Test by Greenland & WC

Test shootings to test the precision of the minke and fin whale tags and to test the ballistics of a fin whale tag with only a 10 cm shaft were conducted in the suburb of Copenhagen on the 28th and 29th June 2023.

The specific objectives included: • test of carriers with and without flights •test of flight performance including precision during target shooting • modifications of existing fin whale tags

Target shooting was conducted at 20 m distance from a target of 6 rockwool batts with a plywood plate behind.

The test showed that the precision is apparently improved when shooting with a tag compared to shooting with an empty carrier. For both the minke and the fin whale tag precision improved slightly with increased pressure (>5 bar). The flights were damaged when hitting the rockwool batts but using a new carrier with intact flights improved the precision and reduced the tendency of the tags to hit at angle (i.e. the carrier is not flying straight). Most hits were below target so this needs to be taken into account when shooting at whales.

Figure 1. Target of 6 rockwool batts with a plywood plate

Tests by Greenland

Test shootings to test the ballistics of the MINTAGs were conducted in the suburb of Copenhagen on the 28th of February 2023 and 28th of March 2023. In February, 7 shots were fired on a target of 6 Rockwool batts from 20 m with a pressure between 10-12 bar (see video).

The test showed that the aluminium launcher worked fine and the MINTAG for minke whales hit the target precisely from a distance of 20 m. The hollow cone performed better on average than the solid cone, as observed during the test in Japan. It is therefore recommended to use hollow cones. Suggestions to improve the resin holder were also made.
The conclusion of the test was that more equipment is needed to do more opportunistic tests to be able to make decisions about the tag design.

The test in March was to specifically assess the ballistics of the fin whale tag. The test conditions were the same as in February and 3 shots were fired in total. The tag had a sideway drift in all shots (Figure 1) which will need to be accounted for in the field. Additionally, it was concluded that fin whale tags will need at least 12 bar when shooting from a distance from 20 m.

Figure 1. Tag hit 15 cm to the right and at the level of target

Test in Japan

The shooting test was conducted on 9th February in Yokohama, Japan using the blubber and muscle of Bryde’s whale as targets. The objective of the test was to investigate the performance of wooden stop-plates and of solid and hollow retention cones in penetration and retention abilities for the minke and fin whale tags. A total of 13 shots were fired with shooting distances in 7, 10 and 15 m, and air pressure varied from 10 to 18 bar.

Figure 1. MINTAG for fin whale set in the barrel of LK-ARTS

A conclusion on wooden stop-plates could not be drawn due to a lack of adequate penetration in many shots. However, retention functions were all good when the cones were inserted into blubber tissue and the flight of both types of retention cones were good, but the tag equipped with the hollow cone seemed to have a better ballistic performance.

Figure 2. Shooting scene with the target of blubber and grass mats (7m in distance)

A 2nd test of the tags was conducted in the Faroe Islands in January 2023

A 465 cm long stranded Sowerby’s beaked whale was estimated to have been dead for less than three days and in good condition for testing of the function of the retention cone of the tags (see photo 1).

Figure 1. MINTAG minke whale housing (TTL 14 cm) fitted with a medium size retention cone

The test shots were fired towards the back of the whale, at an angle of ca. 80-90 dg relative to the longitudinal axis, midway between the blowhole and the dorsal fin. The tags were fired with an ARTS, fitted with an 81 cm barrel, and a 56.5 cm long rocket launcher and a 46 cm wooden stop plate. The blubber thicknesses at the impact locations were 40 mm for all trials.

After the shot the retention of the tag was examined by pulling the tag out of the skin (see Photo 2) and it was clear that a pull of >100 kg was not enough the pull the tag out of the whale.

Figure 2. Testing the pull (kg) needed to extract the tag from the whale body

Dissection of the whale where the tag was embedded showed that the tag nicely penetrated the fascia with the retention under the fascia leaving a hole in the skin with the diameter of the tag housing (11 mm).

Figure 3. Penetration hole in the fascia.


Two model designs for tags for use on minke and fin whales are now available for test shooting (see Photo 4). The small minke whale tag (upper part of photo) has a steel housing with a sharp cutting point. The intention is that the tag should be embedded under the skin with a retention cone (white conical part) in the rear part of the tag. When deployed a wooden stop plate at the distal end stop the tag at the skin of the whale. The stop plate is made out of a fragile wooden disk and will disintegrate upon impact of hitting the skin of the whale.

The large fin whale tag (lower part of photo) is similar to the minke whale tag except that it has an extension rod that will allow the front mounted retention cone to embed below the fascia of the fin whale.

The two models will be used for additional test shootings on carcasses of whales, and based on the combined experience from testing of the tags, the first 25 MINTAGs will be modified for deployment on whales in the North Pacific and North Atlantic in summer 2023.

Figure 4. Model design for minke whale tag (top) and fin whale tag (bottom)

Tag design workshop

On the 26th and 27th of October 2022, the Steering Group and Wildlife Computers held a workshop in the Greenlandic representation in Copenhagen, Denmark. The design of the V0b tags for minke and fin whales which will be deployed in 2023 were discussed and final designs agreed upon.
How will the MINTAG data contribute to marine mammal management/conservation?

Longer tracking times will give information on migration patterns and contact with other populations.

What is challenging about the development of the MINTAG?

Everything is a challenge as we try to develop a whole new tag but it is hard to get there without repeating things. The most challenging is for the new tags to stay inside in the whales for a long time.

WhatsApp Image 2022-10-28 at 09.07.08
WhatsApp Image 2022-10-28 at 09.07.09
What is the potential of the MINTAG?

It will be a smaller and less intrusive tag with the opportunity to tag a variety of species, especially smaller cetaceans which are difficult to tag. During the development, more sensors for behavioural and oceanographic data can be implemented to further improve data.

Why is the MINTAG project important?

The extensive knowledge on population dynamics and migration of whales as well as interactions of populations are crucial for the successful management and conservation of these animals.

Testing in Iceland

From the 10th to 16th July 2022, scientists from the project Steering Group and Iceland as well as engineers from Wildlife Computers tested the deployment and specific characteristics (carriers, biopsy tip system, stop plate, penetration depth, barbs, retention, flight performance) of dummy tags on fin whale carcasses in Iceland. Kristján Loftsson, from Hvalur hf, is gratefully acknowledged for providing access to the whaling station and the whale carcasses and made this testing possible.

Tests could be performed on seven fin whales, three females and four males of different sizes. A total of 28 shots were performed and their characteristics and results were duly documented both in writing and with photos and videos.

The testing provided information invaluable for the progress of the project and the design of successful tags. The specific layering of the dermis and blubber, and the intersection to the muscle layer, cannot easily be modelled, and no other animals can be used as proxy for whale skin. Even within cetaceans there are huge variations in the thickness of epidermis, the blubber layer, and the composition of the muscle layer. Although the sample size was only of seven whales of the same species, considerable differences were noted, notably between the males and the big females. Overall, the Group considered that important lessons were learned about the basic functioning of the tags and which characteristics function best.

The Group recommended tests conducted in this study be repeated on minke whales due to differences in blubber thickness between fin and minke whales. Based on the experience from the trials, with the understanding that the possible range of test trials were not exhausted, the Group draw possible tag designs that were discussed by the MINTAG Steering Group in a workshop in October 2022.

Example of a test performed: penetration of the tag below the fascia*

In both shot 3.1 and 3.2, the shaft** of the tag housing bended. Either the shaft (31.5 cm) was too long or the pressure (20 bar) was too high. The Group concluded that it was better to use a shorter total tag length (<35 cm). However, the test was not considered conclusive because of the strong interference from the wind that clearly affected the flight of the carrier.

*Dense layer of connective tissue that separates blubber from muscle

** The threaded or unthreaded part in front of the transmitter part of the tag, also called ‘spear’ and ‘anchor’

Figure 1. Both shots 3.1 (above) and 3.2 (below) resulted in a bended shaft
Figure 2. Different models of carriers, shaft and dart tips
Figure 3. Participants in the MINTAG testing at the Icelandic Whaling Staion in July 2022: A. Leask (WC), C. Hunter (WC), M. P. Heide-Jørgensen (GINR), B. Mikkelsen (FAMRI), N. Øien (IMR) and S. D. Halldórsson (MFRI)

Timeline (tentative)

2021 – 2022: Development phase

Summer – Autumn 2021

  • Virtual Meeting of the Steering Group and agreement on required tags specifications
  • Development of tender material for manufacturers
  • Contact with potential manufacturers and request for offer
  • Research on legal aspects of contracts

Winter – Spring 2022

  • Review of manufacturers proposals
  • Choice of manufacturer
  • Kick-off tag project seminar with Wildlife Computers
  • Annual Spring reporting to the NAMMCO Council and FAJ
  • Start of tag housing and carrier
  • Development and signing of the MOU
    between NAMMCO and Wildlife Computer

2022 – 2023: Tests

Summer – Autumn 2022

  • Test of ballistic performance at the Icelandic whaling station
  • Development of project website
  • Project year-1 reporting to the NAMMCO Council and FAJ
  • Seminar on tag design between the Project Steering Group and Wildlife Computer
  • Tag and carrier development

Winter 2022 – 2023

  • Development of tag, carrier and biopsy sampler continue
  • Development of tagging protocol for the deployment of the prototype tags

Spring – Summer 2023

  • Testing prototype (V0b) on carcasses
  • Deployment of 25 V0b tags on whales, some in the Atlantic (Greenland, Norway), some in the Pacific (Japan)
2023 – 2024: Tests
Autumn 2023
  • Evaluation of deployment

Winter 2023 2024

  • Refinement of the tag design
  • Development of final deployment protocols
  • Development of tracking database
  • Project year-2 reporting to NAMMCO and FAJ

Spring – Summer 2024

  • Testing prototype (V0c) on carcasses
  • Deployment of 30 fully functional V0c tags on whales, some in the Atlantic (Iceland, Norway), some in the Pacific (Japan)

2025 – 2026: Tag deployment

Spring, summer, autumn 2025 & 2026

  • Large tag deployment both in the Atlantic and the Pacific
  • Data collection
  • Dissemination to a wider public
  • Analyses
  • Project year-3 & year-4 reporting to NAMMCO and FAJ

2025 – 2027: Analyses & preparation of publications

2027: Project completion

  • Completion of analyses and publications
  • End-project workshop (presentation of major results both regarding tag performance relative to deployment strategy and whale species movements)
  • Final reporting to NAMMCO and FAJ

Tagging plan

The tagging plan will be further developed as the project advances. The prototype tags and the tags are common to all partners that have committed to deploy them. However, the agreement is also that for each species, the main deployment will be carried out where it is the easiest in term of effort (time & ship time), so the areas where the whales are the most common and the closest to the coast. At present, the planning for the deployment is as follows.

Tag version Period Areas
25 V0b tags (prototypes)
Spring - Autumn 2023

East Greenland, Japan & Norway

30 V0c tags
Spring - Autumn 2024
Iceland, Japan & Norway
ca. 80 V1a tags
Spring - Autumn 2025
All areas, all partners
ca. 80 V1b tags
Spring - Autumn 2026
All areas, all partners