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Publication
Impacto de ruído antropogénico no desenvolvimento, sobrevivência e comportamento de estádios iniciais de corvina, Argyrosumus regius
Authors
Abstract(s)
A corvina (Argyrosumus regius) é um peixe vocal que utiliza o Estuário do Tejo, área com tráfego marinho intenso, como zona reprodutiva. Procurámos estudar o efeito da exposição a ruído de barco na sobrevivência e desenvolvimento de larvas, e no comportamento – nomeadamente aproximação e perseguição – de juvenis de corvina.
Para tal, expusemos ovos e larvas a tratamentos de ruído (playback de ruído de barco) ou de controlo (bobines produzindo um campo eletromagnético semelhante ao gerado pelas colunas) e analisámos as suas características morfométricas à eclosão e dois dias depois da eclosão (dph). Os resultados mostraram que existe impacto do ruído na gestão das reservas energéticas das larvas, que aumentaram o consumo da gota lipídica sob este stressor. Verificou-se, ainda, um condicionamento do desenvolvimento das larvas apresentando, aos 2dph, uma altura máxima de corpo inferior quando expostas a ruído de embarcação. Expusemos, ainda, juvenis a condições de tratamento e de controlo semelhantes, durante 2 ou 7 dias, analisando o seu comportamento antes e depois da alimentação. O rácio de aproximação pós/pré alimentação diminuiu do dia 2 ao 7 no grupo de ruído, mas aumentou no controlo, sugerindo uma influência negativa do ruído na sua estimulação social. Implicações destes resultados em estádios mais avançados ainda não foram investigados. Importa salientar que estes peixes provêm de ambiente de aquacultura onde o ruído é superior ao do ambiente natural. Estudos complementares com corvina selvagem podem contribuir para aprofundar o conhecimento atual, ajudando a compreender o impacto do ruído antropogénico nos estádios inicias da corvina.
Meagre (Argyrosumus regius) is a vocal fish that uses the Tagus estuary, an area with intense marine traffic, as breeding grounds. Here, we studied the effects of boat noise exposure on the development and survival of larvae, and on the behaviour – namely approach and pursuit – of meagre juveniles . We exposed eggs and larvae to either noise (boat noise playback) or control treatments (coils producing a similar electric field to the speakers) and analysed their morphometric characteristics at hatching and 2 days-post-hatching (dph). Our results showed an impact of boat noise playback on the management of energy reserves by meagre larvae, which increased their lipid droplet consumption when under this stressor. There was also a conditioning of their development illustrated by the smaller body depth achieved by larvae exposed to boat noise at 2 dph. We further exposed juveniles to similar treatment and control conditions and recorded their pre- and post-feeding behaviour after 2 and 7 days of exposure. Post/pre-feeding approach ratio decreased from day 2 to day 7 in the noise group but increased in the control, suggesting that the arousal or search behaviour with feeding is being affected by prolonged noise exposure. Whether these results have implications in later stages remains to be investigated. Also, tested fish were reared in an aquaculture facility, i.e. in a much noisier environment than the natural one. Further studies with wild meagre could help deepen this knowledge and give us a better understanding of how anthropogenic noise can impact meagre early stages.
Meagre (Argyrosumus regius) is a vocal fish that uses the Tagus estuary, an area with intense marine traffic, as breeding grounds. Here, we studied the effects of boat noise exposure on the development and survival of larvae, and on the behaviour – namely approach and pursuit – of meagre juveniles . We exposed eggs and larvae to either noise (boat noise playback) or control treatments (coils producing a similar electric field to the speakers) and analysed their morphometric characteristics at hatching and 2 days-post-hatching (dph). Our results showed an impact of boat noise playback on the management of energy reserves by meagre larvae, which increased their lipid droplet consumption when under this stressor. There was also a conditioning of their development illustrated by the smaller body depth achieved by larvae exposed to boat noise at 2 dph. We further exposed juveniles to similar treatment and control conditions and recorded their pre- and post-feeding behaviour after 2 and 7 days of exposure. Post/pre-feeding approach ratio decreased from day 2 to day 7 in the noise group but increased in the control, suggesting that the arousal or search behaviour with feeding is being affected by prolonged noise exposure. Whether these results have implications in later stages remains to be investigated. Also, tested fish were reared in an aquaculture facility, i.e. in a much noisier environment than the natural one. Further studies with wild meagre could help deepen this knowledge and give us a better understanding of how anthropogenic noise can impact meagre early stages.
Description
Dissertação de Mestrado apresentada no ISPA – Instituto Universitário para obtenção de grau de Mestre na especialidade de Biologia Marinha e Conservação
Keywords
Corvina Estadios iniciais Ruído antropogénico Morfologia Comportamento Meagre Anthropogenic noise Early life Morphology Behaviour