title: Early-life exposure to climate change impairs tropical shark survival.
abstract: Sharks are one of the most threatened groups of marine animals worldwide, mostly owing to overfishing and habitat degradation/loss. Although these cartilaginous fish have evolved to fill many ecological niches across a wide range of habitats, they have limited capability to rapidly adapt to human-induced changes in their environments. Contrary to global warming, ocean acidification was not considered as a direct climate-related threat to sharks. Here we show, for the first time, that an early ontogenetic acclimation process of a tropical shark (Chiloscyllium punctatum) to the projected scenarios of ocean acidification (ΔpH = 0.5) and warming (+4°C; 30°C) for 2100 elicited significant impairments on juvenile shark condition and survival. The mortality of shark embryos at the present-day thermal scenarios was 0% both at normocapnic and hypercapnic conditions. Yet routine metabolic rates (RMRs) were significantly affected by temperature, pH and embryonic stage. Immediately after hatching, the Fulton condition of juvenile bamboo sharks was significantly different in individuals that experienced future warming and hypercapnia; 30 days after hatching, survival rapidly declined in individuals experiencing both ocean warming and acidification (up to 44%). The RMR of juvenile sharks was also significantly affected by temperature and pH. The impact of low pH on ventilation rates was significant only under the higher thermal scenario. This study highlights the need of experimental-based risk assessments of sharks to climate change. In other words, it is critical to directly assess risk and vulnerability of sharks to ocean acidification and warming, and such effort can ultimately help managers and policy-makers to take proactive measures targeting most endangered species.
authors.affiliation: Faculdade de Ciências da Universidade de Lisboa, Laboratório Marítimo da Guia, Centro de Oceanografia, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais, Portugal rrosa@fc.ul.pt.
authors.forename: Rui
authors.initials: R
authors.lastname: Rosa
authors.affiliation: Faculdade de Ciências da Universidade de Lisboa, Laboratório Marítimo da Guia, Centro de Oceanografia, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais, Portugal.
authors.forename: Miguel
authors.initials: M
authors.lastname: Baptista
authors.affiliation: Faculdade de Ciências da Universidade de Lisboa, Laboratório Marítimo da Guia, Centro de Oceanografia, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais, Portugal.
authors.forename: Vanessa M
authors.initials: VM
authors.lastname: Lopes
authors.affiliation: Faculdade de Ciências da Universidade de Lisboa, Laboratório Marítimo da Guia, Centro de Oceanografia, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais, Portugal.
authors.forename: Maria Rita
authors.initials: MR
authors.lastname: Pegado
authors.affiliation: Faculdade de Ciências da Universidade de Lisboa, Laboratório Marítimo da Guia, Centro de Oceanografia, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais, Portugal.
authors.forename: José Ricardo
authors.initials: JR
authors.lastname: Paula
authors.affiliation: Faculdade de Ciências da Universidade de Lisboa, Laboratório Marítimo da Guia, Centro de Oceanografia, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais, Portugal.
authors.forename: Katja
authors.initials: K
authors.lastname: Trübenbach
authors.affiliation: Departamento de Biologia and CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal Skidaway Institute of Oceanography, 10 Ocean Science Circle, 31411 Savannah, GA 31411, USA.
authors.forename: Miguel Costa
authors.initials: MC
authors.lastname: Leal
authors.affiliation: Departamento de Biologia and CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Calado
authors.affiliation: Faculdade de Ciências da Universidade de Lisboa, Laboratório Marítimo da Guia, Centro de Oceanografia, Av. Nossa Senhora do Cabo, 939, 2750-374 Cascais, Portugal.
authors.forename: Tiago
authors.initials: T
authors.lastname: Repolho
mesh_terms: D000064:Acclimatization; D000818:Animals; D057231:Climate Change; D057232:Global Warming; D006863:Hydrogen-Ion Concentration; D009792:Oceans and Seas; D012623:Seawater / Q000737:chemistry*; D012754:Sharks / Q000196:embryology / Q000235:genetics* / Q000502:physiology; D014329:Tropical Climate
keywords: climate change; early ontogeny; sharks