Small pelagics in a changing ocean: biological responses of sardine early stages to warming.
Small pelagic fishes are known to respond rapidly to changes in ocean climate. In this study, we evaluate the effects of future environmental warming (+2°C) during the early ontogeny of the European sardine, Sardina pilchardus. Warming reduced the survival of 30-day-old larvae by half. Length at hatching increased with temperature as expected, but no significant effect was observed on the length and growth at 30 days post-hatching. Warming did not significantly affect the thermal tolerance of sardine larvae, even though the mean lethal temperature increased by 1°C. In the warm conditions, sardine larvae showed signs of thermal stress, indicated by a pronounced increase in larval metabolism (Q 10 = 7.9) and a 45% increase in the heat shock response. Lipid peroxidation was not significantly affected by the higher temperature, even though the mean value doubled. Warming did not affect the time larvae spent swimming, but decreased by 36% the frequency of prey attacks. Given the key role of these small pelagics in the trophic dynamics off the Western Iberian upwelling ecosystem, the negative effects of warming on the early stages may have important implications for fish recruitment and ecosystem structure.
MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências , Universidade de Lisboa, Laboratório Marítimo da Guia , Av. Nossa Senhora do Cabo 939, Cascais 2750-374 , Portugal.
Filipa
F
Faleiro
MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências, Universidade de Lisboa, Laboratório Marítimo da Guia, Av. Nossa Senhora do Cabo 939, Cascais 2750-374, Portugal; Instituto Ciências Biomédicas Abel Salazar, Universidade do Porto, Largo Prof. Abel Salazar 2, Porto 4099-003, Portugal.
Marta
M
Pimentel
MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências , Universidade de Lisboa, Laboratório Marítimo da Guia , Av. Nossa Senhora do Cabo 939, Cascais 2750-374 , Portugal.
Maria Rita
MR
Pegado
MARE - Marine and Environmental Sciences Centre , ISPA - Instituto Universitário , Rua Jardim do Tabaco 34, Lisboa 1149-041 , Portugal.
Regina
R
Bispo
MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências , Universidade de Lisboa, Laboratório Marítimo da Guia , Av. Nossa Senhora do Cabo 939, Cascais 2750-374 , Portugal.
Ana Rita
AR
Lopes
UCIBIO, REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia , Universidade NOVA de Lisboa , Quinta da Torre, Caparica 2829-516 , Portugal.
Mário S
MS
Diniz
MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências , Universidade de Lisboa, Laboratório Marítimo da Guia , Av. Nossa Senhora do Cabo 939, Cascais 2750-374 , Portugal.
Rui
R
Rosa
Heat shock response; Sardina pilchardus; lipid peroxidation; metabolism; ocean warming; thermal tolerance