July 2008
Report of the Large Whale Tagging Workshop
Convened by the
U.S. Marine Mammal Commission
U.S. National Marine Fisheries Service
10 December 2005
San Diego, California USA
Contract Report to
U.S. Marine Mammal Commission
David W. Weller
NOAA Fisheries
Southwest Fisheries Science Center
La Jolla, California USA
dave.weller@noaa.gov
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Table of Contents
Introduction
3
Potential Physical/Physiological Effects
5
Healing Responses
6
Observations of Wound Healing
7
Behavioral Effects of Tagging
9
Follow-up Studies
10
Measures to Reduce Tag Effects
13
Alternative Tags
14
Ethics and Guidelines
15
Conclusions
15
Acknowledgments
16
Literature Cited
17
Addendum – A Case Study of the Western North Pacific Gray Whale Population
23
Appendix I – Workshop Agenda
28
Appendix II – Workshop List of Participants
30
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Introduction
Waterproof, animal-borne archival and transmitting technology has greatly advanced our
knowledge of the movements, distribution, physiology, and behavior of marine mammals
and the characteristics of their marine environment (see reviews by Costa 1993, Stone
and Kraus 1998, Read 2002). Information derived from such studies also has improved
our understanding of human/marine mammal interactions that pose risks to some
populations, especially those that are small and at elevated threat of extinction.
The devices used to track and monitor marine mammals have been attached by a variety
of methods, including harnesses, tethering, glue, suction, bolting through body parts, and
implantation into the body. Such methods vary in their ease of application, duration of
attachment, and effect on the subject animals. The aim of all methods is to secure the
devices in a way that ensures instrument performance while preventing, or at least
minimizing, influence on the animal either though alteration of its behavior or risk to its
health. As is the case for many new research methods, scientists have spent years
attempting to perfect instrument design and attachment methods both to improve the
efficacy of their studies and to ensure that the applications are humane.
Tagging studies of whales have been particularly challenging because of the difficulty of
approaching large, powerful animals to attach an instrument. The challenges have been
overcome in many instances, yielding valuable data on a number of species and
populations, including some that are listed under the U.S. Endangered Species Act as
endangered or threatened (e.g., Mate et al. 1997, 1998, 1999, 2000, Baumgartner and
Mate 2005, Wade et al. 2006).
Despite the clear benefits of tagging, the scientific and conservation communities have
debated the advisability of tagging large whales under certain circumstances. A general
cost-benefit analysis for tagging is not practical because both the costs and the benefits
vary depending on a range of variables, such as the species involved, tagging methods,
the condition of animals to be tagged, their natural history, their conservation needs, and
the utility of tagging information with regard to those needs. For that reason, cost-benefit
analyses are best carried out on a case-by-case basis.
Few would question the benefits derived from tagging studies. Those benefits are
relatively easy to describe and are related to information about the distribution and
movement patterns of the animals, their behavior, features of their environment, and the
risks they face as they move about the world’s oceans. Such information is vital to
promote conservation in the context of the ever-expanding human use of and presence in
the marine environment.
Much of the debate over tagging has not been about the potential benefits, but rather the
potential costs. Like the benefits, the costs are relatively easy to describe hypothetically,
but they are more difficult to describe based on data and observations. At the individual
level, costs are defined in terms of the potential risks associated with approaching and
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tagging individual whales. Those costs may take the form of disturbance of behavior and
habitat-use patterns, physical injury, infection, and (again, at least hypothetically) death.
At the population level, costs are defined in terms of possible effects on survival and
reproductive rates and are of particular concern for small populations. Evaluating effects
has proven difficult due to the large-scale movements of these animals and the difficulty
and cost of locating and observing them at sea after they have been tagged. Similar
debates have surrounded other scientific tools or methods of study (e.g., branding), and
the net effect of such has been to provide the impetus for continual improvements in
research technology and procedures.
To provide an opportunity for discussion of the risks (i.e., costs) of tagging and of ideas
for evaluating and reducing them, the Marine Mammal Commission and the National
Marine Fisheries Service sponsored a workshop on 10 December 2005, in conjunction
with the Society for Marine Mammalogy’s 16th Biennial Conference on the Biology of
Marine Mammals in San Diego, California (the workshop agenda and list of participants
are attached as Appendix I and II, respectively). The purpose of the workshop was stated
as follows:
Acknowledging the many important benefits of tagging large whales, the purpose
of this workshop is to identify potential adverse effects of tagging, consider the
evidence regarding the significance of such effects, consider research to better
describe them, and consider potential mechanisms to avoid or mitigate them if
necessary. Ultimately, our purpose is to promote the conservation of marine
mammals through better decision-making and science.
The following questions were used to guide the workshop presentation and discussions:
(1) What are the potential effects of tagging? Is the information currently
available sufficient to determine whether these effects occur?
(2) What factors should be considered when assessing the potential risks and
benefits of tagging (e.g., to what extent are sample size needs factored into
tagging studies; to what extent should they be)?
(3) What are the key remaining questions and information/research needs to be
addressed relative to potential effects of tagging? What are the impediments to
short- and long-term monitoring and how might monitoring capabilities be
improved? Are there specific studies that can and should be completed to bring
clarity to this issue?
This report, co-funded by the Marine Mammal Commission (MMC) and the International
Union for Conservation of Nature (IUCN), provides a record of the workshop based on:
(1) notes from the workshop rapporteur (M. Simpkins), (2) slide presentations of invited
speakers at the workshop, and (3) recently published papers, unpublished reports, and
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personal communications. The addendum to the report provides background for the
Western Gray Whale Advisory Panel established by IUCN and for the Scientific
Committee of the International Whaling Commission (IWC). Both of these bodies are
considering the advisability of tagging studies on western North Pacific gray whales
(Eschrichtius robustus), a population classified in the IUCN Red List as “critically
endangered.”
Potential Physical/Physiological Effects
Tagging may have both acute and chronic effects. Immediate physical effects may
include those related to blunt trauma from tag implantation (i.e., impact upon penetration
of the tag), such as hemorrhage and cell damage with possible radiating damage in both
the dermis and muscle. Immediate physiological responses to tagging include blood
clotting and the onset of inflammation to remove debris from the wound. The
inflammatory response includes swelling from an influx of blood and serous fluid.
Potentially chronic effects of tagging also are attributed to the cutting/tearing trauma
from piercing of the skin, blubber, fascia, and muscle (or variable combinations thereof).
In addition, contemporary tags are generally percutaneous in application, keeping the
wound partially open to the surrounding environment to allow the function of external
components such as saltwater conductivity switches or antennae. The wound serves as a
pathway or portal for saltwater ingress and the introduction of epithelial cells and
associated fauna, including bacteria. Bacteria and fauna on the epidermis are sources of
infection that may be carried deep into the wound and, depending on the depth of the
wound, may enter the blood stream or muscle. Saltwater ingress may lead to osmotic cell
death, particularly at the blubber-muscle interface, and also may promote bacterial
growth resulting in localized or regional infection and inflammation. Whether and how
often such infections might become systemic (i.e., affecting the whole organism) is
uncertain. Chronic physiological responses may include the persistence of inflammation
or infection, swelling from the influx of blood and pus, epithelial proliferation, and
development of granulation tissue working to sequester or reject the tag. Chronic
consequences are thought to include: (1) fossa (ruptured swelling), (2) development of
excessive scar tissue, and (3) the loss of surface (epidermal) tissue.
Chronic health effects also might result from complications (e.g., lipid leakage) related to
protracted tag movement in the form of continued vertical tearing of the wound within
the blubber layer, and/or horizontal shearing/movement-induced trauma, such as at the
blubber-muscle interface. The implantation of tags must result in a protracted healing
process, which imposes elevated energetic costs and, conceivably, predisposes the tagged
animal to other risk factors such as disease.
Finally, tagging may result in both acute and chronic pain and stress. St. Aubin et al.
(2001) described two belugas (Delphinapterus leucas) that were recaptured 19 and 24
days after tagging and that had leucocytic responses consistent with inflammation and
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stress assumed to be related to handling and tagging. In general, however, the nature,
persistence, and significance of pain and stress, and their effects on behavior,
reproduction, and survival, are largely unknown.
Despite studies such as those by St. Aubin et al. (2001), the actual evidence for long-term
effects of tagging is limited and inconclusive. Wild animals are known to suffer and
recover from large and more serious injuries (e.g., from predation, ship strikes,
entanglement). Records of whales surviving the subcutaneous implantation of Discovery
tags (small stainless-steel bolts implanted in the muscle via shotgun or rifle), harpoon
points (made of stone, slate and metal) as well as metal harpoon bomb-lances (Rayner
1940, Philo et al. 1993, New Bedford Whaling Museum 2007) provide evidence that at
least some whales have tolerated those kinds of wounds.
Healing Responses
Healing responses to penetrating wounds and tag implantation in whales are poorly
understood because of limited information on the types of tissue damage that occur from
tagging, the healing properties of those tissues, particularly blubber, and the probability
and nature of secondary wound effects. For mammals, the typical wound healing
response involves: (1) stopping blood loss, (2) restoring function, and (3) preventing
infection. The inflammatory phase begins at the time of injury and serves to curtail
bleeding, cleanse/sterilize the wound area, and initiate removal of debris from the wound.
The proliferative-repair phase is characterized by the filling and closure of the wound
area. The remodeling-maturation phase may or may not include formation of scar tissue,
and constitutes final resolution of the wound (Dee et al. 2002).
In general, wound healing can be divided into two broad categories: (1) primary wound
healing or healing by first intention and (2) secondary wound healing or healing by
second intention. Primary wound healing usually occurs when a wound is the result of a
“clean cut” (e.g., surgical incision) where the margins of the wound can be neatly brought
back together (sutures are used to facilitate this process in surgical situations). Primary
healing generally results in a minimum of scarring. Secondary healing, the process which
best approximates healing of tag-related wounds in whales, occurs when a full-thickness
wound is allowed to close or “fill in” and heal. Secondary healing results in an
inflammatory response that is more intense than with primary wound healing and is,
overall, a slower process. Here, cells move in from the border of the wound, one layer at
a time, and ultimately fill in the wound cavity. As a result, a larger quantity of
granulomatous tissue is fabricated because of the need for wound closure. Secondary
healing results in pronounced contraction of wounds as well as scarring.
The integument of cetaceans, including large whales, is well described (for example see
Ling 1974, Haldiman et al. 1993, Reeb et al. 2007), but most information on wound
healing is based on studies and observations of smaller odontocetes, particularly
bottlenose dolphins (Tursiops truncatus) and belugas. The inflammatory response and
7
rate of healing in the skin of those species have been characterized (Bruce-Allen and
Geraci 1985, Geraci and Bruce-Allen 1987) and responses to implants, tags, and marks
also have been studied (Geraci and Smith 1990). The results from those studies have been
used in the development of tags for large whales (Mate et al. 2007). The hematology and
plasma chemistry of belugas that were captured, tagged, and released also have been
studied (St. Aubin et al. 2001), and related findings have been used, to some degree, as a
proxy for what might be expected in large whales.
As noted above, however, the normal progression of wound healing is disrupted when an
implanted tag remains in place. Presumably, the persistent presence of the tag elicits a
foreign body response as observed in other mammals, including humans. This response
begins as normal wound healing, but full healing cannot occur until the tag has been fully
rejected (i.e., shed) from the body. Unlike Discovery tags that are fully implanted and
over time become permanently encapsulated within the body, percutaneous tags keep the
wound at least partially open until the tag has been rejected.
Observations of Wound Healing
Seeking to investigate the potential effects of their tagging efforts, some investigators
have been able to describe the physical appearance of tag sites subsequent to attachment
(Watkins et al. 1981, Quinn et al. 1999; Kraus et al. 2000; Best and Mate 2007; Mate et
al. 2007). In a tagging study of humpback (Megaptera novaeangliae) and fin whales
(Balaenoptera physalus) off Alaska, Watkins et al. (1981) observed no signs of infection
or tissue reaction at four tag-related wound sites 16-18 days post-attachment. Mate et al.
(2007) indicated that over 40 of the more than 430 whales they tagged between 1990 and
2005 had been resighted either opportunistically or during follow-up studies. Although
some of these whales exhibited varying levels of swelling or scarring at the tag site, none
were in poor health or showed signs of tissue sloughing at the tag site. Mate et al. (2007)
summarized some of their observations of physiological responses to tagging as follows:
Nine of 16 North Atlantic right whales tagged in the Bay of Fundy in 2000 have
been resighted, with four of them exhibiting swelling (two regional and two
localized) around their tag sites. After a single year, only one of these animals
maintained swelling. Four of 15 resighted sperm whales (of a total of 57 tagged
whales) showed slight localized swelling around their tag sites, after periods of
213-351 days after tagging. Because we have seen swelling over time and no
degradation in body condition, we believe such swellings are not debilitating.
During a tagging study on eastern gray whales, one whale was found dead on the beach
without its tag 18 days post-attachment (Mate and Urbán 2005). A necropsy performed
on this whale approximately two weeks post-mortem found no evidence of tag site
infection or other signs suggesting that the death was tag-related (WGWAP 2006).
However, the pronounced state of decomposition and the fact that the tag was no longer
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implanted precluded a detailed evaluation of the tag-induced wound, including
histological assessment.
Quinn et al. (1999) reported a study of North Atlantic right whales (Eubalaena glacialis),
which was summarized in the report of a 1999 workshop on tagging effects (Kraus et al.
2000) and in a presentation at the 2005 workshop. In that study, 55 tags of varying design
were deployed on 49 individual whales between 1988 and 1997. It should be noted that
the tagging operations evaluated in this study were based on tag designs that are now one
to two decades old and considerable design changes have occurred in the intervening
period (Mate et al. 2007). Pre- and post-tagging photographs from the photo-
identification catalogue maintained by the New England Aquarium were used to look for
evidence of effects attributable to tagging. Forty-eight (87 percent) of the tag sites were
classified as either: (1) scar, (2) divot, (3) divot with cyamids (“whale lice”), (4) localized
swelling, or (5) regional swelling. A divot was defined as an indentation varying in size
depending on tag type. Localized swelling (< 30 cm in diameter) and regional swelling
(30-90 cm in diameter) described swollen areas near the tag site that were not present
before tagging. The types of injuries observed did not appear to be related to tag type
(i.e., any of the tag types could have caused any of the five types of injury). In some
cases, divots persisted for over five years and twenty percent of the divot sites hosted
cyamid communities. Sixty percent of the whales tagged were observed to have some
level of swelling at the tag site. For a few of these whales, swelling persisted for up to
seven years.
Participants at the 1999 right whale workshop expressed no major concern about divots
or scars, although a question was posed regarding cyamids and whether their presence in
divots might indicate compromised health status. Local and regional swelling, however,
raised concern. Possible explanations for such swelling include: (1) hematoma, (2)
abscess, (3) active inflammatory response to a foreign body or agent (such as bacteria),
(4) rupture through the subdermal sheath, (5) foreign body granuloma, (6) infection, (7)
scar tissue, or (8) benign tumor.
In summary, participants at the 1999 workshop considered the available data insufficient
to determine conclusively if tagging posed significant risks to individual whales. They
were divided as to how future tagging efforts should proceed, some being more cautious
than others. Despite the differences in opinion, all participants agreed that workshops
should be held regularly to: (1) facilitate improvements in tag technology and discuss
issues related to tag success and failure as well as alternative technologies (e.g., suction
cup tags), (2) evaluate, modify, and standardize protocols for follow-up assessment, and
(3) review the implications of observed physical, physiological, and behavioral effects.
Recommended actions from the 1999 workshop included: (1) search for funding to
support follow-up studies on tagged whales, (2) mine existing data to evaluate long-term
effects of tags, (3) conduct dedicated follow-up studies in future tagging efforts, and (4)
make visual assessments of body condition of tagged whales for comparison to non-
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tagged whales. Participants also agreed that, if available, alternatives to invasive tags
should be used if they provide the necessary data. Finally, the workshop emphasized the
need to minimize the size of tags to help reduce the likelihood of effects, particularly
physical or physiological effects, in future tagging studies.
Behavioral Effects of Tagging
The behavioral effects of tagging large whales are not well understood. While several
studies have provided descriptions of the reactions of individual whales to tagging, these
accounts are mostly qualitative and non-systematic. Despite the limitations of the existing
observations, they generally indicate that the reactions of large whales to tagging are
frequently unnoticeable or mild and quickly followed by a return to “normal behavior”
within a “short time” (Watkins 1981, Watkins et al. 1981, Watkins and Tyack 1991, Mate
et al. 2007). More pronounced reactions, albeit less frequently observed, include vigorous
swimming, underwater exhalations, breaching, and group disaffiliation (Watkins 1981,
Mate et al. 2007). Mate et al. (2007) described their observations of short-term responses
as follows:
The behavioural responses whales exhibit when tagged are usually identical to
those exhibited during a close approach by the tagging vessel when tags are not
deployed. Responses most often include head lifts, fluke lifts, exaggerated fluke
beats on diving, quick dives, or increased swimming speeds. Less frequently,
responses include fluke slaps, head lunges, fluke swishes, defecation, decreased
surfacing rates, disaffiliation with a group of whales, evasive swimming
behaviour, or cessation of singing (in the case of humpback whales). In all cases
where we have followed tagged whales, the responses to tagging have been short-
term. For example, a humpback whale that stopped singing upon tagging,
resumed singing 13 min later. A North Atlantic right whale that was tagged while
sleeping, went back to sleep within five min after tagging. Feeding blue whales
have resumed lunge feeding immediately after tagging, as have bubble-net
feeding humpback whales. Curious gray whales continued to be inquisitive after
tagging. Seven of a group of 10 sperm whales were tagged within 90 min, without
dispersing the group. We have never had any serious whale–boat contact
problems, nor seen a whale act aggressively after tagging. All of the preceding
experiences give us some measure of confidence that the immediate effects of
tagging are minimal. Responses to tagging appear to vary by species, with sperm
whales reacting more often than other species.
Those authors also present a table indicating the propensity for response of different
whale species, ranging from 22 responses to 146 tagging attempts (15 percent) for blue
whales (Balaenoptera musculus) to 51 responses to 60 attempts (85 percent) for sperm
whales (Physeter macrocephalus). Such data are informative, although as Mate et al.
(2007) themselves and other authors (Hooker et al. 2001) point out; more in-depth
analyses would be useful. Responsiveness and types of response probably depend on
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circumstances and a variety of factors such as the whale’s species, age, sex, body
condition, environmental context, behavior, reproductive state, and experience. Short-
term responses should be relatively simple to document, at least as indicated by surface
behavior. Long-term effects would be more difficult, although certain populations that
return to the same feeding and reproductive sites each year may be particularly amenable
to such studies. Effects may range from negligible to severe, and from acute to chronic.
In the few cases where data on behavior have been collected, the results are largely
subjective, have not been standardized, and are difficult to compare to control animals or
evaluate in a statistical manner.
The need for close approach to tag whales adds a level of disturbance that is difficult to
distinguish from the effects specific to tag attachment (Watkins 1981, Watkins et al.
1981). Although approach requirements vary for different species and deployment
systems (e.g., air rifle, pole, crossbow), researchers often must approach whales
repeatedly to within several meters to achieve the position needed for successful tag
deployment. In contrast to the summary statistics provided by Mate et al. (2007), the
literature contains little information on such matters (e.g., number of approaches made
per whale, reactions of whales to vessel approach, etc.). Close vessel approaches may
cause increases in: (1) blood adrenaline and cortisol, (2) metabolic rate, (3) heart rate, (4)
body temperature, and (5) respiratory rate. Potentially significant behavioral responses
include leaving preferred habitat or, in the case of an adult female, disassociation with her
calf.
Arguably, behavioral responses are not biologically significant unless they affect the
probability of survival and reproduction of an animal or its offspring. Because
information to evaluate such potential effects is generally lacking, participants at the
2005 workshop emphasized the importance of collecting the data needed to fully evaluate
potential long-term behavioral effects. This obviously will require commitments by
investigators to carry out the necessary observations, and certain whale populations may
be more amenable than others to such studies, as described below. Participants also
emphasized that certain activities (boat driving, tag attachment, and photo-identification)
should be conducted by, or at least under the guidance of, experienced personnel. This
practice should help reduce the amount of disturbance from approach, the number of
approaches necessary for tag attachment, and mistakes or uncertainty about which
animals are tagged.
Follow-up Studies
With few exceptions, published studies involving the tagging of large whales (and other
wildlife, for that matter) provide little detailed information regarding the long-term
responses of animals to tag attachment. This shortage of information is understandable
given the difficulty of relocating animals that may move about entire ocean basins, and it
pertains not just to studies of marine mammals, but to other animal groups as well.
Godfrey and Bryant (2003) found that only 10 percent of 836 radio-tagging studies (on a
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variety of species) attempted to address tag-related effects, with studies on mammals less
likely than those on birds or fish to test for effects. Clearly, more studies are needed to
evaluate the effects of tagging so that the potential risks and benefits in any particular
case can be weighed in a more informed manner (Wilson and McMahon 2006, Cooke
2008).
Three important attempts have been made to evaluate the long-term effects of tagging
large whales. In the first case, an unpublished assessment by M. Fujiwara (cited in Kraus
et al. 2000, Mate et al. 2007) found resighting rates of tagged versus untagged North
Atlantic right whales to be the same, suggesting no tagging effect on the survival of
tagged whales. In the second study, the sighting patterns and reproductive intervals for
southern right whales (Eubalaena australis) tagged off South Africa were examined
(Best and Mate 2007). In this study, six of seven reproductive females that were resighted
post-tagging had given birth to a new calf and exhibited calving intervals that were
similar to untagged whales, supporting the null hypothesis of no major effect on the
reproductive success of adult females or (by inference) the survival of their calves. In a
third study, conducted by S. Mizroch and colleagues, photographs of seven humpback
whales tagged with implantable radio-tags between 1976 and 1978 off Alaska were
compared to a longitudinal humpback whale photo-identification archive. Of the seven
whales tagged in the 1970s, all had subsequent resightings extending over at least a 17-
year period in the same general vicinity of where they were tagged. Five of the seven
individuals had resightings extending over a 30-year period, including one reproductive
female that produced a number of calves at regular intervals subsequent to being tagged
(S. Mizroch, pers. comm.). These observations represent the longest follow-up records
from any large whale telemetry study and provide insight regarding the survival and, in at
least one case, reproduction of tagged individuals.
Such studies are of great value to assessing potential effects, and more studies of this type
would be useful to further test the null hypothesis that tagging poses little or no long-term
effect on behavior, reproduction, or survival, irrespective of the particular species
involved, age of tagged animals, behavior, environmental conditions, and so on. For this
purpose, direct monitoring of tagged animals is more useful than remote tracking, as the
status of remotely tracked animals can only be inferred based on downloaded data on
distribution and behavior (Scott et al. 1990). To address the remaining need for
information on tagging effects, the 2005 workshop participants suggested that follow-up
monitoring of tagged individuals should be an integral component of any research plan
and warranted significant attention whenever possible. Research proposals should include
budgets for the costs of follow-up studies, and agencies should give priority to such
funding. Scientists engaged in tagging studies should be expected to conduct follow-up
monitoring of tagged animals as they are able to do so and to publish the results in peer-
reviewed literature. Without wider adherence to such practices, participants were
concerned that tagging would continue to be considered experimental and somewhat
controversial, as has been pointed out by Wells (2005) for tagging studies on dolphins.
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Some populations of large whales are especially suitable for studies of the long-term
effects of tagging. Those populations are sufficiently large that there is only a negligible
risk that tagging will have significant effects on reproductive and survival rates. Also,
individuals in such populations can be identified and tracked, they are sufficiently
accessible so that costs of research are not prohibitive, and their movements are suitably
predictable in time and space (e.g., seasonal habitat use) that they can be relocated over
time to allow long-term assessment of their condition. Workshop participants identified
several regional populations meeting those criteria, including (1) humpback whales off
southeast Alaska, (2) blue whales off California, (3) the Pacific feeding aggregation of
gray whales off the west coast of North America or those summering off Chukotka,
Russia and (4) southern right whales off South Africa.
Eastern gray whales off Chukotka were highlighted as providing a unique opportunity for
follow-up work. Individuals from this population come near shore in summer (i.e., they
are accessible for study), they are seasonally residential (or semi-residential), and local
hunters kill a number of individuals each year. Thus, there is the possibility that in this
special circumstance tagged individuals can be monitored closely over the course of a
feeding season (by using real-time positional data being transmitted from the tag for
relocation), and, ultimately, evaluated post-mortem for tag-related wounds and other
parameters.
North Atlantic right whales also are a useful study population because, as noted earlier,
49 individuals were tagged in the period from 1988 to 1997, and many of those animals
are likely still alive. The photo-identification catalogue maintained by the New England
Aquarium provides sufficient records to evaluate the fates of those animals and compare
their reproduction, survival, distribution, and habitat use patterns to those of untagged
individuals. Such a study would provide a useful test of the potential long-term effects of
earlier tag designs.
Where tags are necessary to identify and track individual animals, studies will be
compromised by the fact that comparisons can only be made among tagged whales rather
than comparing tagged whales to untagged control animals. To address this issue,
workshop participants concluded that longitudinal studies would be ideal if they allowed
comparisons of animals pre-tagging (which may require other types of technology such
as suction cups), animals with tags attached, and animals after tag rejection. Whether
such study designs are feasible will depend on a number of factors, such as listed above
(e.g., accessibility, abundance, natural history, ease of identification). Companion studies
also might provide important supplemental data, including: (1) fecal analysis, (2) stress
hormone analysis, and (3) isotope analysis.
Finally, a relatively simple and direct approach to follow-up evaluation is to use real-time
positional data to relocate tagged whales. Such relocation provides the opportunity for
direct observation of the animal and the tagging site. Although this kind of follow-up is
often difficult and costly due to the distribution and movement patterns of the whales, it
13
is being used with some success in a study of blue whales off California (J.
Calambokidis, pers. comm.).
Investigators also might establish an online database to compile an up-to-date listing of
the following information: (1) animals tagged - including approximate size, sex (if
known) and descriptions or photographs of any distinctive marks useful for individual
identification, (2) geographic location and date where the tag was deployed, (3) position
on the body where the tag was attached, and (4) description of the type of tag used.
Stranding networks could, in turn, use such information as a guide to search for tag sites
on stranded whales suspected to have been tagged and, when possible, conduct
examinations of tag-related wounds (F. Gulland, pers. comm.).
Measures to Reduce Tag Effects
Since the inception of tagging studies on large whales, a variety of tag designs,
deployment systems, and attachment techniques have been used (Watkins 1979, Mate et
al. 2007). At present, scientists are generally using pointed, cylindrical tags that are
implanted through the skin and into the blubber. In many cases, these tags also are likely
to penetrate the fascia and muscle. The cylinders are held in place by barbs of various
designs (Heide-Jørgensen et al. 2003, Mate et al. 2007). Development of this design has
attempted to ensure prolonged tag attachment, reduced drag, minimal tissue damage and
risk of infection, and prevention of tag migration.
The depth to which a tag should penetrate into the body of a whale has long been a topic
of discussion. For many years scientists, in an effort to minimize the health risks to
tagged whales, used tags that penetrated only into the blubber. However, the poor
structural stability of blubber allowed significant tag movement to occur, resulting in
premature detachment. Investigators then developed tags that penetrated deeper to attach
to the muscle and fascia. The aim was to reduce tag movement and the propensity for
upward/outward lift, thereby increasing attachment duration and, ultimately, the volume
and value of data obtained. The increased stability of deeper tags also was expected to
promote healing by reducing tag movement. New epithelial cells and scar tissue were
expected to form around the tag to encapsulate and wall it off to minimize adverse
internal effects. In addition, investigators anticipated that the greater circulation of blood
in muscle (as opposed to blubber) might allow white blood cells to mobilize more quickly
to fight infections at the tag site.
Although implantation into the fascia and muscle appears to increase the longevity of tag
attachment, it also may increase the chance of systemic infection. In addition, deeply
seated tags may remain attached beyond their functional lifetimes, prolonging the healing
process and the period of exposure to sources of infection. Matching the period of tag
attachment with the functional lifespan of the tag will be a difficult undertaking, but
workshop participants considered it a task worth pursuing to reduce the risk to tagged
animals.
14
Other practices currently being used to mitigate physical damage and infection caused by
tagging include: (1) use of surgical quality tag materials, (2) sterilization of tag
components prior to deployment, (3) use of topical and long-dispersant antibiotics, and
(4) use of tapered, bladed cutting tips at the entry point of the tag to reduce blunt trauma,
minimize the unwanted introduction of epidermal cells and bacteria into the wound, and
better control inward trajectory. Mate et al. (2007) described the development of these
practices over the past several decades.
With one exception, workshop participants agreed on the four practices listed above and
on the need to minimize tag size and related hydrodynamic drag to reduce the potential
for adverse effects. The single disagreement pertained to antibiotics. Some participants
argued that application of antibiotics could not hurt, regardless of how effective they are,
and may help prevent transfer of pathogens from the tag itself. Other participants cited
the potential drawbacks of using antibiotics, including the creation of antibiotic-resistant
bacteria and the ineffectiveness of single-dose treatments. Although workshop
participants did not arrive at consensus on this particular issue, various approaches are
being used that should, over time, provide a better understanding of the usefulness of
antibiotic treatment during tag application.
Alternative Tags
Suction cup tags have proven to be very useful in short-term deployments on whales
(Nowacek et al. 2001, Calambokidis 2003, Baumgartner and Mate 2003, Watwood et al.
2006) but are not yet suitable for collecting data over periods longer than a few days.
Further, their potential effects over longer periods have not been evaluated. Other highly
miniaturized satellite-linked tags, capable of transmitting for up to several months, in
which the transmitter package remains external to the body and only the attachment
system penetrates the skin, are being used successfully to track odontocetes (Andrews et
al. 2005, Baird et al. 2007, Pitman et al. 2007, Schorr et al. 2007). Observations of killer
whales (Orcinus orca) and short-finned pilot whales (Globicephala macrorhynchus) after
tag detachment suggest that this type of tag causes minimal physical damage and, in the
few documented cases, complete healing has occurred (Andrews et al. 2005,
www.cascadiaresearch.org/robin/satellite.htm).
A miniaturized tag designed for use on killer whales (Andrews et al. 2005) was attached
to a gray whale off Alaska in May 2008. As of July 2008, nearly 60 days post-
deployment, this tag remained attached to the whale and continued to function (J.
Durban, pers. comm.). Similarly, external tags (i.e., surface-mounted transmitter with
implanted attachment device) were used to track Antarctic humpback whales for up to 80
days – outperforming the implantable tags used in the same study (Dalla-Rosa et al.
2008). The use of highly miniaturized external tags may become increasing prevalent in
studies of large whales. Such use would alleviate at least some of aforementioned
physical/physiological concerns surrounding the use of implantable tags.
15
Other alternative tag technologies, including a non-invasive towed telemetry buoy being
developed for use on North Atlantic right whales, were discussed briefly during the 2005
workshop. Another device called a “float tag”, in which a floating tag package is tethered
to a whale via an implanted anchoring system, has been used to track bowhead whales
(Heide-Jørgensen et al. 2006). Although these tags had the benefit of low initial failure
rates, deployment durations were relatively short (2–33 d).
In general, workshop participants favored increased efforts to find alternative, non-
invasive techniques for studying large whales over long timescales. All other things being
equal, non-invasive tags would be preferable if they can provide similar information with
less risk. However, all other things probably are not equal as, in some cases at least, non-
invasive tags may pose more risk of energy-consuming drag and in most cases the period
of attachment is shorter.
Ethics and Guidelines
Scientific ethics and professional guidelines also were discussed at the workshop.
Participants agreed that tagging research should be conducted within an ethical
framework following standards of acceptable practice (see Wilson and McMahon 2006)
and, on balance, should not further endanger already threatened populations. Participants
also discussed the establishment of an expert panel to create a set of guidelines and
recommendations for studies using telemetry on whales. These guidelines could be
adopted by relevant scientific societies, permitting agencies, and regulatory bodies to
help ensure that tagging practices conform to standards designed to prevent unnecessary
risks to the health and welfare of tagged individuals.
Conclusions
It stands to reason that information on the effects of tagging large whales would be
difficult to collect—after all, scientists use telemetry devices to provide information that
cannot be obtained easily by other existing methods. Given the difficulty of operating in
the marine environment and the vast range of many large cetaceans, follow-up studies to
monitor potential effects of tagging are inherently difficult, will require considerable
resources to undertake, and will call for determination on the part of investigators to
ascertain whether such effects occur. Nonetheless, such studies are important for both
humane and scientific reasons. The intent of tagging large whales is not to harm them,
but to learn about them, usually for the purposes of informing conservation efforts. In
addition, verifying that such effects do not occur is necessary for accurate interpretation
of collected data, particularly data that are intended to provide insights into the behavior
of whales under natural conditions.
For the past several decades, scientists carrying out tagging studies of whales have made
significant progress in developing more effective tags and attachment methods. Such
16
enhancement improves the quality of the resulting data and reduces the likelihood of
adverse effects on the whales. Still, more work is necessary to reduce risks further and
provide assurance that the residual risks are at an acceptably low level for all species of
interest. Similar processes have occurred in the development of other invasive scientific
methods or methods that involve or pose a risk of injury. Scientists themselves will need
to lead this effort and should make every effort to collect information on tag effects as
part of their study designs. Such efforts should be published and thereby incorporated
into the body of scientific information on large whales, where it is available to all.
At the same time, funding agencies and organizations also must assume responsibility by
providing the support needed to carry out such studies. The progress made to date is good
evidence that we, collectively, can improve on study methods such as tagging, and the
responsibility to do so lies with all of us.
Acknowledgments
The workshop on which this report is based would not have been possible without the
efforts of L. Lowry (panel moderator), M. Simpkins (rapporteur), and the presenters
and/or panelists including: N. Gales, M. Johnson, S. Kraus, B. Mate, M. Moore, B.
Woodward and S. Young. The author, Marine Mammal Commission, and National
Marine Fisheries Service gratefully acknowledge their contribution. T. Ragen and R.
Reeves offered support, encouragement, editorial reviews and sage advice. F. Gulland, S.
Kraus, F. Larsen and M. Simpkins provided insightful reviews of an earlier version of
this report. Useful communications and materials were provided by: R. Andrews, P. Best,
J. Calambokidis, J. Durban, N. Gales, M.P. Heide-Jørgensen, S. Kraus, F. Larsen, B.
Mate, S. Mizroch, M. Moore, D. Nowacek, R. Pitman, R. Rolland, T. Rowles and M.
Simpkins. The U.S. Marine Mammal Commission and IUCN co-funded the development
and completion of this report.
17
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23
Addendum
A Case Study of the Western North Pacific Gray Whale Population
The above issues and concerns regarding tagging of large whales recently have been
raised with regard to the critically endangered western North Pacific population of gray
whales (WGWAP 2007, 2008, IWC 2004, 2007, 2008, in press). Since 1995 these whales
have been monitored and studied on their summer feeding grounds off the northeastern
coast of Sakhalin Island, Russia. Their wintering area(s) and migratory path(s) are largely
unknown (Weller et al. 2002), but entanglements in fishing gear off the Pacific coast of
Japan are reminders that the whales face a number of threats throughout their range
(Weller et al. in press). Satellite telemetry has been proposed to investigate their
migratory routes and winter grounds and provide information about both their natural
history (e.g., reproduction) and obstacles to recovery.
Scientists have been cautious about tagging these whales largely because of the
population’s critically endangered status. The population consists of about 130
individuals age one or older (i.e., excluding calves) and only a small portion of those are
reproductively active females (about 25) (Cooke et al. 2008, Weller et al. 2008). Tag-
related harm to a single female could have population-level consequences. The Scientific
Committee of the IWC has commented that the potential risks to individual whales from
the tagging process must be carefully weighed against the potential benefits of the study
and agreed that the process should first be tested on gray whales from the eastern North
Pacific population (IWC 2004).
In keeping with the Scientific Committee’s recommendation, Sakhalin Energy
Investment Company and Exxon-Neftegas Limited, both oil and gas companies working
on the Sakhalin Island shelf, funded telemetry studies on eastern gray whales. The aim of
those studies was to determine (1) potential challenges and complications of tagging gray
whales, (2) effectiveness of deployment techniques, performance of tags, and longevity
of attachments, and (3) potential physical, physiological and behavioral effects related to
tagging. Evaluation of tag performance on feeding whales was considered particularly
valuable because gray whales are in regular physical contact with the bottom while
feeding and tag effectiveness in such a situation had not been evaluated previously, and
because any future tagging of western gray whales likely would occur when they are
actively feeding in shallow waters off Sakhalin Island.
In 2006, the IWC Scientific Committee reviewed the results of a tagging study on eastern
gray whales conducted by B. Mate and J. Urbán in San Ignacio Lagoon, Baja California,
Mexico (IWC 2007). In March 2005, satellite-monitored radio tags were attached to 17
adult gray whales (16 females with calves and one unaccompanied adult). All tags
transmitted data (albeit for varying durations) indicating migratory movements by some
whales exceeding 17,000 km. Four whales were tracked for more than 200 days, six for
24
more than 100 days and seven for fewer than 30 days. The tagged single adult (i.e., not
accompanied by a calf) was found dead on the beach 18 days after tagging. As noted
earlier in this report, a necropsy conducted approximately 11 days post-mortem found no
evidence of tag site infection or that the death was in any way tag-related. Another whale
lost its tag, which was subsequently recovered in a gill net outside the lagoon 23 days
after tagging. Finally, local hunters killed one whale 202 days post-tagging off the
Chukotka Peninsula in Russia.
The tagging study by Mate and Urbán was deemed highly successful with tag
performance and data return exceeding previous efforts of a similar nature. Despite the
fact that tags were attached on the wintering grounds where feeding behavior does not
often occur, a number of tags continued to function throughout the northward migration,
through the entire summer feeding season while the whales were in the Bering and
Chukchi Seas, and during the onset of the following southward migration. Importantly,
data return of 100+ days by some tags should be sufficient to determine the southern
migratory destination for western gray whales if swim speeds are similar between eastern
and western gray whales. In addition, the persistence of tag attachments throughout an
entire feeding season bodes well for tag duration on the Sakhalin feeding ground if the
feeding behavior of eastern gray whales in the deeper-water habitat of the Bering and
Chukchi Seas is comparable to that of western gray whales in the shallow waters off
Sakhalin.
Follow-up observations were available for three of the 17 whales tagged in this study.
The whale killed off Chukotka was noted to have mild swelling within 2-4 cm of the tag
site. A second individual resighted 41 days post-tagging off the coast of central Oregon
showed no adverse effects at the tag site. The third whale (described above) showed no
apparent tag-induced effects, although necropsy was approximately two weeks post-
mortem and it is possible that because of decomposition any effects no longer would have
been discernible.
The study by Mate and Urbán provided valuable information regarding the utility of
tagging gray whales to determine migratory paths and destinations. At its 2006 meeting,
the IWC Scientific Committee recommended that telemetry studies on western gray
whales be initiated, but with certain caveats intended to minimize risk to the whales.
Specifically, it recommended that the study be conducted by experienced investigators
using only proven techniques, and that tags be attached only to known males (IWC
2007).
More recently, the Western Gray Whale Advisory Panel (WGWAP), convened by the
IUCN, reviewed the study of Mate and Urbán and other related materials on the topic and
concluded (WGWAP, 2006):
After considerable discussion, the WGWAP agreed that, in principle, telemetry
work on western gray whales should be carried out provided that:
25
(a) it be under the direction of B. Mate using his tags;
(b) it be restricted to ‘non-skinny’ males and take into account the occurrence of
males with rare and common haplotypes when the final tagging protocol is
adopted (A. Bradford of the Russia-USA programme is able to identify animals in
real time in the field);
(c) Mate submits to the Panel, for review, a detailed experimental protocol
including measures to be taken to minimise the possibility of accidental injury or
stress to the animals, and a proposal on sample size in terms of attempts as well
as successful attachments;
(d) a formal report is submitted to the Panel by the vet who determined the cause
of death of the gray whale in Mate’s Mexican study (see WGWAP 1/INF.12);
(e) the Panel receives and considers the report of the Society for Marine
Mammalogy’s workshop on whale tagging [this report];
(f) experience from around the world on safeguards for the process (e.g. number
of approaches allowed per day or other unit of time, total time spent with a
particular animal) has been reviewed by the Panel – initial collation and drafts of
associated recommendations to be carried out by Weller under contract to the
Panel (IUCN);
(g) efforts have been made by the Panel to arrange contacts with appropriate
range-state scientists for possible follow-up work;
(h) a final recommendation on protocols, time in the season to attempt tagging
and sample size is not made until after consideration of the results of (c) – (g) and
taking into account the view of the IWC Scientific Committee at its forthcoming
meeting in Anchorage in May 2007; and
(i) weekly positional updates from transmitting tags are made available to the
Panel (while maintaining the usual rights of data owners).
In a second satellite tagging study conducted on eastern gray whales in September 2006
off Chukotka, Russia (Heide-Jørgensen in prep.), 13 tags were deployed. Nine provided
locations for an average of 39 days (range = 12-81 days), while the remaining four failed
to provide information. No information was provided regarding the behavioral, physical,
or physiological effects of tagging on individual whales in that study.
The investigators conducting the Chukotka study suggested that attachment problems and
the limited data return from some tags were likely the result of whales making contact
with the bottom during feeding. They recommended that smaller tags be designed and
tested on eastern gray whales on their feeding grounds. They also recommended
development of a new or modified tag delivery system to allow longer-range deployment
because whales were difficult to approach closely (the average approach time for tag
deployment in their study was 45 min). Finally, they concluded that investigators would
need to attach tags to more than 20 western gray whales to obtain meaningful results
26
(Heide-Jørgensen in prep.).
After reviewing the Chukotka study, the WGWAP agreed with the authors that their
system had not been adequate for use on western gray whales and emphasized the
following points: (1) any new tag and delivery system should be evaluated first on eastern
gray whales in a feeding area, (2) the question of how many animals should be tagged
will be a function of the efficacy of tagging efforts and the specific questions to be
addressed, and (3) it is premature to determine the most appropriate sample size for a
western gray whale tagging experiment. The WGWAP summarized its review of the
study by reiterating its conclusion from a previous meeting that, in principle, telemetry
work on western gray whales is desirable but should be conducted only after the above
conditions have been met (WGWAP 2007).
Most recently, during the April 2008 meeting of the WGWAP, satellite tagging of
western gray whales and the related recommendations made by the IWC Scientific
Committee at its 2007 meeting were discussed (WGWAP 2008). In summary, the IWC
Scientific Committee had recommended that it act as a coordinator for a
tagging/telemetry project to ensure, among other things, that such a project is carried out
in a risk-averse manner (IWC 2008). Further, a coordination group was established to
ensure consistency between the Scientific Committee’s recommendations and those of
the WGWAP. With this advice in mind, the WGWAP again agreed that, in principle,
tagging/telemetry work on western gray whales should be carried out. Moreover, the
WGWAP agreed that all of its previous recommendations concerning satellite tagging
would be superseded by the following single recommendation:
The Panel recommends that telemetry work on western gray whales should be
carried out provided that it is guided by an IWC Scientific Committee
coordination group. This guidance would include specific advice on experimental
protocols, study design and measures to be taken to minimise the risk of negative
impacts on the whales or the population as a whole.
Finally, the IWC Scientific Committee also discussed the subject of telemetry studies on
western gray whales at its annual meeting in June 2008. A summary of the discussion, as
presented in Annex F of the Scientific Committee report (IWC in press), states the
following:
The sub-committee reiterated the fact that the development of mitigation measures
for the threats to the western gray whale population are greatly hindered by the
lack of information on migratory routes, breeding destinations and extent of its
feeding range. The Committee has recognised the great value of telemetry work to
providing this information but also the need to exercise great care before
undertaking such work on an endangered population (e.g. IWC, 2008). The
Committee had expected to finalise its discussions of the use of telemetry and
potential effects on western gray whales this year based on the report (edited by
27
Weller) from a 2005 workshop on tagging of large whales (convened by the U.S.
Marine Mammal Commission). Last year, the Committee recommended that the
IWC act as a co-ordinator for a tagging/telemetry project inter alia to ensure that
it is carried out in a risk-averse manner and to enable potential sponsors to
contribute financially without necessarily assuming any responsibility for the
programme’s design, conduct or results. In that context a number of rigorous
safety precautions had been recommended (IWC, 2007).
Last year, a co-ordination group had been established, consisting of Brownell,
Donovan, Gales, Reeves and Weller, to provide scientific advice and ensure
consistency between the IWC Scientific Committee’s recommendations and those
of the WGWAP. Noting that any telemetry work will occur in Russian waters, the
sub-committee suggested that a Russian scientist be identified and added to this
co-ordination group.
The sub-committee noted that the aforementioned Marine Mammal Commission
report has not yet been finalised for public release and could therefore not be
reviewed by the sub-committee at this meeting. However, the sub-committee noted
that a near-final version had been presented in April 2008 to the WGWAP and
carefully reviewed. The WGWAP concluded that, in principle, tagging/telemetry
work on western gray whales should be carried out provided that such work is
guided by the co-ordination group referred to above, recognising that this
guidance would include specific advice on experimental protocols, study design
and measures to be taken to minimize the risk of negative impacts on the whales
or the population as a whole.
The sub-committee noted that the final MMC report should be available for
discussion at the rangewide western gray whale meeting convened by IUCN that
will take place in Tokyo in September 2008 (Appendix 2). The report of that
meeting and the final MMC report will be presented to the Committee at the 2009
annual meeting. This will allow for a review of information on the use of
telemetry and potential effects on whales with an emphasis on the use of such
techniques on endangered populations prior to making recommendations
regarding a 2010 or later tagging effort.
Given the critically endangered status of the western gray whale population, alternatives
to tagging should be explored at the same time as additional research and development of
tags and deployment systems proceeds. Surveys of local knowledge might be conducted
and historical records examined (e.g. Reeves et al. 2008) in combination with vessel
surveys in regions where whales were present historically. Photo-identification also
might be used at locations known or thought to be along the migratory route. Some initial
efforts along these lines have been undertaken and more are underway using photographs
from Japan (e.g., Weller et al. in press).
28
Appendix I
Large Whale Tagging Workshop
Agenda
Convened by the
U.S. Marine Mammal Commission
U.S. National Marine Fisheries Service
10 December 2005
San Diego, California USA
9:00 – 9:15 INTRODUCTION
Tim Ragen
• Statement of Purpose
• Genesis of need for workshop
• Benefits of tagging and need
• General concerns regarding effects of tagging
• Summary of workshop structure and anticipated products
• Introduction of presenters and panelists
9:15 – 9:30 SUMMARY OF A 1999 WORKSHOP ON THE EFFECTS OF
TAGGING ON NORTH ATLANTIC RIGHT WHALES
Michael Moore
9:30 – 10:15 OVERVIEW OF CURRENT METHODS AND TECHNOLOGY
Bruce Mate and Mark Johnson
• Size and types of tags
• Benefits of different types of tags
• Information obtained by using various tags on different species
• Tag size and placement for various species and size classes
• Attachment methods, including methods of tag deployment
• Multiple tagging of individual animals (e.g., double-tagging an individual animal
or multiple tagging of an individual animal over time)
• Current practices for antibiotic usage during tag application
29
10:15 – 10:30 BREAK
10:30 – 11:00 OVERVIEW OF POTENTIAL PHYSIOLOGICAL/PHYSICAL
EFFECTS
Nick Gales
• Describe potential effects of tagging activities, including attachment and close
approach for deployment, etc.
• Summarize studies and evidence related to potential effects
• Summarize “critical uncertainties”
• Suggest studies or approaches to gathering evidence to address uncertainties
•
11:00 – 11:30 OVERVIEW OF POTENTIAL BEHAVIORAL EFFECTS
Scott Kraus
• Describe potential effects of tagging activities, including attachment and close
approach for deployment, etc.
• Summarize studies and evidence related to potential effects
• Summarize “critical uncertainties”
• Suggest studies or approaches to gathering evidence to address uncertainties
11:30 – 12:00 DISCUSSION (QUESTION AND ANSWER PERIOD)
12:00 – 1:30 LUNCH
1:30 – 2:45 PANEL I: PHYSIOLOGICAL/PHYSICAL EFFECTS
Nick Gales, Bruce Mate, Michael Moore
2:45 – 3:00 BREAK
3:00 – 4:15 PANEL II: BEHAVIORAL EFFECTS
Nick Gales, Mark Johnson, Scott Kraus, Bruce Mate, Sharon Young
4:15 – 5:00 DISCUSSION AND RECOMMENDATIONS
5:00 ADJOURN
30
Appendix II
Large Whale Tagging Workshop
List of Participants
Name
Workshop Role
Tim
Ragen
Workshop Chair
Lloyd
Lowry
Panel Moderator
Mike
Simpkins
Rapporteur
Nick
Gales
Presenter and Panelist
Mark
Johnson
Presenter and Panelist
Scott
Kraus
Presenter and Panelist
Bruce
Mate
Presenter and Panelist
Michael
Moore
Presenter and Panelist
Becky
Woodward
Presenter
Sharon
Young
Panelist
Richard
Abrams, Jr.
Tammy
Adams
Olive
Andrews
Mark
Baumgartner
Matteo
Bernasconi
Peter
Best
Daniel
Burns
Simone
Canese
Danielle
Cholewiak
Luiz
Cla'udio Alves
Bob
Cooper
Luciano
Dalla Rosa
Erin
Estrada
Bob
Gisiner
Mike
Gosliner
Karina
Groch
Katia
Groch
Shane
Guan
James
Hall
Cyd
Hanns
Brad
Hanson
Rob
Harcourt
31
Name
Elsa
Haubold
John
Hildebrand
Roger
Hill
Kim
Holland
Carrie
Hubard
Nathalie
Jaquet
Amber
Kumek
Bill
Lang
Jennifer
Latusek
Kevin
Lay
Steve
Leathery
Allan
Ligon
Peter
Madsen
Christie
Mahaffey
Yoko
Mitani
Maria Emilia
Morete
Kyoichi
Mori
Chris
Morris
Michael
Noad
Tom
Norris
Erin
Oleson
Joel
Ortega
Christian
Ortega Ortica
Richard
Pace
Simone
Panigada
David
Paton
Lori
Quakenbush
Carol
Roden
Teri
Rowles
Ann
Rupley
Ted
Rupley
Greg
Schorr
Ruth
Searle
Brian
Sharp
Steve
Shippee
Trevor
Spradlin
Alison
Stimpert
32
Name
Kate
Swails
Gisli
Vikingsson
Cecile
Vincent
Leslie
Ward
Bridget
Watts
Frederick
Wentzel
Sarah
Wilkin
Nicky
Wiseman
Ulrike
Wolf
Andrew
Wright
Alex
Zerbini