Local ecological knowledge of vulnerable marine ecosystems of the Portuguese mainland continental shelf and upper slope

• Autor(a) principal: Soares, Ana Sofia Carvalho
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/33509
• topic: Fishers’ perceptions; Bottom fisheries; Sponges and corals; Species distributions; Mesophotic; Deep-sea

Sponges and corals form highly structured and vulnerable marine ecosystems (VMEs) that serve as refuge areas and feeding grounds for many marine species. Knowledge on the distribution of these VMEs is critical to ensure their sustainable management and conservation but is largely lacking in some areas. This study aimed to co-develop a knowledge baseline on the diversity and distribution of VME-indicator species (VMEIs) by assembling Local Ecological Knowledge (LEK) of professional fishers operating bottom-contacting gears in mainland North and Central Portugal. In total, 70 fishermen of commercial vessels (trawlers, gill- and trammel netters and bottom longliners) were interviewed in three fishing harbours (Póvoa de Varzim, Matosinhos, Aveiro). We assessed fishers’ LEK, by asking them to identify species from a catalogue, and provide information on their geographical and bathymetric distribution, and abundance. In total, 54 species in the catalogue were recognised by the fishermen, of which 33 are currently classified as indicators of various VME habitat types such as cold-water coral reefs, coral gardens, seapen fields and deep-sea sponge aggregations. The framework-forming scleractinian corals Dendrophyllia cornigera, Lophelia pertusa, Dendrophyllia ramea, alongside the soft coral Callogorgia verticillata, the red Corallium rubrum and the hydrocoral Errina dabneyi were the species most commonly recognised. Sponges were only occasionally recognised but among these, rock sponges (Neochrammeniella bowerbankii and Neophrissospongia nolitangere) and other demospongiae (Axinella infundibuliformis and Cliona celata) were the ones fishermen recognised most. The higher average number of species recognised by fishermen using gill-/trammel nets vs trawls reflects the communities associated with the type of seafloor (hard vs soft substrate) over which these two fleets operate. Level of fishing experience and role onboard doesn’t seem to influence their LEK. This study shows the immense potential of LEK as a tool for the possible precense of vulnerable marine ecosystems and provides a framework that could play an important role in the identification and codevelopment of area-based management tools (e.g., designation of MPAs), and other effective conservation measures (e.g., bottom-fisheries closures and move-on rule protocols). It could also inform potential restoration activities where these habitats may have been impacted. Ensuring that fishing communities are directly involved in these processes is likely to result in better management outcomes.