Vessel departure orders to Parque Nacional Arrecife Alacranes (Yucatán, Mexico), 2008–2020: anonymised recreational and lobster-fleet records and code for MPA human-pressure indicators

What this is. Anonymised records of 811 recreational-vessel departure orders (órdenes / avisos de zarpe; 2016, 2017, 2019 and 2020) and 1,538 lobster-fleet dispatch documents (2008–2020) issued by the Port Captaincy of Yucalpetén (Progreso, Yucatán, Mexico) for trips to Parque Nacional Arrecife Alacranes (Alacranes Reef National Park, Scorpion Reef), southern Gulf of Mexico, together with the Python code that reproduces every number and figure of the associated paper. Why it matters. Remote, uninhabited marine protected areas (MPAs) are reached only by sea, yet managers rarely know how many vessels and people arrive, when and for how long. Departure notices filed before the maritime authority are an unused, free archive of this information. The dataset allows three human-pressure indicators to be computed — vessels by NOAA small-boat class, trips, and person-days in the MPA — and compared with the tourist carrying capacity (111 persons per day) and with the access bracelets sold by the park administration (CONANP). Contents. Data files: recreational trips (Captaincy stamp, departure and return dates, vessel code, rounded dimensions and tonnage, NOAA class, registry group, marina of origin, number of people by sex and role); people per recreational trip (anonymous person code, sex, role); lobster-fleet trips (document type, dates, dispatch validity, vessel code, cooperative, anonymous consignee agent, permits, crew); crew per lobster trip; lobster vessels; establishments of origin with coordinates; annual access bracelets sold (CONANP); reef polygons of Alacranes; marinas of the 2019 Yucalpetén survey (locations only) and a water/land mask of Yucalpetén harbour. code.zip: anonymisation script (run on the original, non-public database), analysis, figures, supplementary tables and graphical abstract, and outputs (results.json with every statistic of the paper, daily occupancy summary, and lobster-fleet effort and workforce by year). See README.md for the field dictionary and instructions to reproduce the results. Anonymisation. The original orders contain personal data. Names, vessel names, registration and permit numbers, and consignee agents were removed; person, vessel and agent codes are random permutations; vessel length and beam are rounded to 0.5 m and tonnage to whole tonnes; port of registry is reduced to USA / Mexico / other foreign. The records were obtained under Mexico's transparency law with a written commitment to code all personal data. Statistics recomputed from this release may differ from the paper in the last decimal for vessel dimensions and tonnage. Coverage and caveats. One port only (Port Captaincy of Yucalpetén; the separate Captaincy of the commercial port of Progreso is not included). Recreational orders for 2018 and all orders after 2020 were lost by the issuing authority; 2016, 2017 and 2020 appear incomplete. Return dates exist for 14% of recreational orders; missing trip durations are imputed in the code by resampling.