Assessing the impact of the threatened crucian carp (Carassius carassius) on pond invertebrate diversity: A comparison of conventional and molecular tools
Assessing the impact of the threatened crucian carp (Carassius carassius) on pond invertebrate diversity: A comparison of conventional and molecular tools
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DOI：
10.1111/mec.15670
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发表时间：
2020-10-24
影响因子：
4.9
通讯作者：
Hanfling, Bernd
中科院分区：
文献类型：
--
作者：
Harper, Lynsey R.;Lawson Handley, Lori;Hanfling, Bernd
为娱乐和垂钓而放养的鱼类可能会破坏淡水栖息地，并对生物多样性产生负面影响。池塘相关的鲫鱼(Carassius Carassius)在整个欧洲都很罕见，在英国被放养进行保护管理，但它对池塘生物群的影响还没有得到充分的研究。淡水无脊椎动物对水生生物多样性有很大贡献，包括许多稀有和特有物种，但它们的小体型和高丰度使它们的评估变得复杂。从业者使用了扫网和用显微镜进行踢采样(形态分类学)，但标本的大小/质量和经验可能会对鉴定产生偏见。DNA和环境DNA(EDNA)变位编码为无脊椎动物评估提供了替代手段。采用形态分类鉴定、DNA后置生物编码和EDNA后置生物编码等方法，比较了养银鱼和不养银鱼池塘(N=18)的无脊椎动物多样性。每个池塘采集5个2L水样和3min扫网水样。比较了网状样品的形态分类鉴定、大块组织样品的DNA代谢编码和水样的Edna代谢编码产生的清单。DNA或Edna变位编码的Alpha多样性最大，这取决于考虑的是标准方法还是无偏方法。DNA代谢编码反映了形态分类鉴定，而Edna代谢编码产生了明显不同的群落。这些补充工具应该结合起来，进行全面的无脊椎动物评估。鲫鱼的存在极小地减少了池塘中的α多样性，但通过分类单元的更替对β多样性产生了积极的影响(即，有鲫鱼的池塘包含不同的无脊椎动物和无鱼的池塘)。鲫鱼的存在有助于景观规模的无脊椎动物多样性，支持英格兰持续的保护管理。我们的结果表明，分子工具可以加强淡水无脊椎动物的评估，并有助于制定更准确和生态有效的池塘管理策略。
Fishes stocked for recreation and angling can damage freshwater habitats and negatively impact biodiversity. The pond-associated crucian carp (Carassius carassius) is rare across Europe and is stocked for conservation management in England, but its impacts on pond biota are understudied. Freshwater invertebrates contribute substantially to aquatic biodiversity, encompassing many rare and endemic species, but their small size and high abundance complicate their assessment. Practitioners have employed sweep-netting and kick-sampling with microscopy (morphotaxonomy), but specimen size/quality and experience can bias identification. DNA and environmental DNA (eDNA) metabarcoding offer alternative means of invertebrate assessment. We compared invertebrate diversity in ponds (N = 18) with and without crucian carp using morphotaxonomic identification, DNA metabarcoding and eDNA metabarcoding. Five 2L water samples and 3min sweep-net samples were collected at each pond. Inventories produced by morphotaxonomic identification of netted samples, DNA metabarcoding of bulk tissue samples and eDNA metabarcoding of water samples were compared. Alpha diversity was greatest with DNA or eDNA metabarcoding, depending on whether standard or unbiased methods were considered. DNA metabarcoding reflected morphotaxonomic identification, whereas eDNA metabarcoding produced markedly different communities. These complementary tools should be combined for comprehensive invertebrate assessment. Crucian carp presence minimally reduced alpha diversity in ponds, but positively influenced beta diversity through taxon turnover (i.e., ponds with crucian carp contained different invertebrates to fishless ponds). Crucian carp presence contributes to landscape-scale invertebrate diversity, supporting continued conservation management in England. Our results show that molecular tools can enhance freshwater invertebrate assessment and facilitate development of more accurate and ecologically effective pond management strategies.