Mugil cephalus stock identification in two protected wetlands of the Valencian Community, Spain.

• Main Authors: Roberta Callicó Fortunato, Vicent Benedito Durà
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2015-11-01
• Series: Frontiers in Marine Science
• Subjects: Management; wetlands; Mugilidae; mugil cephalus; Fish stocks
• Online Access: http://journal.frontiersin.org/Journal/10.3389/conf.fmars.2015.03.00117/full

The Mugilidae family is widely distributed all over the world. In the Mediterranean Sea there are 8 species of mullets (Thomson, 1997). Mugil cephalus is the most cosmopolitan one and has an important economic value in the region (Whitfield et al., 2012). It is a euryhaline species that migrates during some periods of the year from the sea to brackish or freshwater areas. The analysis of otolith morphology, morphometric and chemical composition has been used to identify stocks of important commercial species, and has facilitated the study of movements and migration. Particularly, the simultaneous use of Sr:Ca and Ba:Ca otolith ratios is used by several authors for stock and migration studies (Schuchert et al., 2010; Tabouret et al., 2010; Avigliano et al., 2014,2016). This research proposes the identification of Mugil cephalus stocks in two protected wetlands of the Valencian Community: Parque Nartural de l’Albufera de Valencia and Parque Natural Salinas de Santa Pola (Figure 1) using otolith microchemistry. For this, Sr:Ca and Ba:Ca ratios were obtained of 48 sub-adults (25 – 35 cm total length) from the selected areas. Otoliths were digested to obtain solutions from each individual. Using ICP-OES, Sr, Ba concentrations were obtained; Ca concentration was determined by titration with ethylenediaminetetraacetic acid (EDTA) (APHA 1993). Element:Ca relations were compared with ANOVA analysis with Bonferroni contracts between the selected places. A discriminant analysis was performed to test the accuracy of using that variable (element:Ca) for the localization of fish site. Significant differences (p < 0.0001) were observed among the ratios studied, having Albufera individuals smaller Sr/Ca and higher Ba/Ca ratios than Salinas de Santa Pola ones (Figure 2). The discriminant analysis separated 87.5% of individuals to the wetland where it was sampled (Table 1). Results might be suggesting that there are two sub-adult stocks associated with each wetland, consistent with knowledge of ecology of this species.