Spatial heterogeneity of Pelagia noctiluca ephyrae linked to water masses in the Western Mediterranean

PLoS One. 2021 Apr 7;16(4):e0249756. doi: 10.1371/journal.pone.0249756. eCollection 2021.

Abstract

Pelagia noctiluca is the most common jellyfish in the Western Mediterranean Sea, living in oceanic waters with a holoplanktonic lifecycle. Frequent outbreaks have been well documented in coastal areas, yet little is known about their offshore distribution. In this study we address the relationship between oceanographic structures and the distribution of P. noctiluca ephyrae along the central continental slope of the Western Mediterranean, covering a wide latitudinal gradient, during July-August 2016. The region is characterized by a rich and complex mesoscale surface circulation driven by the inflow of Atlantic Water into the Western Mediterranean through the Strait of Gibraltar. The results revealed a high variability in the ephyrae spatial paterns related with different water masses and the resulting mesoscale hydrographic features. Their horizontal distribution showed a clear latitudinal gradient with high abundances in the south, associated with recent Atlantic Water, and low abundances or absence in the north, in coincidence with the old Atlantic Water transported by the Northern Current. Ephyrae showed diel vertical migrations of short-extent in the first 50 m, with a wide distribution above the thermocline and the Deep Chlorophyll Maximum during daytime, being more concentrated towards the surface at night. The results suggest the population connectivity of P. noctiluca between the Atlantic and the Mediterranean. In that case, the abundance variability of the species in the Mediterranean could be modulated by its entrance associated with the inflow of Atlantic Water through the Strait of Gibraltar.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Gibraltar
  • Mediterranean Sea
  • Scyphozoa / physiology*
  • Water / chemistry*

Substances

  • Water

Grants and funding

This research was supported by the projects CONECTA (CTM2014-54648-C2-1-R) and WINFISH (CTM2015-68543-R) funded by the Spanish Ministry of Economy and Competitiveness. MP-P and MC were supported by a predoctoral fellowship (FPU16/06794 and FPU2015/04339, respectively) from the Spanish Ministry of Education, Culture and Sport. The publication fee was partially supported by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript”.