Data-mining social media platforms highlights conservation action for the Mediterranean Critically Endangered blue shark Prionace glauca

Abstract The Mediterranean Sea represents an area of elevated risk of extinction for sharks, where data deficiency is a pervasive problem. To compensate for such a paucity of information, this study investigated the use of social media content as a complementary approach to evaluate the distribution and habitat use of the Critically Endangered blue shark Prionace glauca in coastal waters, as well as public perceptions of the sharks. Through social media data mining a total of 146 records, comprising 158 individual blue sharks approaching Italian coastal waters, have been recorded from 2011 to 2020. This study revealed that, over the past decade, blue sharks regularly visited Italian coastal habitats for extended periods of time. Differences in the temporal distribution of blue sharks by sex and size appear to be linked to reproductive activity. The higher number of adult females approaching the shore in spring and the increase in young‐of‐the‐year (YOY) sightings in the following months possibly indicate parturition in coastal waters. Spatial analyses also showed that certain Italian coastal areas, such as those in Calabria and Puglia, were preferred coastal habitats for this species. Results also indicate that social media platforms can be considered an ever‐growing source of data on wildlife, which can shed light on the occurrence and distribution of endangered shark species in poorly known habitats. Furthermore, social media platforms should be used for awareness campaigns to educate the public, as this study showed that negative reactions to shark encounters remain widespread

Osservazione su di una femmina gravida di Prionace Glauca

ItDomenica 23 marzo 2003, nel porto di San Leone (Agrigento, Sicilia) una femmina gravida di verdesca, Prionace glauca (Linnaeus, 1758) lunga cm 270 (TL), legata al molo da una sagola che le attraversava le fessure branchiali, è stata osservata mentre, agonizzante, partoriva 12 piccoli.I 12 neonati, lunghi circa cm 30, vivi e vitali, sono stati visti allontanarsi verso il largo. Durante il recupero del corpo della madre è stato espulso un altro embrione privo di vita. L’evento, filmato e fotografato da uno degli autori, è stato analizzato e confrontato con altri episodi di parto in agonia o dovuto a stress da cattura, relativi alla stessa specie, avvenuti precedentemente ed in particolare segnalazioni provenienti dall’Alto Adriatico del 1993, dal Mar Ionio del 1995 e dal Canale di Sicilia del 1996.Alla luce di queste indagini, vengono formulate alcune ipotesi e considerazioni sulla possibile presenza di una nursery-area per P. glauca nei distretti meridionali dei mari italiani e sull’importanza del rilascio incentivato dei pesci cartilaginei da parte dei pescatori quale strumento di ricerca e di conservazione.EnOn Sunday, March 23rd 2003, into the harbour of San Leone (Agrigento, Sicily), a pregnant female of blue shark, Prionace glauca (Linnaeus, 1758) has been observed while, in agony, gave birth 12 baby sharks. The female (TL, cm 270) was trapped by a long line at level of the gills.The twelve newborns, measuring about cm 30 TL, swim away towards the open sea.During the operations of shark rescue, another embryo was expelled from the mother’s body.The event, filmed and photographed by one of the authors (Figg. 1, 2), has been investigated and compared with other records of birth in agony or birth caused by capture-stress, concerning the same species, and previously occurred, particularly the cases collected from the Northern Adriatic Sea during 1993, from the Ionian Sea during 1995 and from the Sicily Channel during 1996 (Fig. 3).Based on the results of these investigations, some hypotheses and considerations can be formulated about the possible existence of a nursery-area for P. glauca in the Southern areas of the Italian seas and on the importance of the collaboration with fishermen (encouraging the release of captured cartilaginous fishes) as a tool for research and conservation