Environmental migratory patterns and stock identification of Mugil cephalus in the Spanish Mediterranean Sea, by means of otolith microchemistry

CALLICÓ FORTUNATO, ROBERTA; VOLPEDO, ALEJANDRA; GARCÍA ALONSO, IGNACIO; BENEDITO DURA, VICENT; REGUERA GALÁN, AIDA; BENEDITO DURA, VICENT

ESTUARINE COASTAL AND SHELF SCIENCE

ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2017 vol. 188 p. 174 - 180

0272-7714

The Flathead grey mullet, Mugil cephalus is the most worldwide distributed Mugilidae species. Migrations and movement patterns have been studied globally but not in-depth in the Mediterranean region. Thus, two main objectives were set out in the present study: (1) to identify migratory patterns throughout the life-history of the Mugil cephalus in different Spanish Mediterranean wetlands, and (2) to study the presence of potential fish stocks of the species in the region; using otolith microchemistry as a tool of choice. Specimens (n = 43) were obtained in three wetlands: Parque Natural Delta de l?Ebro (DE), a stratified estuary; Parque Natural de l?Albufera de Valencia (AV), a Mediterranean lake; and Parque Natural Salinas de Santa Pola (SP), a coastal salt marsh. Otolith microchemistry was studied using LA-ICP-MS (chronological variation of Sr:Ca and Ba:Ca ratios). The analysis of lifetime profiles revealed four behavioral patterns: Type I: most frequent use of estuarine environments (estuarine resident); Type II: freshwater behaviour during early life history, moving though estuarine to marine waters at the end of their profile (freshwater migrant); Type III: estuarine water use in early life stages moving then towards sea waters (estuarine migrant); and Type IV: sea/high salinity water habitat use during their entire lifetime (seawater resident). A Canonical Discriminant Analysis, using Sr:Ca and Ba:Ca ratios from core and edge as variables, assigned individuals to the detected patterns with high accuracy (Type I > 95%; Type II and Type III > 83%; and Type IV > 88%). Moreover, two potential fish stocks were identified by the analysis of Sr:Ca otoliths-edge ratios: one in the Valencian Gulf, DE-AV areas presented similar ratios, and the other in the southern location, SP (higher Sr:Ca values). Mugil cephalus presented diverse life patterns on the Valencian Community Mediterranean coast. Different strategies could be identified by the used methodology: some particular to an area (Type IV-SP); others shared among areas, changing environments in different stages of their life. The presence of different fish stocks could be influenced by a mesoscale current phenomenon observed in the region associated with the Balearic front.