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2022 Continuation Funding
2019 Whitley Award
Ilena Zanella Costa Rica Marine
Strengthened sanctuary for the scalloped hammerhead shark


The Golfo Dulce is one of only four tropical fjords in the world. The unique nutrient cycling at this site means its waters are teeming with life. Nine years of research by Ilena, Co-founder of Misión Tiburón, has proven the further significance of the site as key nursery habitat for juvenile scalloped hammerhead sharks.


Hammerheads migrate thousands of miles each year connecting populations across Ecuador, Panama, Colombia and Costa Rica in the Eastern Tropical Pacific. The focus of conservation efforts on sharks around oceanic islands where adults congregate to breed and feed has demonstrated the critical need to protect sharks throughout their lifecycle. Based on the data collected by Ilena and her team, the coastal wetlands of Golfo Dulce were declared a Scalloped Hammerhead Shark Sanctuary in May 2018, including a 4,000Ha no take zone. This marks the first shark sanctuary in Costa Rica, and the first shark sanctuary globally to focus specifically on juvenile nursery habitat.


Building on this political good will, Ilena will continue to work with the local community to reduce the use of juvenile scalloped hammerheads as fishing bait and improve detection of illegal fishing activity. Misión Tiburón’s new Education Station will provide an education programme for children in the community promoting a shift towards increased environmental awareness and sustainable fishing practices.

Ilena’s project will:

  • Work with coast guards and local fishermen to halve illegal catch of hammerheads.
  • Double the number of students involved in Misión Tiburón’s education programme to reach 1,000 school children.
  • Evaluate the impact of management decisions on the abundance of juvenile sharks in the Golfo Dulce.

Why it matters:

  • Whales and dolphins are easily observed in the calm waters of the fjord and threatened sea turtles breed along its shores.
  • At its mouth the Golfo Dulce is only 60m deep, but sheltered inland waters reach more than 200m in depth.
  • Misión Tiburón is part of the Migramar network, involving collaborations with other Whitley Award winners, conserving migratory species in the Eastern Tropical Pacific marine corridor.

“I hope to engage the communities in the protection of the scalloped hammerhead shark and I would like the local people to feel proud of the sanctuary.”

Image credits: David Garcia




Sink or Swim: Protecting and restoring blue carbon sinks in the Hammerhead Shark Sanctuary Golfo Dulce, Costa Rica
Nature-Based Solution Funding: £100,000 over 2 years

One of only four tropical fjords in the world, the waters of the Golfo Dulce on the Pacific coast of Costa Rica are teeming with life due to its unique nutrient cycle. However, illegal, unreported and unregulated fishing in the area have led to drastic declines in marine biodiversity, and the people who live there have some of the lowest socioeconomic opportunities in the country. However, after Ilena Zanella and her team identified the area as an important nursery ground for the Critically Endangered scalloped hammerhead shark, the Costa Rican government declared the Golfo Dulce’s wetlands a Scalloped Hammerhead Shark Sanctuary (HSS), which now covers over 15,000 ha. Since then, Ilena and her NGO Misión Tiburón have been working with local stakeholders to scale up the protection of these important breeding grounds.

The mangroves that line this coastline have been degraded at an alarming rate, leaving the area vulnerable to threats such as sea level rise, erosion, and sedimentation. Recognising the important role these mangroves play as carbon sinks and the ecosystem services they provide to local people, Ilena and her team have established a pilot mangrove restoration plan for the HSS Golfo Dulce to further improving the health of this hammerhead shark nursery site.

Working with local stakeholders through participatory restoration and monitoring, this project will increase the mangrove restored area in the site by 200% in 3 years. It will also build on Ilena’s previous work engaging local communities in ocean conservation, promoting alternative livelihoods based on a blue economy, including the expansion of a newly established women’s initiative. Offering a collaborative and holistic solution, Ilena’s work is supporting the Costa Rican government in achieving its international climate commitments while benefiting communities and allowing endangered marine species to recover.