Banning Fisheries Discards Abruptly Has a Negative Impact on the Population Dynamics of Charismatic Marine Megafauna.
Banning Fisheries Discards Abruptly Has a Negative Impact on the Population Dynamics of Charismatic Marine Megafauna.
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DOI：
10.1371/journal.pone.0144543
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Skilleter GA
中科院分区：
文献类型：
--
作者：
Fondo EN;Chaloupka M;Heymans JJ;Skilleter GA
粮食补贴有可能改变生态系统并影响商品和服务的提供。可预测的人为食品补贴（PAFS）通过改变生态过程和食物网来改变生态系统。全球对 PAFS 对生态系统影响的关注导致制定了旨在限制 PAFS 生产或最终禁止 PAFS 的环境政策。然而，减少或禁止 PAFS 的效果尚不清楚。我们探讨了两种情况下海洋生态系统中 PAFS 去除的后果：1）逐渐减少，或 2）突然禁止，使用质量平衡模型来检验这些假设——PAFS 的减少或丧失将：i）通过影响机会性物种的觅食来改变营养水平和食物网，ii）增加机会性物种对食物短缺的恢复力，以及 iii）通过猎物消费的变化改变捕食者与猎物的相互作用。我们发现 PAFS 降低了机会性食腐动物的营养水平并增加了它们的食物途径。当 PAFS 逐渐减少时，食腐动物能够转换猎物，但当 PAFS 突然禁止时，食腐动物的数量会减少。 PAFS 减少到某个最低水平会导致生态系统稳定性下降。我们建议逐步将 PAFS 减少到最低水平，以维持生态系统的稳定性，并使利用 PAFS 的物种习惯于粮食补贴的减少。
Food subsidies have the potential to modify ecosystems and affect the provision of goods and services. Predictable Anthropogenic Food Subsidies (PAFS) modify ecosystems by altering ecological processes and food webs. The global concern over the effects of PAFS in ecosystems has led to development of environmental policies aimed at curbing the production or ultimately banning of PAFS. However, the effects of reducing or banning PAFS are not known. We explore the consequences of PAFS removal in a marine ecosystem under two scenarios: 1) gradual reduction, or 2) an abrupt ban, using a mass balance model to test these hypotheses–The reduction or loss of PAFS will: i) modify trophic levels and food webs through effects on foraging by opportunistic species, ii) increase the resilience of opportunistic species to food shortages, and iii) modify predator–prey interactions through shifts in prey consumption. We found that PAFS lower the trophic levels of opportunistic scavengers and increase their food pathways. Scavengers are able to switch prey when PAFS are reduced gradually but they decline when PAFS are abruptly banned. PAFS reduction to a certain minimal level causes a drop in the ecosystem’s stability. We recommend gradual reduction of PAFS to a minimal level that would maintain the ecosystem’s stability and allow species exploiting PAFS to habituate to the food subsidy reduction.