Herpetology Notes, volume 13: 795-800 (2020) (published online on 30 September 2020) Sicilians are not easily hooked! First assessment of the impact of recreational fishing on the endemic Sicilian pond turtle Emys trinacris (Testudines, Emydidae) Luca Vecchioni1,§, Alessia Cicerone1,§, Rita Scardino1, Vincenzo Arizza1, Marco Arculeo1, and Federico Marrone1,* Abstract. The possible impact of recreational fishing on the Sicilian pond turtle Emys trinacris was investigated in two permanent water bodies in western Sicily (Italy). Overall, 120 specimens were temporarily captured and X-rayed in order to determine the possible presence of fishhooks in their mouth, throat, or gastrointestinal tract. At the studied sites, none of the X- rayed turtles showed any evidence of ingested fishhooks or other fishing gears, thus suggesting limited impact of recreational fishing. However, the occasional but not negligible findings of E. trinacris specimens injured by fishhooks or entangled in abandoned fishing lines prove the actual existence of such impact, raising some concerns about the long-term conservation of this endemic pond turtle. The need of monitoring the possible impacts of angling where pond turtles are present is briefly stressed. Keywords. Bycatch impact, illegal angling, citizen science, wetland management, Sicily Introduction tendency of the species (Iannella et al., 2018, and references therein), hinder the connectivity among The Sicilian endemic pond turtle Emys trinacris Fritz, local populations, so that even proximally-located Fattizzo, Guicking, Tripepi, Pennisi, Lenk, Joger and populations should be considered as independent Wink, 2005 is the only autochthonous freshwater turtle units for management purposes and threats to local occurring in Sicily. It is included (sub E. orbicularis populations should be carefully evaluated with a case- (Linnaeus, 1758)) in the Appendix II of the EU Council by-case approach (Vecchioni et al., 2020). In addition Directive 92/43/EEC (“Habitats Directive”) and in the to habitat destruction and fragmentation (Fritz et al., Appendix II of the “Bern Convention on the Conservation 2005), E. trinacris populations are also under pressure of European Wildlife and Natural Habitats”, and listed by invasive alien species (Marrone and Naselli-Flores, as “EN” (i.e.: “Endangered”) in the Italian IUCN red 2015; Ottonello et al., 2016; Naselli-Flores and Marrone, list of threatened species (Rondinini et al., 2013). 2019), hybridisation with introduced E. orbicularis Emys trinacris is widely but non-homogeneously specimens (Vamberger et al., 2015; Scardino et al., distributed in Sicily (Vamberger et al., 2015; Marrone 2020), and possibly parasite spill-over (see discussion et al., 2016; Iannella et al., 2018). Moreover, the on- in Arizza et al., 2016). Another potential threat, which going human-induced aquatic habitat fragmentation has been overlooked up to date, is recreational fishing (Fritz et al., 2005), coupled with the limited dispersal (cf. Steen et al., 2017). In sharp contrast with the detailed information available on the impact of fishing activities on sea turtles, only few data are currently available for freshwater turtles (e.g. Beregi et al., 2003; Nemoz et al., 2004; Steen et al., 2014), and no data at all are available for Italian 1 University of Palermo, Department of Biological, Chemical mainland E. orbicularis populations, nor for E. trinacris. and Pharmaceutical Sciences and Technologies (STEBICEF), Via Archirafi 18, 90123 Palermo, Italy. It is however clear that mortality related to angling * Corresponding author. E-mail: federico.marrone�unipa.it activities can significantly contribute to the decline and § These authors contributed equally to this work local extinction of freshwater turtle populations (Nemoz 796 Luca Vecchioni et al. et al., 2004; Steen et al., 2017), and recent occasional findings of E. trinacris specimens with ingested hooks or entangled in fishing lines in western Sicily suggest that this practice may also threaten Sicilian pond turtles (Table 1). The growing concern regarding the obvious negative impact of fishing on pond turtles, and the absence of an assessment of angling impact on the endemic E. trinacris, prompted us to investigate the impact of recreational fishing on two Sicilian populations. Materials and Methods Sampling activities were carried out in June and Figure 1. Location of the two study sites in Sicily, Italy. July 2016 in Sicily in two permanent water bodies: i) “Laghetti Coda di Riccio” (37.8736°N, 13.3997°E), located within the Nature Reserve “Bosco della Ficuzza, Rocca Busambra, Bosco del Cappelliere In the frame of this survey, E. trinacris specimens were e Gorgo del Drago” (province of Palermo), and ii) captured using baited hoop traps; in fact, the presence of “Laghetto Gorgo” (37.4080°N, 13.3269°E), located ingested fishhooks seems not to significantly inhibit the close to Montallegro (province of Agrigento) (Fig. 1). feeding behaviour of aquatic turtles (Steen et al., 2014). Both study sites are man-made lakes where recreational The hoop traps were immersed in water and equipped fishing is not allowed, but where poaching aimed at with a flotation system, so that air-breathing animals Cyprinus carpio Linnaeus, 1758 with baited hooks, and eventually caught could breathe on the surface (Ream Micropterus salmoides (Lacépedè, 1802) with baited and Ream, 1966). The traps were left in the water for hooks and fishing lures is routinely practised (pers. about 48h per session, and then checked for the possible obs.). Moreover, a dead E. trinacris specimen with presence of captured turtles. Details on sampling dates an ingested fishhook was found in “Laghetti Coda di and number of implemented traps are reported in Table 2. Riccio” in May 2015 (Table 1, Fig. 2), thus proving that All captured Sicilian pond turtles were sexed according illegal fishing is actually a threat to pond turtles in this to D’Angelo et al. (2008) and Corti et al. (2011). site. Both locations host abundant populations of the E. Captured individuals were transported to the trinacris (Arizza et al., 2014, 2016; Vamberger et al., “Laboratorio di Biologia Evoluzionistica e delle 2015). Popolazioni” at the Department STEBICEF of the Table 1. Opportunistic observations of Emys trinacris specimens injured by fishing activities. Table 1. Opportunistic observations of Emys orbicularis trinacris specimens injured by fishing activities. Locality Date Source Notes Nature Reserve “Bosco della Ficuzza, Rocca, March 2001 CRRFS Ficuzza 1 specimen with a fishhook stuck in the mouth and Busambra, Bosco del Cappelliere e Gorgo del Drago” superficial wounds. Successfully released in the wild Godrano (Tagliavia) March 2001 CRRFS Ficuzza 2 specimens entangled in fishing lines and with superficial wounds. Successfully released in the wild. Piana degli Albanesi April 2001 CRRFS Ficuzza 1 specimen entangled in fishing lines and with superficial wounds. Successfully released in the wild. Nature Reserve “Bosco della Ficuzza, Rocca, April 2002 CRRFS Ficuzza 1 specimen with a fishhook stuck in the mouth and Busambra, Bosco del Cappelliere e Gorgo del Drago” superficial wounds. Successfully released in the wild Madonie mountains March or S. D’Angelo (pers.comm.) 1 specimen with a fishhook stuck in the gastro-intestinal April 2004 tract. The hook was surgically removed by D. Freggi and A. Di Bello, and the specimen was successfully released in the wild. Nature Reserve “Monte Capodarso e Valle dell’Imera July 2013 V. Cumbo (pers.comm.) 1 heavily debilitated specimen with a fishhook in the throat. Meridionale” The specimen died during its transport to the hospital Nature Reserve “Bosco della Ficuzza, Rocca, May 2015 F. Marrone, F. Sacco and 1 dead specimen with a fishhook in the gastro-intestinal Busambra, Bosco del Cappelliere e Gorgo del Drago” R. Scardino (unpubl. data) tract. Table 2. Synopsis of the origin, sampling sessions and number of captured Emys orbicularis trinacris specimens during the current study Site Sampling session # of deployed traps # Turtles (tot: m + f + j) Laghetti Coda di Riccio 6 – 8 June 2016 7 17: 14+2*+1 Laghetti Coda di Riccio 20 – 22 June 2016 7 9: 8+1 Laghetti Coda di Riccio 22 – 24 June 2016 7 14: 9+5 Lago Gorgo 27 – 29 June 2016 5 54: 33+21§ Lago Gorgo 29 June – 1 July 2016 5 26: 18+7+1 * 1 female bearing 4 eggs; §: Three females bearing 4, 4, and 5 eggs, respectively. 1 First assessment of the impact of recreational fishing on Sicilian pond turtles 797 Figure 2. Dead Emys trinacris specimen found in May 2015 in Laghetti Coda di Riccio, with a focus on the ingested fishhook (see Table 1 for details). University of Palermo (Italy), and X-rayed (40 kV, 150 Sicily. In order to reach these aims, in June 2016 a leaflet mA, 0.06-0.08 s) to determine the possible presence was distributed in local fishing stores, and a Facebook of hooks or Tableother 1.fishing Opportunistic gears observationsin their gastrointestinal of Emys orbicularis page trinacris (“Save specimens the injuredEmys by”; fishinghttps://www.facebook.com/ activities. tracts. According to Gibbons and Greene (1979) and savetheemys/) was published and promoted online Locality Date Source Notes Hinton et al. (1997), the implemented radiographic (Supplementary Fig. 1A, 1B and Table S1). approach is Naturenot harmfulReserve “Bosco for bothdella Ficuzza,adults Rocca,and turtle March 2001 CRRFS Ficuzza 1 specimen with a fishhook stuck in the mouth and Busambra, Bosco del Cappelliere e Gorgo del Drago” superficial wounds. Successfully released in the wild embryos. All X-ray plates are available from the authors Godrano (Tagliavia) ResultsMarch 2001 CRRFS Ficuzza 2 specimens entangled in fishing lines and with superficial on request. After radiographic analyses, all pond turtles wounds. Successfully released in the wild. Overall, 120 pond turtles were captured and sexed were releasedPiana at deglitheir Albanesi point of capture. Before being April 2001 CRRFS Ficuzza 1 specimen entangled in fishing lines and with superficial released into the wild, the captured individuals were (Table 2). In “Laghetti Coda di Riccio” 40wounds. specimens Successfully released in the wild.