SC/59/PFI2

CONCEPTS FOR A RESEARCH PROGRAM ON NORTHPACIFIC BRYDE’S WHALE -RMP VARIANT 2 WITHRESEARCHLuis A. Pastene1, Shigeyuki Kawahara2 and Hiroshi Hatanaka1
1

Institute of Cetacean Research, Toyomi 4-5, Chuo-ku, Tokyo 104-0055, Japan
National Research Institute of Far Seas Fisheries, Fukuura 2-12-4, Kanazawa, Yokohama, Kanagawa 236-8648,
Japan

2ABSTRACT
During the Second Intersessional Workshop on western North Pacific Bryde’s whale RMP Implementation theconservation performance of each trial and RMP variant was examined. In reviewing trials results the Workshopagreed that Variants 1, 3 and 4 were ‘acceptable without research’ (conservation performance was acceptable forboth ‘high’ and ‘medium’ weight trials) while Variant 2 had acceptable performance for all ‘high’ weight trials
but it was ‘unacceptable’ for three ‘medium’ weight trials, therefore this variant could not be ranked ‘acceptedwithout research’. All these trials are related to stock structure hypothesis 4, which involve sub-stock structure
within sub-area 1. This paper presents the concepts for a research program on western North Pacific Bryde’s
whale focused to elucidate the possibility of sub-stock structure in sub-area 1.
BACKGROUND
Figure 1, Appendix 1 and Appendix 2 shows the hypotheses on stock structure, the list of final trials and the listof RMP variants used during the RMP Implementation of North Pacific Bryde’s whale, respectively. During theSecond Intersessional Workshop (SIW) on western North Pacific Bryde’s whale RMP Implementation (IWC,2006a) the conservation performance of each trial and RMP variant was examined.
In reviewing trials results the Workshop agreed that Variants 1, 3 and 4 were ‘acceptable without
research’ (conservation performance was acceptable for both ‘high’ and ‘medium’ weight trials). Variant 2 had
acceptable performance for all ‘high’ weight trials. However, the conservation performance was ‘unacceptable’for three ‘medium’ weight trials (BR13, BR15 and BR17 in Appendix 1), therefore this variant could not beranked ‘accepted without research’.
Allison and Punt (2007) examined the impact of using Variant 2 for ten years, e.g. they examined theconservation performance assuming that management is based on variant 2 for 10 years after which management
reverts, via a five-year-out process to one of the other three variants. Results of their analyses suggested that thisvariant will be acceptable from the conservation point of view.
Next a research programme should be prepared by Japan, which addresses the uncertainties on the trials
on which Variant 2 performed poorly. This research programme should be presented for discussion andendorsement by the Scientific Committee. For guidance purposes an Advisory Group was established during theSIW:Members: Best, Butterworth, Donovan, Kitakado, Mate, Palsboll, Pastene (Convenor), Perrin
The Guidelines for Implementations (IWC, 2005a pp. 84-92) establishes that a ‘less conservative’variant that did not perform ‘acceptably’ in some trials could also be recommended with research requirements.
The associated research programme will be formulated such that it identifies expected progress in a manner thatwill allow the Committee to review annually whether the programme is being adequately followed. If, after a
pre-specified period (e.g. 10 years), the research program cannot show that the trials concerned should haveassigned ‘low’ weight, catch limits would be set using a ‘more conservative’ RMP variant that performed‘acceptably’ on all the trials (IWC, 2005 pp78). If the research programme associated with the RMP variant has
not progressed to the satisfaction of the Committee, the Committee will recommend that catch limits
immediately be based on the ‘more conservative’ RMP variant (IWC, 2005a pp78).

1This paper presents the concepts for a research program on North Pacific Bryde’s whale -associated tomanagement Variant 2- focused on stock structure.
CONCEPTS FOR A RESEARCH PROGRAM ON WESTERN NORTH PACIFIC BRYDE’S WHALE
As mentioned above the conservation performance of Variant 2 was ‘unacceptable’ for trials BR13, BR15 andBR17, all these trials are related to mixing across the boundary of the 1W and 1E sub-stocks for stock structure
hypothesis 4 (see Fig. 1 and Appendix 1). This means that the research programme should be focused toelucidate whether or not sub-stocks occur in sub-area 1 (stock structure scenario 4) and if so, the rate of mixing.
The programme is planned for a period of ten years (2007-2017), and annual progress reports will bepresented to the annual meeting of the IWC Scientific Committee. The programme would include the following
research elements:
Further genetic studies and power analysis
Genetic analysis on western North Pacific Bryde’s whales were conducted based on all available samples frompast commercial whaling operations (coastal whaling around the Ogasawara Island in 1984 and pelagic whaling
in the central western North Pacific in 1979), and samples from the JARPN II in the western North Pacificobtained between 2000 and 2003.
Two standard genetic techniques have been used: mitochondrial DNA control region sequencing andmicrosatellite analysis using 17 loci. Statistical comparison of haplotype and allele frequencies between whales
in sub-areas 1W and 1E (divided at 155ºE) were made and no significant genetic heterogeneity was detected forsample sizes of 261/140 and 260/125 for mtDNA and microsatellites, respectively (Pastene et al., 2004).
There are two approaches that can be used to improve the resolution of the genetic analysis during theresearch programme:1) Analysis using mtDNA and microsatellites of the available samples from JARPN II 2004-2006. The
sample sizes for sub-areas 1W and 1E for that period are 92 and 58, respectively. Furthermore
additional samples in the western North Pacific can be expected from future JARPN II surveys andthese additional samples will be used for the genetic analysis as well. Increase of sample sizes will
enable us to conduct further analytical approaches such as assignment tests. It will also enhance thepower of the hypothesis testing analysis.
2) Examination of the power of the statistical analysis of genetic data. Kitakado et al. (2005) evaluatedpower under an island model. The use of this model makes it easy to control population differentiationin an alternative hypothesis using just a single parameter, Fst. The workshop on the pre-implementationassessment of western North Pacific Bryde’s whale (IWC, 2006b) believed that this approach provided
a defensible means of identifying the power of hypothesis tests. This workshop had recommended some
additional work in this field as follows:i)Develop a distribution for Fst for the western North Pacific Bryde’s whales to interpret the resultsof the power analysis;ii) Consider the feasibility of evaluating power using models which explicitly include changes overtime in demographics and that can be tailored to the data for the resource under consideration.
In the context of the research programme, these recommendations will be considered in the analysis
focused to evaluate the power of the statistical analysis of genetic data in the western North Pacific Bryde’s
whale.
Satellite telemetry
One of the assumptions of stock structure hypothesis 4 is that there are two breeding grounds (containing twoseparated sub-stocks) in low latitude waters. Whales from these breeding grounds migrate in summer to highlatitude feeding grounds of sub-areas 1W and 1E. Genetic differences between sub-areas are not detected
because whales from the two breeding grounds are well mixed in the feeding ground.
Satellite telemetry experiments (see methodology in Nishiwaki et al., 1994) will be conducted toinvestigate the possibility of site fidelity of whales in sub-areas 1W and 1E to particular low latitude breedingareas. Biopsy sampling will be conducted on the whales targeted for the satellite telemetry experiments. In case2

of fidelity of whales from sub-areas 1W and 1E to particular breeding areas, genetic analysis between differentbreeding grounds will be possible.
Some experience on satellite telemetry has been accumulated during JARPA (for Antarctic minke andhumpback whales) and JARPN II (western North Pacific Bryde’s whale. In this latter case a Bryde’s whale wasmarked during the 2006 JARPN II surveys and the animal was tracked for a period of two weeks (Tamura et al.,2007).
Satellite telemetry experiments, similar to those conducted previously in JARPA and JARPN II, will beconducted along future JARPN II surveys. Ideally whales should be marked in both sub-areas 1W and 1E at theend of the feeding season.
Ageing research
The First Intersessional Workshop (FIW) (IWC, 2005b) reported differences in age composition between whales
in sub-areas 1E+2 (past commercial samples) and that in sub-area 1W (JARPN II samples), and three different
hypotheses were offered to explain such results:i)ii)
iii)

The differences are related to age reading and/or sampling issues in the commercial data. This has
no implication for stock structure.
The differences are real and reflect age-segregated distribution within a population.
The differences are real and may indicate some degree of stock structure between sub-area 1W and
1E+2.

Hypothesis iii) above would support the sub-stock scenario (stock structure hypothesis 4). The FIW agreed
that in order to investigate whether any of these possibilities can be eliminated, an inter-reader calibration
experiment should be conducted (see Annex K in IWC, 2005b).
In the context of the research programme, two steps are necessary for this particular work:
1) Check the availability of earplug samples from past commercial whaling operations, and2) Conduct the experiment as indicated in Annex K or in a modified form depending on the results of 1)
COMMENTS FROM MEMBERS OF THE ADVISORY GROUP
By 12 April 2007 comments from two members of the Advisory Group were received. Both agreed with thebasic ideas in this paper. One member noted that the work on ageing is essential, and that the satellite tracking
should yield useful results, if a sufficient number of whales are tracked. The other member considered all thethree research items important, particularly the experiment on satellite tracking. Regarding the genetic analyses
he suggested R-metasim, which can evaluate power in combination with demographic.
The authors of the present paper hope that the Scientific Committee endorses the concepts and ideas
expressed here, for a research program on western North Pacific Bryde’s whale associated with management
variant 2.
REFERENCES
International Whaling Commission. 2005a. Report of the Sub-Committee on the Revised Management Procedure.
J. Cetacean Res. Manage. 7: 77-113.
International Whaling Commission. 2005b. Western North Pacific Bryde’s whale Implementation: Report of theFirst Intersessional Workshop.41pp.
International Whaling Commision. 2006a. Report of the Second Intersessional Workshop on western North
Pacific Bryde’s whale RMP Implementation. 100pp.
International Whaling Commission. 2006b. Report of the Workshop on the Pre-Implementation Assessment ofWestern North Pacific Bryde’s Whales. J. Cetacean Res. Manage. 8: 337-355.

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Kitakado, T., Kanda, N. and Pastene, L.A. 2005. A prospective evaluation of statistical power for population
identification under island models. Paper SC/M05/BR3 presented to the Workshop on the PreImplementation Assessment of Western North Pacific Bryde’s Whales.
Nishiwaki, S., Ishikawa, H., Itoh, S., Matsuoka, K., Yuzu, S., Nagatome, I., Yamagiwa, D., Murase, H., Tanifuji,S., Miyakoshi, H. and Ono, K. 1994. Report of the 1993/94 cruise of the Japanese Whale Research
Programme under Special Permit in the Antarctic Area IV. Paper SC/46/SH15 presented to the IWC
Scientific Committee, May 1994 (unpublished). 42pp.
Pastene, L.A., Goto, M. and Kanda, N. 2004. An update of the mitochondrial DNA and microsatellite analyses inwestern North Pacific Bryde’s whale. Paper SC/56/PFI4 presented to the IWC Scientific Committee, June
2004 (unpublished). 9pp.
Allison, C. and A.E. Punt. 2007. Results of additional Bryde’s whale Implementation Simulation Trials.
Document SC/59/RMP1 presented at this meeting (21pp).
Tamura, T., Matsuoka, K., Bando, T., Mogoe, T., Konishi, K., Mori, M., Tsunekawa, M., Okamoto, K.,
Funasaka, N., Sakajiri, H., Yoshida, Y., Kumagai, K., Takamatsu, T., Konagai, T., Sasaki, S., Kuwaoka, J.
and Ogawa, T. 2007. Cruise report of the Second Phase of the Japanese Whale Research Program underSpecial Permit in the Western North Pacific (JARPN II) in 2006 (Part I)-Offshore component. Document
SC/59/O5 presented at this meeting.

Figure 1: Stock structure hypotheses for western North Pacific Bryde’s whale4

Appendix 1: List of ISTs (from IWC, 2006a)

Appendix 2: List of management variants

Variant 1: sub-areas 1W, 1E and 2 are Small Areas and catch limits are set by Small Area.
Variant 2: sub-area 2 is taken to be a Small Area and the complete sub-area 1 is treated as a
Small Area. For this management option, all of the future catches in sub-area 1 are taken fromsub-area 1W.
Variant 3: Sub-area 2 is taken to be a Small Area and sub-area 1 is taken to be a CombinationArea. Sub-areas 1W and 1E are Small Areas, with catch-cascading applied.
Variant 4: Sub-areas 1 and 2 (combined) are taken to be a Combination Area, and sub-area 2and sub-areas 1W and 1E are Small Areas, with catch-cascading applied.

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