Key CalCOFI station natural key as the source records it (line/station, e.g. 090.0 060.0). Present on 13 of the 18 source event tables, so it is carried on the event dimension rather than lost to consolidation; grid_key is the derived grid cell, this is the source's own station id. VARCHAR CalCOFI station natural key as the source records it (line/station, e.g. 090.0 060.0). Present on 13 of the 18 source event tables, so it is carried on the event dimension rather than lost to consolidation; grid_key is the derived grid cell, this is the source's own station id. cruise_key Cruise Key CalCOFI cruise natural key YYYY-MM-NODC. VARCHAR CalCOFI cruise natural key YYYY-MM-NODC. order_occ Order of Occupation Order in which the station was occupied on the cruise. Source spelling varies (order_occ, ord_occ) and CTD stores it as text; normalised to an integer here. INTEGER dimensionless integer latitude Latitude Event latitude (WGS84). DOUBLE degree real longitude Longitude Event longitude (WGS84). DOUBLE degree real datetime Datetime Event start time (UTC). TIMESTAMP YYYY-MM-DDThh:mm:ss depth_min_m Depth Min Shallowest depth sampled by this event. DOUBLE meter real depth_max_m Depth Max Deepest depth sampled by this event; for swfsc_ichthyo tows and nets the maximum possible depth of the net (SWFSC Net.NetDepth, nominal: over a shallower sea floor the net did not reach it). DOUBLE meter real tow_type Tow Type Net gear code where the dataset records one (C1/CB/CV/PV oblique or vertical, MT manta); NULL for gears and datasets without one. Needed to compute gear-appropriate CPUE. VARCHAR Net gear code where the dataset records one (C1/CB/CV/PV oblique or vertical, MT manta); NULL for gears and datasets without one. Needed to compute gear-appropriate CPUE. data_stage Data Stage The source's own processing state for this event: final (post-cruise calibrations applied) or preliminary (not for publication — the source warns that oxygen, nitrate and chlorophyll may change significantly once calibrated). Populated by calcofi_ctd-cast; NULL where the dataset draws no such distinction, which is not a claim that the data are final. VARCHAR The source's own processing state for this event: final (post-cruise calibrations applied) or preliminary (not for publication — the source warns that oxygen, nitrate and chlorophyll may change significantly once calibrated). Populated by calcofi_ctd-cast; NULL where the dataset draws no such distinction, which is not a claim that the data are final. geom Geometry Point geometry minted from longitude/latitude (OGC:CRS84). GEOMETRY('EPSG:4326') Point geometry minted from longitude/latitude (OGC:CRS84). source_uuid Source Uuid Source Uuid UUID Source Uuid hex7 H3 Cell (res 7) One UBIGINT H3 cell at resolution 7: the parent of the resolution-10 cell of this event's own latitude / longitude (not the resolution-7 cell the position falls in), defined exactly as obs_bio.hex7 / obs_env.hex7; NULL without a finite position. Lets a per-sample value in sample_measurement be drawn in hexagons. An observation carries its own position, so a CTD scan can sit in another cell than its cast. UBIGINT dimensionless whole seafloor_depth_m seafloor_depth_m DOUBLE dimensionless real station_uuid station_uuid UUID station_uuid station_uuid_method station_uuid_method VARCHAR station_uuid_method obs The occurrence-headline long table: one scalar measurement per row, environmental (realm = 'env') and biological (realm = 'bio') together. Biological taxon is the global taxon_key; sub-occurrence detail (length/stage bins, behavior) lives in obs_attribute, and event-level effort in sample_measurement. data_0.parquet 19854 2ddcc92df3a87c63e87460bbc4ab712ffc18de44192f6330f85e1c413383d61b Apache Parquet https://storage.googleapis.com/calcofi-db/ducklake/tables/obs/dataset_key=cdfw_dungeness-crab/1bd58153aefc8147fac7c598/data_0.parquet obs_id Observation ID Surrogate key, renumbered globally when the release concatenates the per-dataset shards. BIGINT dimensionless integer realm Realm env for physical/chemical measurements, bio for organism observations. VARCHAR env for physical/chemical measurements, bio for organism observations. dataset_key Dataset Key Provenance stamp: provider_dataset. VARCHAR Provenance stamp: provider_dataset. sample_key Sample Key The sampling event this observation came from; joins sample. VARCHAR The sampling event this observation came from; joins sample. grid_key Grid Key CalCOFI station grid cell, denormalized from sample so rollups need no join. NULL for region-pooled data. VARCHAR CalCOFI station grid cell, denormalized from sample so rollups need no join. NULL for region-pooled data. cruise_key Cruise Key Cruise, denormalized from sample so rollups need no join. VARCHAR Cruise, denormalized from sample so rollups need no join. latitude Latitude Observation latitude (WGS84). DOUBLE degree real longitude Longitude Observation longitude (WGS84). DOUBLE degree real datetime Datetime Observation time (UTC). NULL for region-pooled data with no event time. TIMESTAMP YYYY-MM-DDThh:mm:ss depth_min_m Depth Min Shallowest depth this observation represents. DOUBLE meter real depth_max_m Depth Max Deepest depth this observation represents; equal to depth_min_m for point measurements (bottle, CTD scan). DOUBLE meter real taxon_key Taxon Key Global taxon key, worms:<AphiaID> or itis:<TSN> for birds. NULL for env rows. Joins taxon. VARCHAR Global taxon key, worms:<AphiaID> or itis:<TSN> for birds. NULL for env rows. Joins taxon. life_stage Life Stage Life stage where the source resolves one (larva, adult, juvenile, egg, phyllosoma). VARCHAR Life stage where the source resolves one (larva, adult, juvenile, egg, phyllosoma). measurement_type Measurement Type Measured quantity; joins the measurement_type vocabulary. VARCHAR Measured quantity; joins the measurement_type vocabulary. measurement_value Measurement Value The measured value, in the units measurement_type declares. DOUBLE dimensionless real measurement_qual Measurement Qualifier Source quality flag, verbatim. VARCHAR Source quality flag, verbatim. measurement_prec Measurement Precision Source-reported precision where available. DOUBLE dimensionless real hex_id Hex ID H3 cell at resolution 10, stored as UBIGINT. Aggregate coarser at query time with h3_cell_to_parent(hex_id, res) — there is no per-resolution column ladder. UBIGINT dimensionless whole obs_attribute Sub-occurrence attribution: the breakdown within an obs headline row. Covers numeric frequency distributions (length bins, stage numbers) and categorical breakdowns (seabird behavior). Counts here sum to the headline where the source is internally consistent. obs_attribute_id Observation Attribute ID Surrogate key. BIGINT dimensionless integer dataset_key Dataset Key Provenance stamp: provider_dataset. VARCHAR Provenance stamp: provider_dataset. sample_key Sample Key The sampling event; joins sample. VARCHAR The sampling event; joins sample. taxon_key Taxon Key Global taxon key; joins taxon. VARCHAR Global taxon key; joins taxon. life_stage Life Stage Life stage the attribution applies to. VARCHAR Life stage the attribution applies to. measurement_type Measurement Type The attribute being broken down: body_length, stage or behavior. VARCHAR The attribute being broken down: body_length, stage or behavior. bin_value Bin Value Numeric bin — length in mm, stage number. NULL for categorical attributes. DOUBLE dimensionless real bin_label Bin Label Category label — stage description, behavior name. NULL for purely numeric bins. VARCHAR Category label — stage description, behavior name. NULL for purely numeric bins. count Count Number of individuals in this bin. INTEGER number integer measurement_qual Measurement Qualifier Source quality flag, verbatim. VARCHAR Source quality flag, verbatim. sample_measurement Event-level (effort) measurements: quantities that describe the sampling event itself rather than anything observed in it — net volume filtered, standard haul factor, proportion sorted, bottle cast conditions. Kept apart from obs so effort is never mistaken for an observation. sample_measurement_id Sample Measurement ID Surrogate key. BIGINT dimensionless integer sample_key Sample Key The sampling event this effort measurement describes; joins sample. VARCHAR The sampling event this effort measurement describes; joins sample. dataset_key Dataset Key Provenance stamp: provider_dataset. VARCHAR Provenance stamp: provider_dataset. measurement_type Measurement Type Measured quantity; joins the measurement_type vocabulary. VARCHAR Measured quantity; joins the measurement_type vocabulary. measurement_value Measurement Value The measured value, in the units measurement_type declares. DOUBLE dimensionless real measurement_qual Measurement Qualifier Source quality flag, verbatim. VARCHAR Source quality flag, verbatim. taxon Taxonomic hierarchy for species via WoRMS and ITIS authorities (built from spp.duckdb via recursive CTEs) taxon_key Taxon Key Global taxon key: lowercase authority prefix plus id, worms:127023 or itis:176754. VARCHAR Global taxon key: lowercase authority prefix plus id, worms:127023 or itis:176754. worms_id WoRMS ID WoRMS AphiaID. INTEGER dimensionless integer itis_id ITIS ID ITIS Taxonomic Serial Number. INTEGER dimensionless integer gbif_id GBIF ID GBIF backbone taxon key. INTEGER dimensionless integer ncbi_id NCBI ID NCBI Taxonomy id. INTEGER dimensionless integer inat_id iNaturalist ID iNaturalist taxon id. INTEGER dimensionless integer scientific_name Scientific Name Accepted scientific name. VARCHAR Accepted scientific name. common_name Common Name Common name where one is recorded. VARCHAR Common name where one is recorded. rank Rank Taxonomic rank. VARCHAR Taxonomic rank. rank_order Rank Order Ordinal for sorting ranks from kingdom down. INTEGER dimensionless integer taxonomic_status Taxonomic Status Status as fetched from the keying authority (accepted, unaccepted, superseded combination, ...). Read it with status_checked — before v2026.08.05 this column was the literal string "accepted" on every row, stamped rather than fetched. VARCHAR Status as fetched from the keying authority (accepted, unaccepted, superseded combination, ...). Read it with status_checked — before v2026.08.05 this column was the literal string "accepted" on every row, stamped rather than fetched. status_checked Status Checked Date taxonomic_status was last confirmed against the authority. A status with no check date is not a fact. VARCHAR Date taxonomic_status was last confirmed against the authority. A status with no check date is not a fact. parent_taxon_key Parent Taxon Key Lineage parent; walk this to expand a taxon to its descendants. VARCHAR Lineage parent; walk this to expand a taxon to its descendants. kingdom Kingdom Kingdom. VARCHAR Kingdom. phylum Phylum Phylum. VARCHAR Phylum. class Class Class. VARCHAR Class. order_taxon Order Order (named order_taxon because order is a SQL keyword). VARCHAR Order (named order_taxon because order is a SQL keyword). family Family Family. VARCHAR Family. notes Notes Append-only provenance log, one datestamped line per entry: how each id was resolved and any re-key onto an authority-accepted id (e.g. itis:174553 Puffinus griseus -> itis:1255050 Ardenna grisea). The dataset's own original code and name stay in dataset_taxon. VARCHAR Append-only provenance log, one datestamped line per entry: how each id was resolved and any re-key onto an authority-accepted id (e.g. itis:174553 Puffinus griseus -> itis:1255050 Ardenna grisea). The dataset's own original code and name stay in dataset_taxon. dataset_taxon Crosswalk from each dataset's own taxon vocabulary to the global taxon_key. obs resolves its taxon by joining this on (dataset_key, ds_taxa_code), so a dataset can keep its local codes without leaking them into the shared model. ds_taxon_key Dataset Taxon Key Key of this crosswalk row, <dataset-or-known-list>:<local code>. VARCHAR Key of this crosswalk row, <dataset-or-known-list>:<local code>. dataset_key Dataset Key The dataset whose vocabulary this row belongs to. VARCHAR The dataset whose vocabulary this row belongs to. taxon_key Taxon Key The global taxon it resolves to; joins taxon. VARCHAR The global taxon it resolves to; joins taxon. ds_scientific_name Dataset Scientific Name Scientific name as the source dataset spells it. VARCHAR Scientific name as the source dataset spells it. ds_common_name Dataset Common Name Common name as the source dataset spells it. VARCHAR Common name as the source dataset spells it. ds_taxa_code Dataset Taxa Code The dataset's own code, as stored on its measurement rows. VARCHAR The dataset's own code, as stored on its measurement rows. ds_source_json Ds Source Json Ds Source Json VARCHAR Ds Source Json Rogers-Bennett, L.; Jones, E.; Klemmedson, A. (2026). CDFW Dungeness Crab Megalopae from archived CalCOFI plankton samples (1949-2014). California Department of Fish and Wildlife, published through CalCOFI / Scripps Institution of Oceanography. cdfw_dungeness-crab https://calcofi.io/datasets/cdfw_dungeness-crab/ v2026.10.21 CalCOFI (2026). CalCOFI Integrated Database, release v2026.10.21 [Data set]. Scripps Institution of Oceanography, NOAA Fisheries, and California Department of Fish and Wildlife. https://calcofi.io/db-schema/?v=v2026.10.21 2026-10-21