Muddy waters: protecting Fiji’s shark pups
The Ba River and its estuary on the north-western coast of Viti Levu, Fiji, is an Important Shark and Ray Area and a potential nursery area for scalloped hammerhead, great hammerhead and blacktip sharks. The area has been dredged for decades and is a site of black sand extraction, and since the pandemic illegal gill netting has been widespread. All these activities threaten the Ba’s viability as a safe nursery haven, especially for the Fijian bull shark population, which is genetically closed and insular. Natasha is partnering with the Ministry of Fisheries to determine whether the Ba estuary and lower river still function as a nursery and aggregation site for shark and ray pups.
Natasha Marosi
I was born in New York City, far from the turquoise waters of the South Pacific. As a child I had the Atlantic Ocean to play in and a healthy fear of sharks; my sister and I solemnly swore to never wade in water where we could not see our own toes. As an adult I was determined to confront my fears, which resulted in an even healthier obsession to dive with sharks in every ocean around the globe. Although I was a defence attorney at the time, I knew then I would someday use my voice to...
Muddy Waters: Ecological Impact of Dredging on Juvenile Shark Habitats in The Ba River, Fiji
The main objective of this project is to implement legislative protection for essential elasmobranch habitats in the Ba River and its estuary, Fiji.
Fiji’s rivers and estuaries provide essential habitats for the young of threatened elasmobranch species, yet illegal gill netting, overfishing, dredging and pollution result in extremely high mortality rates, with evidence of whole cohorts disappearing. Despite Fiji’s commitments to marine and biodiversity protection, elasmobranch populations continue to be threatened and the enforcement of existing laws is limited. Protecting these habitats will not only ensure the survival of these species, but the long-term health of marine ecosystems, fisheries and coastal communities.
Fiji has a deep-rooted cultural and ecological connection to the ocean. For centuries, indigenous communities have managed their qoliqoli (traditional fishing ground) through customary practices such as tabu (local taboos), which restricted fishing in certain areas to ensure that marine life remained healthy and abundant. Recent decades have shown Fiji to be committed at national and international level to protecting biodiversity and managing its marine resources sustainably. Despite these efforts, recent challenges have placed enormous pressure on marine ecosystems. The economic downturn during the pandemic led to widespread unemployment and an explosion in overfishing and poaching that has only partly subsided. Although the 2019 fin export ban helped reduce Fiji’s role in the international fin trade, local elasmobranch populations remain under threat. This is especially true in Fiji’s rivers and estuaries, which serve as critical habitats for young sharks. In these areas, illegal gill netting, overfishing and poaching, coupled with habitat destruction from dredging, mining and pollution, have increased the mortality rate for pups, and research shows that entire generations have disappeared. In the Ba River alone, surveys documented a majority of individual fishers using illegal fishing methods (gill netting); one individual claimed to consistently catch about 100 sharks in 4–5 days. Previous scientific research identified these sites as essential habitats, earning them ISRA designation. It is now imperative that these sites be adequately protected. Several years ago we initiated Operation Shark Pups in collaboration with the Ministry of Fisheries to enforce the existing ban on gill netting in the rivers, estuaries and bays. To date we have supported the ministry in patrolling two of the five major riverine systems in Viti Levu. Our partnership extends to the present project, which seeks the implementation of legislative protection in the Ba River and its estuary to safeguard threatened elasmobranch species and contribute to their recovery.
- To determine whether the lower Ba River and its estuary still function as a multi-species aggregation area and nursery for threatened elasmobranch juveniles.
- To identify essential habitats for young bull sharks in the Ba River.
- To implement essential habitat protection legislation for the Ba River and its estuary.