Hello Adarsh ,

May be you can dive into sea and take marine animals photos research on them . Generally marine biologist activities are .

• Marine biologist invent different species in seas or oceans or any water bodies.
• Testing and monitor changes occur in  sea and oceans .
• Collect and testing the different ocean samples .
• Testing different types of water pollutants and diseases.

I think this answer will help you

All the best !!!