Dungeness Crab Megalopae
CDFW Dungeness Crab Megalopae
cdfw_dungeness-crabCDFWCreative Commons Attribution 4.0 Internationalv2026.09.05ingested
- years
- 1984–2014
- observations
- 1,456
- sampling events
- 523
- stations
- 56
- taxa
- 3
- depth
- 0–223 m
Overview
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.
Open with the provider
- Q14 link_data_source — open
Access
Every endpoint this dataset can be reached through, grouped by how you would use it. Every URL is in the release record and answered when the release was cut.
Explore
Apps that read this dataset from the release. A row marked “this dataset” opens with it already selected.
https://calcofi.io/explore/?datasets=cdfw_dungeness-crab
https://app.calcofi.io/station/?dataset=cdfw_dungeness-crab
https://app.calcofi.io/hex/?datasets=cdfw_dungeness-crab
https://app.calcofi.io/cruise/?datasets=cdfw_dungeness-crab
Query
SQL against the release itself, in the browser — nothing to install and nothing downloaded until a query asks for it. __TBL:obs__ resolves to the pinned release’s parquet.
-- cdfw_dungeness-crab in the CalCOFI release v2026.09.05
SELECT *
FROM __TBL:obs__
WHERE dataset_key = 'cdfw_dungeness-crab'
LIMIT 100;https://calcofi.io/db-query/?sql=--+cdfw_dungeness-crab+in+the+CalCOFI+release+v2026.09.05%0ASELECT+%2A%0AFROM+__TBL%3Aobs__%0AWHERE+dataset_key+%3D+%27cdfw_dungeness-crab%27%0ALIMIT+100%3B#sql-shell--shell
Code
The same release, from a script.
con <- calcofi4r::cc_get_db()
calcofi4r::cc_cite("cdfw_dungeness-crab")con = calcofi4py.cc_get_db()
calcofi4py.cite("cdfw_dungeness-crab")SELECT * FROM read_parquet('https://storage.googleapis.com/calcofi-db/ducklake-staging/tables/obs/dataset_key=cdfw_dungeness-crab/1c745a30376e1849871cfa1e/data_0.parquet') LIMIT 100;Get the data
Every way to have the bytes, by source. Nothing here asks you to register first.
Files from the release (Parquet)
The frozen objects this release is made of. A partition holds only this dataset’s rows; a shared table holds every dataset’s, so filter on dataset_key.
https://storage.googleapis.com/calcofi-db/ducklake-staging/tables/obs/dataset_key=cdfw_dungeness-crab/1c745a30376e1849871cfa1e/data_0.parquet
CF netCDF
One self-describing file, for a tool that reads netCDF.
how far this file is CF
CF-1.10 where CF applies (coordinates, units, standard names, time). The subsample -> tow -> occurrence hierarchy uses netCDF-4 groups with explicit parent_index links; CF defines no feature type for this nesting.
https://storage.calcofi.io/calcofi-files-public/netcdf/cdfw_dungeness-crab/v2026.09.04/cdfw_dungeness-crab.nc
ERDDAP (erddap.calcofi.io)
One ERDDAP dataset per grain, each with its own data formats and its own pages. Subset in the browser or query it from a script.
- length/stage frequency
- one row per size or stage class of a specimen
- observations
- one row per measurement, joined to the event it was taken on
- sampling events
- one row per cast, tow or transect — when, where and how it was sampled
From the provider
The dataset as its provider publishes it, before CalCOFI ingested it.
https://library.ucsd.edu/dc/search?q=CalCOFI+Dungeness+crab+megalopae
Metadata records
Records about the data, in the standards each portal harvests.
https://erddap.calcofi.io/erddap/metadata/iso19115/xml/cdfw_dungeness-crab_iso19115.xml
https://erddap.calcofi.io/erddap/metadata/fgdc/xml/cdfw_dungeness-crab_fgdc.xml
https://calcofi.io/datasets/cdfw_dungeness-crab.jsonld
https://calcofi.io/datasets/cdfw_dungeness-crab.json
https://calcofi.io/data.json
https://calcofi.io/stac/#/collections/cdfw_dungeness-crab/collection.json
Archives & portals
Where this dataset is registered outside calcofi.io, by the identifier each portal knows it as.
https://erddap.calcofi.io/erddap/info/cdfw_dungeness-crab/index.html
https://doi.org/10.5281/zenodo.22281994
Everything here is open — nothing on calcofi.io asks you to register first. If this dataset ends up in something you build or publish, register your use so it can be credited and linked back; to hear when a release changes it, stay informed. Questions: data@calcofi.io.
Cite
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.
License: CC-BY-4.0BibTeX
@misc{cdfw_dungeness-crab,
title = {CDFW Dungeness Crab Megalopae},
howpublished = {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.
},
year = {2026},
note = {License: CC-BY-4.0}
}…and the release it came from
CalCOFI (2026). CalCOFI Integrated Database, release v2026.09.05 [Data set]. Scripps Institution of Oceanography, NOAA Fisheries, and California Department of Fish and Wildlife. https://calcofi.io/db-schema/?v=v2026.09.05BibTeX
@misc{calcofi_release_v2026_09_05,
title = {CalCOFI Integrated Database, release v2026.09.05},
author = {CalCOFI},
year = {2026},
publisher = {Scripps Institution of Oceanography, NOAA Fisheries, and California Department of Fish and Wildlife},
url = {https://calcofi.io/db-schema/?v=v2026.09.05}
}