Fact: Even if soap (liquid or bar) is biodegradable, it is not safe to use directly in the river, lake or ocean. Never, ever. All soap, whether biodegradable or not, affects the chemistry of rivers and lakes and has a negative impact on fish and other organisms.
To learn more visit
https://mountaingirlessentials.com/blogs/news/is-your-soap-safe-for-bathing-in-lakes-and-rivers