There is a study under way in the United States to determine the effectiveness of the barrier. To date the work that has been done to monitor the situation of the barrier is showing us that it is working as it's intended to. They do tag other species in the area and they do swim up toward the electrical barrier and get uncomfortable and turn around and head the other way. Although we didn't evaluate the barrier per se, we took into account that it is in place and it is working as intended.
On October 16th, 2012. See this statement in context.