A closer look into copepod’s morphology: in situ imaging reveals links with environment and marine heat waves

Within marine mesozooplankton communities, copepods are a key group both in terms of abundance and biomass, hence contributing to central ecological functions of aquatic ecosystems. Analyzing their morphological traits can provide valuable insight into ecosystem processes and relation with the environment that might otherwise go unnoticed. Imaging techniques are an increasingly used tool to sample the traits of mesozooplankton, and especially of copepods. In this study, we use in situ imaging from the Underwater Vision Profiler (UVP) to explore the relationship between copepod’s morphology and environmental conditions in the upwelling of the California Current Ecosystem (CCE). Over 4 years, from 2008 to 2016, morphological traits such as size, complexity, and transparency were measured from copepod’s images captured by the UVP deployed as part of the CCE-Long-Term Ecosystem Research. Our findings reveal that copepod’s size is linked with environmental seasonal variations, with larger copepods in fall, smaller in summer/spring and even smaller during a summer marine heatwave. Change of transparency also occurs during seasons, especially between spring and fall showing a significant relationship between copepod transparency and seasonal productivity. Interestingly, our results indicate more transparent copepods in the CCE are associated with higher carbon flux. By uncovering these morphological-environmental patterns, our study contributes to a better understanding of copepods’ roles in aquatic ecosystem functioning and consequences of environmental change on this group.

Presentation Preference: Oral

Primary Presenter: Rubén Tournier-Broer, Laboratoire d’Océanologie et Géosciences (LOG ) - Université du Littoral Côte d'Opale (ULCO) (ruben.tournier-broer@univ-littoral.fr)

Authors:

Rubén Tournier-Broer, Laboratoire d'Océanologie et de Géosciences, Université du Littoral Côte d'Opale, Université de Lille, CNRS, IRD, UMR 8187, Wimereux, France  (ruben.tournier-broer@univ-littoral.fr)

Tristan Biard, Laboratoire d'Océanologie et de Géosciences, Université du Littoral Côte d'Opale, Université de Lille, CNRS, IRD, UMR 8187, Wimereux, France  (tristan.biard@univ-littoral.fr)

Sakina Dorothée-Ayata, Sorbonne Université, CNRS, IRD, MNHN Laboratoire d'Océanographie et du Climat, Institut Pierre Simon Laplace, LOCEAN-IPSL, Paris, France  (sakina-dorothee.ayata@locean.ipsl.fr)