README — Lionfish observations at Tela
Dataset file: Confirmed_data.xlsx | README prepared: 2026
About the data set
Title: Lionfish in hot water: Temporal shifts in aggregation, relative abundance, and sex distribution following a mass coral mortality in Honduras
Dataset creators: Skye Crawford1, Alex H. O’Brien2, and Monica McCard1,2
1 School of Geography and Environmental Sciences, Liverpool John Moore University, Byrom Street, Liverpool, LA3 3AF, UK
2 Operation Wallacea, Wallace House, Old Bolingbroke, Lincolnshire, PE23 4EX, England
Year of publication: Just got accepted for publication – 2026

Description
The dataset contains 1,455 lionfish observation records from Tela across nine recorded years (2015-2024). It documents observation date, source, aggregation size, solitary/aggregating classification, dive site, age category and sex. The workbook contains nine variables in one worksheet. Species-level identification within lionfish was confirmed as Pterois volitans – red lionfish.
Lionfish (Pterois volitans) data were collected by Operation Wallacea researchers between June and August across survey years from 2014 to 2024 in Tela Bay, Honduras. Surveys were conducted at eleven dive sites across two reef systems, Banco Capiro and La Ensenada, using a repeated seasonal survey design to enable comparisons between years.
Roving diver surveys were conducted using SCUBA, with a single diver responsible for lionfish extraction on each dive to maintain consistent sampling effort. Lionfish were culled using a Hawaiian sling pole spear and stored in a Zookeeper container. Aggregations were defined as two or more stationary lionfish observed within 1 m of one another. Following collection, specimens were dissected immediately or refrigerated and dissected within 12 hours. Species identification and sex determination were carried out through dissection, with sex identified using gonad morphology following established protocols (Green et al., 2012).
Suggested provisional citation: Crawford, S., O’Brien, A. and McCard, M. (2026) Lionfish in hot water: Temporal shifts in aggregation, relative abundance, and sex distribution following a mass coral mortality in Honduras
Contact details
Principal investigator email: S.Crawford@2022.ljmu.ac.uk
Terms of use
Copyright holder: Open Source 
https://doi.org/10.24377/LJMU.d.00000291 
 
Please cite: McCard, Monica and Crawford, Skye (2026) Lionfish in hot water: Temporal shifts in aggregation, relative abundance, and sex distribution following a mass coral mortality in Honduras. [Data Collection]
Project and funding information
Project title: Lionfish in hot water: Temporal shifts in aggregation, relative abundance, and sex distribution following a mass coral mortality in Honduras
Dates: 2014-2024
Funding: This work was carried out through Operation Wallacea.
Contents
Confirmed_data.xlsx — Microsoft Excel workbook, worksheet “Sheet1”, 1,455 data rows and 9 columns. The original workbook can be opened in Microsoft Excel or compatible spreadsheet software.
Columns: Year (calendar year); Data_origin (OPWALL/LAB); Agg_size (integer of how many found together 1–7); Grouping (Solitary/Aggregating); Date (observation date); Location (Tela); Dive_site (name of specific site); AGE (ADULT/JUVE/NA); Sex (M/F/Male/Female/m/f/NA).
README — accompanying documentation. 
Methods
The workbook records lionfish observations at dive sites in Tela on 217 distinct dates. Records cover 2015, 2016, 2017, 2018, 2019, 2023 and 2024. The exact sampling protocol, equipment, survey effort, definition of the observation unit, and processing procedures are found in the publication when released.
Within the file, Agg_size = 1 corresponds to one individual lionfish. Solitary and Agg_size > 1 corresponds to Aggregating. Some rows have identical values in all nine fields; these should not be removed as duplicates without confirmation of the sampling protocol.
Data interpretation notes: sex is coded using mixed abbreviations, full words and letter case; dive-site names contain apparent spelling/format variations; NA occurs as a literal category in AGE and Sex to show it was not discovered even through dissections. The absence of 2020–2022 records does not imply absence of lionfish this occurred through Covid pandemic as there were no dives performed then.

2026