Pile Driving Pressure Change Laboratory Apparatus (IMAGE) DOE/Pacific Northwest National Laboratory Caption Researchers from Battelle and the University of Maryland developed this apparatus to evaluate fish injuries related to pile driving. Fish are held in the center of this water-filled metal tube while pistons at each end fluctuate to simulate the pressure changes that happen when metal piles are pounded into the ocean floor. Credit Battelle Usage Restrictions None License Licensed content 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.