Should Satellite Tags Be Attached To The Endangered Southern Resident Orcas? Part One: The Tags

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Researchers at NOAA (The National Oceanic and Atmospheric Administration) have applied for a general permit to apply up to 20 suction cup and six dart type tags, per year for several years, to select individuals of the Southern Resident orca population. These tags will provide information on the basic habits and distribution of the whales, and the researchers are eager to hear your opinion as to whether you think the amount of information gained will offset the effects the tagging effort may have on the animals.

In my opinion the available technology is still too crude and the application too broad to risk any detriment to this fragile society of whales, but as we examine the issue I hope you will make your own decision and express it to NOAA during the comment period (by December 23rd).

The following information is taken directly from the National Marine Fisheries Service Assurance of Animal Care and Use Form:

IACUC Use Only
IACUC Number:A/NW 2010- 6

Satellite tag in dorsal fin of an orca (NOAA)
X-ray of tag in deceased orca’s dorsal fin (NOAA)

“Figure 4. A: Current configuration of the dart used for larger odontocetes and mysticetes with two rows of backward facing petals. B: X-ray image showing a dart (with one row of petals only) in a killer whale dorsal fin (collected from a stranded individual unrelated to any tagging activities) after dart penetration.

Note the backward facing petals are tight against the dart shaft, indicating that they were compressed upon entry into the fin which will minimize tissue damage upon entry. C: X-ray image of the same dart in B, after 11.4 kg of outward pull was exerted on the dart shaft. Note the petals have splayed outward from the dart shaft as they cut through tissue and moved into the holding position as designed (note the tips of two other darts visible in this x-ray). D: X-ray image of the same dart after 22.7 kg of outward pull. The petals have more fully splayed outward from the dart shaft and are now presenting a flat surface nearly perpendicular to the axis of outward force.”

“Limpet” tag (NOAA)

“Based on follow-up observations of more than 40 tagged individuals, in most cases the release appears to be a result of tissue breakdown immediately adjacent to the dart penetration site. This tissue breakdown is most likely associated with a foreign body response to the dart but the process may be accelerated by the additional tension put on the tissue adjacent to the darts by drag forces acting on the tag body.”

Wounds from tag (Marine Stewardship)

There is also the possibility of vascular disruption if a dart intersects with an artery in the dorsal fin. This could lead to a lessening or loss of blood flow distal from the tag site. Most cetacean fins have ample cross-current circulation, so it is thought that this type of disruption would not result in a complete loss of blood flow to the distal areas of the dorsal fin. Only one animal from our re-sighting history has shown any type of tissue loss distal to the tag site. However, no other individuals with similar sized dorsal fins have been sighted post-tagging showing anything other than small white scars and/or small depression or raised area.”

Orcas are highly tactile (Photo by Dave Ellifrit)

“It is also possible that the tag might be dislodged by a conspecific–we have seen suction cup tags pulled off with one species–or by the tagged animal rubbing on other animals or against an inanimate object. However, we have seen no behaviors or evidence to suggest this occurrence with LIMPET tags.

Because the dart tags penetrate the skin, connective tissue and/or blubber, and remain attached for up to several months, a risk of infection is a potential long-term effect. It should be noted however that odontocetes inhabiting warmer tropical waters are regularly bitten by cookie-cutter sharks, which create wounds up to several cm deep and 5-10 cm in diameter, and thus the injury associated with tag attachment may not be particularly unusual for these species. The findings by Hanson et al. (2008) indicate that no major long-term impacts have been associated with attachment of dart-style tags and no tagging-related mortalities have ever been documented.

If, during the course of follow up studies, an unusual wound or healing process is noted, the information will be brought to the attention of a vet.” (Good luck with that one…).

In contrast, the suction type tags are relatively non-invasive, but remain in place for just a few hours, yielding less information:

The suction cup tags are less invasive (Photo by Ari Friedlaender, Duke University).
Example of a suction cup tag (data logging).

For more information and to make comments:

SUMMARY: Notice is hereby given that the Northwest Fisheries Science
Center (NWFSC, Dr. M. Bradley Hanson, Principal Investigator), 2725
Montlake Blvd. East, Seattle, Washington 98112-2097, has applied for an
amendment to Scientific Research Permit No. 781-1824-01.

DATES: Written, telefaxed, or e-mail comments must be received on or
before December 9, 2010.

ADDRESSES: The application and related documents are available for
review by selecting ”Records Open for Public Comment” from the
Features box on the Applications and Permits for Protected Species home
page,, and then selecting File No. 781-1824
from the list of available applications.
These documents are also available upon written request or by
appointment in the following office(s):
Permits, Conservation and Education Division, Office of Protected
Resources, NMFS, 1315 East-West Highway, Room 13705, Silver Spring, MD
20910; phone (301) 713-2289; fax (301) 713-0376; and
Northwest Region, NMFS, 7600 Sand Point Way NE, BIN C15700, Bldg.
1, Seattle, WA 98115-0700; phone (206) 526-6150; fax (206) 526-6426.
Written comments on this application should be submitted to the
Chief, Permits, Conservation and Education Division, at the address
listed above. Comments may also be submitted by facsimile to (301) 713-
0376, or by e-mail to Please include File
No. 781-1824 in the subject line of the e-mail comment.

Playing with mom! (Photo by Ken Balcomb)

Next: The pros and cons.

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