POLICYFORUM ECOLOGY We examine the scientific evidence for the Should Whales Be Culled to assertion that commercial fisheries are negatively impacted by whales in tropical Increase Fishery Yield? breeding areas. Leah R. Gerber,1* Lyne Morissette,1,2 Kristin Kaschner,3,1 Daniel Pauly4 cience and international politics play complicated roles in the global arena of Swhale conservation and the manage- ment of the resources of the world’s oceans. The International Whaling Commission (IWC), charged with the global conservation of whales and the management of whaling, introduced a moratorium on commercial whaling in 1986 because of the widespread depletion of whale species and stocks. Despite a lack of scientific data to indicate that many whale stocks have recovered, every year a heated debate takes place at the IWC meeting about the future of commercial whaling. 2011 2000 2000 Recently, whaling countries have introduced a Whale Fishing Whale Fishing new argument for resuming whaling by blam- feeding rate rate feeding rate rate on February 13, 2009 ing whale populations for the decline in com- 1581 1500 1500 mercial fish stocks. Couched in terms of “ecosystem manage- ment,” whaling countries, including Japan, 1000 1000 advocate the culling of whales as a solution 746 to recover overexploited fish stocks and to increase fishery yield (1, 2). Some develop- 500 442 500 ing countries, which may benefit economi- or fishing moratorium (average %) 188 cally and politically by supporting pro-whal- www.sciencemag.org Fish biomass increase after whale removal 0.07 0.15 0.26 2.74 2.50 2.62 4.13 ing nations at IWC (3–7), have also sup- 0 0 ported the “whales-eat-fish” assertion. The best 5x 10x best 1.5x 2x best 5x 10x best 1.5x 2x estimate higher higher estimate higher higher estimate higher higher estimate higher higher Caribbean-driven St. Kitts Declaration at the 58th Annual Meeting of the IWC stated: Northwest Africa Caribbean “scientific research has shown that whales consume huge quantities of fish making the Negligible effects of removing whales on commercial fish biomass relative to the effect of a fishing issue a matter of food security for coastal moratorium. Estimated increases in fish biomass for best estimates of whale feeding and fishing rates, 5- and Downloaded from nations” (6). This issue was also claimed to 10-fold underestimates of whale feeding, and 1.5 and 2-fold underestimates of fishing. For details, see (9). be one of global concern at a 2008 sympo- sium of IWC members in the Northwest tries. Whaling does not provide direct benefit available data on whale abundance, Japanese Africa region (8). to the fisheries that these countries closely scientists estimate that whales consume sev- When scientific information about the depend on (9), but rather leads to the loss of eral times as much food as the combined role of whales in marine ecosystems and for species that are important for the structural global fisheries catch in recent years (18). the economies of developing nations are con- integrity of their ecosystem (10–12). Living However, the methodology used by Japanese sidered, it becomes clear that delegates from whales, on the other hand, may actually repre- researchers to support their claim that developing countries who support the pro- sent an alternative source of income through whales’ consumption of fish is an important whaling nations at the IWC may in fact be whale watching (13, 14). component of fish declines has been repeat- acting against the best interest of their coun- The rationale for whaling as the solution edly criticized (19–22). Although these dis- to depleted fisheries has been questioned by cussions have been insightful, they have not 1Ecology, Evolution, and Environmental Science, School of Life many in the scientific community in light of stimulated movement within the IWC to Sciences, Arizona State University, Tempe, AZ 85287–4501, documented overfishing in oceans globally break the current deadlock. USA. 2Institut des Sciences de la Mer de Rimouski, 310 Allée (15), a lack of spatially explicit overlap of One of the obstacles in scientific studies des Ursulines, Rimouski, QC, G5L 3A1, Canada. 3Institute of Biology I (Zoology), Evolutionary Biology and Ecology resource exploitation between fisheries and of whales is that there are few data and mod- Laboratory, Albert-Ludwigs-University, Freiburg, Germany. whales (2), and the unpredictable conse- els available to inform policy discussions. 4Sea Around Us Project, Fisheries Centre, University of British quences of culling (16, 17). Based on stom- This is particularly true in the tropical waters Columbia, Vancouver, BC, V6T 1Z4, Canada. ach content analyses of whales caught during bordering many of the developing countries *Author for correspondence. E-mail: [email protected] the Japanese scientific whaling program and that support the resumption of commercial GERBER; JUPITER IMAGES PHOTO CREDITS (LEFT TO RIGHT): ERIKA ANTONIAZZO/ALAMY;LEAH 880 13 FEBRUARY 2009 VOL 323 SCIENCE www.sciencemag.org Published by AAAS POLICYFORUM whaling, although these areas are known to be whales from marine ecosystems could result 3. L. Busby, in Global Corruption Report, R. Hodess, T. Inowlocki, D. Rodriguez, T. Wolfe, Eds. (Transparency primarily breeding (not feeding) grounds for in fewer fish available to the fisheries (9). International and Pluto Press, London, 2004), pp. 76–88. baleen whales (23–27). We conducted an Today, the majority of fish stocks (33) and 4. A. R. Miller, N. Dolsak,v Glob. Environ. Polit. 7, 69 (2007). extensive literature search to compile and many whale populations (34) are seriously 5. Third Millennium Foundation, Japan’s “Vote Consolidation Operation” at the International Whaling Commission (Third make use of all available sources of local data depleted, but most available evidence points Millennium Foundation, Paciano, Italy, 2007). to provide a scientific starting point to the toward human overexploitation as the root 6. IWC, Chairman’s Report from the International Whaling discussion (9). We also sought to actively of the problem. When developing tropical Commission 58th Annual Meeting, St. Kitts and Nevis, 16 involve scientific advisers of delegates who countries are encouraged to focus on the to 20 June 2006 (IWC, St. Kitts, 2006), 15 pp. 7. K. Stringer, Dipl. Statecraft 17, 547 (2006). support Japan’s position at the IWC meetings notion that “whales eat fish,” they risk being 8. IWC, in Symposium sur I’Utilisation Durable des Ressources and to foster regional collaboration and active diverted from addressing the real problems Marines Vivantes de la Région Africaine, Rabat, 11 to 12 dissemination of our findings to inform dis- that their own fisheries face, primarily, over- February 2008; originally made available at the request of the Republic of Guinea via Circular Communication cussions in local communities among scien- exploitation of their marine resources by IWC.CCG.672 of 26 February 2008. tists, managers, and other local experts distant-water fleets (35). 9. Materials and methods are available as supporting materi- (e.g., 2008 “Whales-Eat-Fish” regional Here, we offer a set of recommendations for als on Science Online. 10. J. E. Duffy, Ecol. Lett. 6, 680 (2003). workshops held in Senegal and Barbados, rational decision-making by effectively apply- 11. A. M. Springer et al., Proc. Natl. Acad. Sci. U.S.A. 100, http://lenfestocean.org/whales_fisheries.html). ing ecosystem management concepts to man- 12223 (2003). Using data available from the literature, aging whales. 12. M. R. Heithaus, A. Frid, A. J. Wirsing, B. Worm, Trends Ecol. and, e.g., the Sea Around Us Project (www. First, the question of “who is eating our Evol. 23, 202 (2008). 13. E. Hoyt, G. T. Hvenegaard, Coast. Manage. 30, 381 (2002). seaaroundus.org) and obtained during our fish” should be considered in a larger context 14. J. E. S. Higham, D. Lusseau, Conserv. Biol. 21, 554 (2007). regional stakeholder workshops, we devel- (with respect to foreign fleets, ecosystem col- 15. R. A. Myers, B. Worm, Nature 423, 280 (2003). oped ecosystem models to examine the lapses, and climate change). Indirect social and 16. R. T. Paine, M. J. Tegner, E. A. Johnson, Ecosystems 1, 535 (1998). potential increase in the biomass of com- economic benefits of whales in tropical ecosys- 17. M. Scheffer, S. Carpenter, J. A. Foley, C. Folke, B. Walker, mercially important fish stocks that would tems [e.g., tourism (36, 37)] should also be Nature 413, 591 (2001). result from a reduction in whale abundance taken into account. 18. T. Tamura, in Responsible Fisheries in Marine Ecosystems, M. Sinclair and G. Valdimarsson, Eds. (Food and in the Northwest African and Caribbean Second, despite complicated politics, sci- on February 13, 2009 Agricultural Organization of the United Nations & CABI ecosystems (9). Any discussion about the ence should be an integral component of the Publishing, Wallingford, UK, 2003), pp. 143–170. interactions between whales and fisheries discussions about managing whale and fish- 19. N. J. Gales, T. Kasuya, P. J. Clapham, R. L. Brownell, Nature must be considered in an ecosystem con- ery interactions. An effort must be made to 435, 883 (2005). 20. P. J. Clapham et al., Mar. Policy 31, 314 (2007). text, which allows investigation of the com- actively engage scientists and managers from 21. S. J. Holt, Mar. Pollut. Bull. 54, 1081 (2007). plex indirect effects of trophic relationships countries that support Japan’s claims (3–5) to 22. P. Corkeron, Mar. Ecol. Prog. Ser. 375, 305 (2009). that would otherwise be very difficult to help them investigate this issue within an 23. S. K. Katona, J. A. Beard, Rep. Int. Whaling Comm. 12, 295 (1990). study. Although the IWC Scientific Com- ecosystem context in their own regions. In 24. P. J. Corkeron, R. C. Connor, Mar. Mamm. Sci.