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Publication
Insights for an ecological assessment of spiny and slipper lobsters in the Azores
Authors
Advisor(s)
Abstract(s)
A pesca comercial do Cavaco (Scyllarides latus) e da Lagosta (Palinurus elephas)
tem vindo sempre a crescer devido ao seu alto valor comercial, no entanto, não há muito
conhecimento sobre o estado destas duas espécies. Conhecer o estado das diferentes
espécies através de estudos de avaliação dos “stocks” pesqueiros é essencial para a
implementação de medidas de proteção mais eficazes, de forma a garantir uma exploração
sustentável. Desde 1985 que se sabe que a maioria das capturas destas espécies são
vendidas clandestinamente. O Cavaco está atualmente classificado como “Data
Deficient” na Lista Vermelha da IUCN, comprovando que os estudos sobre esta espécie
são escassos, e a Lagosta está classificada como “Vulnerável”. A determinação de um
tamanho mínimo legal de captura para estas espécies provou não ser efetiva em 1998,
contudo, nada foi alterado em termos de regulamentação desde essa data. Os últimos
estudos realizados nos Açores para S. latus foram há quase 40 anos, e já passou uma
década desde o último estudo sobre P. elephas.
Com este estudo pretende-se contribuir com nova informação para esclarecer o
estado das populações de S. latus e P. elephas nos Açores, comparando-o com os dados
históricos. Para tanto, foram analisados: os padrões de migração vertical para S. latus; os
tamanhos dos espécimes comparando profundidades e sexos; e os tamanhos médios das
populações ao longo dos anos, comprovando que o tamanho médio de P. elephas
diminuiu quase 1cm em 20 anos. Este conhecimento é essencial para alertar a população
e o governo para criar melhores medidas de regulação, a fim de cessar a depleção destas
espécies.
ABSTRACT: The commercial fishing of the Slipper lobster (Scyllarides latus) and the Spiny lobster (Palinurus elephas) has always been increasing, due to these species’ high commercial value, however, there is not much knowledge about their status. Getting to know the status of different species through studies on the assessment of fish stocks is essential for the implementation of better protection measures, to ensure a sustainable exploitation. Since 1985 that it is known that most catches of these species are sold clandestinely. The S. latus is currently classified as “Data deficient” on the IUCN Red List, proving that the studies on this species are scarce, and the P. elephas is classified as “Vulnereble”. The determination of a minimum legal capture size for these species has proven not to be effective in 1998, however, nothing has been changed in terms of regulations since then. The last studies conducted in the Azores for S. latus were almost 40 years ago, and a decade has passed since the last study on P. elephas. This study pretends to contribute with new information to enlighten the recent S. latus and P. elephas populations’ status in the Azores, comparing them to the historical data. For that, it was analyzed: the vertical migration patterns for S. latus; the specimens sizes comparing depths and sexes; and that the populations’ mean sizes through the years, proving that the P. elephas mean size has almost decreased 1cm in 20 years. This knowledge is essential to alert the population and the government to create better regulation measures, in order to cease these species depletion.
ABSTRACT: The commercial fishing of the Slipper lobster (Scyllarides latus) and the Spiny lobster (Palinurus elephas) has always been increasing, due to these species’ high commercial value, however, there is not much knowledge about their status. Getting to know the status of different species through studies on the assessment of fish stocks is essential for the implementation of better protection measures, to ensure a sustainable exploitation. Since 1985 that it is known that most catches of these species are sold clandestinely. The S. latus is currently classified as “Data deficient” on the IUCN Red List, proving that the studies on this species are scarce, and the P. elephas is classified as “Vulnereble”. The determination of a minimum legal capture size for these species has proven not to be effective in 1998, however, nothing has been changed in terms of regulations since then. The last studies conducted in the Azores for S. latus were almost 40 years ago, and a decade has passed since the last study on P. elephas. This study pretends to contribute with new information to enlighten the recent S. latus and P. elephas populations’ status in the Azores, comparing them to the historical data. For that, it was analyzed: the vertical migration patterns for S. latus; the specimens sizes comparing depths and sexes; and that the populations’ mean sizes through the years, proving that the P. elephas mean size has almost decreased 1cm in 20 years. This knowledge is essential to alert the population and the government to create better regulation measures, in order to cease these species depletion.
Description
Dissertação de Mestrado
apresentada no Ispa – Instituto
Universitário para obtenção de grau de
Mestre na especialidade de Biologia
Marinha e Conservação.
Keywords
Scyllarides latus Palinurus elephas Estado das populações Esgotamento e conservação do estoque Stock depletion and conservation