Do Oceans EVER Freeze?

I am thinking of a project to do that interests me. I decided that I am going to answer the question "Does salt affect the way water freezes?" I have heard many things about this topic, some people say salt water does freeze, and some people say it doesn't. Also, It relates to the topic of Global Warming or "climate change" that I feel strongly about, because it seems to be getting worse. In the beginning of the semester, we had a presentation about climate change and sustainability. This is a topic that is very important to me, so I wanted to do a project on that. I am excited to share my results and observations about my project with my peers!