Presentation on theme: "CAN WHALING BE MANAGED TO PROTECT WHALES AND WHALERS? Judith E. Zeh Chair of the Scientific Committee (SC) of the International Whaling Commission (IWC)"— Presentation transcript:
CAN WHALING BE MANAGED TO PROTECT WHALES AND WHALERS? Judith E. Zeh Chair of the Scientific Committee (SC) of the International Whaling Commission (IWC)
Research Professor, Statistics University of Washington Seattle, Washington, USA My presentation style: Overheads with words and equations! Thanks for pictures from
Greg Donovan, IWC Secretariat Chairman of the Aboriginal Subsistence Whaling Management Procedure (AWMP) Standing Working Group of the SC Extinction is forever… Unless you use… Balaena electronicus
Craig George, Dept. of Wildlife Management North Slope Borough, Barrow, Alaska, USA
ISANA (Brave Fish) published by Japan Whaling Association
Christmas cards and calendar pictures from Seiji Ohsumi and Hiroshi Hatanaka Former and current Director-General, ICR The Institute of Cetacean Research, Tokyo, Japan Minke Whale in the Ross Sea
The Bowhead Whale, Special Publication Number 2 of the Society for Marine Mammalogy Editors J.J. Burns, J.J. Montague and C.J. Cowles. Figure 1.2. Bowhead whale in scattered ice in the Beaufort Sea. Photo by D. Ljungblad for U.S. Minerals Management Service.
Gray Minke Sperm Right (Humans) Bryde’s Sei Blue Fin Humpback Bowhead
Other references: Gambell, R The International Whaling Commission and the contemporary whaling debate. pp in J.R. Twiss Jr. and R.R. Reeves (eds.) Conservation and Management of Marine Mammals. Smithsonian Institution Press. Web sites: Zeh, J.E. and Punt, A.E Updated abundance estimates and their correlations for the Bering-Chukchi-Beaufort Seas stock of bowhead whales. The Journal of Cetacean Research and Management: in press.
The Whales: Stocks of large baleen whales The Whalers: Commercial Aboriginal subsistence
What is a whale stock? SC established a working group to answer this question in Biological stock: population of interbreeding whales of a particular species that maintains itself over time in a definable area Management stock: all or part of a biological stock in an area where it may be subject to human- induced mortality and management Working group decided in 2002 to focus on ‘unit- to-conserve’ rather than ‘stock’.
I use ‘stock’ as shorthand for ‘management stock’ or ‘unit-to-conserve’ May not correspond to biological stock Definition depends on management objectives Stock boundaries may be temporal as well as spatial, may be hard to determine Significant genetic differences between areas may not mandate management as separate stocks if migration rates between the areas are high
Aboriginal Subsistence Whaling No formal definition Traditionally ‘accepted’: Greenland Alaska Washington State Chukotka, Siberia St Vincent and The Grenadines
Long traditions! 19 th century stone spear points from bowhead whales landed since 1980 in Alaska Bangudae petroglyphs, Ulsan, Korea
Below, remains of structures made from bowhead bones, Wales, Alaska. Photo by I.I. Krupnik. Right, towing a whale to the shorefast ice for butchering and pulling onto the ice. Photos by J.C. George.
‘Small-type’ (commercial) whaling Iceland Norway Japan
Also long traditions! Below, 1773 picture of whaling station, Hizen, Japan. Right, right whale being harpooned off Ikitsuki Misaki. Lower right, 1997 whaling boat race, Muroto City, western Japan (from ISANA, Oct. 1997).
Large-scale commercial whaling using factory ships in the Antarctic Hauling a fin whale up the slipway Factory ship Jan Wellem at anchor with catcher boats alongside
IWC established in 1946 by the International Convention for the Regulation of Whaling, signed by 14 whaling nations. Convention Schedule …the history of whaling has seen over-fishing of one area … and of one whale species after another… convention to provide for the proper conservation of whale stocks and thus make possible the orderly development of the whaling industry… Precise regulations governing whaling operations Amendments Require ¾ majority vote
Convention mandated management based on scientific findings. The SC was established in But trade-offs with industry demands: Contracting Governments objecting to amendments are not bound by them; Norway now whales under objection. Any Contracting Government may grant a special permit to its nationals to kill, take and treat whales for purposes of scientific research; Iceland and Japan now conduct scientific permit whaling. The blue whale story involves trade-offs:
Continued decline of blue whales D.G. Chapman The Plight of the Whales. pp in Statistics: a guide to the unknown. Edited by J.M. Tanur et al. 1961: IWC appointed Committee of Three scientists (Chapman, Allen, Holt) from non-whaling nations to work with SC to determine size of Antarctic stocks and safe catch limits. Reported to IWC in 1963.
The Blue Whale Unit (BWU) 1 blue whale = 2.5 humpbacks = 6 sei 2 fin whales = 2 fin whales =
Results of Committee of Three Report IWC banned Antarctic humpback catches in 1963, blue whale catches in BWU => doubled fin whale catches; report said reduce from 27,000 to 7,000 and predicted would drop to 14,000 next season in any case; IWC reduced quota only when prediction proved correct. In 1972, catch limits finally set by species rather than by BWU. All these species now fully protected from whaling throughout the Southern Hemisphere.
SC developed a new management procedure based on a density-dependent population dynamics model: K = initial (unexploited) population size Lower production rate at K than at lower population sizes MSY = Maximum Sustainable Yield MSYR = MSY rate as a percent of abundance MSYL = MSY level as a percent of K (60%)
New Management Procedure (NMP) 0 Blue whales 2,244 Minkes Acme quotas MSY rate Mortality rates Pregnancy rate Age at sexual maturity CPUE data Abundance Catch history Initial population size IMS = >72% catch 72% catch
NMP adopted 1975 – not all bad! Designed to bring stocks to optimum level Protected stocks at 54% initial Formal structure Took power away from politicians Assumed near-perfect knowledge of dynamics of all whale stocks (MSYR, MSYL, K) SC couldn’t agree on stock classifications or catch limits except for PS stocks clearly in need of protection
The ‘Moratorium’ and the ‘Comprehensive Assessment’ Moratorium: pause in commercial whaling, adopted by IWC in 1982, took effect Comprehensive Assessment: mandated by IWC in 1982; defined by SC as ‘an in-depth evaluation of the status of all whale stocks in the light of management objectives and procedures… that … would include the examination of current stock size, recent population trends, carrying capacity and productivity’; included development of a Revised Management Procedure (RMP)
Management procedures Objectives must be explicitly stated, assigned priorities, specified in a quantitative way Data and analysis requirements must be realistic and specified Data limitations and uncertainty must be taken into account in designing and testing procedure Rigorous testing must be done via computer simulations Must include feedback monitoring, e.g. implementation reviews to be sure data and status of stock remain within tested parameter space
Management objectives (extremes) Avoid extinction of cetacean Do not affect profitability TRADE-OFFS $$$
RMP objectives involve trade-offs (less extreme) Catches should not be allowed on stocks below 54% of the estimated carrying capacity (as in the NMP). Catch limits should be as stable as possible. The highest possible continuing yield should be obtained from the stock.
RMP Data Requirements Time series of catches by sex in area being managed (including other human- induced mortalities, e.g. from entanglement in fishing gear or ship strikes) Absolute abundance estimates obtained by direct methods, e.g. sightings surveys; survey interval not to exceed 6 years
Catch Limit Algorithm Specifies the way catch limits are calculated from required information Initially ‘true’ situation poorly known –Depletion level, productivity –Abundance estimates Range of possible catch limits –Acceptable level of risk ‘Learns’ as more data become available
Test CLA via many computer simulations of 100 years of management, e.g. Different population dynamics models Different MSYR, MSYL, K Bias in estimated abundance Errors in historic catch records Balaenoptera electronicus
SC completed RMP in 1993, unanimously recommended adoption by Commission SC provided specification of CLA and other aspects of the RMP, notes regarding data requirements Commission wanted to complete Revised Management Scheme (RMS) but also expressed concerns about the RMP Commission did not adopt the RMP in 1993 SC Chair Phil Hammond resigned in protest Commission adopted RMP in 1994
RMS Independent monitoring Accounting for bycatch Guidelines for surveys Data standards Inspectors and observers DNA register of catches and market sampling Apportioning costs Humane killing RMP CLA
IWC now has 66 member nations, most not whaling nations Meets at least annually Passes Resolutions by majority vote, e.g. to complete RMS Meanwhile, Norway whales using its version of the RMP, Iceland and Japan whale without catch limits IWC should resume managing whaling!
IWC does manage subsistence whaling! Adopted Bowhead SLA, part of Aboriginal Subsistence Whaling Management Procedure (AWMP)
Objectives of AWMP (1982, 1994) Different from RMP objectives! Ensure risks of extinction not seriously increased (highest priority) Enable harvests in perpetuity appropriate to cultural and nutritional needs Maintain stocks at highest net recruitment level and if below that ensure they move towards it
Some assumptions (bowhead case) Strikes versus catches –Assume that strikes all result in kills –Termed ‘Strike Limit Algorithm’ – SLA Future need – uncertain –Need ‘envelope’ to set bounds –Agreed with Commission in 1997 Options after 100 years: 134 and 201 strikes –If need request outside bounds – new trials Like RMP CLA, required data are abundance and catches, SLA tested via simulation trials
Features of AWMP and AWS (Aboriginal Whaling Scheme) based on dialogue with hunters Account for Arctic conditions –Block quota (5 yrs) and carryover Up to 50% carryover between years (and blocks) –Survey interval and grace period Surveys at least every 10 years Cannot manage without data – 5 yr ‘grace’ Phase-out rule: block quota reduced by 50% in absence of survey – user decides strategy Not expected to be needed
Abundance estimates from visual counts, but could there be more? Can only count what you can see… Hunters believed whales pass through closed leads…
Acoustic monitoring added to visual to improve abundance estimates: 10,500 (CV 13%) in 2001 Chris Clark records bowhead calls A visual census perch near Point Barrow, Alaska, used in 1984
AWS AWMP SLA Bowhead SLA adopted 2002 First Implementation Review will occur in 2007; focus on whether single stock Implementation reviews every 5 years or as needed Review new data to be sure within tested ‘space’ > stock structure > abundance > biology > unusual deaths > information from hunters
Recurring polynyas available to bowheads in winter and spring Whales caught around St. Lawrence Island differ genetically from others Separate stock? Or age or some other differences? If separate, abundance? Catch of 1-8 whales/yr around SLI safe?
Being taken by whalers not the only threat! Entanglement in fishing gear (below) and ship strikes (left) cause deaths in the most endangered populations, e.g. North Atlantic right whale below.
Take-home messages Worry most about endangered whales that would never be subject to whaling! AWMP and RMP may be more conservative than whalers like, but whalers are not protected unless whales are. Whales are protected by management procedures > based on monitoring abundance, catches; > tested over plausible range of uncertainties. Whales fulfill cultural and nutritional needs for nations as well as aboriginal people with whaling traditions!
THANK YOU! If the IWC does not manage whaling, it will take place without international oversight. That is not good for the whales!