Reply To: Questions on Yoreh Deah, Choshen Mishpat

I understand that the ocean is considered as a spring and is therefore a kosher mikveh. Under what circumstances are any of the following kosher mikvaot:

(1) Tidal estuaries such as Long Island Sound

(2) Navigable rivers such as the Hudson that have a direct connection to the ocean

(3) Fresh water lakes

Thanks!!!