Welcome to part 2 of our series on the Indian River Lagoon dolphins. If you missed part 1, check it out here

Previously, we discussed the similarities between lagoon and oceanic dolphin populations. This time, we’ll dive into another dolphin fact and highlight recent research that sets our lagoon-loving friends apart from their ocean-dwelling counterparts.


Have you ever wondered how dolphins sleep?

In our last dolphin post, we mentioned that dolphins are marine mammals. Like all mammals, they breathe through their lungs instead of gills, so they must stay alert to avoid drowning in their underwater habitats.

To get around this dilemma, dolphins evolved with a fascinating sleeping adaptation shared by other marine mammals like whales.

If you’ve ever seen a dolphin swimming with only one eye open, it was probably sleeping. Dolphins rest with unihemispheric sleep, meaning they only rest half of their brain at a time. The other half remains aware enough to handle basic tasks like breathing, swimming, and looking for hazards. 

Dolphins are most active during the day, but that doesn’t mean they sleep all night. Instead, they take short naps as needed, ranging from a few minutes to a few hours. Their peculiar sleeping patterns leave plenty of time for moonlit adventures.


Researchers in Indian River County were among the world’s first to start peeking into dolphins’ nighttime activities.

In 2012, marine scientists from nearby FAU-Harbor Branch Oceanographic Institute and Hubbs-SeaWorld Research Institute teamed up with Seven Degrees of Mapping LLC. The research team tagged four lagoon dolphins and tracked them for four months using satellite telemetry, a technology similar to GPS. What they found was surprising.

The satellite data, released in 2020, revealed that the dolphins traveled all over the lagoon at night. Since they had the water primarily to themselves, they took full advantage of the lack of boat traffic.

All four dolphins seized the opportunity to travel through the inlets safely, and each returned by morning after their ocean excursions.

Three of the four dolphins ventured into freshwater areas, which can harm their health, but they seemed to know the risks. They swam nearly 12 miles into freshwater canals, creeks, and rivers, yet they were never out of saltwater for long.

Researchers aren’t sure why our flippered friends leave the lagoon at night, but they have several theories. The dolphins could be searching for a wider variety of prey, avoiding predators, or taking shortcuts to different locations. Future studies should shed more light on these exciting behaviors.


There’s still much to uncover about the mysterious lives of dolphins, and we have only just begun to scratch the surface. One of the best ways to learn more about our local dolphins is to see them yourself with a guide.

Our boat tours allow you to witness these intelligent and captivating creatures in their natural habitat. With our experienced guides, you can explore the lagoon and observe the dolphins’ playful behaviors, socialization, and communication. 

Sunset tours are an excellent way to watch dolphins as they start their evening escapades. The gentle glow of the sunset creates a beautiful backdrop while you get a unique look at the lagoon dolphins. Sunset boat tours are relaxing, but if you want an up-close-and-personal experience, choose a sunset kayak or paddle board tour. 

As advocates of the Indian River Lagoon and its inhabitants, we are committed to educating and sharing our enthusiasm for these marine animals with others. Join us on the water and stay tuned for more!