From egg production to recruits: Connectivity and inter-annual variability in the recruitment patterns of European anchovy in the northwestern Mediterranean

• Published in: Progress in oceanography 2015-11, Vol.138, p.431-447
• Main Authors: Ospina-Alvarez, Andres, Catalán, Ignacio A., Bernal, Miguel, Roos, David, Palomera, Isabel
• Format: Article
• Language: English
• Subjects: Life Sciences
• ISSN: 0079-6611; 1873-4472
• DOI: 10.1016/j.pocean.2015.01.011

•Biological and ecological processes of European anchovy relevant to recruitment and connectivity are reviewed.•An egg and larval dispersal model was used to explore European anchovy connectivity in NW Mediterranean.•Rhône River plume plays an important role in the modulation of the spawning areas and late larval recruitment.•Indices from a dispersal model are coherent with existing recruitment proxies for European anchovy.•The use of recruitment indices from dispersal models open new possibilities for fisheries management. We show the application of a Spatially-Explicit Individual-Based Model (SEIBM) to understand the recruitment process of European anchovy. The SEIBM is applied to simulate the effects of inter-annual variability in parental population spawning behavior and intensity, and ocean dynamics, on the dispersal of eggs and larvae from the spawning area in the Gulf of Lions (GoL) towards the coastal nursery areas in the GoL and Catalan Sea (northwestern Mediterranean Sea). For each of seven years (2003–2009), we initialize the SEIBM with the real positions of anchovy eggs during the spawning peak, from an acoustics-derived eggs production model. We analyze the effect of spawners’ distribution, timing of spawning, and oceanographic conditions on the connectivity patterns, growth, dispersal distance and late-larval recruitment (14mm larva recruits, R14) patterns. The area of influence of the Rhône river plume was identified as having a high probability of larval recruitment success (64%), but up to 36% of R14 larvae end up in the Catalan Coast. We demonstrate that the spatial paths of larvae differ dramatically from year to year, and suggest potential offshore nursery grounds. We showed that our simulations are coherent with existing recruitment proxies and therefore open new possibilities for fisheries management.