Do trophic subsidies affect the outcome of introductions of a non-native freshwater fish?
Do trophic subsidies affect the outcome of introductions of a non-native freshwater fish?
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DOI：
10.1111/fwb.12197
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发表时间：
2013-10-01
影响因子：
2.7
通讯作者：
Britton, J. Robert
中科院分区：
文献类型：
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作者：
Jackson, Michelle C.;Allen, Rachel;Britton, J. Robert
1. 了解环境变量和人为干扰如何影响引进非本地淡水鱼的结果是其风险管理不可或缺的一部分。这在获得增加粮食供应补贴的淡水生态系统中可能是复杂的，因为这些补贴可能通过增加引进繁殖体获得粮食资源的机会来促进它们的生存、繁殖和建立，从而影响引进的结果。我们确定了自然和/或人工营养补贴如何影响复制池塘中游生态系统中引进的上嘴鲟（Pseudorasbora parva）的繁殖和建立。所有的中子代都是从8条成熟鱼开始，在繁殖季节运行100天。补贴包括天然陆地猎物和/或鱼粉颗粒（一种常见的营养补贴，在用作运动渔业或水产养殖的系统中可能很重要）。100天后，自然补助池中的鱼生长缓慢，繁殖产量极低。δ C-13和δ N-15的分析表明，它们在池塘中产生的后代0+鱼以陆地猎物为食。相比之下，添加颗粒的池塘矿质养分有效性和初级产量显著提高，成熟鱼主要以水生资源为食。池塘生产力的提高显著提高了鱼类的生长和适应性，导致大量的0+个体以颗粒为食。因此，可以增加初级生产和粮食资源（如颗粒鱼粉）的补贴可以显著影响殖民者迅速建立种群的能力。因此，尽量减少引进风险的管理工作应考虑到这类外来补贴的作用。
1. Understanding how environmental variables and human disturbances influence the outcomes of introductions of non-native freshwater fish is integral to their risk management. This can be complex in freshwater ecosystems that receive subsidies that increase food availability, as these may influence the outcome of introductions through promoting the survival, reproduction and establishment of the introduced propagules through increasing their access to food resources.2. We determined how natural and/or artificial trophic subsidies affected the reproduction and establishment of the introduced topmouth gudgeon (Pseudorasbora parva) in replicated pond mesocosms. The mesocosms all started with eight mature fish and were run for 100days during their reproductive season. The subsidies consisted of natural terrestrial prey and/or fishmeal pellets (a common trophic subsidy that can be significant in systems that are used as sport fisheries or for aquaculture).3. After 100days, fish in the natural subsidy ponds showed minimal growth and very low reproductive output. Analysis of delta C-13 and delta N-15 indicated that their progeny, 0+ fish produced in the ponds, exploited the terrestrial prey. By contrast, in ponds where pellets were added, mineral nutrient availability and primary production were significantly increased, and the mature fish fed mainly on the aquatic resources. The increased productivity of the ponds significantly increased fish growth and fitness, resulting in high numbers of 0+ individuals that did feed on the pellets.4. Thus, subsidies that can increase both primary production and food resources (such as pelletised fishmeal) can significantly influence the ability of colonists to establish a population rapidly. Management efforts to minimise the risk of introductions should thus consider the role of these types of allochthonous subsidies.