Yes, marine water is generally alkaline (basic).
The average pH of the ocean is currently around 8.1, placing it on the alkaline side of the pH scale. However, this alkalinity is under threat. Due to increased levels of carbon dioxide (CO2) in the atmosphere from human activities, more CO2 is dissolving into the ocean. This process leads to ocean acidification, where the pH gradually decreases, making the ocean less alkaline and more acidic over time. While still alkaline, the trend is towards lower pH values.
