Golfo Dulce Whale Heritage Area

Golfo Dulce is a rich and important marine area for whales and dolphins. There are 7 cetacean species recorded, including bottlenose dolphins, pantropical spotted dolphins, false killer whales and humpback whales. Occasionally other species are seen, such as Bryde's whale, spinner dolphins and killer whales.

Golfo Dulce provides a suitable breeding and calving ground for Northeast and Southeast Pacific populations of humpback whales. The calving seasons run from July to November (Southern populations) and November to March (Northern populations).

There are also year-round resident and non-resident dolphin populations. Bottlenose dolphins are more likely to be seen close to shore compared to the pantropical spotted dolphins.

The threats faced by cetaceans in Golfo Dulce include global issues like climate change, in addition to localised threats such as water contamination and increasing boat traffic (noise pollution and risk of propellor strikes).

The bottlenose dolphin population is an “inshore” ecotype, with fewer than 500 individuals along the Pacific coast of Costa Rica and Panama. Numerous individuals show signs of a skin disease (lacaziosis-like disease).

Building development is also potential threat, as there is a new marina proposed in one of the hotspot areas for humpback whales.

Several local and regional programmes and projects are working to address these threats, including some carried out by research institutes, universities, or NGOs.

• Migrant humpback whales from the Northeast and Southeast Pacific populations arrive in different seasons; the northern population migrates to the wintering grounds between December and April, whereas those from the southern zones make their journey from June to October.
• Tour boat observations have found that dolphins are regularly seen swimming near/around visiting whales. A scientific paper on these interactions is currently being prepared with the collected data.
• Dolphins are also seen relatively frequently interacting with (“harassing”) venomous sea snakes, a behaviour noted in a few other areas of the world but not to the extent observed in Golfo Dulce.
• Bottlenose and pantropical spotted dolphins in Golfo Dulce exhibit playful behaviours that resonate with local traditions of ingenuity and connection to nature. They are often seen pushing coconuts, wrapping seagrass on their fins, or pulling leaves for fun.
• Humpback whales in Golfo Dulce use a unique local landmark, Widow Rock, for "spa sessions" to scrape off barnacles. Mothers teach their calves this behaviour, passing down knowledge and strengthening the bond between generations. By removing barnacles, humpback whales improve their hydrodynamics, supporting their long migrations and overall health. This behaviour also benefits the marine ecosystem by recycling organic matter into the ocean's food chain.