Page 6 - Espinosa_alii_2013
P. 6

The marine limpet Patella ferruginea  271


                   (a)
                                                                                                       1986















                   (b)             20
                                   16
                                                                                                       2003
                                   12
                                    8
                                    4
                                    0
                                     0–1 1–2 2–3 3–4 4–5 5–6 6–7 7–8 8–9 9–10








           FIG. 4 Size (measured on the longitudinal axis) frequency
           distribution of P. ferruginea at Galéria, Corsica, in (a) 1985 (data
           from Laborel-Deguen & Laborel, 1991b) and (b) 2009 (present
           study).                                                                                     2009


           as souvenirs at the tourist site of Kerkouan, Carthage.
           Accessibility is the most important factor influencing
           collection, regardless of the legally protected status of the
           species (Guerra-García et al., 2004; Espinosa et al., 2009a).
           To protect threatened molluscs such as P. ferruginea we
           recommend, based on our findings, use of marine protected
           areas combined with effective control of human visitation,
           as has been implemented on Asinara island and the Zembra
           archipelago. Although exploitation is evident in several
           areas of Sardinia (Cristo & Caronni, 2008), the marine
           protected area of Asinara has the largest individuals and   0–1 1–2 2–3 3–4 4–5 5–6 6–7 7–8 8–9 9–10
           highest densities in the Corsica–Sardinia region, and the
           population in the Zembra marine protected area (estab-  FIG. 5 Size (measured on the longitudinal axis) frequency
           lished in 1977 and where human visitation is prohibited)  distribution of P. ferruginea at Zembra in 1986 (adapted from
           showed strong recruitment and had many large reproduc-  Boudouresque & Laborel-Deguen, 1986), 2003 (adapted from
           tive individuals, indicating a well-structured and viable  Limam et al., 2004) and 2009 (this study).
           population (Espinosa et al., 2009a). Changes in the popu-
           lation on Zembra during the last 25 years have been positive
                                          −1
           (Fig. 5) in terms of density (from 0.7 m in 1986 to 2.65 m −1  (e.g. Algeciras Bay and Ceuta; Espinosa et al., 2009a), could
           in 2009) and mean length (mean of specimens .2 cm was  be a source of larvae for adjacent areas. Connectivity
           4.4 cm in 1986 and 5.4 cm in 2009). Marine protected areas  between populations needs to be guaranteed by establish-
           (Asinara, Zembra: present study; Habibas and Chafarinas  ment of a large number of small and proximate (no more
           islands: Espinosa, 2009; Guallart et al., 2006) and also non-  than 10–20 km apart) marine protected areas, as suggested
           legally protected sites, many of them on artificial substrates  by Boudouresque et al., (2005).


           © 2013 Fauna & Flora International, Oryx, 48(2), 266–275

           http://journals.cambridge.org    Downloaded: 14 Mar 2014                        IP address: 150.214.246.48
   1   2   3   4   5   6   7   8   9   10