How long can fish be left out?
A quote from the below link;  


  "Do not thaw frozen seafood at room temperature. Thaw in the
  refrigerator or defrost in the microwave oven. If thawing in the
  refrigerator, allow one to two hours per pound of seafood".


http://www.uaex.edu/Other_Areas/publications/PDF/fsfcs100.pdf

&amp;

Another quote from the link below; 


  "... If food is allowed to remain at room temperature for two hours or
  longer, bacteria can multiply and cause food poisoning. - Even a tiny
  amount of contaminated food can cause severe illness. If you have any
  doubt about the safety of the food, throw it out!"


http://www.calpoison.com/public/food.html