In saltwater fish - the chloride cell operate the other way - transport out chloride - this is maybe a reason why nitrite uptaken by the digestive tract do not accumulate in the body. But this cost energy in the long run. however - one of the articles in my post above show a rise in methemoglobin in flounders tested in nitrite rich water.chloride through the chloride cells in the gills
Sincerely Lasse