Brian Kastl is passionate about fish, and he’s traveled all over the world to help protect them. Kastl is an ecologist and geologist who helps empower local communities to protect their natural resources, including fish like coho salmon (Oncorhynchus kisutch​).

Kastl studies the migration patterns of salmon to better understand fish populations. He tracks the animals as they migrate to the Pacific Ocean, using microchips that are implanted into the young fish by his collaborators at California Sea Grant. Tracing the migration timing and paths that fish take during their migration is important because rivers and streams are changing, due to human-caused pressures such as urbanization. For instance, reservoirs, dams, and canals all alter the aquatic landscape and potentially affect how and where fish can migrate. 

A lot of Kastl’s research is done on the west coast of the United States, but he has also traveled throughout Southeast Asia and the Pacific for work. Kastl is particularly interested in supporting indigenous knowledge and sharing scientific practices with communities to empower them to conduct their own conservation efforts. That’s important because sharing skills allows communities to continue to do work long after Kastl or other researchers have departed.

Some of Kastl’s projects have included informing the expansion of marine protected areas in Fiji, helping residents of Micronesia estimate the value of water resources, and working to protect the livelihoods of fishermen in Cambodia.

Kastl is additionally a teacher. He has co-led National Geographic Student Expeditions in Belize and Alaska, where he advises students on various hands-on projects. “I love seeing students’ excitement as they discover their greatest interests in our water-driven world,” Kastl told “Watching our students grow as freshwater science leaders is immensely rewarding.”



artificial waterway.


structure built across a river or other waterway to control the flow of water.


scientist who studies the relationships between organisms and their environments.


to guess based on knowledge of the situation or object.


small semiconductor with electrical circuits that carry information.


movement of a group of people or animals from one place to another.


natural or man-made lake.


process in which there is an increase in the number of people living and working in a city or metropolitan area.