A Niskin Bottle is a specialized device used in oceanography to collect water samples from various depths in the ocean. It is designed to close at specific depths, allowing researchers to capture water without contamination. The bottle is typically made of plastic or glass and is attached to a frame that can be lowered into the water. When the Niskin Bottle reaches the desired depth, it is triggered to close, sealing the water inside. This method helps scientists study the chemical, physical, and biological properties of ocean water, contributing to our understanding of marine ecosystems and the effects of climate change on the oceans.