Large-scale ocean connectivity and planktonic body size

Abstract

Global patterns of planktonic diversity are mainly determined by the dispersal of propagules with ocean currents. However, the role that abundance and body size play in determining spatial patterns of diversity remains unclear. Here we analyse spatial community structure - β-diversity - for several planktonic and nektonic organisms from prokaryotes to small mesopelagic fishes collected during the Malaspina 2010 Expedition. β-diversity was compared to surface ocean transit times derived from a global circulation model, revealing a significant negative relationship that is stronger than environmental differences. Estimated dispersal scales for different groups show a negative correlation with body size, where less abundant large-bodied communities have significantly shorter dispersal scales and larger species spatial turnover rates than more abundant small-bodied plankton. Our results confirm that the dispersal scale of planktonic and micro-nektonic organisms is determined by local abundance, which scales with body size, ultimately setting global spatial patterns of diversity.

Biodiversity assessment of tropical shelf eukaryotic communities via pelagic eDNA metabarcoding

“…Additionally, when using COI as a metabarcoding marker, particularly when applied to samples containing highly complex signals, false-negative detection errors are likely to occur. Conversely, the number of species (MOTUs) will often be overestimated due to the detection of pseudogenes, such as "numts," nuclear sequences of mitochondrial origin (Bensasson, Zhang, Hartl, & Hewitt, 2001;Vamos, Elbrecht, & Leese, 2017) studies have been adapting their strategy concerning the detection of community structure with single-assay studies, and instead opt to include multiple assays to improve detection probability, in order to provide an improved approximation of eukaryotic community diversity, derived from eDNA samples (Djurhuus et al, 2018;Günther et al, 2018;Stat et al, 2017;Villarino et al, 2018). These studies aim to overcome the occurrence of false negatives due to primer bias, at the expense of the potential for quantitative inference, so that only presence/absence methods can be used in downstream analyses.…”

“…DNA-based methods are revolutionizing the analysis of biodiversity, as they offer advantages over traditional, visual, and morphological survey methods (Thomsen &Willerslev, 2015). Accordingly, eDNA metabarcoding approaches have been successfully employed to characterize specific marine plankton communities in natural seawater samples, such as zooplankton, mesozooplankton, and full eukaryotic plankton diversity (Chain, Brown, MacIsaac, & Cristescu, 2016;Deagle, Clarke, Kitchener, Polanowski, & Davidson, 2017;de Vargas et al, 2015;Djurhuus et al, 2018;López-escardó et al, 2018;Villarino et al, 2018), as well as benthic communities from both soft (Guardiola et al, 2015;Lejzerowicz et al, 2015;Pawlowski, Esling, Lejzerowicz, Cedhagen, & Wilding, 2014) and hard (Leray & Knowlton, 2015;Wangensteen, Cebrian, Palacín, & Turon, 2018;Wangensteen, Palacín, Guardiola, & Turon, 2018) bottom habitats.…”

Ocean current connectivity propelling the secondary spread of a marine invasive comb jelly across western Eurasia

“…However, it has also been shown that ocean currents are essential for the transport, hence for connectivity of marine plankton organisms from differing subpopulations (Gaylord & Gaines, 2000) at regional (Grosholz, 1996;Wasson, Zabin, Bedinger, Diaz, & Pearse, 2001) and global scales (Dawson, Sen Gupta, & England, 2005;Van Gennip et al, 2017;Villarino et al, 2018;Wood, Paris, Ridgwell, & Hendy, 2014). Therefore, transport via ocean currents should also be considered for the dispersal of invasive species (Grosholz, 1996;Wasson et al, 2001), as documented for lionfish in the Caribbean (Cowen, Paris, & Srinivasan, 2006;Johnston & Purkis, 2011).…”

Diversity patterns of marine heterotrophic culturable bacteria along vertical and latitudinal gradients

“…Indeed, dispersal limitation tends to increase with body size in planktonic communities [62,63,65]. Due to the significant overlap between photic, OMZ and bathypelagic isolates, mainly those affiliating to genera Alteromonas, Halomonas, Marinobacter and Erythrobacter, our results suggest that these heterotrophic bacteria are well adapted to live in both environments (photic and aphotic), and therefore adapted to different temperatures, light and pressure.…”

“…Small-sized planktonic organisms, such as the prokaryotes, are expected to have a great capacity of dispersion [61][62][63], more than those of larger planktonic organisms [63,64].…”