TY - JOUR
T1 - Exploring the future of the Coral Sea micronekton
AU - Receveur, Aurore
AU - Dutheil, Cyril
AU - Gorgues, Thomas
AU - Menkes, Christophe
AU - Lengaigne, Matthieu
AU - Nicol, Simon
AU - Lehodey, Patrick
AU - Allain, Valerie
AU - Menard, Frederic
AU - Lebourges-Dhaussy, Anne
N1 - Funding Information:
This document has been produced with the financial assistance of the European Union. The contents of this document are the sole responsibility of A. Receveur and can under no circumstance be regarded as reflecting the position of European Union. We thank R/V ALIS officers and crews and science parties who participated to the cruises which data are included in the present paper. This work was supported by the French national program LEFE/INSU.
Publisher Copyright:
© 2021
PY - 2021/7
Y1 - 2021/7
N2 - Ecosystem models forced by future climate simulations outputs from the Coupled Model Intercomparison Project Phase 5 (CMIP5) simulate a substantial decline of tropical marine animal biomass over the course of the 21st century. Regional projections are however far more uncertain because of well-known biases common to most CMIP5 historical simulations that propagate within the food web. Moreover, the model outputs for high trophic levels marine fauna suffer from lack of validation based on in situ data. In this study, we implement a “bias-mitigation” strategy to reduce the physical oceanography and biogeochemical biases simulated by three CMIP5 models under the future RCP8.5 scenario. We force two very different micronekton models with these “bias-mitigated” outputs to infer the future micronekton changes in the Coral Sea: a 3-D deterministic population dynamics model; and a 3-D statistical model based on in situ hydro-acoustic data. These two models forecast a consistent pattern of micronekton abundance changes in the epipelagic layer (0–150 m) by 2100 for three different climate forcing used, with a marked decrease south of 22°S and a smaller increase further north mostly related to temperature and chlorophyll changes. In contrast, changes in the vertical patterns of micronekton predicted by the two models considerably differ in the upper mesopelagic layers (150–450 m) and lower mesopelagic layer (450–1000 m), highlighting the structural sensitivity in model type. Since micronekton are prey of all larger marine predators, those discrepancies in vertical structures of micronekton may hamper our potential to predict how top predators may evolve in the future.
AB - Ecosystem models forced by future climate simulations outputs from the Coupled Model Intercomparison Project Phase 5 (CMIP5) simulate a substantial decline of tropical marine animal biomass over the course of the 21st century. Regional projections are however far more uncertain because of well-known biases common to most CMIP5 historical simulations that propagate within the food web. Moreover, the model outputs for high trophic levels marine fauna suffer from lack of validation based on in situ data. In this study, we implement a “bias-mitigation” strategy to reduce the physical oceanography and biogeochemical biases simulated by three CMIP5 models under the future RCP8.5 scenario. We force two very different micronekton models with these “bias-mitigated” outputs to infer the future micronekton changes in the Coral Sea: a 3-D deterministic population dynamics model; and a 3-D statistical model based on in situ hydro-acoustic data. These two models forecast a consistent pattern of micronekton abundance changes in the epipelagic layer (0–150 m) by 2100 for three different climate forcing used, with a marked decrease south of 22°S and a smaller increase further north mostly related to temperature and chlorophyll changes. In contrast, changes in the vertical patterns of micronekton predicted by the two models considerably differ in the upper mesopelagic layers (150–450 m) and lower mesopelagic layer (450–1000 m), highlighting the structural sensitivity in model type. Since micronekton are prey of all larger marine predators, those discrepancies in vertical structures of micronekton may hamper our potential to predict how top predators may evolve in the future.
KW - Climate change
KW - Coral Sea
KW - Dynamical ecosystem model
KW - Echosounder
KW - Micronekton
KW - Statistical ecosystem model
UR - http://www.scopus.com/inward/record.url?scp=85105891965&partnerID=8YFLogxK
U2 - 10.1016/j.pocean.2021.102593
DO - 10.1016/j.pocean.2021.102593
M3 - Article
AN - SCOPUS:85105891965
SN - 0079-6611
VL - 195
SP - 1
EP - 13
JO - Progress in Oceanography
JF - Progress in Oceanography
M1 - 102593
ER -