Dutch Delta is an important reproductive area for one shark species.

A Starry Smoothhound mark-recapture programme was led by anglers between 2011–2019. Sharks were caught by a group of licensed taggers and fishing occurred in the river Scheldt outer estuary (Westerschelde) and the adjacent sea arm in the Netherlands (Oosterschelde) within this area. During this period, 4,495 individuals were captured, of which 3,699 were tagged using unique plastic rototags (Brevé et al. 2016, 2020). Fishing took place year-round, but 99.9% of all Starry Smoothhounds were caught between May and October, supporting a seasonal nature to their habitat use at this location. The size and numbers of recaptures included 76 neonates measuring <33 cm total length (TL); 179 males (46 young-of-the-year [YOY] measuring 33–65 cm TL; 21 juveniles, 65–70.4 cm TL; 112 adults, >70.4 cm TL); and 187 females (46 YOY measuring 33–69 cm TL; 63 juveniles, 69–81.9 cm TL; 78 adults, >81.9 cm TL). The size-at-birth for this species is ~28–38 cm TL and it reaches maturity at 72–85 cm TL for males and ~83–96 cm TL for females (Ebert et al. 2021). Whether females were pregnant or not was not recorded. It is unclear where mating takes place, but gravid females move into the English Channel and into sheltered waters for pupping, with parturition occurring June to July in the eastern English Channel and southern North Sea, including the Dutch Delta (Brevé et al. 2016). In addition, expert knowledge surveys in the region have informed consensus maps of important pupping and reproduction areas for Starry Smoothhound in this area (V van den Berg unpubl. data 2025). There is additional photographic evidence of neonates in the area, and the data indicate that the Dutch Delta is used on an annual and seasonal basis as a pupping area, the only one known along the Dutch coastline.