Autonomous underwater vehicles are becoming increasingly prevalent, and their emergence will allow for the execution of previously unfeasible underwater missions. These missions include seeking naval mines, navigation and mapping of ocean features, and sampling on the ocean floor at extreme depths. One method to achieve this latter objective involves the attachment of a robotic manipulator to an underwater vehicle and use of the manipulator to collect specimens and deposit them in containers. This thesis focuses on the design and testing of an end-effector to be used on such a manipulator. End-effectors previously utilized in underwater robotics were evaluated during the conceptualization of the selected tool design. These evaluations in conjunction with manipulator interface requirements were used to produce the end-effector design that was constructed and subsequently tested. In addition, sample containers were designed and fabricated, and kinematics software used to determine sample container position, orientation, and quantity was developed.