* Dolphins: Marine biologists study dolphin behavior, communication, physiology, population dynamics, and conservation. They may work in the field collecting data, conduct research in labs, or advocate for dolphin protection.
* Turtles: Marine biologists also focus on sea turtle research, including their nesting habits, migration patterns, threats (like entanglement in fishing gear or habitat loss), and conservation efforts.
While not every marine biologist works with these specific animals, they are popular areas of study due to their fascinating biology and the challenges they face in the changing ocean environment.