Stocked trout have minimal effects on littoral invertebrate assemblages of productive fish-bearing lakes: a whole-lake BACI study
Stocked trout have minimal effects on littoral invertebrate assemblages of productive fish-bearing lakes: a whole-lake BACI study
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DOI：
10.1111/fwb.12095
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发表时间：
2013-05-01
影响因子：
2.7
通讯作者：
Scrimgeour, Garry J.
中科院分区：
文献类型：
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作者：
Hanisch, Justin R.;Tonn, William M.;Scrimgeour, Garry J.
1.虹鳟鱼（Oncorhynchus mykiss [Walbaum]）通常作为运动鱼类在世界各地放养，但可能对本地物种产生严重的负面影响，特别是在源头系统中。生产性鱼类承载湖泊代表了一个经常放养但不经常研究的系统，鳟鱼在这些系统中的影响可能不同于那些在源头湖泊。2.在加拿大阿尔伯塔北部山麓地区，我们采用前-后控制-影响（BACI）设计，以确定放养鳟鱼对放养湖泊中沿岸的无脊椎动物的群落水平和分类水平生物量、丰度和平均长度的影响。在放养前1a和放养后2a对湖泊进行了研究。由于生产性鱼类承载湖泊的特点，应缓冲引进鱼类的影响，我们预测，鳟鱼不会影响组合水平结构的沿岸的无脊椎动物，但可能会减少丰度或平均长度的大型团体经常消耗鳟鱼。3.相对于未放养的控制湖泊，生物量，但不是丰度，的沿岸的无脊椎动物组合的鳟鱼间接影响，通过增加一些类群后鳟鱼放养。在个人分类层次上，鳟鱼放养没有影响大多数（27个）类群，放养后的丰度或生物量增加的四个类群。只有一个分类群，摇蚊科，显示出证据的大小选择性捕食鳟鱼，经常被消耗的鳟鱼和放养后的平均长度显着下降。4.我们的研究结果对比强烈的负面影响鳟鱼放养无脊椎动物群落通常报告从源头湖泊。综合因素，包括大型和强大的本地饲料鱼类种群，鳟鱼的一般饮食，越冬通风，相对较高的生产力和密集的大型植物床，可能会协同工作，以减少潜在的负面影响，在这些系统中的鳟鱼库存。因此，生产力，鱼轴承湖泊可能是一个合适的系统鳟鱼放养，特别是在本地运动鱼类种群缺乏。
1.Rainbow Trout (Oncorhynchus mykiss [Walbaum]) is commonly stocked as a sport fish throughout the world but can have serious negative effects on native species, especially in headwater systems. Productive fish-bearing lakes represent a frequently stocked yet infrequently studied system, and effects of trout in these systems may differ from those in headwater lakes. 2.We used a Before-After Control-Impact (BACI) design to determine how stocked trout affected assemblage-level and taxon-level biomass, abundance and average length of littoral invertebrates in a stocked lake relative to three unstocked control lakes in the boreal foothills of Alberta, Canada. Lakes were studied 1year before and for 2years after stocking. Because characteristics of productive fish-bearing lakes should buffer impacts of introduced fish, we predicted that trout would not affect assemblage-level structure of littoral invertebrates but might reduce the abundance or average length of large-bodied taxa frequently consumed by trout. 3.Relative to the unstocked control lakes, biomass, but not abundance, of the littoral invertebrate assemblage was affected indirectly by trout through increases of some taxa after trout stocking. At the individual taxon-level, trout stocking did not affect most (23 of the 27) taxa, with four taxa increasing in abundance or biomass after stocking. Only one taxon, Chironomidae, showed evidence of size-selective predation by trout, being consumed frequently by trout and decreasing significantly in average length after stocking. 4.Our results contrast with the strong negative effects of trout stocking on invertebrate assemblages commonly reported from headwater lakes. A combination of factors, including large and robust native populations of forage fish, the generalised diet of trout, overwinter aeration, relatively high productivity and dense macrophyte beds, likely works in concert to reduce potentially negative effects of stocked trout in these systems. As such, productive, fish-bearing lakes may represent a suitable system for trout stocking, especially where native sport fish populations are lacking.