Integração da genómica nas pescarias de profundidade: avaliação da diversidade adaptativa e da estrutura populacional, para uma melhor compreensão do ciclo de vida do peixe-espada preto e para uma gestão baseada no conhecimento científico

Deep-sea fisheries suffer from a critical lack of information regarding species ecology, life cycles, population structures, and large-scale migrations. Traditional fisheries management relies on stock assessment models to predict variability in stock-recruitment relations to determine sustainable catch limits and for this, it is crucial to know species stock structure and life cycle. However, stocks are predominantly delimited based on administrative units, which are often not closely connected with population biology. This contradicts the basis of fisheries science whereby the maximum sustainable yield (MSY) can only be achieved by the efficient management of distinct populations. Although genetics offers more precise data, its integration into fisheries assessment remains scarce, with stock structure assessment currently relying predominantly on phenotypic traits. Recently, novel technologies have emerged replacing traditional genetic markers and allowing the collection of genome-wide data. But, like traditional genetic markers, these genomic tools are seldom used in the development of management policies. This innovative project leverages genomic tools to gather genome-wide data on one of the most important living marine resources in the NE Atlantic – the BSF. The issues highlighted in this proposal's description concerning the species prompt crucial questions. Through this project, we will answer these questions, shedding new light on key aspects, and contributing with upgraded scientific knowledge, which will improve the BSF’s assessment and advice. The questions posited are as follows: Q1: Are BSF and APH different or one single species? And, despite their apparent morphological similarity, their overlapped geographical range, depth distribution, and coincident spawning season and grounds, what intrinsic biological and/or environmental factors underlie their taxonomic divergence? Q2: How many populations/stocks does BSF form along its distribution area? Is there evidence to suggest a single, panmictic population wherein migratory behaviours balance population depletions, or does the BSF comprise multiple, discrete populations characterized by limited gene flow amongst them? Q3: Can we detect evidence of genomic associations with environmental variables within the species? What is the species’ adaptative response to the current environment and what are the environmental variables shaping its dynamics? And how will the species genomically respond to deep-sea environmental changes? In sum, the objectives of the APHANOMICS project, aimed at addressing the raised key questions are: 1) to understand whether BSF and APH are different species, and which are the underlying factors (environmental and/or biological) for this putative cryptic speciation; 2) to study the BSF (the most abundant species and the one assessed by ICES) population structure and unravel its life cycle and dynamics in the NE Atlantic; and 3) to identify the genomic responses of BSF to the current selective environmental pressures and its adaptive potential to the ongoing and future environmental changes. In pursuit of addressing these inquiries and fulfilling the project's objectives, an interactive and interdisciplinary 5-tasks methodology will be employed.