Observations of juvenile sandbar sharks Carcharhinus plumbeus (Nardo, 1827) around the Bojana River delta (Southern Adriatic Sea)

Abstract

The sandbar shark (Carcharhinus plumbeus) is considered rare in the Adriatic Sea and the majority of records originate from the northern Adriatic, where a nursery area for this species close to the Po delta system has been repeatedly proposed. This study provides 5 new records and analyses the previously published records of sandbar sharks recorded around the delta of the River Bojana (in Montenegro, in the south-eastern Adriatic). The River Bojana located on the border between Montenegro and Albania, is the second largest river flowing into the Adriatic Sea, where it forms a highly productive ecosystem already known as a local hotspot for smooth-hound sharks (Mustelus spp.). New records of sandbar sharks have emerged as a result of citizen science (a social media survey) and direct reports from fishermen. The total length of C. plumbeus juveniles ranged from approximately 800 mm to 1100 mm, and most (n=5) were caught by set gillnets. The data presented here show that juveniles are consistently present around the estuary and indicate the importance of this fragile estuarine ecosystem for sandbar sharks. Additionally, this study also provides morphometric data collected from a single individual.

Too young to die: Mapping nursery areas for early juveniles of the endangered sandbar shark (Carcharhinus plumbeus) to inform conservation in the Mediterranean Sea

“…As an ectotherm species, the neonates of sandbar shark could find overwintering nursery grounds within or in neighbouring Mediterranean subbasins that undergo large seasonal variations in temperature that, in turn, influence their seasonal use of space (Schlaff et al, 2014). Indeed, occasional reports of neonate and juvenile occurrence were reported during winter or early spring in the Southern Adriatic Sea (Ćetković et al, 2022), the Western Ionian coast (Leonetti et al, 2020) and the Southern Tyrrhenian Sea (Consoli et al, 2004). The seasonal use of space remains to be studied in detail by complementary approaches (e.g.…”