Modeling the interactions between the seasonal and diel migration behaviors of Calanus finmarchicus and the circulation in the Gulf of St. Lawrence (Canada)

• Published in: Journal of Marine Systems
• Main Authors: Maps, Frederic, Zakardjian, Bruno, Plourde, Stephane, Saucier, Francois J.
• Other Authors: Laboratoire de sondages électromagnétiques de l'environnement terrestre (LSEET), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: Numerical modeling; Biological-physical coupling; Zooplankton; Diel vertical migrations; Ontogenetic migrations; Calanus finmarchicus; Atlantic; Gulf of St.-Lawrence; SPRING PHYTOPLANKTON BLOOM; DRIVEN COASTAL JET; NOVA-SCOTIA SHELF; VERTICAL MIGRATION; GASPE CURRENT; COPEPOD POPULATIONS; CLIMATE VARIABILITY; NORTHEAST ATLANTIC; NORTHWESTERN GULF; NORWEGIAN SEA; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Northeast Atlantic; Norwegian Sea
• Online Access: https://hal.science/hal-00704096; https://doi.org/10.1016/j.jmarsys.2011.04.004

The Gulf of St.-Lawrence (GSL) is a dynamic region supporting a productive pelagic ecosystem. This environment presents unique opportunities to study the interactions between the population dynamics of planktonic species and the variability of physical processes. The copepod Calanus finmarchicus is a dominant component of zooplankton biomass and abundance in the GSL We developed a 3-D coupled physical-biological numerical model in order to study the population dynamics of C. finmarchicus in the GSL for the year 1999. We coupled a life cycle model of C. finmarchicus representing the average properties of the population in terms of egg production, development, migration behavior and mortality to a regional circulation model driven by realistic atmospheric, hydrological and oceanic forcing. The distribution and abundance patterns of C. finmarchicus were sensitive to the migration behavior owing to the strong vertical and horizontal shears in the circulation. Both the timing of seasonal ontogenetic vertical migrations and the diel vertical migrations appeared to be essential to produce simulation results similar to the observations and to ensure the perennial presence of a local population in the GSL. (C) 2011 Elsevier B.V. All rights reserved.