An aquatic biologist studies the ecology of freshwater and marine ecosystems. Their duties include conducting field research, collecting samples, making observations of plant and animal organism health or behavior, analyzing data, and writing reports on their findings. Some biologists may study a specific oceanic ecosystem, while others study systems, such as rivers, streams, wetlands, or lakes. In addition to research, an aquatic biologist may attend marine or freshwater science conferences and write grants to fund further research. Qualifications to become an aquatic biologist include an advanced college degree in aquatic science or marine biology, typically a master’s degree or Ph.D., and some people in this field pursue a career as an oceanographer or limnologist.