Grading Tuna (image) University of New Hampshire Share Print E-Mail Caption Grading tuna at the Tsukiji fish market in Japan. UNH researchers found the quality of tuna has declined significantly since the early 1990s. Credit Kaori Sato Usage Restrictions None Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.