TY - JOUR
T1 - Ecophysiological responses of juvenile seabass (Dicentrarchus labrax) exposed to increased temperature and dietary methylmercury
AU - Maulvault, Ana Luísa
AU - Barbosa, Vera
AU - Pinheiro-Alves, Ricardo
AU - Custódio, Ana
AU - Anacleto, Patrícia
AU - Repolho, Tiago
AU - Pousão-Ferreira, Pedro
AU - Rosa, Rui
AU - Marques, António
AU - Diniz, Mário
N1 - Sem PDF.
European Union Seventh Framework Programme under the ECsafeSEAFOOD project
(311820)
Fundacao para a Ciencia e Tecnologia (FCT), through the strategic project (UID/MAR/04292/2013)
PhD Grant (SFRH/BD/103569/2014)
post-PhD Grant (SFRH/BPD/100728/2014)
PY - 2017/5/15
Y1 - 2017/5/15
N2 - The ecotoxicological effects of methylmercury (MeHg) exposure have been intensively described in literature. Yet, it is still unclear how marine biota will respond to the presence of MeHg under climate change, namely ocean warming. The present study aimed to investigate, for the first time, fish condition [Fulton's K index (K), hepatosomatic index (HIS) and brain-to-body mass ratio (BB-ratio)] and several stress-related responses in an ecologically and commercially important fish species (Dicentrachus labrax) exposed for 28 days to dietary MeHg (8.0 mg kg-1 dw) and temperature increase (+ 4 °C). Results showed significant impairments on fish condition, i.e. up to 34% decrease on K, > 100% increase on HIS and 44% decrease on BB-ratio, compared to control conditions. Significant changes on tissue biochemical responses were observed in fish exposed to both stressors, acting alone or combined, evidencing the relevance of assessing possible interactions between different environmental stressors in ecotoxicological studies. For instance, muscle showed to be the least affected tissue, only revealing significant alterations in GST activity of MeHg-enriched fish. On the other hand, liver exhibited a significant induction of GST (> 100%) and CAT (up to 74%) in MeHg-enriched fish, regardless of temperature exposure, as well as decreased SOD activity (19%) and increased HSP70/HSC70 content (87%) in fish exposed to warming alone. Brain showed to be affected by temperature (69% of GST inhibition and > 100% of increased CAT activity), MeHg (> 100% of increased CAT activity, 47% of SOD inhibition and 55% of AChE inhibition), as well as by the combination of both (GST, SOD and AChE inhibition, 17%, 48% and 53%, respectively). Hence, our data provides evidences that the toxicological aspects of MeHg ca be potentiated by warmer temperatures, thus, evidencing the need for further research combining contaminants exposure and climate change effects, to better forecast ecological impacts in the ocean of tomorrow.
AB - The ecotoxicological effects of methylmercury (MeHg) exposure have been intensively described in literature. Yet, it is still unclear how marine biota will respond to the presence of MeHg under climate change, namely ocean warming. The present study aimed to investigate, for the first time, fish condition [Fulton's K index (K), hepatosomatic index (HIS) and brain-to-body mass ratio (BB-ratio)] and several stress-related responses in an ecologically and commercially important fish species (Dicentrachus labrax) exposed for 28 days to dietary MeHg (8.0 mg kg-1 dw) and temperature increase (+ 4 °C). Results showed significant impairments on fish condition, i.e. up to 34% decrease on K, > 100% increase on HIS and 44% decrease on BB-ratio, compared to control conditions. Significant changes on tissue biochemical responses were observed in fish exposed to both stressors, acting alone or combined, evidencing the relevance of assessing possible interactions between different environmental stressors in ecotoxicological studies. For instance, muscle showed to be the least affected tissue, only revealing significant alterations in GST activity of MeHg-enriched fish. On the other hand, liver exhibited a significant induction of GST (> 100%) and CAT (up to 74%) in MeHg-enriched fish, regardless of temperature exposure, as well as decreased SOD activity (19%) and increased HSP70/HSC70 content (87%) in fish exposed to warming alone. Brain showed to be affected by temperature (69% of GST inhibition and > 100% of increased CAT activity), MeHg (> 100% of increased CAT activity, 47% of SOD inhibition and 55% of AChE inhibition), as well as by the combination of both (GST, SOD and AChE inhibition, 17%, 48% and 53%, respectively). Hence, our data provides evidences that the toxicological aspects of MeHg ca be potentiated by warmer temperatures, thus, evidencing the need for further research combining contaminants exposure and climate change effects, to better forecast ecological impacts in the ocean of tomorrow.
KW - Animal condition
KW - Dietary MeHg
KW - Heat shock
KW - Neurotoxicity
KW - Oxidative stress
KW - Seawater warming
UR - http://www.scopus.com/inward/record.url?scp=85012927010&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2017.02.016
DO - 10.1016/j.scitotenv.2017.02.016
M3 - Article
C2 - 28216029
AN - SCOPUS:85012927010
SN - 0048-9697
VL - 586
SP - 551
EP - 558
JO - Science of the Total Environment
JF - Science of the Total Environment
ER -