Copepod functional traits and groups show divergent biogeographies in the global ocean

Abstract

Aim: To define global zooplankton functional groups (FGs) and to estimate their environmental niche and habitat distribution. We model the spatial patterns of copepod FGs habitat and identify regions sharing similar functional trait expression at the community level. Taxon: Marine planktonic Neocopepoda. Location: Global ocean. Methods: Factor analysis on mixed data and hierarchical clustering were used to identify copepod FGs based on five species-level functional traits. An ensemble of species distribution models was used to estimate the environmental niches of the modelled species, project the mean annual habitat suitability of the FGs, and to estimate the community weighted mean values of the traits studied. Ocean regions were defined based on their community-level mean trait expression using a principal component analysis and hierarchical clustering. Results: Eleven global copepod FGs were identified. They displayed contrasting latitudinal patterns in mean annual habitat suitability that could be explained by differences in environmental niche preferences: two FGs were associated with polar conditions, one followed the global temperature gradient, five were associated with tropical oligotrophic gyres, and the remaining three with boundary currents and counter currents. Four main regions of varying community weighted mean trait values emerged: the Southern Ocean, the northern and southern high latitudes, the tropical gyres, and the boundary currents and upwelling systems. Conclusions: We build on an exhaustive species trait dataset to put forward novel FGs that will improve the representation of zooplankton in global marine ecosystem models. Our results contribute to our understanding of the spatial patterns and drivers of marine plankton trait biogeography and will serve as a basis for studying the links between zooplankton biodiversity and ecosystem functioning and how they might evolve in the context of climate change.

The Spatial Distribution of Copepod Functional Traits in a Highly Anthropized Mediterranean Coastal Marine Region

“…Our results identified nine different functional groups, which differed in their spawning and feeding strategies and trophic habits. These groups have consistently been found in other studies conducted at both the regional [18,28] and global scales [17,19,65].…”

“…Transitional groups were established to separate species that, while being technically omnivorous, showed a relative preference for herbivory or detritivory [23]. Information on copepod functional traits was obtained from the literature [18,[63][64][65][66] and from the knowledge of experts in the field. Concerning the feeding strategy, three different categories have been considered: the ambush strategy, in which copepods encounter and intercept prey and capture them with active attacks; current feeding, in which copepods are able to generate a feeding current and convey prey to their mouth appendages; cruise feeding, in which copepods navigate through the water, catching individual prey [64].…”

Biodiversity patterns of epipelagic copepods in the South Pacific Ocean: Strengths and limitations of current data bases

“…These gradients in the water column structure may contribute to the generation of large-scale spatial trends in the distribution of organisms such as copepods [ 120 ]. Although this study did not separate copepods into functional groups according certain traits more specifically linked to environmental variations, the fact that composition changed mainly due to oceanographic factors that influence the nesting of functional groups, highlights and support those findings [ 121 ], as beta diversity is a proxy of difference in number of species among ecosystems, thus reflecting changes or gradients in the environment as well.…”

Trait-based approach revealed the seasonal variation of mesozooplankton functional groups in the South Yellow Sea

“…Although size is the master trait of an organism, relying on it alone will definitely oversimplify the community functions and ecosystem responses (Flynn et al 2015). As identified in several modeling studies, in the context of global biogeography and biogeochemical cycles under climate change, simultaneously considering multiple traits in modeling is crucial to clarifying the contribution of species and identifying the environmental determinants (e.g., Benedetti et al 2022;Prowe et al 2012). Therefore, investigating the link between zooplankton diversity and ecosystem function using a trait-based approach will improve the representation of zooplankton in global marine ecosystem models and enhance the model predictability and interpretation.…”