Abstract

Fisheries enforcement relies on visual catch identification and quantification at sea or when landed. Silage (fish dissolved in acid) and fish blocks (block frozen fish) are promising methods for on-board processing and storage of low-value catches. We examined the use of non-destructive sampling and two DNA-based methods, quantitative PCR (qPCR) and metabarcoding, to assess species composition and relative abundance in industrial grade experimental silage and fish blocks. We demonstrate the ability to identify and quantify DNA from fish species in both products. qPCR analysis of small silage samples collected over 21 days detected all target control species. DNA from one species (Atlantic wolffish) was consistently overrepresented while, for three species of gadoids (Atlantic cod, haddock and whiting), the DNA content matched input tissue proportions with high accuracy. qPCR and metabarcoding of fish blocks, sampled as run-off water and exterior swabs, provided consistent species detection, with the highest variance observed in quantification from swab samples. Our analysis shows that DNA-based methods have significant potential as a tool for species identification and quantification of complex on-board-processed seafood products and are readily applicable to taxonomically and morphologically similar fish. There is, however, a need for establishing DNA/weight calibration factors for primary fisheries species.

中文翻译：

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从DNA到生物质：大宗渔业产品物种量化的机遇与挑战

摘要

渔业执法依靠海上或登陆时目视渔获物的识别和量化。青贮饲料（溶于酸的鱼）和鱼块（冷冻鱼块）是船上加工和储存低价值渔获物的有前途的方法。我们检查了非破坏性采样和两种基于DNA的方法（定量PCR（qPCR）和元条形码）的使用，以评估工业级实验青贮饲料和鱼块中的物种组成和相对丰度。我们展示了从两种产品中的鱼类物种鉴定和定量DNA的能力。对超过21天收集的小青贮饲料样品的qPCR分析检测到所有目标对照物种。来自一种物种（大西洋狼鱼）的DNA一直被高估，而对于三种类型的gadoids（大西洋鳕鱼，黑线鳕和鳕鱼），DNA含量与输入组织的比例高度匹配。鱼块的qPCR和metabarcoding（作为流水和外部拭子采样）提供了一致的物种检测，在拭子样品定量中观察到的变异最大。我们的分析表明，基于DNA的方法作为一种工具，可用于识别和量化复杂的船上加工海产品，具有巨大的潜力，并且很容易应用于分类学和形态相似的鱼。但是，需要为初级渔业物种建立DNA /重量校准因子。我们的分析表明，基于DNA的方法作为一种工具，可用于识别和量化复杂的船上加工海产品，具有巨大的潜力，并且很容易应用于分类学和形态相似的鱼。但是，需要为初级渔业物种建立DNA /重量校准因子。我们的分析表明，基于DNA的方法作为一种工具，可用于对复杂的船上加工海鲜产品进行物种识别和定量，并且很容易应用于分类学和形态相似的鱼。但是，需要为初级渔业物种建立DNA /重量校准因子。