For each whale-watching tour, each ship accommodates one guide trained by KOEF’s cetacean experts to record cetacean sightings (approximately 70% of our guides have three or more years of experience in detecting and identifying cetaceans, last updated on 2023-09-05). The boat follows a random path until cetaceans are detected and sometimes we also receive sighting reports from other whale-watching boats. While observing cetaceans, the guide documents the location and time of each sighting with a hand-held GPS device (Garmin GPSMAP 64st), identifies the cetacean species, estimates the number of individuals and confirms the presence of mother-calf pairs and mixed-species groups in the vicinity. Upon returning, the guide fills in the cetacean record sheet, which contains fields included in the Global Biodiversity Information Facility (GBIF) dataset. To avoid collecting duplicate sighting data, when there are trips with more than one vessel in the same area, only the data of one ship is recorded within the same trip. Trained volunteers subsequently input the data into a computer for digital storage. Most whale-watching tours are divided into five time periods: 6 am (on average 2 trips per month), 8 am (on average 8 trips per month), 10 am (on average 6 trips per month), 2 pm (on average 6 trips per month) and 4 pm (on average 4 trips per month), each trip is approximately 1.5 to 2.0 hours long; there are an average of 26 trips per month (Fig. 2).

Figure 2.  

Whale-watching boat of the Turumoan whale-watching company, photo taken by Chieh-Hsi Hu.

Following electronic data entry, the records undergo a rigorous data cleaning process by a biologically-trained cetacean researcher of KOEF. All the scientific names of cetaceans are validated by the NomenMatch tool, which compares the names to the taxonomy backbones of GBIF, Catalogue of Life, Taiwan Catalogue of Life and Taiwan Biodiversity Network (Mai 2023) before they are added to the database. Geolocations are transformed into decimal degrees and verified by the Geographic Information System QGIS 3.10 (long-term release) software (QGIS.org 2019).

Citizen scientists' training

KOEF's training for new guides is a 15-week course that combines onboard internships and practices with indoor training by cetacean experts to enhance citizen scientists' professional abilities to identify different cetacean species, estimate the cetacean group size, understand the definitions of the various terms on cetacean sighting record sheets and use the handheld GPS (Garmin GPSMAP 64st). Through two stages of evaluation, it ensures that all guides that pass the training possess sufficient skills for being citizen scientists and follow a standardised protocol.

Data collection

1. While leaving Hualien port, the guide records the departure time using a hand-held GPS (Garmin GPSMAP 64st).
2. The boat follows a random path until cetaceans are detected and sometimes we also receive sighting reports from other whale-watching boats. When cetaceans appear, the ship slowly approaches. The guide then marks the location and time with a hand-held GPS, identifies the cetacean species, estimates the number of individuals and confirms the presence of mother-calf pairs and mixed-species groups in the vicinity. The average speed of the ship is approximately 3-4 knots while it is close to the cetaceans and the average time the vessel stayed with each species is approximately 15 minutes.
3. When leaving the cetaceans, the guide marks the leaving time with a hand-held GPS. When entering the port, the guide uses the GPS to mark the arrival time. Apart from the spatiotemporal information, which is recorded through the hand-held GPS, the guide remembers all the other information until returning to the whale-watching company.
4. After returning to the whale-watching company, the guide fills in the cetacean record sheet, which contains fields included in the GBIF dataset.

Data transcription:

The cetacean record sheets are organised once a month and the information on the data sheets are entered into an Excel spreadsheet file by trained interns, volunteers and guides of KOEF.

Open data preparation

Before uploading data to GBIF, we use a Darwin Core quick reference guide (Darwin Core Maintenance Group 2021) to match each type of record in our dataset and convert each column's data following the Darwin Core Standard. After data formatting, the dataset is categorised into core and extension files. We use the GBIF data validator (Global Biodiversity Information Facility 2017) to determine potential issues and the data correcting process is completed and verified by a biologically-trained cetacean researcher of KOEF. If the identification of uncertain cetaceans lacks identification by description or photographic evidence, their species identification will be annotated as uncertain and will be excluded from this dataset.

All of the sighting data were collected inshore of Hualien, eastern Taiwan (Fig. 3). Cetacean sighting records are all within an approximate range of 20 kilometres from Hualien Port, following the max speed of the vessels (10 to 12 knots) and the duration of whale-watching tours (1.5 to 2.0 hours).

Figure 3.  

Sighting points of cetaceans inshore of Hualien, eastern Taiwan (n = 9,810; 91.9% of all sighting records are with coordinates). The map was plotted by using QGIS 3.10 (long-term release) software (QGIS.org 2019).

23.6° N and 24.3° N Latitude; 121.5° E and 121.9° E Longitude.

This dataset contains 10,675 cetacean sighting records covering 20 different species, from which 41 records were identified up to the genus level, which is Kogia Gray, 1846 and 31 records were identified up to the family level, which is Hyperoodontidae (Ziphiidae) (Fig. 4). In addition, six to 10 different species of cetaceans were observed each year, most of which were small to medium-sized odontocetes like the spinner dolphin (Stenella longirostris (Gray, 1828)) and Risso's dolphin (Grampus griseus (G.Cuvier, 1812)) (Fig. 5). This dataset has achieved a higher record number for some species. For instance, in the case of the spinner dolphin, this dataset currently has the highest number of records amongst all datasets in GBIF and, for Risso's dolphin, it ranks fourth (last updated on 2023-09-05).

Figure 4.  

List of observed cetacean species in this dataset from 1998 to 2021. Prior to 2015, beaked whales were only recorded at the family level: Hyperoodontidae (Ziphiidae) and both dwarf sperm whale (Kogia sima (Owen, 1866)) and pygmy sperm whale (Kogia breviceps (Blainville, 1838)) were mostly recorded at the genus level: Kogia Gray, 1846.

a

b

Figure 5.

The most commonly seen species of cetaceans in whale-watching tours inshore of Hualien, eastern Taiwan.

a: Spinner dolphin (Stenella longirostris (Gray, 1828)), photo taken by Chieh-Hsi Hu.  
b: Risso's dolphin (Grampus griseus (G.Cuvier, 1812)), photo taken by Captain Wen-Lung Jiang.  

This dataset in the current work is licensed under a Creative Commons Attribution (CC-BY) 4.0 License. Any image materials in this data paper are licensed under the Creative Commons Attribution (CC-BY-NC) 4.0 License.