Genetics as a tool for sustainable fishing and protection of vulnerable marine ecosystems - VME

Abstract

Bottom trawling activities can alter significantly deep-water ecosystems, by degrading the seabed integrity and causing the depauperation of benthic biodiversity. Deep-sea environments are often characterized by fragile benthic biodiversity hotspots, known as vulnerable marine ecosystems (VMEs). These ecosystems show structural and functional fragility and include organisms that are unique or rare, with slow growth, large longevity and/or limited dispersion, which makes their recovery difficult when their habitats are altered. VMEs may be negatively affected by fishing, pollution and climate change, including rising water temperatures and ocean acidification. Many aggregations of deep-water corals and sponges are classified by the FAO as VMEs, since they host in their habitat a great biodiversity of epibenthic fauna that is fundamental for the general maintenance at the ecosystem level. The conservation and protection of these habitats requires detailed information on the distribution of VMEs but these are generally poorly described. The general objective of this study is the development of a non-invasive tool to detect and delineate the spatial distribution of VMEs, to ultimately protect them against fishing and develop strategies to prevent their damage. Our case study is focused in the Flemish Cap, Northwest Atlantic, where an annual research survey provides information on the ecosystem and the vulnerable benthic species living in the area. A total of 418 invertebrate samples, collected during the survey in 2022, were characterized using both, classical and molecular taxonomy based on two mitochondrial markers (COI and 16S rDNA). The resulting molecular barcodes are unique to each species inhabiting the ecosystem and served to create a complete and curated reference database to characterize VMEs in this region. The newly created database will help in the immediate future to recognize VME sites through non-invasive tools based on environmental DNA coupled with metabarcoding, providing a cost-effective, fast, and accurate tool to assess the presence, distribution and community composition of vulnerable ecosystems