Recruiting at the edge: kinetic energy inhibits anchovy populations in the western Mediterranean

PLoS One. 2013;8(2):e55523. doi: 10.1371/journal.pone.0055523. Epub 2013 Feb 25.

Abstract

The Strait of Gibraltar replenishes the Mediterranean with Atlantic waters through an intense eastward current known as the Atlantic Jet (AJ). The AJ fertilizes the southwestern Mediterranean and is considered to be the ultimate factor responsible for the comparatively high fish production of this region. Here, we perform an analysis of the available historical catches and catch per unit effort (CPUE), together with a long series of surface currents, kinetic energy and chlorophyll concentration. We show that the high kinetic energy of the AJ increases primary production but also negatively impacts the recruitment of anchovy. We contend that anchovy recruitment in the region is inhibited by the advection and dispersion of larvae and post-larvae during periods of strong advection by the AJ. The inhibitory impact of kinetic energy on anchovy landings is not a transient but rather a persistent state of the system. An exceptional combination of events creates an outbreak of this species in the Alboran Sea. These events depend on the Mediterranean-Atlantic exchange of water masses and, therefore, are highly sensitive to climate changes that are projected, though not always negatively, for fish landings.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Environmental Monitoring / methods
  • Fishes / growth & development*
  • Mediterranean Sea
  • Population Dynamics*

Grants and funding

This work was supported by projects ECOKNOWS (FP7-244706), MEDEX (CTM2008-04036-E), PERSEUS (FP7-287600) and G2Coupling (CTM2011-22580). Margarita M. Rincón was funded by P09-RNM-5358 of the Junta de Andalucía. D. Macías was supported by a JaeDOC contract (X0SC000087) of the Spanish Science and Technology Council (CSIC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.