Dreketi is an important reproductive area for two shark species.

In a study during January–February 2020, 47 Scalloped Hammerheads were captured from 75 bottom-set gillnets deployed in the Dreketi River (n = 20) and the estuary (n = 55) within the area (Paris 2020). Gillnets were 100 m long, 3 m high, and had a 10 cm mesh size. Up to two nets were deployed simultaneously and hauled in after 40 minutes for each deployment. All Scalloped Hammerheads captured were either neonates with a semi-healed umbilical scar (n = 14) or young-of-the-year (YOY) with a healed umbilical scar (n = 33) (Paris 2020). Individuals measured 49–58 cm total length (TL), with a mean of 52.8 cm TL. Size-at-birth for the species is 31–57 cm TL (Ebert et al. 2021). Most Scalloped Hammerheads (87%) were captured in shallow water (<1.5 m deep) close to the river mouth, but six individuals were captured 6 km upstream in the river, showing the connectivity within this area. Traditional Ecological Knowledge (TEK) gathered in 2010 through interviews with representatives from six villages from the estuary to 33 km upstream showed that hammerhead sharks (family Sphyrnidae) are commonly caught in this area, particularly at the estuary village (Rasalato et al. 2010). Respondents indicated that hammerhead sharks were generally <1 m TL, but larger individuals up to 3 m TL were also caught. Additionally, an interview survey in three villages in the area conducted in August 2024 confirmed the continued capture of Scalloped Hammerheads in this area (D Williams pers. obs. 2024). Combined, these data show that Dreketi is important for the early life stages of Scalloped Hammerheads.

A total of eight Bull Sharks were captured in January–February 2020 from bottom-set gillnets, with six neonates having open umbilical scars, indicating recent birth, and one YOY having a semi-healed umbilical scar (Paris 2020). Their size ranged from 74–100 cm TL, with a mean of 79.3 cm TL. The size-at-birth for the species is 56–81 cm TL (Ebert et al. 2021). All Bull Sharks were captured in the river, from near the estuary to 18 km upstream. TEK provides evidence that Dreketi has long been an important reproductive site for Bull Sharks. Fishers noted that they usually catch individuals <100 cm TL, with the largest individuals ~250 cm TL (Rasalato et al. 2010). Recent interviews confirm continued regular captures of small Bull Sharks in this area (D Williams pers. obs. 2024). Dreketi is the only known important reproductive area for Bull Sharks on the island of Vanua Levu, with other areas located on Viti Levu (Glaus et al. 2019).