Marine biology is the study of life in the ocean and other saltwater environments. It encompasses a wide range of organisms, from the smallest plankton to the largest whales, and examines their interactions with each other and their habitats. Marine biologists often study ecosystems such as coral reefs, estuaries, and deep-sea environments to understand the complex relationships that sustain marine life. This field is crucial for understanding the health of our oceans, which are vital for global biodiversity and human well-being. Research in marine biology helps address issues like overfishing, climate change, and pollution, ensuring the sustainability of marine resources for future generations.