GSTDTAP  > 气候变化
DOI10.1126/science.abc7060
Costs and benefits of living with predators
James A. Estes; Lilian P. Carswell
2020-06-12
发表期刊Science
出版年2020
英文摘要Although money isn't everything, today's world operates by means of capitalism. This fundamental truth has led to an intersection between economics and ecology wherein natural resources and ecological processes are often valued in monetary terms. A central challenge to the intersection of ecology and natural resource management is thus twofold—understanding ecological processes and valuing the outcomes. Nowhere has this challenge caused more confusion and debate than in the arena of decision-making about how to conserve and manage large predators. On page 1243 of this issue, Gregr et al. ([ 1 ][1]) evaluate the recovery of an apex predator—sea otters in the Canadian Pacific coast—and report that certain economies have been either negatively or positively affected by sea otter restoration, but the overall economic outcomes are positive. Large apex predators occur in virtually all ecosystems, or once did. They were disproportionately lost or depleted during the age of exploration, discovery, and industrialization. While they are continuing to decline in some cases, they are recovering in many parts of the world following protection and purposeful repatriation. These predators commonly initiate a diverse array of effects on other species and ecological processes ([ 2 ][2]). Although ecology still has much to learn about the myriad influences of apex predators, most occur through the depletion and fear-induced behavior of their prey. The most well-known ecological pathway from predator through ecosystems is the so-called “trophic cascade,” wherein a predator limits the abundance and distribution of its herbivore prey, in turn enhancing the abundance and distribution of plants ([ 3 ][3]). Inasmuch as plants are the foundation for nearly all life on Earth, this link from predator to herbivore to plant extends broadly through nature. Many of the details are reasonably well known for various predators and ecosystems ([ 4 ][4]). Rarely, however, have these processes been rigorously valued on the basis of a common currency. The resulting “apples and oranges” have made it impossible to assess the net costs and benefits of predators to human societies, thereby resulting in irresolvable scientific arguments, irreconcilable management conflicts, and an inability of the responsible management agencies to establish defensible policies. The study of Gregr et al. is transformational because it provides a way through this conundrum. The authors conduct a cost-benefit analysis for the extensively studied and well-known case of sea otters and kelp forest ecosystems that accounts not only for shellfish depredation but also for a suite of knock-on effects of this interaction. Sea otters prey on, and thus limit the size and abundance of, various shellfish, thereby imposing a substantial cost on shellfisheries. However, sea otters also create economic benefits by way of wildlife viewing opportunities and tourism, and through the enhancement of kelp forests that results from a reduction in the number of herbivorous sea urchins. Kelp increases coastal production and provides habitat for other species, thereby enhancing coastal fin fisheries. Kelp also sequesters carbon, thus reducing atmospheric carbon dioxide (CO2) and ocean acidification. There are numerous other ecological influences of sea otters, although Gregr et al. focus on just these, from which they find that the monetary benefits of sea otters outweighed the costs sevenfold. The responsible management agencies in southeast Alaska and British Columbia heretofore have been unable to resolve the severe local conflicts that are developing because of sea otter recovery. Gregr et al. do not offer a solution, although they do provide the template for a more holistic and objective means of policy development. The importance of the analysis of Gregr et al. is not so much in the exact findings but as a method for looking beyond depredation in assessing the costs and benefits of living with predators. In the case of sea otters and kelp forests, the web of interactions that emanate from otter predation on shellfish and the otter-urchin-kelp trophic cascade might be expanded to include other interactions that bear on human financial welfare. For example, Pacific herring spawn on kelp, are targeted by fisheries, and provide the nutritional base for other iconic and valued species, such as salmon and whales. The ecological data are not yet sufficient to assess the magnitudes of potential influence by sea otters on these and other species and ecological processes, but in the future they may be. Moreover, the details of Gregr et al. 's analysis are specific to the west coast of Vancouver Island, and these will surely vary in different places and at different times, perhaps substantially. For example, although tourism is important to many coastal economies along the west coast of Canada and the United States, this isn't so everywhere, nor is it likely that all local communities wish it to be. The ledger of net monetary benefit from sea otters would not switch to a net cost with the removal of tourism, but it would be greatly reduced, given the factors that Gregr et al. considered. The important point is that quantifying indirect effects broadens the base of stakeholders in natural resource management by identifying interests that could otherwise be overlooked or dismissed as trivial. Such an expanded perspective alerts the public that they may indeed have a stake in decisions made by natural resource agencies, and it directs policymakers and managers to constituencies they may not have previously consulted. There is also the larger question of how the monetary costs and benefits of predators affect other ecosystems. This is an important future arena for science and policy. One such scenario involves the gray wolf, which has been the focus of similar controversy and societal discord. The ecological influences of wolves in North American boreal forests are broadly similar to those of sea otters and kelp forests ([ 5 ][5]). One especially topical segment of the web of interactions that emerges from wolves as predators is that of disease. The removal of wolves from the midwestern and eastern United States was likely instrumental in the spread of coyotes into these regions, which in turn depleted fox populations. This led to an increase in small-mammal populations, an associated increase in tick abundance, and the rise of Lyme disease risk ([ 6 ][6]). Such a possibility creates an entirely new dimension to the costs and benefits of living with wolves. The analysis by Gregr et al. should spark a new era of ecological-economic research that can be used by natural resource policy-makers and managers to make and defend more rational, equitable, and far-sighted decisions affecting predators. 1. [↵][7]1. E. J. Gregr et al ., Science 368, 1243 (2020). [OpenUrl][8][Abstract/FREE Full Text][9] 2. [↵][10]1. J. A. Estes et al ., Science 333, 301 (2011). [OpenUrl][11][Abstract/FREE Full Text][12] 3. [↵][13]1. W. J. Ripple et al ., Trends Ecol. Evol. 31, 842 (2016). [OpenUrl][14] 4. [↵][15]1. J. Terborgh, 2. J. A. Estes , Eds., Trophic Cascades: Predators, Prey, and the Changing Dynamics of Nature (Island Press, 2010). 5. [↵][16]1. W. J. Ripple et al ., Science 343, 1241484 (2014). [OpenUrl][17][Abstract/FREE Full Text][18] 6. [↵][19]1. T. Levi, 2. A. M. Kilpatrick, 3. M. Mangel, 4. C. C. Wilmers , Proc. Natl. Acad. Sci. U.S.A. 109, 10942 (2012). [OpenUrl][20][Abstract/FREE Full Text][21] Acknowledgments: The findings and conclusions are those of the authors and do not necessarily represent the views of the U.S. Fish and Wildlife Service. [1]: #ref-1 [2]: #ref-2 [3]: #ref-3 [4]: #ref-4 [5]: #ref-5 [6]: #ref-6 [7]: #xref-ref-1-1 "View reference 1 in text" [8]: {openurl}?query=rft.jtitle%253DScience%26rft.stitle%253DScience%26rft.aulast%253DGregr%26rft.auinit1%253DE.%2BJ.%26rft.volume%253D368%26rft.issue%253D6496%26rft.spage%253D1243%26rft.epage%253D1247%26rft.atitle%253DCascading%2Bsocial-ecological%2Bcosts%2Band%2Bbenefits%2Btriggered%2Bby%2Ba%2Brecovering%2Bkeystone%2Bpredator%26rft_id%253Dinfo%253Adoi%252F10.1126%252Fscience.aay5342%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [9]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6Mzoic2NpIjtzOjU6InJlc2lkIjtzOjEzOiIzNjgvNjQ5Ni8xMjQzIjtzOjQ6ImF0b20iO3M6MjM6Ii9zY2kvMzY4LzY0OTYvMTE3OC5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30= [10]: #xref-ref-2-1 "View reference 2 in text" [11]: {openurl}?query=rft.jtitle%253DScience%26rft.stitle%253DScience%26rft.aulast%253DEstes%26rft.auinit1%253DJ.%2BA.%26rft.volume%253D333%26rft.issue%253D6040%26rft.spage%253D301%26rft.epage%253D306%26rft.atitle%253DTrophic%2BDowngrading%2Bof%2BPlanet%2BEarth%26rft_id%253Dinfo%253Adoi%252F10.1126%252Fscience.1205106%26rft_id%253Dinfo%253Apmid%252F21764740%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [12]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6Mzoic2NpIjtzOjU6InJlc2lkIjtzOjEyOiIzMzMvNjA0MC8zMDEiO3M6NDoiYXRvbSI7czoyMzoiL3NjaS8zNjgvNjQ5Ni8xMTc4LmF0b20iO31zOjg6ImZyYWdtZW50IjtzOjA6IiI7fQ== [13]: #xref-ref-3-1 "View reference 3 in text" [14]: {openurl}?query=rft.jtitle%253DTrends%2BEcol.%2BEvol.%26rft.volume%253D31%26rft.spage%253D842%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [15]: #xref-ref-4-1 "View reference 4 in text" [16]: #xref-ref-5-1 "View reference 5 in text" [17]: {openurl}?query=rft.jtitle%253DScience%26rft.stitle%253DScience%26rft.aulast%253DRipple%26rft.auinit1%253DW.%2BJ.%26rft.volume%253D343%26rft.issue%253D6167%26rft.spage%253D1241484%26rft.epage%253D1241484%26rft.atitle%253DStatus%2Band%2BEcological%2BEffects%2Bof%2Bthe%2BWorld%2527s%2BLargest%2BCarnivores%26rft_id%253Dinfo%253Adoi%252F10.1126%252Fscience.1241484%26rft_id%253Dinfo%253Apmid%252F24408439%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [18]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6Mzoic2NpIjtzOjU6InJlc2lkIjtzOjE2OiIzNDMvNjE2Ny8xMjQxNDg0IjtzOjQ6ImF0b20iO3M6MjM6Ii9zY2kvMzY4LzY0OTYvMTE3OC5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30= [19]: #xref-ref-6-1 "View reference 6 in text" [20]: {openurl}?query=rft.jtitle%253DProc.%2BNatl.%2BAcad.%2BSci.%2BU.S.A.%26rft_id%253Dinfo%253Adoi%252F10.1073%252Fpnas.1204536109%26rft_id%253Dinfo%253Apmid%252F22711825%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [21]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoicG5hcyI7czo1OiJyZXNpZCI7czoxMjoiMTA5LzI3LzEwOTQyIjtzOjQ6ImF0b20iO3M6MjM6Ii9zY2kvMzY4LzY0OTYvMTE3OC5hdG9tIjt9czo4OiJmcmFnbWVudCI7czowOiIiO30=
领域气候变化 ; 资源环境
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条目标识符http://119.78.100.173/C666/handle/2XK7JSWQ/274454
专题气候变化
资源环境科学
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James A. Estes,Lilian P. Carswell. Costs and benefits of living with predators[J]. Science,2020.
APA James A. Estes,&Lilian P. Carswell.(2020).Costs and benefits of living with predators.Science.
MLA James A. Estes,et al."Costs and benefits of living with predators".Science (2020).
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