We conducted monthly trapping of invasive European green crabs to gather demographic data in Seadrift Lagoon, Stinson Beach, CA (lat 37.907440, long -122.6661694). All sites were accessed by either kayak or by foot via shore entry. At each of the six sites used for monthly trapping plus three additional sites, we placed 15 baited traps (folding Fukui fish traps) in shallow (<2 m) subtidal areas. Traps were retrieved 24 hours later and were rebaited and collected again the following day. Trapping was continued for four consecutive days with traps removed on the final day. Crabs were marked by clipping two adjacent anterio-lateral spines. Each day, data for crab species, size, sex, reproductive condition, injuries, and presence of marks were collected for all crabs in the field. Following data collection, all marked crabs were returned to the lagoon at the same site that the crabs were collected.
\nSee Turner et al. (2016) for additional methodological details.
Mark recapture data for introduced crab\u00a0in Seadrift Lagoon (Central California coast, shallow subtidal (<3 m depth)) from 2011 to 2018.
Data were entered and checked in MS Excel spreadsheets.\u00a0Statistical analyses were run with either (R Development Core Team) or SAS (Statistical Analysis Systems).
\nBCO-DMO Processing:
\nv1 (2017-06-02):
\n- converted date to YYYY-MM-DD format;
\n- modified parameter names to conform with BCO-DMO naming conventions (changed to lowercase from mixed case,\u00a0replaced spaces with underscores);
\n- created column for full species names and added names corresponding to each code from metadata page; changed 'species' column provided to 'species_code';
\n- replaced commas with semi-colons;
\n- replaced blanks (missing data) with 'nd';
\n- replaced spaces with underscores;
\n- sorted by date, site, then size.
v2 (2021-03-16):
\n- replaced version 1 of dataset with version 2, which includes a longer time series of data;
\n- replaced commas with semi-colons in the injury and recap_mark columns;
\n- converted date to YYYY-MM-DD format;
\n- replaced invalid values in sex and size columns with 'nd'.