Marine food webs destabilized

doi:10.1126/science.abd5739

GSTDTAP > 气候变化

DOI	10.1126/science.abd5739
	Marine food webs destabilized
	Steven L. Chown
	2020-08-14
发表期刊	Science
出版年	2020
英文摘要	Forecasting the ecological consequences of climate change requires both observations and experiments. Among the most informative experiments are manipulations of ecosystems, either through large outdoor interventions or through the construction of mesocosms ([ 1 ][1])—replicas of the natural world that enable conditions to be carefully controlled. Mesocosms typically mimic the complexity of natural ecosystems, enabling researchers to disentangle how these systems work now and what path they might follow as future conditions change. They can also be replicated, enabling signal to be distinguished from the variability that is an inherent feature of natural systems. On page 829 of this issue, Nagelkerken et al. ([ 2 ][2]) report on their use of mesocosms to better understand the future of marine systems and the ecological services they deliver. They find that marine benthic ecosystems have limited capacity to respond to a future combination of warming and acidification, with considerable degradation a potential outcome. Nagelkerken et al. address several key questions. Their experiments explore the way that ecological interactions will play out under end-of-century temperature and ocean acidification conditions compared with those now. They assess how species with similar functions, but different responses to changing physical conditions, replace each other, thus preserving the form of ecological interactions (especially feeding) among community members. They also aim to determine whether the trophic structure of present-day marine systems (see the figure, left)—with a high biomass of primary producers and lower biomasses of primary and secondary consumers—will be maintained as physical conditions change. Nagelkerken et al. constructed replicas of Australian marine benthic systems, including all of the major groups of organisms that might be expected: cyanobacteria, algae, copepods, shrimps, crabs, molluscs, polychaetes, brittle stars, sponges, and fish. Primary producers (such as algae) and both primary (molluscs) and secondary (fish, crabs) consumers were represented by the species included in the mesocosms, as were typical feeding interactions among species and trophic levels. The 1800-liter mesocosms were then either exposed to conditions typical of those along the South Australian coast (a control setting) or exposed to increased temperature, simulated acidification, or a combination of the two, as expected at the end of this century under the Intergovernmental Panel on Climate Change's Representative Concentration Pathway 8.5 (RCP8.5) scenario. RCP8.5 is based on an extreme anthropogenic greenhouse gas emissions scenario, but one that continues to be plausible ([ 3 ][3]). Nagelkerken et al. then investigated food web structure in the form of feeding interactions and the way in which biomass and productivity change among trophic groups. Simulated ocean acidification had little effect, except for a benefit from bottom-up resource enrichment. By contrast, although food web structure was relatively insensitive to temperature and to the combination of temperature and acidification, both biomass and productivity were greatly reorganized among trophic groups (see the figure, center). In effect, and especially under combined warming and acidification, primary producer and secondary consumer biomass and productivity increased, whereas substantial declines occurred among primary consumers. As Nagelkerken et al. point out, such trophic imbalance is unlikely to be stable in the long term. Rather, it represents a transitory state, with one likely outcome the collapse of the system such that primary producers dominate and secondary consumers, such as fish, are largely lost (see the figure, right). Less extreme outcomes might result if species are capable of adapting to the combination of warmer temperatures and higher acidity. The outcomes from these mesocosm experiments are worrying. Secondary marine consumers, such as fish and larger invertebrates, are an important nutritional source for people ([ 4 ][4]). Indeed, demersal and small pelagic fish now dominate global fisheries catch ([ 5 ][5]). Yet these important marine resources are under pressure because of fishing for human consumption ([ 6 ][6]) or the production of fish meal for aquaculture ([ 7 ][7]). These mesocosm trials suggest that this direct pressure, which includes increased benthic trawling ([ 5 ][5]), will further be compounded by the combination of warming and acidification. These local-scale conclusions are well aligned with global models forecasting continual declines in global ocean animal biomass, especially at higher trophic levels, as climates change ([ 8 ][8]). Beyond the end of this century, these impacts are expected to be especially severe in some regions ([ 9 ][9]). Human futures are not the only ones that are at stake. Other species, and ecosystems, also depend on what's happening in the sea. Marine secondary consumers, such as fish, are not the end of the trophic line. Rather, they are also food for seabird and marine mammal species, which are themselves now under pressure from changing climates and human activity ([ 10 ][10]). Moreover, these vertebrates play a role in the transfer of marine nutrients to terrestrial areas, thus contributing to the functioning of coastal margin and island ecosystems ([ 11 ][11]). ![Figure][12] Expected changes to future marine trophic structure Currently, marine nearshore systems have high primary producer biomass and productivity, which declines moderately with increasing trophic level. Mesocosm experiments reveal a sharp decline in primary—but not secondary—consumer biomass and productivity in response to expected end-of-century temperature and acidification conditions. Such trophic structure is unstable. In the absence of adaptation, systems are expected to collapse to those with few secondary consumers and a dominance of primary producers. GRAPHIC: JOSHUA BIRD/ SCIENCE One finding from Nagelkerken et al. 's experiments that might seem unusual is the limited impact of acidification alone. Acidification's effects on animals—such as influences on embryonic development, adult reproduction, and energetics—are now proving in many cases to be less severe than feared ([ 12 ][13]). But the effects of interactions between stressors are not yet well characterized. Rich opportunity exists to determine just how general Nagelkerken et al. 's findings are, by exploring the outcomes of interactions among multiple stressors such as increased temperature, increased carbon dioxide, and changing salinity. Whether their results, which show an absence under future conditions of important stabilizing processes that include species substitution, functional redundancy, and trophic compensation, apply as much to other settings as they do to the system they investigated is far from clear. Indeed, replication in other ways and other settings of this work is critical because mesocosm outcomes can be quite variable ([ 1 ][1]). If the trajectory documented by Nagelkerken et al. is found elsewhere, additional early warning indicators, such as initial declines in primary consumer biomass and productivity, will have been made available. These are indicators that could help detect and perhaps prevent the transition of marine systems to states that are much less rich and productive than they are now. Overall, the message from these marine mesocosm trials is clear: Destabilization of marine food webs can only be mitigated if further concerted action is taken to reduce greenhouse gas emissions. 1. [↵][14]1. R. I. A. Stewart et al ., Adv. Ecol. Res. 48, 71 (2013). [OpenUrl][15][CrossRef][16] 2. [↵][17]1. I. Nagelkerken, 2. S. U. Goldenberg, 3. C. M. Ferreira, 4. H. Ullah, 5. S. D. Connell , Science 369, 829 (2020). [OpenUrl][18][Abstract/FREE Full Text][19] 3. [↵][20]1. Z. Hausfather, 2. G. P. Peters , Nature 577, 618 (2020). [OpenUrl][21] 4. [↵][22]1. C. C. Hicks et al ., Nature 574, 95 (2019). [OpenUrl][23][CrossRef][24] 5. [↵][25]1. R. A. Watson, 2. A. Tidd , Mar. Policy 93, 171 (2018). [OpenUrl][26] 6. [↵][27]1. D. A. Kroodsma et al ., Science 359, 904 (2018). [OpenUrl][28][Abstract/FREE Full Text][29] 7. [↵][30]1. D. Pauly , Nature 574, 41 (2019). [OpenUrl][31] 8. [↵][32]1. H. K. Lotze et al ., Proc. Natl. Acad. Sci. U.S.A. 116, 12907 (2019). [OpenUrl][33][Abstract/FREE Full Text][34] 9. [↵][35]1. J. K. Moore et al ., Science 359, 1139 (2018). [OpenUrl][36][Abstract/FREE Full Text][37] 10. [↵][38]1. M. A. Hindell et al ., Nature 580, 87 (2020). [OpenUrl][39] 11. [↵][40]1. B. Moss , J. Exp. Mar. Biol. Ecol. 492, 63 (2017). [OpenUrl][41] 12. [↵][42]1. L. S. Peck , Oceanogr. Mar. Biol. Annu. Rev. 56, 105 (2018). [OpenUrl][43] [1]: #ref-1 [2]: #ref-2 [3]: #ref-3 [4]: #ref-4 [5]: #ref-5 [6]: #ref-6 [7]: #ref-7 [8]: #ref-8 [9]: #ref-9 [10]: #ref-10 [11]: #ref-11 [12]: pending:yes [13]: #ref-12 [14]: #xref-ref-1-1 "View reference 1 in text" [15]: {openurl}?query=rft.jtitle%253DAdv.%2BEcol.%2BRes.%26rft.volume%253D48%26rft.spage%253D71%26rft_id%253Dinfo%253Adoi%252F10.1016%252FB978-0-12-417199-2.00002-1%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 [16]: /lookup/external-ref?access_num=10.1016/B978-0-12-417199-2.00002-1&link_type=DOI [17]: #xref-ref-2-1 "View reference 2 in text" [18]: {openurl}?query=rft.jtitle%253DScience%26rft.stitle%253DScience%26rft.aulast%253DNagelkerken%26rft.auinit1%253DI.%26rft.volume%253D369%26rft.issue%253D6505%26rft.spage%253D829%26rft.epage%253D832%26rft.atitle%253DTrophic%2Bpyramids%2Breorganize%2Bwhen%2Bfood%2Bweb%2Barchitecture%2Bfails%2Bto%2Badjust%2Bto%2Bocean%2Bchange%26rft_id%253Dinfo%253Adoi%252F10.1126%252Fscience.aax0621%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 [19]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6Mzoic2NpIjtzOjU6InJlc2lkIjtzOjEyOiIzNjkvNjUwNS84MjkiO3M6NDoiYXRvbSI7czoyMjoiL3NjaS8zNjkvNjUwNS83NzAuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9 [20]: #xref-ref-3-1 "View reference 3 in text" [21]: {openurl}?query=rft.jtitle%253DNature%26rft.volume%253D577%26rft.spage%253D618%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 [22]: #xref-ref-4-1 "View reference 4 in text" [23]: {openurl}?query=rft.jtitle%253DNature%26rft.volume%253D574%26rft.spage%253D95%26rft_id%253Dinfo%253Adoi%252F10.1038%252Fs41586-019-1592-6%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 [24]: /lookup/external-ref?access_num=10.1038/s41586-019-1592-6&link_type=DOI [25]: #xref-ref-5-1 "View reference 5 in text" [26]: {openurl}?query=rft.jtitle%253DMar.%2BPolicy%26rft.volume%253D93%26rft.spage%253D171%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 [27]: #xref-ref-6-1 "View reference 6 in text" [28]: {openurl}?query=rft.jtitle%253DScience%26rft.stitle%253DScience%26rft.aulast%253DKroodsma%26rft.auinit1%253DD.%2BA.%26rft.volume%253D359%26rft.issue%253D6378%26rft.spage%253D904%26rft.epage%253D908%26rft.atitle%253DTracking%2Bthe%2Bglobal%2Bfootprint%2Bof%2Bfisheries%26rft_id%253Dinfo%253Adoi%252F10.1126%252Fscience.aao5646%26rft_id%253Dinfo%253Apmid%252F29472481%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 [29]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6Mzoic2NpIjtzOjU6InJlc2lkIjtzOjEyOiIzNTkvNjM3OC85MDQiO3M6NDoiYXRvbSI7czoyMjoiL3NjaS8zNjkvNjUwNS83NzAuYXRvbSI7fXM6ODoiZnJhZ21lbnQiO3M6MDoiIjt9 [30]: #xref-ref-7-1 "View reference 7 in text" [31]: {openurl}?query=rft.jtitle%253DNature%26rft.volume%253D574%26rft.spage%253D41%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 [32]: #xref-ref-8-1 "View reference 8 in text" [33]: {openurl}?query=rft.jtitle%253DProc.%2BNatl.%2BAcad.%2BSci.%2BU.S.A.%26rft_id%253Dinfo%253Adoi%252F10.1073%252Fpnas.1900194116%26rft_id%253Dinfo%253Apmid%252F31186360%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 [34]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6NDoicG5hcyI7czo1OiJyZXNpZCI7czoxMjoiMTE2LzI2LzEyOTA3IjtzOjQ6ImF0b20iO3M6MjI6Ii9zY2kvMzY5LzY1MDUvNzcwLmF0b20iO31zOjg6ImZyYWdtZW50IjtzOjA6IiI7fQ== [35]: #xref-ref-9-1 "View reference 9 in text" [36]: {openurl}?query=rft.jtitle%253DScience%26rft.stitle%253DScience%26rft.aulast%253DMoore%26rft.auinit1%253DJ.%2BK.%26rft.volume%253D359%26rft.issue%253D6380%26rft.spage%253D1139%26rft.epage%253D1143%26rft.atitle%253DSustained%2Bclimate%2Bwarming%2Bdrives%2Bdeclining%2Bmarine%2Bbiological%2Bproductivity%26rft_id%253Dinfo%253Adoi%252F10.1126%252Fscience.aao6379%26rft_id%253Dinfo%253Apmid%252F29590043%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 [37]: /lookup/ijlink/YTozOntzOjQ6InBhdGgiO3M6MTQ6Ii9sb29rdXAvaWpsaW5rIjtzOjU6InF1ZXJ5IjthOjQ6e3M6ODoibGlua1R5cGUiO3M6NDoiQUJTVCI7czoxMToiam91cm5hbENvZGUiO3M6Mzoic2NpIjtzOjU6InJlc2lkIjtzOjEzOiIzNTkvNjM4MC8xMTM5IjtzOjQ6ImF0b20iO3M6MjI6Ii9zY2kvMzY5LzY1MDUvNzcwLmF0b20iO31zOjg6ImZyYWdtZW50IjtzOjA6IiI7fQ== [38]: #xref-ref-10-1 "View reference 10 in text" [39]: {openurl}?query=rft.jtitle%253DNature%26rft.volume%253D580%26rft.spage%253D87%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 [40]: #xref-ref-11-1 "View reference 11 in text" [41]: {openurl}?query=rft.jtitle%253DJ.%2BExp.%2BMar.%2BBiol.%2BEcol.%26rft.volume%253D492%26rft.spage%253D63%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 [42]: #xref-ref-12-1 "View reference 12 in text" [43]: {openurl}?query=rft.jtitle%253DOceanogr.%2BMar.%2BBiol.%2BAnnu.%2BRev.%26rft.volume%253D56%26rft.spage%253D105%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
领域	气候变化 ; 资源环境
URL	查看原文
引用统计
文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/288062
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Steven L. Chown. Marine food webs destabilized[J]. Science,2020.
APA	Steven L. Chown.(2020).Marine food webs destabilized.Science.
MLA	Steven L. Chown."Marine food webs destabilized".Science (2020).