Freshwater mussels alter fish distributions through habitat modifications at fine spatial scales
Freshwater mussels alter fish distributions through habitat modifications at fine spatial scales
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DOI：
10.1086/705666
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发表时间：
2019-09
影响因子：
1.8
通讯作者：
Garrett W. Hopper;Traci P. Dubose;K. Gido;C. Vaughn
中科院分区：
文献类型：
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作者：
Garrett W. Hopper;Traci P. Dubose;K. Gido;C. Vaughn
淡水贻贝聚集形成的斑块可以通过直接改变栖息地或通过营养物质排泄和生物沉积间接刺激营养资源，从而使其他生物受益。废壳和活贻贝的壳通过为捕食者提供庇护和增加栖息地的异质性，增加了底栖生物环境的复杂性。综合起来，这些因素可以提高贻贝生物量高的斑块的初级生产力和大型无脊椎动物的丰度，为某些鱼类提供宝贵的补贴并影响它们的分布。我们进行了一项为期12周的野外实验，以测试贻贝床内的鱼类分布是否受到与活贻贝相关的补贴或贝壳生物栖息地的最大影响。我们使用远程水下视频记录来量化50个0.25平方米的实验围栏中鱼类的数量，这些围栏中有活贻贝（2种组合）、假贻贝（充满沙子的贝壳）或沉积物。藻类和底栖大型无脊椎动物的生物量随时间增加，但不受处理的影响。我们在活贻贝和假处理中检测到的鱼比在只有沉积物的处理中检测到的鱼更多，但在活贻贝和假处理中没有发现差异。因此，贻贝壳提供的栖息地可能是与贻贝共生的鱼类的主要利益。鱼类和贻贝之间的时空重叠增加可能会加强生态系统效应，如营养循环，以及鱼类和贻贝在淡水生态系统中的作用。
Aggregations of freshwater mussels create patches that can benefit other organisms through direct habitat alterations or indirect stimulation of trophic resources via nutrient excretion and biodeposition. Spent shells and the shells of living mussels add complexity to benthic environments by providing shelter from predators and increasing habitat heterogeneity. Combined, these factors can increase primary productivity and macroinvertebrate abundance in patches where mussel biomass is high, providing valuable subsidies for some fishes and influencing their distributions. We performed a 12-wk field experiment to test whether fish distributions within mussel beds were most influenced by the presence of subsidies associated with live mussels or the biogenic habitat of shells. We used remote underwater video recordings to quantify fish occurrences at fifty 0.25-m2 experimental enclosures stocked with either live mussels (2-species assemblages), sham mussels (shells filled with sand), or sediment only. The biomass of algae and benthic macroinvertebrates increased over time but were uninfluenced by treatment. We detected more fish in live mussel and sham treatments than in the sediment-only treatment but found no difference between live mussel and sham treatments. Thus, habitat provided by mussel shells may be the primary benefit to fishes that co-occur with mussels. Increased spatiotemporal overlap between fish and mussels might strengthen ecosystem effects, such as nutrient cycling, and the role of both fish and mussels in freshwater ecosystems.